Group – Refrigeration[LINK]
There are two ways to model a supermarket refrigeration
system. The first, and simplest, approach models the
combination of compressor(s) and condenser as a single
refrigeration compressor rack object. (A list is used to enter
multiple case or walk-in names.)
For the first approach, the input objects needed are:
The second approach requires more input objects but also
allows the user to model more complex systems. This detailed
approach must be used whenever loads are transferred from one
system to another, such as with secondary loops, cascade
condensers, or mechanical subcoolers. Again lists are used to
enter multiple load or compressor names.
For the detailed approach, the input objects needed
are:
One Refrigeration:System
object
At least one refrigeration load object which may
include any combination of:
At least one Refrigeration:Compressor
object (multiple compressors are entered using a
Refrigeration:CompressorList),
One condenser object which may be either:
The object Refrigeration:Subcooler
may optionally be included to describe either a liquid suction
or mechanical subcooler.
Output variables are also available to describe the total
heat exchange between all refrigeration objects and the zones
containing these objects. These variables are described at the
end of this section after all the refrigeration objects.
Refrigeration:CompressorRack[LINK]
The refrigeration compressor rack object works in
conjunction with the refrigeration case and walkin objects
(Ref. Refrigeration:Case
and Refrigeration:WalkIn) to simulate the performance of a
refrigerated case system. This object models the electric
consumption of the rack compressors and the condenser fans.
Heat removed from the refrigerated cases, walkins, and
compressor/condenser fan heat can be rejected either outdoors
or to a zone. Compressor rack waste heat can also be reclaimed
for use by an optional air- or water-heating coil (Ref. Coil:Heating:Desuperheater
and Coil:WaterHeating:Desuperheater).
If heat is rejected outdoors, condenser cooling can either
be accomplished by direct air flow, evaporative water cooling,
or a by water-cooled condenser with appropriate plant loop
piping. With evaporative cooling, water is sprayed through the
air stream to effectively lower the air temperature
experienced by the condenser coil as a result of water
evaporation. The use of a water-cooled condenser requires the
definition of a plant loop to supply cooling to the
condenser. Waste heat can be reclaimed and stored using a
water storage device.
The inputs for the compressor rack object include a name,
the heat rejection location, the compressor rack coefficient
of performance (COP) at design conditions, the design
condenser fan power, and the type of condenser cooling. The
model requires two curve objects to describe performance at
off-design conditions. If the condenser is water-cooled, the
inlet and outlet node names as well as the water outlet
temperature schedule name are required. If the condenser has
evaporative cooling, additional inputs for evaporative
condenser effectiveness, condenser air flow rate, basin heater
parameters, water pump power, water source, and an evaporative
cooling availability schedule are available. The names of
refrigerated cases and walkins connected to the compressor
rack are the final inputs to the model.
A unique user-assigned name for an instance of a
refrigeration compressor rack. Any reference to this
compressor rack by another object will use this name.
Field: Heat Rejection
Location[LINK]
The location of the compressor rack’s condenser. The
compressor rack condenser heat can be directed “Outdoors” to
model an outdoor air or water-cooled condenser or “Zone”
to model a condenser located in a zone (e.g., a stand-alone
packaged refrigerated case with integral condenser located in
a conditioned zone). The default for this field is “Outdoors”.
If the heat rejection location is “Zone”
and no walk-in coolers are served by this compressor rack,
then all refrigerated cases connected to this compressor rack
must be located in the same zone. If however, walk-in coolers
are also served by this compressor rack, then the heat
rejection zone name must be specified (see Heat Rejection Zone
Name field below) and cases and walk-ins can be located in
multiple zones.
NOTE: When modeling a heat reclaim coil, the heat rejection
location must be “Outdoors”. If the heat rejection location is
“Zone”,
the total amount of waste heat available for reclaim (e.g., by
a desuperheater heating coil) is set to zero by this
compressor rack object and the simulation proceeds.
Field: Design
Compressor Rack COP[LINK]
The coefficient of performance (COP) for the compressor
rack at design conditions (compressors only, excluding
condenser fan power). This value must be greater than zero,
with a default value of 2.0 if this field is left blank. This
value should represent the compressor rack COP corresponding
to the lowest evaporating temperature of any case or walkin
served by the rack.
Field:
Compressor Rack COP Function of Temperature Curve Name[LINK]
The name of the curve object defining the change in
compressor rack COP as a function of the temperature of air
entering the condenser. The curve object will be evaluated
using the zone air dry-bulb temperature when rack heat
rejection location equals “Zone”
and the outdoor air dry-bulb temperature when rack heat
rejection location equals “Outdoors” and the condenser type is
air-cooled. As explained below, if the condenser is cooled by
evaporative or water loop cooling, the curve object is
evaluated using an effective temperature. The output from this
curve is multiplied by the design compressor rack COP to yield
the actual COP at the specific air temperature entering the
condenser. This curve must be cubic or quadratic (Curve:Cubic
or Curve:Quadratic), and should be normalized to 1.0 at the
condenser entering air temperature at which the design
compressor rack COP occurs. This curve should represent the
compressor rack COP corresponding to the lowest evaporating
temperature of any case served by the rack.
Field: Design
Condenser Fan Power[LINK]
This field defines the design power for the condenser
fan(s) in Watts. This field is applicable for air or
evaporative cooling only. If the condenser is water-cooled,
the fan power is captured in the cooling object (e.g., cooling
tower). If applicable, this value must be greater than 0.0,
with a default value of 250 Watts if this field is left
blank.
Field:
Condenser Fan Power Function of Temperature Curve Name[LINK]
This field is the name of the curve object defining the
change in condenser fan power as a function of the temperature
of air entering the condenser. This curve is used to simulate
the modulation of air flow by the condenser fans (e.g.,
staging, multi-speed, or variable speed) as a function of
temperature. The curve object will be evaluated using the
zone air dry-bulb temperature when rack heat rejection
location equals “Zone”
and the outdoor air dry-bulb temperature when rack heat
rejection location equals “Outdoors” and the condenser type is
air-cooled. As explained below, if the condenser is cooled by
evaporative cooling, the curve object is evaluated using an
effective temperature. The output from this curve is
multiplied by the design condenser fan power to yield the
actual fan power at the specific air temperature entering the
condenser. This curve must be cubic or quadratic (Curve:Cubic
or Curve:Quadratic), and should be normalized to 1.0 at the
condenser entering air temperature at which the design
condenser fan power occurs. The actual condenser fan power is
not allowed to exceed the design condenser fan power defined
in the previous input field or go below zero (i.e., the output
of the curve object is limited to values from 0.0 to 1.0). If
this field is left blank, then the model assumes the condenser
fan power is at the design power level when any of the
refrigerated cases connected to this rack are operating.
Field: Condenser Type[LINK]
When the heat rejection location is “Outdoors”, the
condenser may be either cooled by dry air by specifying
“AirCooled”, by wet evaporative cooling by specifying
“EvaporativelyCooled”, or by a water loop by specifying
“WaterCooled”. If the condenser type is “WaterCooled”, then a
plant cooling loop will need to be defined using other
EnergyPlus objects, e.g., plant loop, pump, cooling tower,
etc. The default value is “AirCooled”.
Field:
Water-cooled Condenser Inlet Node Name[LINK]
When the condenser type is “WaterCooled”, a node name for
the water-side condenser inlet must be provided.
Field:
Water-cooled Condenser Outlet Node Name[LINK]
When the condenser type is “WaterCooled”, a node name for
the water-side condenser outlet must be provided.
Field: Water-cooled
Loop Flow Type[LINK]
When the condenser type is “WaterCooled”, the type of flow
loop should be specified. The two choices are
VariableFlow, in which a Pump:VariableSpeed
needs to be included in the plant loop, or
ConstantFlow, in which the loop circuit has a
constant flow rate, typically associated with a Pump:ConstantSpeed
object. If the flow type is VariableFlow, the flow needed to
remove the condenser heat energy will be calculated and
requested of the pump. If the flow type is Constant Flow, the
outlet water temperature will be determined based on the fixed
loop flow rate and heat energy to be removed. The default
type is VariableFlow. Refer to additional
discussion in the Engineering Reference.
Field:
Water-cooled Condenser Outlet Temperature Schedule Name[LINK]
When the condenser type is “WaterCooled”, and when the
water-cooled loop flow type is “Variable Flow”, the name of a
schedule (Ref: Schedule) that defines the desired condenser
water outlet temperature must be provided. The schedule may
define an outlet temperature that varies through time.
Field:
Water-cooled Condenser Design Flow Rate[LINK]
When the condenser type is “WaterCooled”, and when the
water-cooled loop flow type is “Constant Flow”, this is the
design water flow rate in m\(^{3}\)/s that will be requested
initially. This requested flow will be passed to the loop
simulation, and resulting actual flow will be dependent upon
supply system capabilities (e.g., pump capability). The
design flow rate must always be less than the maximum flow
rate, defined below.
Field:
Water-cooled Condenser Maximum Flow Rate[LINK]
When the condenser type is “Water Cooled”, this is the
maximum water flow rate in m\(^{3}\)/s that will be allowed
through the condenser. When the loop flow type is Variable
Flow, if the calculated flow rate is higher than the maximum
flow rate, an error message will be generated, and the flow
rate will be reset to the maximum flow rate.
Field:
Water-cooled Condenser Maximum Water Outlet Temperature[LINK]
When the condenser type is “WaterCooled”, this field
specifies the maximum allowed water temperature in degrees C
leaving the compressor rack condenser. The default value is 55
degrees C.
Field:
Water-cooled Condenser Minimum Water Inlet Temperature[LINK]
When the condenser type is “WaterCooled”, this field
specifies the minimum allowed water temperature in degrees C
entering the compressor rack condenser. The default value is
10 degrees C. Refer to additional discussion in the
Engineering Reference.
Field:
Evaporative Condenser Availability Schedule Name[LINK]
When the condenser type is “EvaporativelyCooled”, the name
of the optional schedule (Ref: Schedule) that specifies the
time periods that evaporative cooling is
available/unavailable. In some colder climates, evaporative
cooling is periodically discontinued and the basin sumps
drained to avoid freezing. In these times, the condenser runs
as a typical dry air cooled condenser, and related evaporative
cooling systems (e.g., water pump, basin heaters) do not
operate. Use of this optional schedule permits modeling of
planned, seasonal interruptions of evaporative cooling. All
schedule values must be greater than or equal to zero.
Typically, an ON/OFF schedule type is used with values being
either 0 or 1. A schedule value of 1 indicates that
evaporative cooling is available during the defined time
period, and a value of 0 denotes that evaporative cooling is
not available during the defined time period. If the schedule
name is omitted (blank) and Condenser Type = “Evap Cooled”,
then the model assumes that evaporative cooling of the
condenser is available for the entire simulation period.
Field:
Evaporative Condenser Effectiveness[LINK]
When the condenser type is “EvaporativelyCooled”, this
field specifies the effectiveness of the evaporative system in
modifying the temperature of the air entering the condenser
coil. The resulting effective temperature is determined as
\[{T_{effective}} = {T_{owb}} +
(1 - \varepsilon )*[{T_{odb}} - {T_{owb}}]\]
where:
\({T_{effective}}\)
= effective dry-bulb temperature of air entering the condenser
cooling coil (°C)
\({T_{owb}}\) =
outdoor air wet-bulb temperature (°C)
\({T_{odb}}\) =
outdoor air dry-bulb temperature (°C)
\(\varepsilon\)
= evaporative condenser effectiveness.
The resulting condenser inlet air temperature is used by
the Compressor Rack COP as a Function of Temperature Curve and
the Condenser Fan Power as a Function of Temperature Curve.
The default value for this field is 0.9, although valid
entries can range from 0.0 to 1.0.
If the two function-of-temperature curves (i.e., Compressor
Rack COP as a Function of Temperature Curve and Condenser Fan
Power as a Function of Temperature Curve) are based on
wet-bulb temperature rather than dry-bulb temperature, the
evaporative condenser effectiveness should be set to 1.0 for
consistency.
Field:
Evaporative Condenser Air Flow Rate[LINK]
When the condenser type is “EvaporativelyCooled”, the air
volume flow rate, in m\(^{3}\)per second, entering the
evaporative condenser. This value is used to calculate the
amount of water evaporated when evaporatively cooling the
condenser inlet air. The value for this field must be greater
than zero. This input field is also autocalculatable,
equivalent to 0.000144 m\(^{3}\)/s per watt of total
cooling capacity [850 cfm/ton] where the total cooling
capacity is the sum of the rated total cooling capacities for
the refrigerated cases connected to this compressor rack (Ref.
Refrigeration:Case).
Field: Basin Heater
Capacity[LINK]
When the condenser type is “EvaporativelyCooled”, this
field defines the power level of the basin heater, if
applicable, used to avoid water freezing in an outdoor
evaporative cooler basin. This numeric field contains the
capacity of the electric basin heater in Watts per degree
Kelvin. This field is used in conjunction with the Basin
Heater Set Point Temperature described in the following field.
The basin heater electric power is equal to this field
multiplied by the difference between the basin heater set
point temperature and the dry-bulb temperature of the
condenser coil inlet air. The basin heater only operates when
the condenser fan is off (i.e., no compressor heat rejection).
The basin heater capacity must be greater than or equal to
zero, with a default value of 200 W/K if this field is left
blank.
Field:
Basin Heater Setpoint Temperature[LINK]
When the condenser type is “EvaporativelyCooled”, this
numeric field contains the set point temperature (°C) for the
basin heater described in the previous field. The basin heater
is active when the outdoor air dry-bulb temperature falls
below this set point temperature, as long as the condenser fan
is off. The default value is 2°C if this field is left
blank.
Field:
Design Evaporative Condenser Water Pump Power[LINK]
When the condenser type is “EvaporativelyCooled”, the rated
power of the evaporative condenser water pump in Watts. This
value is used to calculate the power required to pump the
water used to evaporatively cool the condenser inlet air. The
value for this field must be greater than or equal to 0, with
a default value of 1000 Watts if this field is left blank.
This input field is also autocalculatable, equivalent to
0.004266 W per watt [15 W/ton] of total cooling capacity where
the total cooling capacity is the sum of the rated total
cooling capacities for the refrigerated cases and walk-ins
connected to this compressor rack (Ref. Refrigeration:Case
and Refrigeration:WalkIn)).
Field:
Evaporative Water Supply Tank Name[LINK]
When the condenser type is “EvaporativelyCooled”, this
field is used to define where the compressor rack obtains
water used for evaporative cooling of its condenser. If this
field is left blank, the unit will obtain water directly from
the mains (Ref. Water Mains Temperatures). If the name of a
Water Storage Tank object is used here, then the unit will
obtain its water from that tank.
Field:
Condenser Air Inlet Node Name[LINK]
This optional alpha field contains the name of the node
from which the outdoor compressor rack condenser draws its
outdoor air. This field is applicable only when the heat
rejection location is “Outdoors” (if the heat rejection
location is “Zone”,
this field is disregarded). If this field is left blank, the
outdoor air temperature entering the condenser (dry-bulb or
wet-bulb) is taken directly from the weather data. If this
field is not blank, this node name must also be specified in
an OutdoorAir:Node
object where the height of the node is taken into
consideration when calculating outdoor air temperature from
the weather data. Alternately, the node name may be specified
in an OutdoorAir:NodeList
object where the outdoor air temperature is taken directly
from the weather data.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field:
Refrigeration Case Name or WalkIn Name or CaseAndWalkInList
Name[LINK]
This alpha field is the name of a single refrigerated case,
a single walk in cooler, the name of a CaseAndWalkInList for
multiple refrigerated cases and/or walk-ins, the name of a
refrigeration chiller, or the name of a CaseAndWalkInList for
multiple refrigeration chillers connected to this compressor
rack. Note that if a CaseAndWalkInList contains the name(s) of
refrigeration chillers, it CANNOT have the name(s) or any
refrigerated cases or walkins . This field is required.
Field: Heat Rejection
Zone Name[LINK]
If the Heat Rejection Location is “Zone”
and any walk-in coolers are connected to this compressor rack,
then this field is required. The compressor rack heat
rejection will impact the air heat balance in this zone.
The following is an example input for a Refrigeration
Compressor Rack with water cooled condenser.
Refrigeration:CompressorRack,
MediumTempRack, !- Name
Outdoors, !- Heat Rejection Location
1.7, !- Design Compressor Rack COP {W/W}
RackCOPfTCurve, !- Compressor Rack COP as a Function of Temperature Curve Name
1025.0, !- Design Condenser Fan Power {W}
RackCondFanCurve, !- Condenser Fan Power as a Function of Temperature Curve Name
WaterCooled, !- Condenser Type
Condenser Inlet Node, !- Water-cooled Condenser Inlet Node Name
Condenser Outlet Node, !- Water-cooled Condenser Outlet Node Name
VariableFlow, !- Water-cooled Loop Flow Type
Cond Outlet Temp Sch, !- Water-cooled Condenser Outlet Temperature Schedule Name
, !- Water-cooled Condenser Design Flow Rate {m3/s}
0.003, !- Water-cooled Condenser Maximum Flow Rate {m3/s}
55, !- Water-cooled Condenser Maximum Water Outlet Temperature {C}
, !- Water-cooled Condenser Minimum Water Inlet Temperature {C}
, !- Evaporative Condenser Availability Schedule Name
, !- Evaporative Condenser Effectiveness {dimensionless}
, !- Evaporative Condenser Air Volume Flow Rate {m3/s}
, !- Basin Heater Capacity {W/K}
, !- Basin Heater Set Point Temperature {C}
, !- Design Evaporative Condenser Water Pump Power {W}
, !- Evaporative Water Supply Tank Name
, !- Condenser Air Inlet Node Name
, !- End-Use Subcategory
MediumTempCaseList; !- Refrigeration Case Name or WalkIn Name or CaseAndWalkInList Name
If Condenser Type = Water Cooled:
System,Average, Refrigeration Compressor Rack Condenser
Refrigerant Mass Flow Rate [kg/s]
System,Average, Refrigeration Compressor Rack Condenser
Heat Transfer Rate [W]
System,Sum, Refrigeration Compressor Rack Condenser
Heat Transfer Energy [J]
IF THE RACK SERVES CASES AND/OR WALKINS:
Zone,Average, Refrigeration Compressor Rack Electric
Power [W]
Zone,Sum, Refrigeration Compressor Rack Electric Energy
[J]
Zone,Average, Refrigeration Compressor Rack Condenser
Fan Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Condenser Fan
Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Total Heat
Transfer Rate [W]
Zone,Sum, Refrigeration Compressor Rack Total Heat
Transfer Energy [J]
Zone,Average, Refrigeration Compressor Rack COP
[W/W]
If Condenser Type = Evap Cooled:
Zone,Average, Refrigeration Compressor Rack Evaporative
Condenser Pump Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Evaporative
Condenser Pump Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Evaporative
Condenser Basin Heater Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Evaporative
Condenser Basin Heater Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Evaporative
Condenser Water Volume Flow Rate [m\(^{3}\)/s]
Zone,Sum, Refrigeration Compressor Rack Evaporative
Condenser Water Volume [m\(^{3}\)]
If Heat Rejection Location = Zone:
Zone,Average, Refrigeration Compressor Rack Zone
Sensible Heating Rate [W]
Zone,Sum,Refrigeration Compressor Rack Zone
Sensible Heating Energy [J]
Zone,Average, Refrigeration Compressor Rack Return Air
Sensible Heating Rate [W]
Zone,Sum,Refrigeration Compressor Rack Return Air
Sensible Heating Energy [J]
IF THE RACK SERVES REFRIGERATION CHILLERS
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System
Compressor Runtime Fraction []
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Condenser Fan Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Condenser Fan Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Total Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Total Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack
COP [W/W]
If Condenser Type = Evap Cooled:
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Evaporative Condenser Pump Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Evaporative Condenser Pump Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Evaporative Condenser Basin Heater Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Electric PowerRefrigeration Air Chiller Compressor Rack
Evaporative Condenser Basin Heater Electric Energy
[J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Evaporative Condenser Water Volume Flow Rate [m3/s]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack
Evaporative Condenser Water Volume [m3]
If Heat Rejection Location = Zone:
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Zone
Sensible Heating Rate [W]
HVAC,Sum,Refrigeration Air Chiller Compressor Rack Zone
Sensible Heating Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack
Return Air Sensible Heating Rate [W]
HVAC,Sum,Refrigeration Air Chiller Compressor Rack
Return Air Sensible Heating Energy [J]
Refrigeration
Compressor Rack Condenser Mass Flow Rate [kg/s][LINK]
When condenser type is Water Cooled, this is the mass flow
rate of water flowing through the water cooled condenser.
Refrigeration
Compressor Rack Condenser Heat Transfer Rate [W][LINK]
When condenser type is Water Cooled, this is the total heat
transfer across the condenser (i.e., compressor energy and
case cooling).
Refrigeration
Compressor Rack Condenser Heat Transfer Energy [J][LINK]
When condenser type is Water Cooled, this is the total heat
energy flowing across the condenser for the timestep being
reported.
IF THE RACK
SERVES CASES AND OR WALKINS:[LINK]
Refrigeration
Compressor Rack Electric Power [W][LINK]
This output is the electric power input to the rack
compressor(s) in Watts.
Refrigeration
Compressor Rack Electric Energy [J][LINK]
This is the electricity consumption of the rack
compressor(s) in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Compressor Runtime Fraction [][LINK]
This is the runtime operating ratio for the compressor.
Refrigeration
Compressor Rack Condenser Fan Electric Power [W][LINK]
This output is the electric input to the rack condenser
fan(s) in Watts.
Refrigeration
Compressor Rack Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the rack condenser
fan(s) in Joules for the timestep being reported. This output
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Compressor Rack Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the
refrigeration compressor rack in Watts. It is the sum of all
of the heat transfer rates for the refrigerated cases and
walk-ins that are connected to this rack. This value does not
include compressor or condenser fan heat.
Refrigeration
Compressor Rack Total Heat Transfer Energy [J][LINK]
This is the total heat transfer of the refrigeration
compressor rack in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Compressor Rack COP [W/W][LINK]
This field is the refrigeration compressor rack
coefficient of performance. It is the actual compressor rack
COP for the timestep being reported, accounting for the COP
variation as a function of temperature. It is calculated as
the Design Compressor Rack COP times the Compressor Rack COP
as a Function of Temperature Curve evaluated at the effective
condenser entering air temperature for the timestep being
reported.
Refrigeration
Compressor Rack Evaporative Condenser Pump Electric Power
[W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water pump used with
evaporative cooling of the compressor rack condenser.
Refrigeration
Compressor Rack Evaporative Condenser Pump Electric Energy
[J][LINK]
This is the electricity consumption in Joules of the water
pump used with evaporative cooling of the compressor rack
condenser for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant. Use of an optional subkey
category is also available, with default to the General
end-use subcategory (Ref. Output:Meter
objects).
Refrigeration
Compressor Rack Evaporative Condenser Basin Heater Electric
Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water heater in the basin of
the evaporative system used to cool the compressor rack
condenser.
Refrigeration
Compressor Rack Evaporative Condenser Basin Heater Electric
Energy [J][LINK]
This is the electricity consumption in Joules of the water
heater used to prevent freezing of the evaporative cooling
system for the compressor rack condenser for the timestep
being reported. This output is also added to a meter with
Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
Compressor Rack Evaporative Condenser Water Volume Flow Rate
[m3/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while
providing evaporative cooling of the compressor rack
condenser.
Refrigeration
Compressor Rack Evaporative Condenser Water Volume [m3][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing
evaporative cooling of the compressor rack condenser for the
timestep being reported. This output is also added to a meter
with Resource Type = Water, End Use Key = Refrigeration, Group
Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
Compressor Rack Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating in Watts
provided to the zone by condenser waste heat rejection, which
impacts the zone air heat balance.
Refrigeration
Compressor Rack Zone Sensible Heating Energy [J][LINK]
This field is the sensible heating energy in Joules
provided to the zone by condenser waste heat rejection for the
timestep being reported.
Refrigeration
Compressor Rack Return Air Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating in Watts
provided by condenser waste heat rejection to the HVAC return
air (zone return air path outlet node), which impacts the HVAC
return air temperature. If the HVAC system is off for a
simulation timestep (no return air mass flow), then this
sensible heating is actually provided to the zone air instead
(even though a non-zero value is reported here).
Refrigeration
Compressor Rack Return Air Sensible Heating Energy [J][LINK]
This field is the sensible heating energy in Joules
provided by condenser waste heat rejection to the HVAC return
air (zone return air path outlet node) for the timestep being
reported. If the HVAC system is off for a simulation timestep
(no return air mass flow), then this sensible heating is
actually provided to the zone air instead (even though a
non-zero value is reported here).
IF THE RACK SERVES
CHILLERS[LINK]
Refrigeration
Air Chiller Compressor Rack Electric Power [W][LINK]
This output is the electric power input to the rack
compressor(s) in Watts.
Refrigeration
Air Chiller Compressor Rack Electric Energy [J][LINK]
This is the electricity consumption of the rack
compressor(s) in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Compressor Runtime Fraction [][LINK]
This is the runtime fraction for the compressor serving air
chillers.
Refrigeration
Air Chiller Compressor Rack Condenser Fan Electric Power
[W][LINK]
This output is the electric input to the rack condenser
fan(s) in Watts.
Refrigeration
Air Chiller Compressor Rack Condenser Fan Electric Energy
[J][LINK]
This is the electricity consumption of the rack condenser
fan(s) in Joules for the timestep being reported. This output
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Air Chiller Compressor Rack Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the
refrigeration compressor rack in Watts. It is the sum of all
of the heat transfer rates for the refrigerated cases and
walk-ins that are connected to this rack. This value does not
include compressor or condenser fan heat.
Refrigeration
Air Chiller Compressor Rack Total Heat Transfer Energy
[J][LINK]
This is the total heat transfer of the refrigeration
compressor rack in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller Compressor Rack COP [W/W][LINK]
This field is the refrigeration compressor rack
coefficient of performance. It is the actual compressor rack
COP for the timestep being reported, accounting for the COP
variation as a function of temperature. It is calculated as
the Design Compressor Rack COP times the Compressor Rack COP
as a Function of Temperature Curve evaluated at the effective
condenser entering air temperature for the timestep being
reported.
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Pump
Electric Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water pump used with
evaporative cooling of the compressor rack condenser.
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Pump
Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water
pump used with evaporative cooling of the compressor rack
condenser for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant. Use of an optional subkey
category is also available, with default to the General
end-use subcategory (Ref. Output:Meter
objects).
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Basin Heater
Electric Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water heater in the basin of
the evaporative system used to cool the compressor rack
condenser.
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Basin Heater
Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water
heater used to prevent freezing of the evaporative cooling
system for the compressor rack condenser for the timestep
being reported. This output is also added to a meter with
Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Water Volume
Flow Rate [m\(^{3}\)/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while
providing evaporative cooling of the compressor rack
condenser.
Refrigeration
Air Chiller Compressor Rack Evaporative Condenser Water Volume
[m\(^{3}\)][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing
evaporative cooling of the compressor rack condenser for the
timestep being reported. This output is also added to a meter
with Resource Type = Water, End Use Key = Refrigeration, Group
Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller Compressor Rack Zone Sensible Heating Rate
[W][LINK]
This field is the rate of sensible heating in Watts
provided to the zone by condenser waste heat rejection, which
impacts the zone air heat balance.
Refrigeration
Air Chiller Compressor Rack Zone Sensible Heating Energy
[J][LINK]
This field is the sensible heating energy in Joules
provided to the zone by condenser waste heat rejection for the
timestep being reported.
Refrigeration
Air Chiller Compressor Rack Return Air Sensible Heating Energy
[J][LINK]
Refrigeration
Air Chiller Compressor Rack Return Air Sensible Heating Rate
[W][LINK]
These are the sensible heating energy, in Joules or Watts,
provided to the HVAC system return air node by condenser heat
rejection at the compressor rack.
Refrigeration:Case[LINK]
The Refrigeration Case object works in conjunction with a
compressor rack, a refrigeration system, or a secondary loop
object (Refrigeration:CompressorRack, Refrigeration:System,
or Refrigeration:SecondarySystem) to simulate the performance
of a refrigerated case system. The refrigerated case model
uses performance information at rated conditions along with
performance curves for latent case credits and defrost heat
load to determine performance at off-rated conditions. Energy
use for lights, fans and anti-sweat heaters is modeled based
on inputs for nominal power, schedules, and control type. The
refrigerated case model accounts for the sensible and latent
heat exchange with the surrounding environment (termed “case
credits”) which impacts the temperature and humidity in the
zone where the case is located.
A dataset has been provided containing
refrigerated case input data for a large number of
refrigerated cases from multiple manufacturers. See
RefrigerationCases.idf.
The Refrigeration Case object inputs include a case name,
an availability schedule name, the zone name for the location
of the case, and the temperature and relative humidity of the
ambient (zone) air surrounding the refrigerated case at the
rating conditions for case performance. Additional inputs
include the total cooling capacity, latent heat ratio, and run
time fraction of the refrigerated case at rated conditions.
The case length and operating temperature (average temperature
of air/products within the case) must also be specified.
The refrigerated case model requires two curves to describe
performance at off-rated conditions (i.e., at different zone
temperature and humidity levels): the latent case credit curve
and the defrost energy correction curve. The user must enter
cubic performance curves with the independent variable being
user selectable (case temperature, zone relative humidity, or
zone dewpoint temperature).
The user can select from eight case defrost types, with
additional inputs being required depending on the type
selected. The user must enter a defrost schedule (unless Case
Defrost Type = None), and an optional defrost drip-down
schedule can be specified to allow additional time for melted
frost to drain from the cooling coil following the regular
defrost period.
Inputs are required for case fans, lights, and anti-sweat
heaters. Case lighting can be controlled by the user through
entering a schedule. The case fans operate whenever the
cooling coil is operating and during defrost periods for
certain case defrost types. Anti-sweat heater power can be
controlled by several methods which are user selectable. The
model assumes that the fans are contained within the thermal
envelope of the case and provide a direct heat load on the
case cooling coil. For lighting and anti-sweat heaters, the
user can specify the fraction of their respective heat loads
that directly impact the case cooling coil (with the remainder
of their heat load impacting the surrounding zone air).
The user has the option of specifying a case restocking
schedule and a schedule for modifying the case credits if
needed. Finally, the user can specify the under case HVAC
return air fraction which determines the portion of the case
credits that directly impact the HVAC return air conditions
(with the remainder of the case credits impacting the zone
sensible and latent loads).
A unique user-assigned name for an instance of a
refrigerated case. Any reference to this case by another
object will use this name.
Field:
Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigerated case can operate during a given time
period. A schedule value greater than 0 (maximum schedule
value of 1.0 is typically used) indicates that the case will
operate during a given time period. A value equal to 0 denotes
that the case does not operate (everything is OFF:
refrigeration, fans, lights, anti-sweat, etc.). Typically the
refrigerated case will operate throughout the day (i.e., the
schedule will contain 1 for all time periods); however, cases
require maintenance and/or cleaning and this can be modeled
accordingly using this schedule if desired. If this field is
left blank, the case is assumed to be available at all time
periods.
Field: Zone Name[LINK]
The name of the zone where the refrigerated case is
located. The refrigerated case will impact the air heat
balance in this zone. When modeling multiple refrigerated
cases connected to a single compressor rack where the
condenser heat is rejected to the zone (ref:
Refrigeration:CompressorRack), all of the
refrigerated cases connected to that compressor rack must be
located in the same zone.
Field: Rated Ambient
Temperature[LINK]
Dry-bulb temperature of the ambient (zone) air surrounding
the refrigerated case at the rating conditions for
refrigerated case performance. The default value for this
field is 23.9˚C (75˚F). This temperature must be greater than
0˚C and greater than the case operating temperature.
Field: Rated
Ambient Relative Humidity[LINK]
Relative humidity of the ambient (zone) air surrounding the
refrigerated case at the rating conditions for refrigerated
case performance. The default value for this field is 55%
RH.
Field:
Rated Total Cooling Capacity per Unit Length[LINK]
The total, full load cooling capacity (sensible plus
latent) in watts per unit length of refrigerated case (W/m) at
rated conditions (i.e., at the Rated Ambient Temperature,
Rated Ambient Relative Humidity, Case Operating Temperature,
and with the Standard Case Fan Power per Unit Length and the
Standard Case Lighting Power per Unit Length). The value
entered for this field must be greater than zero, with a
default value of 1900 W/m if the field is blank.
Field: Rated Latent
Heat Ratio[LINK]
The latent heat ratio (LHR = latent capacity divided by
total cooling capacity) of the refrigerated case at rated
conditions (i.e., at the Rated Ambient Temperature, Rated
Ambient Relative Humidity, Case Operating Temperature, and
with the Standard Case Fan Power per Unit Length and the
Standard Case Lighting Power per Unit Length). The value for
this field can range from zero to 1.0, with a default value of
0.3 if the field is blank.
Field: Rated Runtime
Fraction[LINK]
The runtime fraction of the refrigerated case at rated
conditions (i.e., at the Rated Ambient Temperature, Rated
Ambient Relative Humidity, and Case Operating Temperature).
Even at rated conditions, refrigerated cases typically include
additional cooling capacity to account for product stocking
and recovery from defrost. The rated runtime fraction for
refrigerated cases typically ranges from 0.8 to 0.9. The
entered value for this field must be greater than 0.0 and less
than or equal to 1.0, and the default value is 0.85 if the
field is blank.
Field: Case Length[LINK]
The length of the refrigerated case in meters. The entered
value for this field must be greater than 0.0, and the default
value is 3 meters if the field is blank.
Field: Case
Operating Temperature[LINK]
The average temperature of the air and products within the
refrigerated case in ˚C. The refrigerated case manufacturer
typically provides this information in the product literature.
Typical operating temperatures for medium temperature cases
are 1.6˚C to 7.2˚C (35˚F to 45˚F). Typical operating
temperatures for low temperatures cases are -28.9˚C to
-17.8˚C (-20˚F to 0˚F). The entered value for this
field must be less than 20˚C and lower than the Rated Ambient
Temperature. The default value is 1.1˚C if the field is
blank.
Field: Latent
Case Credit Curve Type[LINK]
This alpha field defines the form of the curve used to
modify the latent case credits (latent heat removed from the
zone where the refrigerated case is located) at off-rated
conditions. The valid choices for this field are:
This method defines the variation in latent case credits as
a cubic function of Case Operating Temperature. The result
from the cubic curve is multiplied by the difference between
the rated ambient relative humidity and the actual zone
relative humidity, and one minus this value is multiplied by
the Rated LHR to give the operating LHR at the actual zone
humidity condition. (Representative cooefficient values for
single-shelf horizontal and multi-shelf vertical display cases
are given in the EnergyPlus Engineering Reference.)
This method defines the variation in latent case credits as
a cubic function of ambient (zone) air relative humidity.
This method defines the variation in latent case credits as
a cubic function of ambient (zone) air dewpoint
temperature.
The default curve type is the Case Temperature Method.
Refer to the Engineering Reference for further information on
how latent case credits are modeled.
Field: Latent
Case Credit Curve Name[LINK]
The name of a cubic performance curve
(ref: Performance Curves) that parameterizes the variation of
the latent case credits at off-rated conditions. The curve
should be normalized to have a value of 1.0 at the rated
ambient air conditions defined above.
Field:
Standard Case Fan Power per Unit Length[LINK]
The total standard fan power in Watts per unit length of
refrigerated case (W/m). This value represents the fan power
included in the field Rated Total Cooling Capacity per Unit
Length, and is used to determine the sensible case credits.
The entered value for this field must be greater than or equal
to zero, and the default value is 75.0 W/m if the field is
blank.
Field:
Operating Case Fan Power per Unit Length[LINK]
The total operating fan power in Watts per unit length of
refrigerated case (W/m). Enter the actual power for the
installed fans. The entered value for this field must be
greater than or equal to zero, and the value is set equal to
the standard case fan powers if the field is blank.
Field:
Standard Case Lighting Power per Unit Length[LINK]
The total standard lighting power in Watts per unit length
of refrigerated case (W/m). This value should represent the
lighting power provided by the case manufacturer and included
in the “Rated Total Cooling Capacity per Unit Length” field
and is used to determine the sensible case credits. For cases
where the manufacturer does not include the lights in the
Rated Total Cooling Capacity, this value should be zero (0.0).
The entered value for this field must be greater than or equal
to zero, and the default value is 90.0 W/m if the field is
blank.
Field:
Installed Case Lighting Power per Unit Length[LINK]
The total installed lighting power in Watts per unit length
of refrigerated case (W/m). Enter the actual power for the
installed lights. This number may be greater or less than the
standard lighting power value, depending upon the
manufacturer’s practice in specifying the case rated cooling
capacity and whether or not energy-efficient lights are being
modeled. The next field (i.e. Case Lighting Schedule Name)
may be used to specify the name of a schedule that contains
the fraction of the Installed Case Lighting Power per Unit
Length to be modeled for each timestep of the simulation
period. The entered value for this field must be greater than
or equal to zero, and the value is set equal to the standard
case lighting power if the field is blank.
Field: Case
Lighting Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of installed refrigerated case lights that operate
during a given time period. A schedule value greater than 0
indicates that the lights will operate during that time period
(maximum schedule value of 1.0 means lights are fully on at
the Installed Case Lighting Power per Unit Length level). A
schedule value of zero denotes that the lights are off. The
refrigerated case lights will typically operate only when the
store is open for business and can be scheduled off as desired
via this schedule. If this field is left blank, the default
schedule has a value of 1 for all time periods.
Field:
Fraction of Lighting Energy To Case[LINK]
The fraction of the lighting energy that directly
contributes to the case heat load. The remainder of the
lighting energy (1 – fraction) is a heating load to the zone
where the case is located. This field can be used to model
lighting ballasts and bulbs located outside the air curtain of
the refrigerated case. The value for this field can range from
zero to 1.0, with a default value of 1.0 if the field is
blank.
Field:
Case Anti-Sweat Heater Power per Unit Length[LINK]
The electric anti-sweat heater power in watts per unit
length of refrigerated case (W/m). The entered value for this
field must be greater than or equal to zero, and the default
value is 0 W/m if the field is blank.
Field:
Minimum Anti-Sweat Heater Power per Unit Length[LINK]
The minimum electric anti-sweat heater power in watts per
unit length of refrigerated case (W/m). Anti-sweat heater
power will remain at or above this value for anti-sweat heater
control types linear, dewpoint method, or heat balance method.
Other anti-sweat heater control types disregard this field.
The entered value for this field must be greater than or equal
to zero, and the default value is 0 W/m if the field is
blank.
Field:
Anti-Sweat Heater Control Type[LINK]
The type of anti-sweat heater control used for this
refrigerated case. Valid choices are None, Constant, Linear,
DewpointMethod, or HeatBalanceMethod. The default is None if
the field is blank. Refer to the Engineering Reference for
further information on how the different anti-sweat heater
controls are modeled.
Field:
Humidity at Zero Anti-Sweat Heater Energy[LINK]
The value of this numeric field is only used when the
Linear anti-sweat heater control type is selected. Enter the
zone relative humidity where anti-sweat heater energy use is
zero. Negative values for relative humidity may be entered.
Other anti-sweat heater control types disregard this field.
The value entered for this field must be less than the Rated
Ambient Relative Humidity specified above. The default for
this field is -10.0.
Field: Case Height[LINK]
The value of this numeric field is used when Heat Balance
Method anti-sweat heater control is selected. Enter the case
height in meters. Other anti-sweat heater control types
disregard this field. The entered value for this field must be
greater than zero when Heat Balance Method anti-sweat heater
control is selected, and the default value is 1.5 meters if
the field is blank.
Field:
Fraction of Anti-Sweat Heater Energy To Case[LINK]
This value denotes the fraction of anti-sweat heater energy
that results in a direct heat load to the refrigerated case.
The remainder of the anti-sweat heater energy (1-fraction) is
a heating load to the zone where the refrigerated case is
located. The value for this field can range from zero to 1.0,
with a default value of 1.0 if the field is blank.
Field: Case
Defrost Power per Unit Length[LINK]
The defrost power in watts per unit length of refrigerated
case (W/m). This input is required for hot-gas, hot-fluid, or
electric defrost types and is used to evaluate the load on the
case as well as power or heat consumption. Refrigerated case
manufacturers do not typically provide information on the heat
input for hot-gas and hot-fluid defrost. Information provided
for electric defrost power can be substituted here for
refrigerated cases using hot-gas or hot-fluid defrost if other
information is not available. Only electric Case Defrost Types
consume electricity during the defrost period. The entered
value for this field must be greater than or equal to zero,
and the default value is 0 W/m if the field is blank.
Field: Case Defrost Type[LINK]
The type of defrost used for this refrigerated case. Valid
choices are None, OffCycle, HotGas,
HotGaswithTemperatureTermination, Electric,
ElectricwithTemperatureTermination, HotFluid, and
HotFluidwithTemperatureTermination. The default defrost type
is OffCycle if the field is blank. Refer to the Engineering
Reference for further information on how the different case
defrost types are modeled. In particular, hot-fluid defrost
systems may be effective with much shorter defrost times than
other systems, which should be reflected in the defrost and
drip-down schedules.
Field: Case Defrost
Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigerated case requires defrosting. A schedule
value of 1.0 indicates that defrost will be on during a given
time period. A value equal to 0 denotes that the defrost is
off. Defrost schedules normally repeat the duration and number
of defrost cycles for each day of the year. The refrigerated
case manufacturer typically provides this information with the
product literature. The use of Compact Schedules (ref.
Schedules) are ideal for this purpose. In a typical
supermarket with many cases, it is important to diversify the
defrost schedules in order to avoid large swings in the load
placed upon the remainder of the refrigeration system.
Field:
Case Defrost Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigerated case requires additional time for
draining condensate after the defrost period. A schedule value
of 1.0 indicates that the defrost drip-down period is on
during a given time period. A value equal to 0 denotes that
the defrost drip-down period is over. The refrigerated case
manufacturer typically provides this information with the
product literature.
Each defrost drip-down period specified in this schedule
should start at the same time as the corresponding defrost
period specified in the schedule for Case Defrost Schedule,
and the drip-down schedule defrost period should always be
longer than or equal to the length of the defrost schedule
time period. For example, if the case defrost schedule
contains a defrost period from 7:00 to 7:15, you would specify
a case defrost drip-down period from 7:00 to 7:20 if you
wanted to model a 5 minute condensate drip-down period after
the regular defrost period. If no drip-down schedule is
entered, then the case defrost schedule (specified for the
previous input field) will be used. The use of Compact
Schedules (ref. Schedules) are ideal for this purpose.
Field:
Defrost Energy Correction Curve Type[LINK]
This alpha field defines the form of the correction curve
used to modify the defrost energy use (and the associated load
on the case cooling coil) at off-rated conditions. The valid
choices for this field are:
This choice specifies that a defrost energy correction
curve will not be used.
This method defines the variation in defrost energy as a
cubic function of Case Operating Temperature. The result from
the cubic curve is multiplied by the difference between the
rated ambient relative humidity and the actual zone relative
humidity, and one minus this value is multiplied by the Case
Defrost Power to give the (average) operating defrost power at
the actual zone humidity condition. (Representative
cooefficient values for single-shelf horizontal and
multi-shelf vertical display cases are given in the EnergyPlus
Engineering Reference.)
This method defines the variation in defrost energy as a
cubic function of ambient (zone) air relative humidity.
This method defines the variation in defrost energy as a
cubic function of ambient (zone) air dewpoint temperature.
The default curve type is None. The methods described here
(e.g. Case Temperature, Relative Humidity, and Dewpoint) are
applicable only to Electric with Temperature Termination,
Hot-Gas with Temperature Termination, and Hot-Brine with
Temperature Termination case defrost types. Refer to the
Engineering Reference for further information on how the
defrost energy correction types are modeled.
Field:
Defrost Energy Correction Curve Name[LINK]
The name of a cubic performance curve
(ref: Performance Curves) that parameterizes the variation of
the defrost energy (and the associated load on the case
cooling coil) at off-rated conditions. The curve should be
normalized to have the value of 1.0 at the rated ambient air
conditions defined above. The defrost energy correction curve
name is used only for the Electric with Temperature
Termination, Hot-Gas with Temperature Termination, and
Hot-Brine with Temperature Termination case defrost types.
Field:
Under Case HVAC Return Air Fraction[LINK]
This field denotes the fraction of HVAC system (air loop)
return air that passes beneath the refrigerated case, if any.
At times it is necessary to design HVAC systems with under
case returns to avoid overcooling the area around the
refrigerated case, thus providing a more comfortable
environment for the zone occupants. This return air fraction
affects the portion of the case credits (sensible and latent)
that are applied to the air returning to the HVAC system,
while the remainder of the case credits directly impacts the
zone air heat balance. Refer to the Engineering Reference for
further information on how this is modeled. The sum of the
Under Case HVAC Return Air Fractions for all refrigerated
cases located in a single zone must be less than or equal to
1.0. The value for this field can range from zero to 1.0, with
a default value of 0 if the field is blank. The return air
node name may be specified below.
Field:
Refrigerated Case Restocking Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigerated case is being restocked with product.
The schedule should contain values in units of Watts per unit
length of refrigerated case (W/m). This field can be used to
denote the additional load imposed on the refrigerated case
from stocking the case with product that is warmer than the
refrigerated case temperature. This information is difficult
to find and may require additional research for proper
modeling; however, this schedule is available for this purpose
if desired. If restocking of the refrigerated case will not be
simulated, enter a schedule with values of zero for all time
periods or leave this field blank.
Field: Case
Credit Fraction Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes a
fraction of both the sensible and latent case credits to be
applied to the zone and/or the HVAC system return air.
Schedule values must be from 0 to 1. This allows correction of
the case credits for various refrigerated case types. For
instance, if glass door refrigerated display cases are
installed in a store that is operated 12 hours per day, then
the doors will remain closed during the unoccupied times and
would therefore reduce the sensible and latent case credits
during the unoccupied time. Leaving this field blank will
result in no case credit fraction being applied during the
simulation.
Field:
Design Evaporator Temperature or Brine Inlet Temperature[LINK]
The value of this numeric field is used only with the
detailed refrigeration system and is not read for the
compressor-rack system. For the refrigeration system, it is
used to evaluate compressor performance and is also used when
the evaporator pressure and temperature are allowed to float
at loads less than the design load. If the case is cooled by a
secondary system (ref: Refrigeration:SecondarySystem), this
value is the brine inlet temperature. The minimum value is
-70C and the maximum value is 40C. The default value is 5C
less than the case temperature.
Field:
Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant
inventory present in the refrigerated case during ordinary
operation. The value is used to produce an estimate of the
total refrigerant present in the refrigeration system. The
value is entered in kg/m.
Field: Under
Case HVAC Return Air Node Name[LINK]
Name of the return air node for this case. If left blank,
it defaults to the first return air node for this zone.
The following is an example input for a refrigerated
case.
Refrigeration:Case,
Multi-Deck Dairy/Deli Merchandiser with Synergy-E, !- Name [Based on Hill Phoenix 6DMLH-NRG]
, !- Availability Schedule [Used to turn case on/off including all power draws (ie fans, lights, etc)]
UserProvideZoneName, !- Zone Name [Location of Fixture]
23.89, !- Rated Ambient Temperature {C} [75øF]
55, !- Rated Ambient Relative Humidity {percent}
1394, !- Rated Total Cooling Capacity per Unit length {W/m} [1,450 Btu/hr/ft = 11,600 Btu/hr]
0.30, !- Rated Latent Heat Ratio [ Rated Latent Capacity]
0.85, !- Rated Runtime Fraction
2.4, !- Case Length {m} [8 ft]
3.33, !- Case Operating Temperature {C} [38øF]
CaseTemperatureMethod, !- Latent Case Credit Curve Type
Multi_Shelf_Vertical_Latent_Case_Credit_Curve, !- Latent Case Credit Curve Name
27.3, !- Standard Case Fan Power per Unit Length {W/m} [8.3 W/ft]
27.3, !- Operating Case Fan Power per Unit Length {W/m} [8.3 W/ft = 67 W]
0.0, !- Standard Case Lighting Power per Unit Length {W/m} [0.0 W/ft]
114.8, !- Installed Case Lighting Power per Unit Length {W/m} [35.0 W/ft = 280 W]
, !- Case Lighting Schedule Name
1.0, !- Fraction Of Lighting Energy To Case
0.0, !- Case Anti-Sweat Heater Power per Unit Length {W/m} [0.0 W/ft = 0 W]
, !- Minimum Anti-Sweat Heater Power per Unit Length {W/m} []
None, !- Anti-Sweat Heater Control Type
, !- Humidity At Zero Anti-Sweat Heater Energy {%}
, !- Case Height {m} []
1.0, !- Fraction of Anti-Sweat Heater Energy To Case
0.0, !- Case Defrost Power per Unit Length {W/m} [0.0 W/ft 0 W]
Off Cycle, !- Case Defrost Type
UserProvideDefSched6PerDay45MinEa, !- Case Defrost Schedule Name
UserProvideDefSched4PerDay42MinEa, !- Case Defrost Drip-Down Schedule
CaseTemperatureMethod, !- Defrost Energy Correction Curve Type
Multi Shelf Vertical, !- Defrost Energy Correction Curve Name
0.00, !- Under Case HVAC Return Air Fraction
, !- Refrigerated Case Restocking Schedule Name [Not modeling any restocking]
, !- Case Credit Fraction Schedule Name
-3.33, !- Design Evaporator Temperature or Brine Inlet Temperature {C} [26øF]
; !- Average Refrigerant Charge Inventory {kg/m} [ = ]
Zone,Average,Refrigeration Case Evaporator Total
Cooling Rate [W]
Zone,Sum,Refrigeration Case Evaporator Total Cooling
Energy [J]
Zone,Average,Refrigeration Case Evaporator Sensible
Cooling Rate [W]
Zone,Sum,Refrigeration Case Evaporator Sensible Cooling
Energy [J]
Zone,Average, Refrigeration Case Evaporator Latent
Cooling Rate [W]
Zone,Sum, Refrigeration Case Evaporator Latent Cooling
Energy [J]
Zone,Average,Refrigeration Case Zone
Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Case Zone
Sensible Cooling Energy [J]
Zone,Average,Refrigeration Case Zone
Sensible Heating Rate [W]
Zone,Sum,Refrigeration Case Zone
Sensible Heating Energy [J]
Zone,Average,Refrigeration Case Zone
Latent Rate [W]
Zone,Sum,Refrigeration Case Zone
Latent Energy [J]
Zone,Average,Refrigeration Case Return Air Sensible
Cooling Rate [W]
Zone,Sum,Refrigeration Case Return Air Sensible Cooling
Energy [J]
Zone,Average,Refrigeration Case Return Air Sensible
Heating Rate [W]
Zone,Sum,Refrigeration Case Return Air Sensible Heating
Energy [J]
Zone,Average,Refrigeration Case Return Air Latent Rate
[W]
Zone,Sum,Refrigeration Case Return Air Latent Energy
[J]
Zone,Average,Refrigeration Case Evaporator Fan Electric
Power [W]
Zone,Sum,Refrigeration Case Evaporator Fan Electric
Energy [J]
Zone,Average,Refrigeration Case Lighting Electric Power
[W]
Zone,Sum,Refrigeration Case Lighting Electric Energy
[J]
Zone,Average,Refrigeration Case Latent Credit Curve
Value []
If case defrost type is Electric, Hot-Gas, or Hot-Brine
with Temperature Termination
- Zone,Average,Refrigeration Case Defrost Energy Correction
Curve Value
If anti-sweat heater control type is not equal to None:
Zone,Average,Refrigeration Case Anti Sweat Electric
Power [W]
Zone,Sum,Refrigeration Case Anti Sweat Electric Energy
[J]
If case defrost type is Electric or Electric with
Temperature Termination:
Zone,Average,Refrigeration Case Defrost Electric Power
[W]
Zone,Sum,Refrigeration Case Defrost Electric Energy
[J]
Refrigeration
Case Evaporator Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate
of the refrigerated case evaporator coil in Watts.
Refrigeration
Case Evaporator Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of
the refrigerated case evaporator coil in Joules over the
timestep being reported. This output is also added to a meter
with Resource Type = EnergyTransfer, End Use Key =
Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Case Evaporator Sensible Cooling Rate [W][LINK]
This field is the sensible cooling rate of the refrigerated
case evaporator coil in Watts.
Refrigeration
Case Evaporator Sensible Cooling Energy [J][LINK]
This field is the sensible cooling of the refrigerated case
evaporator coil in Joules over the timestep being
reported.
Refrigeration
Case Evaporator Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of
the refrigerated case evaporator coil in Watts.
Refrigeration
Case Evaporator Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the
refrigerated case evaporator coil in Joules over the timestep
being reported.
Refrigeration
Case Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits
delivered to the zone in Watts. If an under case return duct
is simulated, only a portion of the sensible case credits are
applied to the zone. A positive value is reported when the
zone is cooled by sensible case credits, otherwise a zero is
reported.
Refrigeration
Case Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit
energy delivered to the zone in Joules. If an under case
return duct is simulated, only a portion of the sensible case
credits are applied to the zone. A positive value is reported
when the zone is cooled by sensible case credits, otherwise a
zero is reported.
Refrigeration
Case Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits
delivered to the zone in Watts. If an under case return duct
is simulated, only a portion of the sensible case credits are
applied to the zone. A positive value is reported when the
zone is heated by sensible case credits, otherwise a zero is
reported.
Refrigeration
Case Zone Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit
energy delivered to the zone in Joules. If an under case
return duct is simulated, only a portion of the sensible case
credits are applied to the zone. A positive value is reported
when the zone is heated by sensible case credits, otherwise a
zero is reported.
Refrigeration
Case Zone Latent Rate [W][LINK]
This field is the rate of latent cooling (dehumidification)
case credits delivered to the zone in Watts. If an under case
return duct is simulated, only a portion of the latent case
credits are applied to the zone. A negative value (or zero)
will be reported when the refrigerated case provides
dehumidification (thereby reducing the zone latent load).
Refrigeration
Case Zone Latent Energy [J][LINK]
This field is the amount of latent cooling
(dehumidification) case credit energy delivered to the zone in
Joules. If an under case return duct is simulated, only a
portion of the latent case credits are applied to the zone. A
negative value (or zero) will be reported when the
refrigerated case provides dehumidification (thereby reducing
the zone latent load).
Refrigeration
Case Return Air Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits
delivered to the return air duct (zone return air node) in
Watts. If an under case return duct is simulated, a portion of
the sensible case credits are applied to the HVAC (zone)
return air. A positive value is reported when the return air
is cooled by sensible case credits, otherwise a zero is
reported. If the HVAC system is off for a simulation timestep
(no return air mass flow), then this sensible cooling is
actually provided to the zone air instead (even though a
non-zero value is reported here).
Refrigeration
Case Return Air Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit
energy delivered to the return air duct (zone return air node)
in Joules. If an under case return duct is simulated, a
portion of the sensible case credits are applied to the HVAC
(zone) return air. A positive value is reported when the
return air is cooled by sensible case credits, otherwise a
zero is reported. If the HVAC system is off for a simulation
timestep (no return air mass flow), then this sensible cooling
is actually provided to the zone air instead (even though a
non-zero value is reported here).
Refrigeration
Case Return Air Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits
delivered to the return air duct (zone return air node) in
Watts. If an under case return duct is simulated, a portion of
the sensible case credits are applied to the HVAC (zone)
return air. A positive value is reported when the return air
is heated by sensible case credits, otherwise a zero is
reported. If the HVAC system is off for a simulation timestep
(no return air mass flow), then this sensible heating is
actually provided to the zone air instead (even though a
non-zero value is reported here).
Refrigeration
Case Return Air Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit
energy delivered to the return air duct (thereby reducing the
zone latent load). If the HVAC system is off for a simulation
timestep (no return air mass flow), then this latent energy is
actually provided to the zone air instead (even though a
non-zero value is reported here).
Refrigeration
Case Return Air Latent Energy [J][LINK]
Refrigeration
Case Return Air Latent Rate [W][LINK]
These are the amount of latent cooling (dehumidification)
case credit energy delivered to the return air duct (zone
return air node) in Joules or Watts. If an under case return
duct is simulated, only a portion of the latent case credits
are applied to the HVAC (zone) return air. A negative value
(or zero) will be reported since the refrigerated case
provides dehumidification (thereby reducing the zone latent
load). If the HVAC system is off for a simulation timestep (no
return air mass flow), then this latent energy is actually
provided to the zone air instead (even though a non-zero value
is reported here).
Refrigeration
Case Evaporator Fan Electric Power [W][LINK]
This field is the electric power input to the refrigerated
case fan(s) in Watts.
Refrigeration
Case Evaporator Fan Electric Energy [J][LINK]
This field is the electricity consumption of the
refrigerated case fan(s) in Joules over the timestep being
reported. This output is also added to a meter with Resource
Type = Electricity, End Use Key = Refrigeration, Group Key =
Building
(Ref. Output:Meter
objects).
Refrigeration
Case Lighting Electric Power [W][LINK]
This field is the electric power input to the refrigerated
case lights in Watts.
Refrigeration
Case Lighting Electric Energy [J][LINK]
This field is the electricity consumption of the
refrigerated case lights in Joules over the timestep being
reported. This output is also added to a meter with Resource
Type = Electricity, End Use Key = Refrigeration, Group Key =
Building
(Ref. Output:Meter
objects).
Refrigeration
Case Defrost Energy Correction Curve Value[LINK]
This field is the output of the Defrost Energy Correction
Curve which denotes the variation in defrost energy at
off-rated conditions. The output of the defrost energy
correction curve directly impacts the energy used during the
defrost time period. It does not, however, impact the duration
of the defrost period. This output is available only for
Electric with Temperature Termination, Hot-Gas with
Temperature Termination, or Hot-Brine with Temperature
Termination case defrost types.
Refrigeration
Case Latent Credit Curve Value [][LINK]
This field is the output of the Latent Case Credit Curve
which denotes the variation in latent case credits at
off-rated conditions. The output of the latent case credit
curve directly impacts the amount of frost formation on the
refrigerated case evaporator coil and the requirement for
defrost.
Refrigeration
Case Anti Sweat Electric Power [W][LINK]
This field is the electric power input to the refrigerated
case anti-sweat heater in Watts. This output is available
unless anti-sweat heater control type is specified as
NONE.
Refrigeration
Case Anti Sweat Electric Energy [J][LINK]
This field is the total electricity consumption of the
refrigerated case anti-sweat heater in Joules over the
timestep being reported. This output is also added to a meter
with Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Building
(Ref. Output:Meter
objects). This output is available unless anti-sweat heater
control type is specified as NONE.
Refrigeration
Case Defrost Electric Power [W][LINK]
This field is the electric power input to the refrigerated
case electric defrost heater(s) in Watts. This output is
available if case defrost type is Electric or Electric with
Temperature Termination.
Refrigeration
Case Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the
refrigerated case electric defrost heater(s) in Joules over
the timestep being reported. This output is also added to a
meter with Resource Type = Electricity, End Use Key =
Refrigeration, Group Key = Building
(Ref. Output:Meter
objects). This output is available if case defrost type is
Electric or Electric with Temperature Termination.
Refrigeration:CaseAndWalkInList[LINK]
This object provides a list of all the refrigerated cases
and/or walk in coolers cooled by a single refrigeration system
(ref: Refrigeraion:CompressorRack and Refrigeration:System).
This list is extensible. Note that the names of all cases,
walk-ins,air chillers, and caseandwalkinlists must be unique.
That is, you cannot give a list the same name as one of the
cases. Similarly, a walkin cannot have the same name as a
case.This list may contain a combination of case and walk-in
names OR a list of air chiller names. Air chillers may not be
included in any list that also includes cases or walk-ins.
A unique user-assigned name for an instance of a
CaseAndWalkInList. Any reference to this list by another
object will use this name.
Field:
Case or WalkIn or Air Chiller <x> Name[LINK]
Identifies a particular refrigerated case or walk-in. The
name will be validated against the Refrigeration Case,
Refrigeration WalkIn, and Air Chiller names (ref:
Refrigeration:Case, Refrigeration:WalkIn,
and Refrigeration:AirChiller) in the input file. Up to 20 are
provided in the IDD; this object is extensible.
The following is an example input for a
CaseAndWalkInList.
Refrigeration:CaseAndWalkInList,
MediumTempCaselist, !- Name
UprightDairyCase, !- Refrigeration Case or WalkIn Name \#1
LunchmeatCase, !- Refrigeration Case or WalkIn Name \#2
MeatWalkIn, !- Refrigeration Case or WalkIn Name \#3
DeliCaseOne; !- Refrigeration Case or WalkIn Name \#4
Refrigeration:WalkIn[LINK]
The Refrigeration WalkIn object works in conjunction with a
compressor rack, a refrigeration system, or a refrigeration
secondary system object (Ref. Refrigeration:CompressorRack,
Refrigeration:System,
or Refrigeration:SecondarySystem) to simulate the performance
of a walk-in cooler. The walk-in cooler model uses information
at rated conditions along with input descriptions for heat
transfer surfaces facing multiple zones to determine
performance. Energy use for lights, fans, and floor and
anti-sweat heaters is modeled based on inputs for nominal
power, schedules, and control type. The walk-in cooler model
accounts for the sensible and latent heat exchange with the
surrounding environment (termed “case credits”) which impacts
the temperature and humidity in each zone adjacent to the
walk-in.
The walk-in cooler object inputs include a name, an
availability schedule name, the rated cooling capacity, the
rated operating temperature, the rated cooling source
temperature, the rated total heating power and heating power
schedule, the rated fan and lighting power and schedules,
defrost type, defrost control type, defrost schedule name,
drip-down schedule name, defrost power, the portion of the
defrost energy used to melt ice (only for temperature
termination control type), restocking schedule, refrigerant
inventory, and the floor area and U-value.
For each zone adjacent to the walk-in, the user must input
the zone name and the insulated surface area and U-value
facing that zone. The user must also specify, for two types of
doors, the door area, height, U-value, door opening schedule
name, and any door opening protection.
Under case HVAC return air fraction, available for
refrigerated cases, is not available for walk-in coolers.
A unique user-assigned name for an instance of a
refrigerated walk-in. Any reference to this walk-in by another
object will use this name.
Field:
Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the walk in can operate during a given time period. A
schedule value greater than 0 (maximum schedule value of 1.0
is typically used) indicates that the walkin will operate
during a given time period. A value equal to 0 denotes that
the case does not operate (everything is OFF: refrigeration,
fans, lights, anti-sweat, etc.). Typically the walkin will
operate throughout the day (i.e., the schedule will contain 1
for all time periods); however, walkins require maintenance
and/or cleaning and this can be modeled accordingly using this
schedule if desired. If this field is left blank, the default
schedule has a value of 1 for all time periods.
Field: Rated Coil
Cooling Capacity[LINK]
The total, full load cooling capacity (sensible plus
latent) in watts (W) at rated conditions The value entered for
this field must be greater than zero, with no default
value.
Field: Operating
Temperature[LINK]
The rated average temperature of the air and products
within the walk-in cooler in ˚C. The entered value for this
field must be less than 20˚C. There is no default value.
Field: Rated
Cooling Source Temperature[LINK]
For a DX evaporator coil, enter the saturated evaporating
temperature in ˚C. For a fluid coil, enter the fluid coil
entrance temperature in ˚C. There is no default value. This
number is used, with temperatures for other refrigeration
loads on any one system, to set that system’s minimum suction
pressure or minimum circulating fluid temperature. (This value
is not used if the walkin is cooled by a compressor rack
object.)
Field: Rated Total
Heating Power[LINK]
The total heating power in watts including all anti-sweat,
door, drip-pan, and floor heaters (W). This value is required
and has no default value.
Field: Heating
Power Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of heater power that operates during a given time
period. A schedule value of zero denotes that all heaters are
off. A schedule value greater than 0 indicates that some
portion of the total heater power will operate during that
time period (maximum schedule value of 1.0 means all heaters
are fully on). For example, if door and floor heaters
represent 50% of the total heater power and are on all the
time, the minimum schedule value would be 0.5. If anti-sweat
heaters represent 40% of the total heater power and are only
on during certain hours, the schedule value during those hours
would be increased by 0.4. If this field is left blank, the
default schedule has a value of 1 for all time periods.
Field: Rated
Cooling Coil Fan Power[LINK]
The cooling coil fan power in watts (W). This value has a
default value of 375W. This fan is assumed to run continuously
except during electric, hot brine, or hot gas defrost
periods.
Field: Rated
Circulation Fan Power[LINK]
The circulation fan power in watts (W). This value has a
default value of 0 W. This fan is assumed to run
continuously.
Field: Rated Total
Lighting Power[LINK]
The total lighting power in watts including both display
and task lighting (W). This value is required and has no
default value.
Field: Lighting Schedule
Name[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of walk-in lights that operate during a given time
period. A schedule value greater than 0 indicates that the
lights will operate during that time period (maximum schedule
value of 1.0 means lights are fully on). A schedule value of
zero denotes that the lights are off. If this field is left
blank, the default schedule has a value of 1 for all time
periods.
Field: Defrost Type[LINK]
The type of defrost used for this walk-in. Valid choices
are None, Off-Cycle, HotFluid, and Electric. The default
defrost type is Electric if the field is blank. HotFluid
includes both hot gas and hot brine defrost systems. Refer to
the Engineering Reference for further information on how the
different defrost types are modeled.
Field: Defrost Control
Type[LINK]
The type of defrost control used for this walkin. Valid
choices are TimeSchedule and TemperatureTermination. The
default is TimeSchedule if the field is blank. Refer to the
Engineering Reference for further information on how the
different defrost controls are modeled.
Field: Defrost Schedule
Name[LINK]
The name of the schedule (ref: Schedule) that denotes when
the walkin requires defrosting. A schedule value of 1.0
indicates that defrost will be on during a given time period
if the defrost control type is “TimeSchedule”. For the
TemperatureTermination defrost control type, the defrost will
start with the schedule value changes from 0 to 1, but will
end when the ice is melted. A value equal to 0 denotes that
the defrost is off. Defrost schedules normally repeat the
duration and number of defrost cycles for each day of the
year. The walkin manufacturer typically provides this
information with the product literature. If
TemperatureTermination control type is used, the defrost
schedule is used for the defrost cycle start time and the
defrost cycle end time is not allowed to extend beyond the
scheduled off time. The use of Compact Schedules (ref.
Schedules) are ideal for this purpose.
Field: Defrost
Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the walkin requires additional time for draining
condensate after the defrost period. A schedule value of 1.0
indicates that the defrost drip-down period is on during a
given time period. A value equal to 0 denotes that the defrost
drip-down period is over. The walkin manufacturer typically
provides this information with the product literature.
Each defrost drip-down period specified in this schedule
should start at the same time as the corresponding defrost
period specified in the schedule for Defrost Schedule, and the
drip-down schedule defrost period should always be longer than
or equal to the length of the defrost schedule time period.
For example, if the defrost schedule contains a defrost period
from 7:00 to 7:15, you would specify a case defrost drip-down
period from 7:00 to 7:20 if you wanted to model a 5 minute
condensate drip-down period after the regular defrost period.
If no drip-down schedule is entered, then the defrost schedule
(specified for the previous input field) will be used. The use
of Compact Schedules (ref. Schedules) are ideal for this
purpose.
Field: Defrost Power[LINK]
The defrost power in watts. This input is required for
hot-fluid (hot gas or hot brine), or electric defrost types.
Walkin manufacturers do not typically provide information on
the heat input for hot gas and hot brine defrost. Information
provided for electric defrost power can be substituted here
for walkins using hot-gas or hot-brine defrost if other
information is not available. Only electric Defrost Types
consume electricity during the defrost period. The entered
value for this field must be greater than or equal to
zero.
Field:
Temperature Termination Defrost Fraction to Ice[LINK]
When cooling coils go through a defrost cycle, only a
portion of the defrost energy is actually used to melt the
ice. The rest of the defrost energy goes to increasing the
temperature of the coils themselves and to the walkin
environment. The Temperature Termination defrost control type
calculates the end of the defrost cycle that corresponds to
melting all the ice. Therefore, the user must input this
fractional value. The default value is 0.7 for electric
defrost and 0.3 for hot fluid defrost. Refer to the
Engineering Reference for further information on how the
defrost energy control types are modeled.
Field: Restocking
Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the walkin is being restocked with product. The
schedule should contain values in units of Watts (note this is
different from the restocking schedule values for cases that
are entered per unit length). This field can be used to denote
the additional load imposed on the walkin from stocking the
walkin with product that is warmer than the walkin
temperature. This information is difficult to find and may
required additional research for proper modeling; however,
this schedule is available for this purpose if desired. If
restocking of the refrigerated walkin will not be simulated,
enter a schedule with values of zero for all time periods or
leave this field blank.
Field:
Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant
inventory present in the walkin during ordinary operation. The
value is used to produce an estimate of the total refrigerant
present in the refrigeration system. The value is entered in
kg.
Field: Insulated
Floor Surface Area[LINK]
The floor area in square meters. This value is required and
has no default value.
Field: Insulated Floor
U-Value[LINK]
The floor themal transmittance (in W/m\(^{2}\)-K). This value has a
default value of 0.3154. (This corresponds to R18 in Archaic
American Insulation Units. To convert other R-values to
thermal transmittance, divide 5.678 by the R-value. For
example, R15 is 0.3785 W/m\(^{2}\)-K and R5 is 1.136 W/m\(^{2}\)-K.)
THE REMAINING 12 FIELDS FOR THE WALK-IN COOLER
MUST BE REPEATED FOR EACH ZONE WHICH IS IN CONTACT WITH A
WALK-IN WALL, CEILING, OR DOOR. The IDD includes fields for 3
zones, but can be extended by repeating the last 12 values in
the object.
Field: Zone <x> Name[LINK]
The name of a zone adjoining the walkin. The walkin will
impact the air heat balance in this zone. This zone must
represent a conditioned space, that is, it must appear in a ZoneHVAC:EquipmentConnections
object.
Field:
Total Insulated Surface Area Facing Zone <x>[LINK]
The total surface area (walls and ceilings) facing this
particular zone in square meters. This value is required and
has no default value.
Field:
Insulated Surface U-Value Facing Zone <x>[LINK]
The surface (walls and ceilings) themal transmittance (in
W/m\(^{2}\)-K). This value
has a default value of 0.3154. (This corresponds to R18 in
Archaic American Insulation Units. To convert other R-values
to thermal transmittance, divide 5.678 by the R-value. For
example, R15 is 0.3785 W/m\(^{2}\)-K and R5 is 1.136 W/m\(^{2}\)-K.)
Field:
Area of Glass Reach In Doors Facing Zone <x>[LINK]
The total area of glass doors facing this particular zone
in square meters. The default is 0.0.
Field:
Height of Glass Reach In Doors Facing Zone <x>[LINK]
The glass reach in door height in meters. The default is
1.5.
Field:
Glass Reach In Door U-Value Facing Zone <x>[LINK]
The glass door themal transmittance (in W/m\(^{2}\)-K). This field has a
default value of 1.136. (This corresponds to R5 in Archaic
American Insulation Units.)
Field:
Glass Reach In Door Opening Schedule Name Facing Zone
<x>[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of time glass doors are open during a given time
period. The schedule values should be between 0 and 1.0. If no
schedule is specified, the doors are assumed to be open 5% of
the time (corresponding to a schedule value of 0.05).
Field:
Area of Stocking Doors Facing Zone <x>[LINK]
The total area of stock doors facing this particular zone
in square meters. The default is 0.0.
Field:
Height of Stocking Doors Facing Zone <x>[LINK]
The stocking door height in meters. The default is 2.0.
Field:
Stocking Door U-Value Facing Zone <x>[LINK]
The stocking door themal transmittance (in W/m\(^{2}\)-K). This value has a
default value of 0.3785. (This corresponds to R15 in Archaic
American Insulation Units.)
Field:
Stocking Door Opening Schedule Name Facing Zone <x>[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of time stocking doors are open during a given time
period. The schedule values should be between 0 and 1.0. If no
schedule is specified, the doors are assumed to be open 5% of
the time (corresponding to a schedule value of 0.05).
Field:
Stocking Door Opening Protection Type Facing Zone
<x>[LINK]
The type of stocking door opening protection used for this
walkin. Valid choices are None, AirCurtain, and StripCurtain.
The default is AirCurtain if the field is blank. Use the type,
StripCurtain, for both hanging strips and airlock vestibules.
Refer to the Engineering Reference for further information on
how the door protection types are modeled.
The following is an example input for a refrigeration
walkin.
Refrigeration:WalkIn,
WalkInFreezer, !- Name
CaseOperatingSched, !- Availability Schedule Name
4690., !- Rated Coil Cooling Capacity {W}
-2.22, !- Operating Temperature {C}
-6.67, !- Rated Cooling Source Temperature {C}
0.0, !- Rated Total Heating Power {W}
CaseOperatingSched, !- Heating Power Schedule Name
735., !- Rated Cooling Coil Fan Power {W}
0.0, !- Rated Circulation Fan Power {W}
120., !- Rated Total Lighting Power {W}
CaseLightingSched2, !- Lighting Schedule Name
Electric, !- Defrost Type
TimeSchedule, !- Defrost Control Type
CaseDefrostSched3, !- Defrost Schedule Name
CaseDripDownSched3, !- Defrost Drip-Down Schedule Name
5512., !- Defrost Power {W}
, !- Temperature Termination Defrost Fraction to Ice {dimensionless}
WalkInStockingSched, !- Restocking Schedule Name
, !- Average Refrigerant Charge Inventory {kg}
13.0, !- Insulated Floor Surface Area {m2}
0.207, !- Insulated Floor U-Value {W/m2-C}
BackRoom, !- Zone Name
43.4, !- Total Insulated Surface Area Facing this Zone {m2}
.235, !- Insulated Surface U-Value Facing this Zone {W/m2-C}
, !- Area of Glass Reach In Doors Facing this Zone {m2}
, !- Height of Glass Reach In Doors Facing this Zone {m}
, !- Glass Reach In Door U Value Facing this Zone {W/m2-C}
, !- Glass Reach In Door Opening Schedule Name Facing this Zone
2.0, !- Area of Stocking Doors Facing this Zone {m2}
2.0, !- Height of Stocking Doors Facing this Zone {m}
, !- Stocking Door U Value Facing this Zone {W/m2-C}
WIStockDoorOpenSch, !- Stocking Door Opening Schedule Name Facing this Zone
StripCurtain; !- Stocking Door Opening Protection Type Facing this Zone
Refrigeration
Case and WalkIn Outputs[LINK]
Zone,Average,Refrigeration Walk In Evaporator Total
Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Total Cooling
Energy [J]
Zone,Average,Refrigeration Walk In Evaporator Sensible
Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Sensible
Cooling Energy [J]
Zone,Average,Refrigeration Walk In Evaporator Latent
Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Latent
Cooling Energy [J]
Zone,Average,Refrigeration Walk In Ancillary Electric
Power [W]
Zone,Sum,Refrigeration Walk In Ancillary Electric
Energy [J]
Zone,Average,Refrigeration Walk In Fan Electric Power
[W]
Zone,Sum,Refrigeration Walk In Fan Electric Energy
[J]
Zone,Average,Refrigeration Walk In Lighting Electric
Power [W]
Zone,Sum,Refrigeration Walk In Lighting Electric Energy
[J]
Zone,Average,Refrigeration Walk In Heater Electric
Power [W]
Zone,Sum,Refrigeration Walk In Heater Electric Energy
[J]
Report only for WalkIns using electric defrost
Zone,Average,Refrigeration Walk In Defrost Electric
Power [W]
Zone,Sum,Refrigeration Walk In Defrost Electric Energy
[J]
Report for each Zone
exchanging energy with the WalkIn
Zone,Average,Refrigeration Walk In Zone
Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Zone
Sensible Cooling Energy [J]
Zone,Average, Zone,Average,Refrigeration Walk In Zone
Sensible Heating Rate [W]
Zone,Sum,Refrigeration Walk In Zone
Sensible Heating Energy [J]
Zone,Average,Zone,Average,Refrigeration Walk In Zone
Latent Rate [W]
Zone,Sum,Refrigeration Walk In Zone
Latent Energy [J]
Refrigeration
Walk In Evaporator Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate
of the WalkIn evaporator coil in Watts.
Refrigeration
Walk In Evaporator Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of
the WalkIn evaporator coil in Joules over the timestep being
reported. This output is also added to a meter with Resource
Type = EnergyTransfer, End Use Key = Refrigeration, Group Key
= Building
(Ref. Output:Meter
objects).
Refrigeration
Walk In Evaporator Sensible Cooling Rate [W][LINK]
This field is the sensible cooling rate of the WalkIn
evaporator coil in Watts.
Refrigeration
Walk In Evaporator Sensible Cooling Energy [J][LINK]
This field is the sensible cooling of the WalkIn evaporator
coil in Joules over the timestep being reported.
Refrigeration
Walk In Evaporator Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of
the WalkIn evaporator coil in Watts.
Refrigeration
Walk In Evaporator Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the
WalkIn evaporator coil in Joules over the timestep being
reported.
Refrigeration
Walk In Ancillary Electric Power [W][LINK]
This field is the total electricity (fan, heaters, lights,
and electric defrost) used by the walkin in Watts.
Refrigeration
Walk In Ancillary Electric Energy [J][LINK]
This field is the electricity (fan, heaters, lights, and
electric defrost)used by the WalkIn in Joules over the
timestep being reported.
Refrigeration
Walk In Fan Electric Power [W][LINK]
This field is the electric power input to the WalkIn fan(s)
in Watts.
Refrigeration
Walk In Fan Electric Energy [J][LINK]
This field is the electricity consumption of the WalkIn
fan(s) in Joules over the timestep being reported. This output
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Walk In Lighting Electric Power [W][LINK]
This field is the electric power input to the WalkIn lights
in Watts.
Refrigeration
Walk In Lighting Electric Energy [J][LINK]
This field is the electricity consumption of the WalkIn
lights in Joules over the timestep being reported. This output
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Walk In Heater Electric Power [W][LINK]
This field is the electric power input to the WalkIn
heaters in Watts.
Refrigeration
Walk In Heater Electric Energy [J][LINK]
This field is the total electricity consumption of the
WalkIn heaters in Joules over the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Walk In Defrost Electric Power [W][LINK]
This field is the electric power input to the WalkIn
electric defrost heater(s) in Watts. This output is available
if case defrost type is Electric.
Refrigeration
Walk In Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the
WalkIn electric defrost heater(s) in Joules over the timestep
being reported. This output is also added to a meter with
Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Building
(Ref. Output:Meter
objects). This output is available if case defrost type is
Electric.
The following output variables are available for each
zone adjacent to the walkin. An output variable identification
is created for each zone exchanging energy with the walkin.
For example if the walkin, “DairyWalkIn”, were exchanging
energy with the zone, “SalesArea”, the output variable
identification would be “DairyWalkInInZoneSalesArea”.
Refrigeration
Walk In Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits
delivered to the zone in Watts. A positive value is reported
when the zone is cooled by sensible case credits, otherwise a
zero is reported.
Refrigeration
Walk In Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit
energy delivered to the zone in Joules. A positive value is
reported when the zone is cooled by sensible case credits,
otherwise a zero is reported.
Refrigeration
Walk In Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits
delivered to the zone in Watts. A positive value is reported
when the zone is heated by sensible case credits, otherwise a
zero is reported.
Refrigeration
Walk In Zone Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit
energy delivered to the zone in Joules. A positive value is
reported when the zone is heated by sensible case credits,
otherwise a zero is reported.
Refrigeration
Walk In Zone Latent Rate [W][LINK]
This field is the rate of latent cooling (dehumidification)
case credits delivered to the zone in Watts. A negative value
(or zero) will be reported when the WalkIn provides
dehumidification (thereby reducing the zone latent load).
Refrigeration
Walk In Zone Latent Energy [J][LINK]
This field is the amount of latent cooling
(dehumidification) case credit energy delivered to the zone in
Joules. A negative value (or zero) will be reported when the
WalkIn provides dehumidification (thereby reducing the zone
latent load).
Refrigeration:System[LINK]
The refrigeration system object simulates the performance
of a supermarket refrigeration system when used along with
other objects to define the refrigeration load(s), the
compressor(s), and the condenser.
At least one refrigeration load object must be defined
which may be one of four types of load, a refrigerated case, a
walk-in cooler, a chiller providing refrigeration to a
secondary loop, or a cascade condenser which absorbs heat
rejected by a lower-temperature system (Ref. Refrigeration:Case,
Refrigeration:WalkIn,
Refrigeration:SecondarySystem, and
Refrigeration:Condenser:Cascade) If multiple loads are served
by the same system , the user should use one or both of the
list objects available to assign loads to the system. The
first list includes all cases and walkins cooled directly by
this system (Ref. Refrigeration:CaseAndWalkInList). The second
list includes any ‘transfer’ loads, that is refrigeration
loads borne by this system that are transferred from another
refrigeration system via either a secondary loop chiller or a
cascade condenser (Ref. Refrigeration:TransferLoadList,
see the Engineering Reference for more information about these
types of systems).
The refrigeration system object is capable of modeling both
single-stage and two-stage compression refrigeration systems.
The name of at least one compressor must be defined and a list
object is available if the system is served by more than one
compressor (Ref. Refrigeration:Compressor
and Refrigeration:CompressorList).
Heat is rejected outdoors in a condenser by direct air
flow, evaporative water cooling, by a water-cooled condenser
with appropriate plant loop piping, or to a cascade condenser
cooled by another refrigeration system(ref: Refrigeration:Condenser:AirCooled,
Refrigeration:Condenser:EvaporativeCooled,
Refrigeration:Condenser:WaterCooled,
Refrigeration:Condenser:Cascade). With evaporative cooling,
water is sprayed through the air stream to effectively lower
the air temperature experienced by the condenser coil as a
result of water evaporation. The use of a water-cooled
condenser requires the definition of a plant loop to supply
cooling to the condenser. If a cascade condenser is
specified, the refrigeration system absorbing the rejected
heat must also be defined.
The refrigeration system may also include a liquid suction
and/or mechanical subcooler (Ref.
Refrigeration:Subcooler).
The system object coordinates the energy flows between the
other refrigeration objects and is used to set system
parameters. Compressor waste heat can also be reclaimed for
use by an optional air- or water-heating coil (Ref. Coil:Heating:Desuperheater
and Coil:WaterHeating:Desuperheater).
The inputs for the refrigeration system object, in addition
to the names of the other refrigeration objects described
above, include a name for this system, the minimum condensing
temperature, the refrigeration system working fluid, and the
type of saturated suction temperature control. Optional input
fields are also provided for users seeking to keep track of
refrigerant inventory and suction pipe heat gains.
A unique user-assigned name for an instance of a
refrigeration system. Any reference to this refrigeration
system by another object will use this name.
Field:
Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, a single walkin, single air
chiller, or a particular list of refrigerated cases and
walkins or air chillers, that is cooled by this refrigeration
system. The name will be validated against the case, walkin,
air chiller and CaseAndWalkInList names (ref: Refrigeration:Case,
Refrigeration:WalkIn,
Refrigeration:AirChiller,
and Refrigeration:CaseAndWalkInList) in the input file. Only
cases and walkins or air chillers served directly by the
system should be included in this list. Any cases, walkins,
or air chillers served indirectly via a secondary loop should
NOT be included in this list. Note that any system that serves
an air chiller cannot also serve a case or walkin.
Field:
Refrigeration Transfer Load or TransferLoad List Name[LINK]
Identifies a single SecondarySystem, a single Cascade
Condenser, OR or a list of Transfer Loads (where the list is
comprised of SecondarySystems and/or Cascade Condensers) that
are cooled by this refrigeration system. The name will be
validated against the secondary system, cascade condenser, and
TransferLoad list names (ref: Refrigeration:SecondarySystem,
Refrigeration:Condenser:Cascade,
and Refrigeration:TransferLoadList) in the input file. Only
secondary systems and cascade condensers served directly by
the system should be included in this list. (NOTE – this entry
is for a cascade condenser cooled by this system, not
a condenser absorbing heat rejected by this
system.)
Field: Condenser Name[LINK]
The name of the condenser that is used to reject heat
from this refrigeration system. The name will be
validated against the condenser names (ref: Refrigeration:Condenser:AirCooled,
Refrigeration:Condenser:WaterCooled,
Refrigeration:Condenser:EvaporativeCooled,
and Refrigeration:Condenser:Cascade) in the input file.
Field:Compressor
or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of
compressors, that provide cooling energy to this refrigeration
system. The name will be validated against the compressor list
names (ref: List:Refrigeration:Compressors) in the input
file. If the refrigeration systems contains two stages of
compression, this field identifies the low-stage compressors
connected to the two-stage system.
Field: Minimum
Condensing Temperature[LINK]
This numeric field specifies the minimum condensing
temperature (C), which is usually determined by the
temperature required to maintain acceptable thermal expansion
valve performance.
Field:
Refrigeration System Working Fluid Type[LINK]
The type of refrigerant used by the system. Valid choices
are R11, R123, R134A, R12, R22, R404A, R507A, or R410A. This
name will be validated against Fluid Names (ref: Fluid
Properties section) in the input file. Note that the
corresponding property data, available in
FluidPropertiesRefData.idf, must by supplied in the input
file.
Field: Suction
Temperature Control Type[LINK]
The type of saturated suction temperature control used by
the system. Valid choices are
FloatSuctionTemperature and
ConstantSuctionTemperature. If the field is
blank, the default will be
ConstantSuctionTemperature. See the
Engineering Reference section, Variable Evaporator
Temperature, for a discussion of this option.
Field: Mechanical
Subcooler Name[LINK]
This optional field identifies a mechanical subcooler that
absorbs heat from this refrigeration system. This field should
not be used for a mechanical subcooler that absorbs heat from
another system. The name will be validated against the
subcooler names (ref: Refrigeration:Subcooler) in the input
file.
Field:
Liquid Suction Heat Exchanger Subcooler Name[LINK]
This optional field Identifies a particular liquid suction
heat exchanger (LSHX) subcooler present in this refrigeration
system. The name will be validated against the subcooler names
(ref: Refrigeration:Subcooler) in the input file.
Field: Sum UA Suction
Piping[LINK]
This optional field is typically used when trying to
determine the impact of pipe heat gains on system performance
and zone heat balance, particularly in comparing a DX system
to a secondary system. Enter the value for suction piping heat
gain (in W/C). That is, sum up the product of the pipe wall
insulation conductance times the outer surface area of the
pipe insulation. Please see the Engineering Reference for
guidance in calculating this value. If the Sum UA Suction
Piping is entered, the Suction Piping Zone
Name is also required.
Field: Suction Piping
Zone Name[LINK]
This optional field is typically used when trying to
determine the impact of pipe heat gains on system performance,
particularly in comparing a DX system to a secondary system.
(If the previous field, Sum UA Suction Piping, is blank, this
field will not be used.) Enter the name of the zone where the
suction piping is located. The suction piping heat gains will
be calculated based upon the air temperature within this zone.
The heat balance of this zone will also be affected by the
piping heat exchange. Additional output variables are
described at the end of this “Group-Refrigeration” section for
the total impact of refrigeration on zones, including suction
pipe heat exchange.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field: Number of
Compressor Stages[LINK]
This field determines whether the refrigeration system
contains one or two stages of compression. In this field,
enter either “1” for single-stage compression systems or “2”
for two-stage compression systems. If two stages of
compression are selected, then an intercooler will be used
between the compressor stages to cool the discharge of the
low-stage compressors. The default value is “1”.
Field: Intercooler Type[LINK]
This field determines the type of intercooler which is used
for two-stage compression systems. Valid choices for this
field include “None”, “Flash Intercooler” or “Shell-and-Coil
Intercooler”. Single-stage systems require “None” while
two-stage systems require either “Flash Intercooler” or
“Shell-and-Coil Intercooler”. The default selection is
“None”, corresponding to a single-stage compression
system.
Field:
Shell-and-Coil Intercooler Effectiveness[LINK]
When a shell-and-coil intercooler is selected for two-stage
compression systems, this field allows the specification of
the shell-and-coil intercooler effectiveness. Values in this
field will only be valid if “Shell-and-Coil Intercooler” is
selected in the “Intercooler Type” field above. The valid
range of values for this field is between 0.0 and 1.0. A
default value of 0.80 will be used if none is specified.
Field:
High-Stage Compressor or CompressorList Name[LINK]
Identifies a single compressor, or a particular list of
compressors, that comprise the high-stage compression of a
two-stage compression refrigeration system. The name will be
validated against the compressor list names (ref:
List:Refrigeration:Compressors) in the input file. Names in
this field are only valid if two compressor stages have been
specified in the “Number of Compressor Stages” field
above.
The following is an example input for a single-stage
compression refrigeration system.
Refrigeration:System,
MediumTempSystem, !- Refrigeration System Name
MediumTempCaselist, !- Refrigeration Case or Walkin or CaseAndWalkInList Name
, !- Refrigeration Transfer Load or TransferLoad List Name
AirCooledCondenserA, !- Refrigeration Condenser Name
MediumTempCompressorlist, !- Refrigeration Compressor or CompressorList Name
25.0, !- Minimum Condensing Temperture {C}
R134a, !- Refrigeration System Working Fluid
ConstantSuctionTemperature, !- Suction Temperature Control Type
, !- Optional mechanical subcooler name
, !- Optional LSHX subcooler name
, !- Sum UA Distribution Piping {W/K}
, !- Distribution Piping Zone Name
MedTempRefrig; !- End-Use Subcategory
The following is an example input for a two-stage
compression refrigeration system.
Refrigeration:System,
LowTempSystem, !- Refrigeration System Name
LowTempCaselist, !- Refrigeration Case or Walkin or CaseAndWalkInList Name
, !- Refrigeration Transfer Load or TransferLoad List Name
AirCooledCondenserB, !- Refrigeration Condenser Name
LowStageCompressorList, !- Refrigeration Compressor or CompressorList Name
25.0, !- Minimum Condensing Temperture {C}
R404A, !- Refrigeration System Working Fluid
ConstantSuctionTemperature, !- Suction Temperature Control
, !- Optional mechanical subcooler name
, !- Optional LSHX subcooler name
, !- Sum UA Distribution Piping {W/K}
, !- Distribution Piping Zone Name
LowTempRefrig, !- End-Use Subcategory
2, !- Number of Compressor Stages
Shell-and-Coil Intercooler, !- Intercooler Type
0.7, !- Shell-and-Coil Intercooler Effectiveness
HiStageCompressorList !- High-Stage Compressor or CompressorList Name
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE
CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Total Compressor
Electric Power [W]
Zone,Sum, Refrigeration System Total Compressor
Electric Energy [J]
Zone,Average, Refrigeration System Average Compressor
COP [W/W]
Zone,Average, Refrigeration System Total Compressor
Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Compressor Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Total Cases and Walk
Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Cases and Walk Ins
Heat Transfer Energy [J]
Zone,Average, Refrigeration System Total Transferred
Load Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Transferred Load
Heat Transfer Energy [J]
Zone,Average, Refrigeration System Total Suction Pipe
Heat Gain Rate [W]
Zone,Sum, Refrigeration System Total Suction Pipe Heat
Gain Energy [J]
Zone,Average, Refrigeration System Net Rejected Heat
Transfer Rate [W]
Zone,Sum, Refrigeration System Net Rejected Heat
Transfer Energy [J]
Zone,Average,Refrigeration System Estimated Refrigerant
Inventory Mass [kg]
Zone,Average, Refrigeration System Liquid Suction
Subcooler Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Liquid Suction Subcooler Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Estimated
Refrigerant Inventory [kg]
Zone,Average, Refrigeration System Estimated
Refrigerant Mass Flow Rate [kg/s]
Zone,Average, Refrigeration System Condensing
Temperature [C]’
Zone,Average, Refrigeration System Evaporating
Temperature [C]
Zone,Average, Refrigeration System Suction Pipe Suction
Temperature [C]
Zone,Average, Refrigeration System Thermostatic
Expansion Valve Liquid Temperature [C]
Zone,Average, Refrigeration System Estimated High Stage
Refrigerant Mass Flow Rate [kg/s]
Zone,Sum,Refrigeration System Total High Stage
Compressor Electric Energy [J]
Zone,Average,Refrigeration System Total High Stage
Compressor Electric Power [W]
Zone,Sum,Refrigeration System Total High Stage
Compressor Heat Transfer Energy [J]
Zone,Average,Refrigeration System Total High Stage
Compressor Heat Transfer Rate [W]
Zone,Sum,Refrigeration System Total Low and High Stage
Compressor Electric Energy [J]
Zone,Sum,Refrigeration System Total Low Stage
Compressor Electric Energy [J]
Zone,Average,Refrigeration System Total Low Stage
Compressor Electric Power [W]
Zone,Sum,Refrigeration System Total Low Stage
Compressor Heat Transfer Energy [J]
Zone,Average,Refrigeration System Total Low Stage
Compressor Heat Transfer Rate [W]
Zone,Average,Refrigeration System Estimated Low Stage
Refrigerant Mass Flow Rate [kg/s]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE
AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System Total
Compressor Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller System Total
Compressor Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System Average
Compressor COP [W/W]
HVAC,Average, Refrigeration Air Chiller System Total
Compressor Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total
Compressor Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total
Air Chiller Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Case
and Walk In Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total
Transferred Load Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total
Transferred Load Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total
Suction Pipe Heat Gain Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total
Suction Pipe Heat Gain Energy [J]
HVAC,Average, Refrigeration Air Chiller System Net
Rejected Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Net Rejected
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Liquid
Suction Subcooler Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Liquid
Suction Subcooler Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Estimated Refrigerant Inventory Mass [kg]
HVAC,Average, Refrigeration Air Chiller System
Estimated Refrigerant Mass Flow Rate [kg/s]
HVAC,Average,Refrigeration Air Chiller System
Intercooler Temperature [C]
HVAC,Average,Refrigeration Air Chiller System
Intercooler Pressure [Pa]
HVAC,Average, Refrigeration Air Chiller System
Condensing Temperature [C]’
HVAC,Average, Refrigeration Air Chiller System
Evaporating Temperature [C]
HVAC,Average, Refrigeration Air Chiller System Suction
Temperature [C]
HVAC,Average, Refrigeration Air Chiller System TXV
Liquid Temperature [C]
HVAC,Average,Refrigeration Air Chiller System Estimated
High Stage Refrigerant Mass Flow Rate [kg/s]
HVAC,Sum,Refrigeration Air Chiller System Total High
Stage Compressor Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total
High Stage Compressor Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller System Total High
Stage Compressor Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total
High Stage Compressor Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Low
and High Stage Compressor Electric Energy [J]
HVAC,Sum,Refrigeration Air Chiller System Total Low
Stage Compressor Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total Low
Stage Compressor Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller System Total Low
Stage Compressor Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total Low
Stage Compressor Heat Transfer Rate [W]
HVAC,Average,Refrigeration Air Chiller System Estimated
Low Stage Refrigerant Mass Flow Rate [kg/s]
THE
FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES
AND/OR WALKINS[LINK]
Refrigeration
System Total Compressor Electric Power [W][LINK]
This output is the total electric power input to the system
compressor(s) in Watts.
Refrigeration
System Total Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s
compressor(s) in Joules for the timestep being reported. The
individual consumption for each compressor is also added to a
meter with Resource Type = Electricity, End Use Key =
Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
System Total Low Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the
system’s low-stage compressor(s) in Watts. This output is
valid only for two-stage compression systems.
Refrigeration
System Total Low Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s
low-stage compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
System Total High Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the
system’s high-stage compressor(s) in Watts. This output is
valid only for two-stage compression systems.
Refrigeration
System Total High Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s
high-stage compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
System Total Low and High Stage Compressor Electric Energy
[J][LINK]
This is the total electricity consumption of the system’s
low- and high-stage compressor(s) in Joules for the timestep
being reported. The individual consumption for each compressor
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
System Average Compressor COP [W/W][LINK]
This output is the system average compressor COP, the total
refrigeration effect divided by the total power to the
compressors.
Refrigeration
System Total Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the
Refrigeration Compressor rack in Watts. It is the sum of all
of the heat transfer rates for the refrigerated cases,
walk-ins, secondary loops, cascade condensers, and mechanical
subcoolers that are cooled by this system. This value does not
include compressor or condenser fan heat. If specified as in
input value, the suction pipe heat gains are included in this
value.
Refrigeration
System Total Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the Refrigeration
Compressor rack in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
System Total Low Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the
low-stage compressors in Watts. It is the sum of all of the
heat transfer rates for the refrigerated cases, walk-ins,
secondary loops, cascade condensers, and mechanical subcoolers
that are cooled by this system. This value does not include
compressor or condenser fan heat. If specified as in input
value, the suction pipe heat gains are included in this
value. This output is valid only for two-stage compression
systems.
Refrigeration
System Total Low Stage Compressor Heat Transfer Energy
[J][LINK]
This is the total heat transfer of the low-stage
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
System Total High Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the
high-stage compressors in Watts. It is the sum of all of the
heat transfer rates for the refrigerated cases, walk-ins,
secondary loops, cascade condensers, and mechanical subcoolers
that are cooled by this system. This value does not include
compressor or condenser fan heat. If specified as in input
value, the suction pipe heat gains are included in this
value. This output is valid only for two-stage compression
systems.
Refrigeration
System Total High Stage Compressor Heat Transfer Energy
[J][LINK]
This is the total heat transfer of the high-stage
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
System Total Cases and Walk Ins Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the
refrigerated cases and walk-ins served directly by this system
in Watts. It is the sum of all of the heat transfer rates for
the refrigerated cases and walk-ins that are connected
directly to this system. This value does not include
compressor or condenser fan heat or the heat transfer for
cases and walk-ins served by any connected secondary
systems.
Refrigeration
System Total Cases and Walk Ins Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the
refrigerated cases and walk-ins served directly by this system
in Joules. It is the sum of all of the heat transfered for the
refrigerated cases and walk-ins that are connected directly to
this system. This value does not include compressor or
condenser fan heat or the heat transfer for cases and walk-ins
served by any connected secondary systems.
Refrigeration
System Total Transferred Load Heat Transfer Rate [W][LINK]
This output is the sum of the heat transfer rates for any
secondary loops, cascade condensers, and mechanical subcoolers
cooled by this system, minus the benefit of any mechanical
subcooler providing cooling to this system in Watts.
Therefore, if the only transfer load between two systems is a
mechanical subcooler, the same amount will show as a negative
value for the system receiving the cooling effect and as a
positive number for the system serving that cooling load. It
also includes the pump energy for any secondary loops and the
compressor energy for any cascade condenser systems that are
cooled by this system. (See the Engineering Reference for more
details about the loads placed by secondary systems upon the
primary system.)
Refrigeration
System Total Transferred Load Heat Transfer Energy [J][LINK]
This output is the sum of the heat transfered for any
secondary loops, cascade condensers, and mechanical subcoolers
cooled by this system, minus the benefit of any mechanical
subcooler providing cooling to this system in Joules.
Therefore, if the only transfer load between two systems is a
mechanical subcooler, the same amount will show as a negative
value for the system receiving the cooling effect and as a
positive number for the system serving that cooling load. It
also includes the pump energy for any secondary loops and the
compressor energy for any cascade condenser systems that are
cooled by this system. (See the Engineering Reference for more
details about the loads placed by secondary systems upon the
primary system.)
Refrigeration
System Total Suction Pipe Heat Gain Rate [W][LINK]
This output is the total heat transfer rate for suction
piping served by this system in Watts. Note this is an
optional input, and is only available if the user has
described the suction piping heat gain characteristics in the
input.
Refrigeration
System Total Suction Pipe Heat Gain Energy [J][LINK]
This output is the total heat transfer rate for suction
piping served by this system in Watts. Note this is an
optional input, and is only available if the user has
described the suction piping heat gain characteristics in the
input.
Refrigeration
System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to
the system condenser in Watts. It does not include system heat
rejection that has been recovered for useful purposes.
However, if a water-cooled condenser was used to provide heat
to a separate water loop, the energy transferred to that loop
is included here.
Refrigeration
System Net Rejected Heat Transfer Energy [J][LINK]
This output is the total heat rejected by this system to
the system condenser in Joules for the timestep being
reported. It does not include system heat rejection that has
been recovered for useful purposes. However, if a water-cooled
condenser was used to provide heat to a separate water loop,
the energy transferred to that loop is included here.
Refrigeration
System Liquid Suction Subcooler Heat Transfer Rate [W][LINK]
This output is the total heat transferred from the liquid
condensate before the thermal expansion valve to the suction
gas.
Refrigeration
System Liquid Suction Subcooler Heat Transfer Energy [J][LINK]
This output is the total heat transferred from the liquid
condensate before the thermal expansion valve to the suction
gas.
Refrigeration
System Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for
the condenser, receiver, cases, and liquid pipes that are a
part of this system.
Refrigeration
System Estimated Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through
the compressors for this system.
Refrigeration
System Estimated Low Stage Refrigerant Mass Flow Rate
[kg/s][LINK]
This output is the calculated refrigerant mass flow through
the low-stage compressors for this system. This output is
valid only for two-stage compression systems.
Refrigeration
System Estimated High Stage Refrigerant Mass Flow Rate
[kg/s][LINK]
This output is the calculated refrigerant mass flow through
the high-stage compressors for this system. This output is
valid only for two-stage compression systems.
Refrigeration
System Intercooler Temperature [C][LINK]
This is the saturation temperature in the intercooler.
This output is valid only for two-stage compression
systems.
Refrigeration
System Intercooler Pressure [Pa][LINK]
This is the saturation pressure in the intercooler. This
output is valid only for two-stage compression systems.
Refrigeration
System Condensing Temperature [C][LINK]
This is the saturated condensing temperature.
Refrigeration
System Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature.
Refrigeration
System Suction Pipe Suction Temperature [C][LINK]
This is the temperature at the compressor inlet including
superheat after the cases and superheat from any liquid
suction heat exchangers.
Refrigeration
System Thermostatic Expansion Valve Liquid Temperature
[C][LINK]
This is the temperature entering the thermal expansion
valve before the cases, equal to the condensing temperature
minus any subcooling included in the condenser or provided by
mechanical and/or liquid suction heat exchanger
subcoolers.
THE
FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR
CHILLERS[LINK]
Refrigeration
Air Chiller System Total Compressor Electric Power [W][LINK]
This output is the total electric power input to the system
compressor(s) in Watts.
Refrigeration
Chiller System Total Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s
compressor(s) in Joules for the timestep being reported. The
individual consumption for each compressor is also added to a
meter with Resource Type = Electricity, End Use Key =
Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Total Low Stage Compressor Electric Power
[W][LINK]
This output is the total electric power input to the
system’s low-stage compressor(s) in Watts. This output is
valid only for two-stage compression systems.
Refrigeration
Air Chiller System Total Low Stage Compressor Electric Energy
[J][LINK]
This is the electricity consumption of the system’s
low-stage compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total High Stage Compressor Electric Power
[W][LINK]
This output is the total electric power input to the
system’s high-stage compressor(s) in Watts. This output is
valid only for two-stage compression systems.
Refrigeration
Air Chiller System Total High Stage Compressor Electric Energy
[J][LINK]
This is the electricity consumption of the system’s
high-stage compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total Low and High Stage Compressor
Electric Energy [J][LINK]
This is the total electricity consumption of the system’s
low- and high-stage compressor(s) in Joules for the timestep
being reported. The individual consumption for each compressor
is also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Average Compressor COP [W/W][LINK]
This output is the system average compressor COP, the total
refrigeration effect divided by the total power to the
compressors
Refrigeration
Air Chiller System Total Compressor Heat Transfer Rate
[W][LINK]
This output is the total heat transfer rate of the
Refrigeration Compressor rack in Watts. It is the sum of all
of the heat transfer rates for the refrigerated cases,
walk-ins, secondary loops, cascade condensers, and mechanical
subcoolers that are cooled by this system. This value does not
include compressor or condenser fan heat. If specified as in
input value, the suction pipe heat gains are included in this
value.
Refrigeration
Air Chiller System Total Compressor Heat Transfer Energy
[J][LINK]
This is the total heat transfer of the Refrigeration
Compressor rack in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Total Low Stage Compressor Heat Transfer
Rate [W][LINK]
This output is the total heat transfer rate of the
low-stage compressors in Watts. It is the sum of all of the
heat transfer rates for the refrigerated cases, walk-ins,
secondary loops, cascade condensers, and mechanical subcoolers
that are cooled by this system. This value does not include
compressor or condenser fan heat. If specified as in input
value, the suction pipe heat gains are included in this
value. This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total Low Stage Compressor Heat Transfer
Energy [J][LINK]
This is the total heat transfer of the low-stage
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total High Stage Compressor Heat Transfer
Rate [W][LINK]
This output is the total heat transfer rate of the
high-stage compressors in Watts. It is the sum of all of the
heat transfer rates for the refrigerated cases, walk-ins,
secondary loops, cascade condensers, and mechanical subcoolers
that are cooled by this system. This value does not include
compressor or condenser fan heat. If specified as in input
value, the suction pipe heat gains are included in this
value. This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total High Stage Compressor Heat Transfer
Energy [J][LINK]
This is the total heat transfer of the high-stage
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects). This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Total Air Chiller Heat Transfer Rate
[W][LINK]
This output is the total heat transfer rate from the
refrigerated cases and walk-ins served directly by this system
in Watts. It is the sum of all of the heat transfer rates for
the refrigerated cases and walk-ins that are connected
directly to this system. This value does not include
compressor or condenser fan heat or the heat transfer for
cases and walk-ins served by any connected secondary
systems.
Refrigeration
Air Chiller System Total Case and Walk In Heat Transfer Energy
[J][LINK]
This output is the total heat transfer energy from the
refrigerated cases and walk-ins served directly by this system
in Joules. It is the sum of all of the heat transfered for the
refrigerated cases and walk-ins that are connected directly to
this system. This value does not include compressor or
condenser fan heat or the heat transfer for cases and walk-ins
served by any connected secondary systems.
Refrigeration
Air Chiller System Total Transferred Load Heat Transfer Rate
[W][LINK]
This output is the sum of the heat transfer rates for any
secondary loops, cascade condensers, and mechanical subcoolers
cooled by this system, minus the benefit of any mechanical
subcooler providing cooling to this system in Watts.
Therefore, if the only transfer load between two systems is a
mechanical subcooler, the same amount will show as a negative
value for the system receiving the cooling effect and as a
positive number for the system serving that cooling load. It
also includes the pump energy for any secondary loops and the
compressor energy for any cascade condenser systems that are
cooled by this system. (See the Engineering Reference for more
details about the loads placed by secondary systems upon the
primary system.)
Refrigeration
Air Chiller System Total Transferred Load Heat Transfer Energy
[J][LINK]
This output is the sum of the heat transfered for any
secondary loops, cascade condensers, and mechanical subcoolers
cooled by this system, minus the benefit of any mechanical
subcooler providing cooling to this system in Joules.
Therefore, if the only transfer load between two systems is a
mechanical subcooler, the same amount will show as a negative
value for the system receiving the cooling effect and as a
positive number for the system serving that cooling load. It
also includes the pump energy for any secondary loops and the
compressor energy for any cascade condenser systems that are
cooled by this system. (See the Engineering Reference for more
details about the loads placed by secondary systems upon the
primary system.)
Refrigeration
Air Chiller System Total Suction Pipe Heat Gain Rate [W][LINK]
This output is the total heat transfer rate for suction
piping served by this system in Watts. Note this is an
optional input, and is only available if the user has
described the suction piping heat gain characteristics in the
input.
Refrigeration
Air Chiller System Total Suction Pipe Heat Gain Energy
[J][LINK]
This output is the total heat transfer rate for suction
piping served by this system in Watts. Note this is an
optional input, and is only available if the user has
described the suction piping heat gain characteristics in the
input.
Refrigeration
Air Chiller System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to
the system condenser in Watts. It does not include system heat
rejection that has been recovered for useful purposes.
However, if a water-cooled condenser was used to provide heat
to a separate water loop, the energy transferred to that loop
is included here.
Refrigeration
Air Chiller System Net Rejected Heat Transfer Energy [J][LINK]
This output is the total heat rejected by this system to
the system condenser in Joules for the timestep being
reported. It does not include system heat rejection that has
been recovered for useful purposes. However, if a water-cooled
condenser was used to provide heat to a separate water loop,
the energy transferred to that loop is included here.
Refrigeration
Air Chiller System Liquid Suction Subcooler Heat Transfer Rate
[W][LINK]
This output is the total heat transferred from the liquid
condensate before the thermal expansion valve to the suction
gas.
Refrigeration
Air Chiller System Liquid Suction Subcooler Heat Transfer
Energy [J][LINK]
This output is the total heat transferred from the liquid
condensate before the thermal expansion valve to the suction
gas.
Refrigeration
Air Chiller System Mechanical Subcooler Heat Transfer Energy
[J][LINK]
Refrigeration
Air Chiller System Estimated Refrigerant Inventory Mass
[kg][LINK]
This output is the sum of the input inventory values for
the condenser, receiver, cases, and liquid pipes that are a
part of this system.
Refrigeration
Air Chiller System Estimated Refrigerant Mass Flow Rate
[kg/s][LINK]
This output is the calculated refrigerant mass flow through
the compressors for this system.
Refrigeration
Air Chiller System Estimated Low Stage Refrigerant Mass Flow
Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through
the low-stage compressors for this system. This output is
valid only for two-stage compression systems.
Refrigeration
Air Chiller System Estimated High Stage Refrigerant Mass Flow
Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through
the high-stage compressors for this system. This output is
valid only for two-stage compression systems.
Refrigeration
Air Chiller System Intercooler Temperature [C][LINK]
This is the saturation temperature in the intercooler.
This output is valid only for two-stage compression
systems.
Refrigeration
Air Chiller System Intercooler Pressure [Pa][LINK]
This is the saturation pressure in the intercooler. This
output is valid only for two-stage compression systems.
Refrigeration
Air Chiller System Condensing Temperature [C][LINK]
This is the saturated condensing temperature.
Refrigeration
Air Chiller System Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature.
Refrigeration
Air Chiller System Suction Temperature [C][LINK]
This is the temperature at the compressor inlet including
superheat after the cases and superheat from any liquid
suction heat exchangers.
Refrigeration
Air Chiller System TXV Liquid Temperature [C][LINK]
This is the temperature entering the thermal expansion
valve before the cases, equal to the condensing temperature
minus any subcooling included in the condenser or provided by
mechanical and/or liquid suction heat exchanger
subcoolers.
Refrigeration:TranscriticalSystem[LINK]
The Refrigeration:TranscriticalSystem
object allows users to model detailed transcritical carbon
dioxide (CO\(_{2}\)) booster
refrigeration systems used in supermarkets. The object allows
for modeling either a single stage system with
medium-temperature loads or a two stage system with both
medium- and low-temperature loads.
The input objects required to model a detailed
transcritical CO\(_{2}\)
refrigeration system include the following:
Output variables are available to describe the total heat
exchange between all the refrigeration objects and the zones
containing these objects. These variables are described at
the end of this section.
At least one refrigeration load object must be defined
which may be one of two types of loads, including a
refrigerated display case and a walk-in cooler, (Ref. Refrigeration:Case,
and Refrigeration:WalkIn). If multiple loads are served by
the same system, the user should use the refrigerated case and
walk-in list object available to assign all cases and walk-ins
cooled directly by this system (Ref.
Refrigeration:CaseAndWalkInList).
The name of at least one compressor must be defined and a
list object is available if the system is served by more than
one compressor (Ref. Refrigeration:Compressor
and Refrigeration:CompressorList).
Heat is rejected to the outdoors via an air-cooled gas
cooler (Ref. Refrigeration:GasCooler:AirCooled).
The Refrigeration:TranscriticalSystem
object coordinates the energy flows between the other
refrigeration objects and is used to set system
parameters.
The inputs for the refrigeration system object, in addition
to the names of the other refrigeration objects described
above, include a name for this system, the receiver pressure,
the subcooler effectiveness, and the refrigeration system
working fluid. Optional input fields are also provided for
users seeking to keep track of suction pipe heat gains.
A detailed description of the transcritical CO\(_{2}\) booster refrigeration
system may be found in the Refrigeration section of the
Engineering Reference.
A unique user-assigned name for an instance of a
transcritical CO\(_{2}\)
refrigeration system. Any reference to this refrigeration
system by another object will use this name.
Field: System Type[LINK]
Identifies the transcritical CO\(_{2}\) refrigeration system as
either a single-stage system with only medium-temperature
loads, or a two-stage system with both medium- and
low-temperature loads. Valid choices are: SingleStage for
single stage systems or TwoStage for two stage systems.
Field:
Medium Temperature Refrigerated Case or WalkIn or
CaseAndWalkInList Name[LINK]
Identifies a single case, a single walk-in, or a particular
list of refrigerated cases and walk-ins, that is cooled by the
medium-temperature stage of the refrigeration system. The
name will be validated against the case, walk-in, and
CaseAndWalkInList names (Ref. Refrigeration:Case,
Refrigeration:WalkIn,
and Refrigeration:CaseAndWalkInList) in the input file. Only
medium temperature cases and walk-ins served directly by the
system should be included in this list. Note that this entry
is required for both single-stage and two-stage systems.
Field:
Low Temperature Refrigerated Case or WalkIn or
CaseAndWalkInList Name[LINK]
Identifies a single case, a single walk-in, or a particular
list of refrigerated cases and walk-ins, that is cooled by the
low-temperature stage of the refrigeration system. The name
will be validated against the case, walk-in, and
CaseAndWalkInList names (Ref. Refrigeration:Case,
Refrigeration:WalkIn,
and Refrigeration:CaseAndWalkInList) in the input file. Only
low temperature cases and walk-ins served directly by the
system should be included in this list. Note that this entry
is valid only for two-stage systems.
Field:
Refrigeration Gas Cooler Name[LINK]
The name of the gas cooler that is used to reject heat from
the transcritical refrigeration system. The name will be
validated against the gas cooler names (Ref.
Refrigeration:GasCooler:AirCooled) in the input file.
Field:
High Pressure Compressor or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of
compressors, that provides compression for a single-stage
system or the high pressure stage of a two-stage system. The
name will be validated against the compressor list names (Ref.
List:Refrigeration:Compressors) in the input file. Note that
this entry is required for both single-stage and two-stage
systems.
Field:
Low Pressure Compressor or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of
compressors, that provides compression for the low pressure
stage of a two-stage system. The name will be validated
against the compressor list names (Ref.
List:Refrigeration:Compressors) in the input file. Note that
this entry is valid only for two-stage systems.
Field: Receiver Pressure[LINK]
This numeric field specifies the refrigerant pressure (Pa)
in the receiver. The default value for the receiver pressure
is 4.0 × 10\(^{6}\) Pa.
Field: Subcooler
Effectiveness[LINK]
This numeric field specifies the heat exchanger
effectiveness of the subcooler. The default value for the
subcooler effectiveness is 0.4.
Field:
Refrigeration System Working Fluid Type[LINK]
The type of refrigerant used by the system. It is assumed
that carbon dioxide will be the refrigerant used in the
transcritical CO\(_{2}\)
refrigeration system. However, the user must specify the name
used in the input file which refers to carbon dioxide. This
name will be validated against Fluid Names (Ref. Fluid
Properties section) in the input file. Note that the
corresponding property data for carbon dioxide (R744),
available in FluidPropertiesRefData.idf, must be supplied in
the input file.
Field:
Sum UA Suction Piping for Medium Temperature Loads[LINK]
This optional field is typically used to determine the
impact of pipe heat gains on system performance and zone heat
balance. Enter the value for suction piping heat gain (in
W/C) for the medium-temperature suction line, i.e., sum up the
product of the pipe wall insulation conductance times the
outer surface area of the pipe insulation. Please see the
Engineering Reference for guidance in calculating this value.
If the Sum UA Suction Piping for Medium Temperature Loads is
entered, the Medium Temperature Suction Piping Zone
Name is also required.
Field:
Medium Temperature Suction Piping Zone Name[LINK]
This optional field is typically used to determine the
impact of pipe heat gains on system performance. If the
previous field, Sum UA Suction Piping for Medium Temperature
Loads, is blank, this field will not be used. Enter the name
of the zone where the medium-temperature suction piping is
located. The suction piping heat gains will be calculated
based upon the air temperature within this zone. The heat
balance of this zone will also be affected by the piping heat
exchange. Additional output variables are described at the
end of this section for the total impact of refrigeration on
zones, including suction pipe heat exchange.
Field:
Sum UA Suction Piping for Low Temperature Loads[LINK]
This optional field is typically used to determine the
impact of pipe heat gains on system performance and zone heat
balance. Enter the value for suction piping heat gain (in
W/C) for the low-temperature suction line, i.e., sum up the
product of the pipe wall insulation conductance times the
outer surface area of the pipe insulation. Please see the
Engineering Reference for guidance in calculating this value.
If the Sum UA Suction Piping for Low Temperature Loads is
entered, the Low Temperature Suction Piping Zone
Name is also required. Note that this entry is valid only for
two-stage systems.
Field:
Low Temperature Suction Piping Zone Name[LINK]
This optional field is typically used to determine the
impact of pipe heat gains on system performance. If the
previous field, Sum UA Suction Piping for Low Temperature
Loads, is blank, this field will not be used. Enter the name
of the zone where the low-temperature suction piping is
located. The suction piping heat gains will be calculated
based upon the air temperature within this zone. The heat
balance of this zone will also be affected by the piping heat
exchange. Additional output variables are described at the
end of this section for the total impact of refrigeration on
zones, including suction pipe heat exchange. Note that this
entry is valid only for two-stage systems.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Medium Temperature System”). A
new meter for reporting is created for each unique subcategory
(Ref. Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
The following is an example input for a transcritical
CO\(_{2}\) refrigeration
system.
Refrigeration:TranscriticalSystem,
TransRefrigSys, !- Name
TwoStage, !- System Type
MTLoads, !- Medium Temperature Refrigerated Case or Walkin or CaseAndWalkInList Name
LTLoads, !- Low Temperature Refrigerated Case or Walkin or CaseAndWalkInList Name
RefrigGasCooler, !- Refrigeration Gas Cooler Name
HPCompressors, !- High Pressure Compressor or CompressorList Name
LPCompressors, !- Low Pressure Compressor or CompressorList Name
4000000, !- Receiver Pressure
0.4, !- Subcooler Effectiveness
R744, !- Refrigeration System Working Fluid Type
, !- Sum UA Suction Piping for Medium Temperature Loads
, !- Medium Temperature Suction Piping Zone Name
, !- Sum UA Suction Piping for Low Temperature Loads
, !- Low Temperature Suction Piping Zone Name
TransRefrigSys; !- End-Use Subcategory
Zone,Average, Refrigeration Transcritical System Total
High Pressure Compressor Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Total High
Pressure Compressor Electric Energy [J]
Zone,Average, Refrigeration Transcritical System Low
Pressure Compressor Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Low
Pressure Compressor Electric Energy [J]
Zone,Sum, Refrigeration Transcritical System Total
Compressor Electric Energy [J]
Zone,Average, Refrigeration Transcritical System
Average COP [W/W]
Zone,Average, Refrigeration Transcritical System Medium
Temperature Cases and Walk Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Medium
Temperature Cases and Walk Ins Heat Transfer Energy
[J]
Zone,Average, Refrigeration Transcritical System Low
Temperature Cases and Walk Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low
Temperature Cases and Walk Ins Heat Transfer Energy
[J]
Zone,Sum, Refrigeration Transcritical System Total
Cases and Walk Ins Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Medium
Temperature Suction Pipe Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Medium
Temperature Suction Pipe Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Low
Temperature Suction Pipe Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low
Temperature Suction Pipe Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System High
Pressure Compressor Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System High
Pressure Compressor Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Low
Pressure Compressor Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low
Pressure Compressor Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Net
Rejected Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Net
Rejected Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System
Estimated Refrigerant Inventory Mass [kg]
Zone,Average, Refrigeration Transcritical System
Refrigerant Mass Flow Rate [kg/s]
Zone,Average, Refrigeration Transcritical System Medium
Temperature Evaporating Temperature [C]
Zone,Average, Refrigeration Transcritical System Medium
Temperature Suction Temperature [C]
Zone,Average, Refrigeration Transcritical System Low
Temperature Evaporating Temperature [C]
Zone,Average, Refrigeration Transcritical System Low
Temperature Suction Temperature [C]
Refrigeration
Transcritical System Total High Pressure Compressor Electric
Power [W][LINK]
This output is the total electric power input to the
system’s high pressure compressor(s) in Watts.
Refrigeration
Transcritical System Total High Pressure Compressor Electric
Energy [J][LINK]
This is the electricity consumption of the system’s high
pressure compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Transcritical System Low Pressure Compressor Electric Power
[W][LINK]
This output is the total electric power input to the
system’s low pressure compressor(s) in Watts.
Refrigeration
Transcritical System Low Pressure Compressor Electric Energy
[J][LINK]
This is the electricity consumption of the system’s low
pressure compressor(s) in Joules for the timestep being
reported. The individual consumption for each compressor is
also added to a meter with Resource Type = Electricity, End
Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Transcritical System Total Compressor Electric Energy [J][LINK]
This output is the total electric power input to all of the
system’s compressor(s) in Watts.
Refrigeration
Transcritical System Average COP [W/W][LINK]
This output is the system average compressor COP, which is
the total refrigeration effect divided by the total power to
all of the compressors.
Refrigeration
Transcritical System Medium Temperature Cases and Walk Ins
Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the medium
temperature refrigerated cases and walk-ins served directly by
this system in Watts. It is the sum of all of the heat
transfer rates for the medium temperature refrigerated cases
and walk-ins that are connected directly to this system.
Refrigeration
Transcritical System Medium Temperature Cases and Walk Ins
Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the
medium temperature refrigerated cases and walk-ins served
directly by this system in Joules. It is the sum of all of the
heat transferred for the medium temperature refrigerated cases
and walk-ins that are connected directly to this system.
Refrigeration
Transcritical System Low Temperature Cases and Walk Ins Heat
Transfer Rate [W][LINK]
This output is the total heat transfer rate from the low
temperature refrigerated cases and walk-ins served directly by
this system in Watts. It is the sum of all of the heat
transfer rates for the low temperature refrigerated cases and
walk-ins that are connected directly to this system.
Refrigeration
Transcritical System Low Temperature Cases and Walk Ins Heat
Transfer Energy [J][LINK]
This output is the total heat transfer energy from the low
temperature refrigerated cases and walk-ins served directly by
this system in Joules. It is the sum of all of the heat
transferred for the low temperature refrigerated cases and
walk-ins that are connected directly to this system.
Refrigeration
Transcritical System Total Cases and Walk Ins Heat Transfer
Energy [J][LINK]
This output is the total heat transfer energy from all the
low- and medium-temperature refrigerated cases and walk-ins
served directly by this system in Joules. It is the sum of all
of the heat transferred for all the refrigerated cases and
walk-ins that are connected directly to this system.
Refrigeration
Transcritical System Medium Temperature Suction Pipe Heat
Transfer Rate [W][LINK]
This output is the total heat transfer rate for the
medium-temperature suction piping served by this system in
Watts. Note this is an optional input, and is only available
if the user has described the medium-temperature suction
piping heat gain characteristics in the input.
Refrigeration
Transcritical System Medium Temperature Suction Pipe Heat
Transfer Energy [J][LINK]
This output is the total heat transfer rate for the
medium-temperature suction piping served by this system in
Watts. Note this is an optional input, and is only available
if the user has described the medium-temperature suction
piping heat gain characteristics in the input.
Refrigeration
Transcritical System Low Temperature Suction Pipe Heat
Transfer Rate [W][LINK]
This output is the total heat transfer rate for the
low-temperature suction piping served by this system in
Watts. Note this is an optional input, and is only available
if the user has described the low-temperature suction piping
heat gain characteristics in the input.
Refrigeration
Transcritical System Low Temperature Suction Pipe Heat
Transfer Energy [J][LINK]
This output is the total heat transfer rate for the
low-temperature suction piping served by this system in
Watts. Note this is an optional input, and is only available
if the user has described the low-temperature suction piping
heat gain characteristics in the input.
Refrigeration
Transcritical System High Pressure Compressor Heat Transfer
Rate [W][LINK]
This output is the total heat transfer rate of the high
pressure Compressors in Watts. It is the sum of all of the
heat transfer rates for the low- and medium-temperature
refrigerated cases and walk-ins as well as the low pressure
compressors that are cooled by this system. This value does
not include compressor or condenser fan heat. If specified as
in input value, the suction pipe heat gains are included in
this value.
Refrigeration
Transcritical System High Pressure Compressor Heat Transfer
Energy [J][LINK]
This is the total heat transfer of the high pressure
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Transcritical System Low Pressure Compressor Heat Transfer
Rate [W][LINK]
This output is the total heat transfer rate of the low
pressure Compressors in Watts. It is the sum of all of the
heat transfer rates for the low temperature refrigerated cases
and walk-ins that are cooled by this system. This value does
not include compressor or condenser fan heat. If specified as
in input value, the suction pipe heat gains are included in
this value.
Refrigeration
Transcritical System Low Pressure Compressor Heat Transfer
Energy [J][LINK]
This is the total heat transfer of the low pressure
compressors in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Transcritical System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to
the system gas cooler in Watts. It does not include system
heat rejection that has been recovered for useful
purposes.
Refrigeration
Transcritical System Net Rejected Heat Transfer Energy
[J][LINK]
This output is the total heat rejected by this system to
the system gas cooler in Joules for the timestep being
reported. It does not include system heat rejection that has
been recovered for useful purposes.
Refrigeration
Transcritical System Estimated Refrigerant Inventory Mass
[kg][LINK]
This output is the sum of the input refrigerant inventory
values for the gas cooler, receiver, cases, and liquid pipes
that are a part of this system.
Refrigeration
Transcritical System Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow rate
through the high pressure compressors for this system.
Refrigeration
Transcritical System Medium Temperature Evaporating
Temperature [C][LINK]
This is the saturated evaporating temperature for the
medium temperature loads.
Refrigeration
Transcritical System Medium Temperature Suction Temperature
[C][LINK]
This is the temperature at the high pressure compressor
inlet including superheat after the display cases and
superheat from the suction line heat exchanger.
Refrigeration
Transcritical System Low Temperature Evaporating Temperature
[C][LINK]
This is the saturated evaporating temperature for the
low-temperature loads.
Refrigeration
Transcritical System Low Temperature Suction Temperature
[C][LINK]
This is the temperature at the low pressure compressor
inlet including superheat after the display cases.
Refrigeration:Compressor[LINK]
The compressors are described here using manufacturer’s
data for curves that provide the efficiency, cooling capacity,
and power consumption. The corresponding rated values for
cycle superheat and subcooling are also required.
A dataset has been provided containing the
compressor rating data, including the performance curve
inputs, for a large number of compressors. See
RefrigerationCompressorCurves.idf.
A unique user-assigned name for an instance of a
compressor. Any reference to this compressor by another object
will use this name.
Field:
Refrigeration Compressor Power Curve Name[LINK]
This required field provides the name of the curve object
that describes the compressor power as a function of the
evaporating and condensing temperatures, as specified in ARI
540. The curve is of the bicubic form(ref: Curve:Bicubic).
However, the input order for the Energy Plus bicubic curve
does not match the ARI 540 standard order. When this curve is
entered, the user should use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum evaporating temperature and N12 is the
Maximum evaporating temperature.
N13 is the the Minimum condensing temperature and N14 is
the Maximum condensing temperature
Field:
Refrigeration Compressor Capacity Curve Name[LINK]
This required field provides the name of the curve object
that describes the compressor cooling capacity as a function
of the evaporating and condensing temperatures, as specified
in ARI 540. The curve is of the bicubic form(ref:
Curve:Bicubic). However, the input order for the Energy Plus
bicubic curve does not match the ARI 540 standard order. When
this curve is entered, the user should use the following
assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum evaporating temperature and N12 is
Maximum evaporating temperature.
N13 is the Minimum condensing temperature and N14 is the
Maximum condensing temperature
Field: Rated Superheat[LINK]
Some manufacturers specify a constant return gas
temperature while others specify a constant superheat (the
difference between the saturated evaporating temperature and
the actual return gas temperature). Use this field for
compressors that provide their rated superheat. (Do NOT use
both this field and the Rated Return Gas Temperature field.)
The rated superheat is specified in units of delta C.
Field: Rated
Return Gas Temperature[LINK]
Some manufacturers specify a constant return gas
temperature ( which may also be called the Rated Suction
Temperature) while others specify a constant superheat. Use
this field for compressors that provide their rated return gas
temperature. (Do NOT use both this field and the Rated
Superheat field.) The rated return gas temperature is
specified in units of C.
Field: Rated Liquid
Temperature[LINK]
Some compressor manufactures rate their equipment according
to a constant subcooling (the difference between the saturated
condensing temperature and the actual liquid temperature
entering the thermal expansion valve before the refrigeration
load). Other manufacturers specify a constant liquid
temperature.Use this field if the manufacturer specifies the
rated liquid temperature. (Do NOT use both this field and the
Rated Subcooling field.) The units for this field are degrees
C.
Field: Rated Subcooling[LINK]
Some compressor manufactures rate their equipment according
to a constant subcooling (the difference between the saturated
condensing temperature and the actual liquid temperature
entering the thermal expansion valve before the refrigeration
load). Other manufacturers specify a constant liquid
temperature.Use this field if the manufacturer specifies the
rated subcooling. (Do NOT use both this field and the Rated
Liquid Temperature field.) The units for this field are delta
C.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature System”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field: Mode-of-Operation[LINK]
The type of mode of operation. Valid choices are
Subcritical and
Transcritical. If this input field is blank,
the default will be Subcritical. If Transcritical is selected
as mode of operation, the next two input fields are required
to model transcritical cycle operation electric power
consumption and cooling capacity.
Field:
Transcritical-Compressor-Power-Curve-Name[LINK]
This field is the name of the curve object that describes
the transcritical operation compressor power as a function of
the saturated suction temperature and the gas cooler pressure.
The curve is of the bicubic form(ref: Curve:Bicubic).
However, the input order of the coefficients for the
EnergyPlus bicubic curve does not match the ARI 540 standard
order. When this curve is entered, the user should use the
following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum saturated suction temperature.
N12 is the Maximum saturated suction temperature.
N13 is the the Minimum gas cooler pressure and N14 is the
Maximum gas cooler pressure.
If Transcritical is selected as Mode
of Operation, then this input field is required.
Field:
Transcritical-Compressor-Capacity-Curve-Name[LINK]
This field is the name of the curve object that describes
the transcritical compressor operation cooling capacity as a
function of the saturated suction temperature and the gas
cooler outlet enthalpy. The curve is of the bicubic form(ref:
Curve:Bicubic). However, the input order of the coefficients
for the EnergyPlus bicubic curve does not match the ARI 540
standard order. When this curve is entered, the user should
use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum saturated suction temperature.
N12 is the Maximum saturated suction temperature.
N13 is the the Minimum gas cooler outlet enthalpy and N14
is the Maximum gas cooler outlet enthalpy.
If Transcritical is selected as Mode
of Operation, then this input field is required.
The following is an example input for a refrigeration
compressor.
Refrigeration:Compressor,
CompressorA, !- Name
PowerCurveCompA, !- Refrigeration Compressor Power Curve Name
CapCurveCompA, !- Refrigeration Compressor Capacity Curve Name
10.0, ! – Rated Superheat {delta C}
, !- Rated Return Gas Temperature {C}
, ! – Rated Liquid Temperature{C}
15.0, !- Rated Subcooling {delta C}
MedTempRefrig; !- End-Use Subcategory
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE
CASES AND/OR WALKINS:
Zone,Average,Refrigeration Compressor Electric Power
[W]
Zone,Sum,Refrigeration Compressor Electric Energy
[J]
Zone,Average,Refrigeration Compressor Heat Transfer
Rate [W]
Zone,Sum,Refrigeration Compressor Heat Transfer Energy
[J]
Zone,Sum,Refrigeration Compressor Run Time Fraction
[]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE
AIR CHILLERS:
HVAC,Average,Refrigeration Air Chiller System
Compressor Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller System Compressor
Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System
Compressor Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller System Compressor
Heat Transfer Energy [J]
HVAC,Average,Refrigeration Chiller Compressor Run
TimeFraction []
THE
FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES
AND/OR WALKINS[LINK]
Refrigeration
Compressor Electric Power [W][LINK]
This output is the electric power input to the compressor
in Watts.
Refrigeration
Compressor Electric Energy [J][LINK]
This is the electric energy consumed by the compressor in
Joules for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Compressor Heat Transfer Rate [W][LINK]
This output is the heat removed from the refrigerated cases
by the compressor in Watts.
Refrigeration
Compressor Heat Transfer Energy [J][LINK]
This is the heat removed from the refrigerated cases by the
compressor in Joules for the timestep being reported.
Refrigeration
Compressor Run Time Fraction [][LINK]
This is the fraction of the time step when the compressor
ran to meet the load. It is a value between 0.0 and 1.0.
THE
FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR
CHILLERS[LINK]
Refrigeration
Air Chiller System Compressor Electric Power [W][LINK]
This output is the electric power input to the compressor
in Watts.
Refrigeration
Air Chiller System Compressor Electric Energy [J][LINK]
This is the electric energy consumed by the compressor in
Joules for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Compressor Heat Transfer Rate [W][LINK]
This output is the heat removed from the refrigerated cases
by the compressor in Watts.
Refrigeration
Air Chiller System Compressor Heat Transfer Energy [J][LINK]
This is the heat removed from the refrigerated cases by the
compressor in Joules for the timestep being reported.
Refrigeration
Chiller Compressor Run Time Fraction [][LINK]
This is the fraction of the time step when the compressor
ran to meet the load. It is a value between 0.0 and 1.0.
Refrigeration:CompressorList[LINK]
This object provides a list of all the compressors included
within a single refrigeration system (Ref:
Refrigeration:System). Each list must contain at least one
compressor. The order in which the individual compressors are
listed here will be the order in which the compressors are
dispatched to meet the system load. That is, at very low
loads, only compressor #1 will be operating. As the load
increases, the first two compressors will be operating, and so
on. This list is extensible.
A unique user-assigned name for an instance of a compressor
list. Any reference to this compressor list by another object
will use this name. The compressor list cannot have the same
name as any individual compressor.
Field:
Refrigeration Compressor <x> Name[LINK]
Identifies a particular compressor that works in
conjunction with the other compressors on this list to
provides cooling to a single refrigeration system. The name
will be validated against the compressor names (ref:
Refrigeration:Compressor) in the input file. Up to 20 are
available in the IDD; this object is extensible.
The following is an example input for a compressor
list.
Refrigeration:CompressorList,
MediumTempCompressorlist, !- Refrigeration Compressor List Name
CompressorA, !- Refrigeration Compressor Name \#1
CompressorB, !- Refrigeration Compressor Name \#2
CompressorC; !- Refrigeration Compressor Name \#3
Refrigeration:Subcooler[LINK]
Two types of subcoolers are modeled by the detailed
refrigeration system. As described in the Engineering
Reference, the liquid suction heat exchanger uses cool suction
gas to subcool the hot condensate after it leaves the
condenser and before it reaches the thermal expansion valve.
For the liquid suction heat exchanger, both the source and
sink of energy are located within the same refrigeration
system. In contrast, a mechanical subcooler is used to
transfer cooling capacity from one refrigeration system to
another. The mechanical subcooler is listed as a part of the
system for which the condensate is cooled. However, the input
data for the mechanical subcooler includes a field that
identifies the system that provides the cooling capacity.
A unique user-assigned name for an instance of a subcooler.
Any reference to this subcooler by another object will use
this name.
Field: Subcooler Type[LINK]
The type of subcooler. Valid choices are Mechanical and
LiquidSuction. If the field is blank, the default will be
LiquidSuction.
Field:
Liquid Suction Design Subcooling Temperature Difference[LINK]
This numeric field is the design subcooling temperature
difference (DeltaC) for a liquid suction heat exchanger and
should be blank for a mechanical subcooler.
Field: Design
Liquid Inlet Temperature[LINK]
This numeric field is the design inlet temperature (C) for
the hot liquid entering a liquid suction heat exchanger and
should be blank for a mechanical subcooler.
Field: Design
Vapor Inlet Temperature[LINK]
This numeric field is the design inlet temperature (C) for
the cool vapor entering a liquid suction heat exchanger and
should be blank for a mechanical subcooler.
Field:
Capacity-Providing System[LINK]
This field is the name of the refrigeration system object
that provides the cooling capacity for the mechanical
subcooler (ref: Refrigeration:System
Name). This field should be blank for a liquid suction heat
exchanger.
Field: Outlet
Control Temperature[LINK]
This numeric field is the controlled outlet temperature (C)
for subcooled liquid exiting a mechanical subcooler. This
field should be blank for a liquid suction heat exchanger.
The following is example input for both liquid suction and
mechanical subcoolers.
REFRIGERATION:SUBCOOLER,
SampleLSHx, !Subcooler Name
LiquidSuction, !subcooler type
6, !design liquid suction subcooling {deltaC}
16, !design inlet temperature on liquid side {C}
0, !design inlet temperature on vapor side {C}
, !Refrigeration System Detailed Name providing cooling capacity
; !Control Temperature Out for subcooled liquid {C}
! Mechanical Subcooler (uses Med Temp System to cool low
temp liquid to 10C)
REFRIGERATION:SUBCOOLER,
SampleMSC, !Subcooler Name
Mechanical, !subcooler type
, !design liquid suction subcooling {C}
, !design inlet temperature on liquid side {C}
, !design inlet temperature on vapor side {C}
MediumTempSystem, !Refrigeration System Detailed Name providing cooling capacity
10; !Control Temperature Out for subcooled liquid {C}
FOR SUBCOOLERS ON SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Mechanical Subcooler
Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Mechanical Subcooler
Heat Transfer Energy [J]
FOR SUBCOOLERS ON SYSTEMS SERVING AIR CHILLERS:
Zone,Average, Refrigeration Air Chiller System
Mechanical Subcooler Heat Transfer Rate [W]
Zone,Sum, Refrigeration Air Chiller System Mechanical
Subcooler Heat Transfer Energy [J]
FOR
SUBCOOLERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
System Mechanical Subcooler Heat Transfer Rate [W][LINK]
This output is the cooling energy transferred from one
system’s compressor group to the refrigerant leaving the
condenser for another refrigeration system in Watts.
Refrigeration
System Mechanical Subcooler Heat Transfer Energy [J][LINK]
This output is the cooling energy transferred from one
system’s compressor group to the refrigerant leaving the
condenser for another refrigeration system in Joules.
FOR
SUBCOOLERS ON SYSTEMS SERVING AIR CHILLERS[LINK]
Refrigeration
Air Chiller System Mechanical Subcooler Heat Transfer Rate
[W][LINK]
This output is the cooling energy transferred from one
system’s compressor group to the refrigerant leaving the
condenser for another refrigeration system in Watts.
Refrigeration
Air Chiller System Mechanical Subcooler Heat Transfer Energy
[J][LINK]
This output is the cooling energy transferred from one
system’s compressor group to the refrigerant leaving the
condenser for another refrigeration system in Joules.
Refrigeration:Condenser:AirCooled[LINK]
The refrigeration system requires a single condenser to
reject the system heat. The air cooled condenser object is
one of four options for this condenser. In an air-cooled
condenser, the total heat of rejection is characterized by a
linear relationship between the difference between the inlet
air (usually the outside drybulb) and condensing temperatures.
This curve is commonly found in the condenser manufacturers’
literature. This rating curve, which corresponds to ARI 460
standards, also has an associated rated value for subcooling
that should be entered. The rated condenser fan power and fan
speed control type must be specified. If the condenser is not
at ground level, the user may specify an air inlet node name
(ref: OutdoorAir:Node
name). If the condenser is located inside a conditioned zone,
the zone name may be specified(ref: bbbZoneNamebbb). Optional
input is provided to help the user compare refrigerant
inventories for different systems. These inputs represent the
design values for the refrigerant inventory within the
condenser, within a receiver beneath the condenser, and in the
liquid pipes between the condenser and the refrigerated
cases.
Identifies a particular condenser that rejects heat for a
one or more refrigeration system(s). The name must be unique
and will be validated against all the condenser names (ref:
Refrigeration:Condenser:*) in the input file, including names
used for evaporative-cooled, water-cooled, and cascade-cooled
condensers.
Field:
Rated Effective Total Heat Rejection Rate Curve Name[LINK]
This field is the name of a curve object defining the
condenser heat rejection as a function of the difference
between the condensing and entering air temperatures. The
curve should be linear (Curve:Linear). See the Engineering
Reference for more discussion on the curve coefficients.
Field:
Rated Subcooling Temperature Difference[LINK]
This numeric field specifies the rated subcooling (DeltaC)
specified by the manufacturer, consistent with the heat
rejection curve rating data.
Field:
Condenser Fan Speed Control Type[LINK]
The type of fan speed control used by the condenser fan.
Valid choices are Fixed,
FixedLinear, VariableSpeed,
and TwoSpeed. If the field is blank,
Fixed will be used. See the Engineering
Reference for a discussion of this option’s effect on fan
energy consumption.
Field: Rated Fan Power[LINK]
This numeric field specifies the rated fan power (W)
specified by the manufacturer, under standard rating
conditions.
Field: Minimum Fan
Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to
avoid overheating the fan motor or for other reasons. This
numeric field should be between 0. and 1. and has a default
value of 0.2.
Field: Air
Inlet Node Name or Zone Name[LINK]
This optional alpha field contains the name of the node
from which the condenser draws its outdoor air or the name of
the conditioned zone where the condenser is located. If this
field is left blank, the outdoor air drybulb temperature
entering the condenser is taken directly from the weather
data. If this field is not blank and an outdoor air node name
is entered, this node name must also be specified in an OutdoorAir:Node
object where the height of the node is taken into
consideration when calculating outdoor air temperature from
the weather data. Alternately, the node name may be specified
in an OutdoorAir:NodeList
object where the outdoor air temperature is taken directly
from the weather data. If a zone name is entered, the
temperature of that zone is used.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field:
Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condenser (kg) specified by the
manufacturer, under standard rating conditions.
Field:
Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate receiver (kg) specified by the
manufacturer or system designer, under standard rating
conditions.
Field:
Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate piping (kg) specified by the
system designer, under standard rating conditions.
The following is an example input for an air-cooled
condenser.
Refrigeration:Condenser:AirCooled,
MediumTempCondenser, !- Name of condenser
MediumTempCondenserHRCurve, !-name of condenser heat of rejection curve, linear
0., ! Rated subcooling {deltaC}
VariableSpeed, ! Fan speed control type
4000., ! Design condenser fan power {W}
0.25, !Minimum air flow fraction through condenser fan {dimensionless}
Refrigeration MediumTempSystem CondenserNode, !- Condenser Air Inlet Node Name or Zone Name
MediumTempRefrig; !- End-Use Subcategory
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:
Zone,Average, Refrigeration System Condenser Fan
Electric Power [W]
Zone,
Sum, Refrigeration System Condenser Fan Electric Energy
[J]
Zone,Average, Refrigeration System Condenser Heat
Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Transfer Energy
[J]
Zone,Average, Refrigeration System Condenser Total
Recovered Heat Transfer Rate [W] Zone,
Sum, Refrigeration System Condenser Total Recovered Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non
Refrigeration Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Recovered for
Non-Refrigeration Purposes Energy [J]
Zone,Average, Refrigeration System Condenser Defrost
Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Defrost Recovered Heat
Transfer Energy [J]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration System Condenser Fan
Electric Power [W]
HVAC, Sum, Refrigeration System Condenser Fan Electric
Consumption [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Total Recovered Heat Transfer Rate [W] HVAC, Sum,
Refrigeration Air Chiller System Condenser Total Recovered
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Non Refrigeration Recovered Heat Transfer Rate
[W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Defrost Recovered Heat Transfer Energy [J]
FOR
CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser
fan(s) in Watts.
Refrigeration
System Condenser Fan Electric Consumption [J][LINK]
This is the electricity consumption of the system’s
condenser fan(s) in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration load minus any heat
recovered for defrost or other purposes).
Refrigeration
System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported (i.e., compressor energy and
refrigeration load minus any heat recovered for defrost or
other purposes).
Refrigeration
System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for all purposes including defrost and water or air
heating.
Refrigeration
System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for all purposes including defrost and water or air
heating for the timestep being reported.
Refrigeration
System Condenser Non Refrigeration Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating.
Refrigeration
System Condenser Non Refrigeration Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating for the
timestep being reported.
Refrigeration
System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system.
Refrigeration
System Condenser Defrost Recovered Heat Transfer Energy
[J][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system for
the timestep being reported.
FOR
CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Air Chiller System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser
fan(s) in Watts.
Refrigeration
Air Chiller System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s
condenser fan(s) in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration load minus any heat
recovered for defrost or other purposes).
Refrigeration
Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported (i.e., compressor energy and
refrigeration load minus any heat recovered for defrost or
other purposes).
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for all purposes including defrost and water or air
heating.
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for all purposes including defrost and water or air
heating for the timestep being reported.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating for the
timestep being reported.
Refrigeration
Air Chiller System Condenser Defrost Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system.
Refrigeration
Air Chiller System Condenser Defrost Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system for
the timestep being reported.
Refrigeration:Condenser:EvaporativeCooled[LINK]
Each refrigeration system requires a single condenser. The
evaporative cooled condenser object is one of four options for
this condenser. In an evaporative-cooled condenser, the total
heat of rejection is characterized by a four-factor
relationship between the condensing temperature and the
difference between the outside wetbulb and condensing
temperatures. This curve must be developed by regression from
the condenser manufacturers’ literature. This rating curve,
which is based upon rated data taken according to ARI 460
standards, also has an associated rated value for subcooling
that should be entered. The rated condenser fan power and fan
speed control type must be specified. If the condenser is not
at ground level, the user may specify an air inlet node name
(ref: OutdoorAir:Node
name). Optional input is provided to help the user compare
refrigerant inventories for different systems. These input
represent the design values for the refrigerant inventory
within the condenser, within a receiver beneath the condenser,
and in the liquid pipes between the condenser and the
refrigerated cases.
Additional inputs are needed for basin heater parameters,
water pump power, and water source. An evaporative cooling
availability schedule is available.
Identifies a particular condenser that rejects heat for a
one or more refrigeration system(s). The name must be unique
and will be validated against all the condenser names (ref:
Refrigeration:Condenser:*) in the input file, including names
used for air-cooled, water-cooled and cascade-cooled
condensers.
Field:
Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection
effect (W) at standard rating conditions per ARI 490. Be sure
the rating corresponds to the correct refrigerant.
Field:
Rated Subcooling Temperature Difference[LINK]
This numeric field specifies the rated subcooling (DeltaC)
specified by the manufacturer, consistent with the rated value
for total heat rejection.
Field: Fan Speed Control
Type[LINK]
The type of fan speed control used by the condenser fan.
Valid choices are Fixed,
FixedLinear, VariableSpeed,
and TwoSpeed. If the field is blank,
Fixed will be used. See the Engineering
Reference for a discussion of this option’s effect on fan
energy consumption.
Field: Rated Fan
Power[LINK]
This numeric field specifies the rated fan power (W)
specified by the manufacturer, under standard rating
conditions.
Field: Minimum Fan
Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to
avoid overheating the fan motor or for other reasons. This
numeric field has a minimum value of 0. and a default value of
0.2.
Field:
Approach Temperature Constant Term[LINK]
As described in the Engineering Reference (ref
Refrigeration:Condenser:Evaporative), the heat rejection
capacity factor is specified according to the form (where
Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A1 and has a default
value of 6.63, a minimum of 0. and a maximum of 20. (C)
Field:
Approach Temperature Coefficient 2[LINK]
As described in the Engineering Reference (ref
Refrigeration:Condenser:Evaporative), the heat rejection
capacity factor is specified according to the form (where
Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A2 and has a default
value of 0.468, a minimum of 0, and a maximum of 20 (C).
Field:
Approach Temperature Coefficient 3[LINK]
As described in the Engineering Reference (ref
Refrigeration:Condenser:Evaporative), the heat rejection
capacity factor is specified according to the form (where
Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) +(1 + A4)(Twb)
This numeric field is the value for A3 and has a default
value of 17.93, a minimum of 0, and a maximum of 30 (C).
Field:
Approach Temperature Coefficient 4[LINK]
As described in the Engineering Reference (ref
Refrigeration:Condenser:Evaporative), the heat rejection
capacity factor is specified according to the form (where
Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A4 and has a default
value of -0.322, a minimum of -20., and a maximum of 20
(dimensionless).
Field: Minimum Capacity
Factor[LINK]
This numeric field is the minimum heat rejection capacity
factor in the manufacturer’s data used to develop the equation
described in the preceding four fields. The default value is
0.5.
Field: Maximum Capacity
Factor[LINK]
This numeric field is the maximum heat rejection capacity
factor in the manufacturer’s data used to develop the equation
described in the preceding four fields. The default value is
5.0.
Field: Air Inlet Node
Name[LINK]
This optional alpha field contains the name of the node
from which the condenser draws its outdoor air. If this field
is left blank, the outdoor air drybulb temperature entering
the condenser is taken directly from the weather data. If this
field is not blank, this node name must also be specified in
an OutdoorAir:Node
object where the height of the node is taken into
consideration when calculating outdoor air temperature from
the weather data. Alternately, the node name may be specified
in an OutdoorAir:NodeList
object where the outdoor air temperature is taken directly
from the weather data.
Field: Rated Air Flow
Rate[LINK]
The air volume flow rate, in m\(^{3}\)per second, entering the
evaporative condenser. This value is used to calculate the
amount of water evaporated when evaporatively cooling the
condenser inlet air. The value for this field must be greater
than zero. This input field is also autocalculatable,
equivalent to 0.000144 m\(^{3}\)/s per watt of total
cooling capacity [850 cfm/ton] where the total cooling
capacity is the total heat of rejection.
Field: Basin Heater
Capacity[LINK]
This field defines the power level of the basin heater, if
applicable, used to avoid water freezing in an outdoor
evaporative cooler basin. This numeric field contains the
capacity of the electric basin heater in Watts per degree C.
This field is used in conjunction with the Basin Heater Set
Point Temperature described in the following field. The basin
heater electric power is equal to this field multiplied by the
difference between the basin heater set point temperature and
the dry-bulb temperature of the condenser coil inlet air. The
basin heater only operates when the condenser fan is off
(i.e., no compressor heat rejection). The basin heater
capacity must be greater than or equal to zero, with a default
value of 200 W/C if this field is left blank.
Field:
Basin Heater Setpoint Temperature[LINK]
This numeric field contains the set point temperature (°C)
for the basin heater described in the previous field. The
basin heater is active when the outdoor air dry-bulb
temperature falls below this set point temperature, as long as
the condenser fan is off. The default value is 2°C if this
field is left blank.
Field: Rated Water Pump
Power[LINK]
The rated power of the evaporative condenser water pump in
Watts. This value is used to calculate the power required to
pump the water used to evaporatively cool the condenser inlet
air. The value for this field must be greater than or equal to
0, with a default value of 1000 Watts if this field is left
blank. This input field is also autocalculatable, equivalent
to 0.004266 W per Watt [15 W/ton] of total cooling
capacity.
Field:
Evaporative Water Supply Tank Name[LINK]
This field is used to define where the condenser obtains
water used for evaporative cooling. If this field is left
blank, the unit will obtain water directly from the mains
(Ref. Water Mains Temperatures). If the name of a Water
Storage Tank object is used here, then the unit will obtain
its water from that tank.
Field:
Evaporative Condenser Availability Schedule Name[LINK]
For evaporative cooled condensers, the name of the optional
schedule (Ref: Schedule) that specifies the time periods that
evaporative cooling is available/unavailable. In some colder
climates, evaporative cooling is periodically discontinued and
the basin sumps drained to avoid freezing and to avoid ice
formation on the condenser. In these times, the condenser runs
as a typical dry air cooled condenser, and related evaporative
cooling systems (e.g., water pump, basin heaters) do not
operate. Use of this optional schedule permits modeling of
planned, seasonal interruptions of evaporative cooling. All
schedule values must be greater than or equal to zero.
Typically, an ON/OFF schedule type is used with values being
either 0 or 1. A schedule value of 1 indicates that
evaporative cooling is available during the defined time
period, and a value of 0 denotes that evaporative cooling is
not available during the defined time period. If the schedule
name is omitted (blank), then the model assumes that
evaporative cooling of the condenser is available for the
entire simulation period. Note: the use of this schedule is
the correct way to model an evaporative condenser in a climate
subject to freezing weather. However, because some users will
take a single model description and run it for a multiple
climates, the code also includes an automatic switch from wet
to dry operation, as described in the Engineering
Reference.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field:
Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condenser (kg) specified by the
manufacturer, under standard rating conditions.
Field:
Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate receiver (kg) specified by the
manufacturer or system designer, under standard rating
conditions.
Field:
Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate piping (kg) specified by the
system designer, under standard rating conditions.
The following is an example input for an evaporative
condenser
Refrigeration:Condenser:EvaporativeCooled,
MedTempEvapCooledCondenser , !- Refrigeration Condenser Name
64800. , !- Rated Total Heat Rejection Effect, {W}
0. , !- Rated Subcooling
VariableSpeed , !- Condenser Fan Speed Control
746., !- Rated Condenser Fan Power
0.25, !- Minimum air flow fraction through condenser fan {dimensionless}
6.63 , !- Evaporative Condenser Approach Temp Const, {C}
0.468 , !- Evaporative Condenser Approach Temp HRCF Cooefficient
17.93 , !- Evaporative Condenser Approach Temp 1/hrcf coefficient
-0.322, !- Evaporative Condenser Approach Temp Twb coefficient {1/C}
0.6 , !- Minimum Condenser Capacity Factor
4.8 , !- Maximum Condenser Capacity Factor
Outside Air Inlet Node, !- Condenser Air Inlet Node Name
1.79 , !- Rated Air Flow Rate {m3/s}
66.7 , !- Basin Heater Capacity {W/C}
1.0 , !- Basin Heater Set Point Temperature {C}
250. , !- Rated Water Pump Power {W}
EvapWaterStorageTank, !- Evaporative Water Supply Tank Name
EvapCondAvail, !- Evaporative Condenser Availability Schedule Name
, !- End-UseSubcategory
21.9 , !- Condenser Refrigerant Operating Charge {kg}
10. , !- Condensate Receiver Refrigerant Inventory
25. ; !- Condensate Piping Refrigerant Inventory
Zone,Average, Refrigeration System Condenser Fan
Electric Power [W]
Zone,
Sum, Refrigeration System Condenser Fan Electric Consumption
[J]
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:
Zone,Average, Refrigeration System Condenser Heat
Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Transfer Energy
[J]
Zone,Average, Refrigeration System Condenser Total
Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Total Recovered Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non
Refrigeration Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Non Refrigeration
Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Defrost
Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Defrost Recovered Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Pump
Electric Power [W]
Zone,
Sum, Refrigeration System Condenser Pump Electric Energy
[J]
Zone,Average, Refrigeration System Condenser Basin
Heater Electric Power [W]
Zone,
Sum, Refrigeration System Condenser Basin Heater Electric
Energy [J]
Zone,Average, Refrigeration System Condenser Evaporated
Water Volume Flow Rate [m3/s]
Zone,
Sum, Refrigeration System Condenser Evaporated Water Volume
[m3]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System
Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Total Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Total Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Non Refrigeration Recovered Heat Transfer Rate
[W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Defrost Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Pump Electric Power [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Pump Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Basin Heater Electric Power [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Basin Heater Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Evaporated Water Volume Flow Rate [m3/s]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Evaporated Water Volume [m3]
FOR
CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser
fan(s) in Watts.
Refrigeration
System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s
condenser fan(s) in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
Refrigeration
System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose.
Refrigeration
System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose for the timestep being
reported.
Refrigeration
System Condenser Non Refrigeration Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for purposes such as water or air
heating.
Refrigeration
System Condenser Heat Recovered for Non-Refrigeration Purposes
Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for purposes such as water or air
heating for the timestep being reported.
Refrigeration
System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for defrost purposes within the
refrigeration system..
Refrigeration
System Condenser Defrost Recovered Heat Transfer Energy
[J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for defrost purposes within the
refrigeration system for the timestep being reported.
Refrigeration
System Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water pump used with
evaporative cooling of the condenser.
Refrigeration
System Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water
pump used with evaporative cooling of the condenser for the
timestep being reported. This output is also added to a meter
with Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
System Condenser Basin Heater Electric Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water heater in the basin of
the evaporative system used to cool the condenser.
Refrigeration
System Condenser Basin Heater Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water
heater used to prevent freezing of the evaporative cooling
system for the condenser for the timestep being reported. This
output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant.
Use of an optional subkey category is also available, with
default to the General end-use subcategory (Ref. Output:Meter
objects).
Refrigeration
System Condenser Evaporated Water Volume Flow Rate [m\(^{3}\)/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while
providing evaporative cooling of the condenser.
Refrigeration
System Condenser Evaporated Water Volume [m\(^{3}\)][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing
evaporative cooling of the condenser for the timestep being
reported. This output is also added to a meter with Resource
Type = Water, End Use Key = Refrigeration, Group Key = Plant.
Use of an optional subkey category is also available, with
default to the General end-use subcategory (Ref. Output:Meter
objects).
FOR
CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Air Chiller System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser
fan(s) in Watts.
Refrigeration
Air Chiller System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s
condenser fan(s) in Joules for the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose.
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose for the timestep being
reported.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for purposes such as water or air
heating.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for purposes such as water or air
heating for the timestep being reported.
Refrigeration
Air Chiller System Condenser Defrost Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for defrost purposes within the
refrigeration system.
Refrigeration
Air Chiller System Condenser Defrost Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for defrost purposes within the
refrigeration system for the timestep being reported.
Refrigeration
Air Chiller System Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water pump used with
evaporative cooling of the condenser.
Refrigeration
Air Chiller System Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water
pump used with evaporative cooling of the condenser for the
timestep being reported. This output is also added to a meter
with Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Plant. Use of an optional subkey category is also
available, with default to the General end-use subcategory
(Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Condenser Basin Heater Electric Power
[W][LINK]
This is the electrical power requirement in Watts for the
timestep being reported for the water heater in the basin of
the evaporative system used to cool the condenser.
Refrigeration
Air Chiller System Condenser Basin Heater Electric Energy
[J][LINK]
This is the electricity consumption in Joules of the water
heater used to prevent freezing of the evaporative cooling
system for the condenser for the timestep being reported. This
output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant.
Use of an optional subkey category is also available, with
default to the General end-use subcategory (Ref. Output:Meter
objects).
Refrigeration
Air Chiller System Condenser Evaporated Water Volume Flow Rate
[m3/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while
providing evaporative cooling of the condenser.
Refrigeration
Air Chiller System Condenser Evaporated Water Volume [m3][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing
evaporative cooling of the condenser for the timestep being
reported. This output is also added to a meter with Resource
Type = Water, End Use Key = Refrigeration, Group Key = Plant.
Use of an optional subkey category is also available, with
default to the General end-use subcategory (Ref. Output:Meter
objects).
Refrigeration:Condenser:WaterCooled[LINK]
The refrigeration system requires a single condenser. The
water cooled condenser object is one of four options for this
condenser. Manufacturer’s data is required for the rated total
heat rejection, the rated condensing temperature, and the
rated leaving liquid refrigerant temperature, all per ARI
450. These values are used to calculate the subcooling
included in the rated capacity. The inlet and outlet node
names as well as the water outlet temperature schedule name
are required. Optional input is provided to help the user
compare refrigerant inventories for different systems. These
input represent the design values for the refrigerant
inventory within the condenser, within a receiver beneath the
condenser, and in the liquid pipes between the condenser and
the refrigerated cases.
Identifies a particular condenser that rejects heat for one
or more refrigeration system(s). The name must be unique and
will be validated against all the condenser names (ref:
Refrigeration:Condenser) in the input file, including names
used for air-cooled, evaporative-cooled, and cascade-cooled
condensers.
Field:
Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection
effect (W) at standard rating conditions per ARI 450. Be sure
the rating corresponds to the correct refrigerant.
Field: Rated
Condensing Temperature[LINK]
This numeric field provides the rated condensing
temperature (C) corresponding to the rated heat rejection
capacity.
Field:
Rated Subcooling Temperature Difference[LINK]
This numeric field provides the rated liquid refrigerant
subcooling (DeltaC) corresponding to the rated heat rejection
capacity. Note this is equal to the difference between the
saturated condensing temperature and the leaving liquid
refrigerant temperature.
Field: Rated
Water Inlet Temperature[LINK]
This numeric field provides the rated water inlet
temperature (C) corresponding to the rated heat rejection
capacity at the rated condensing temperature.
Field: Water Inlet
Node Name[LINK]
A node name for the water-side condenser inlet must be
provided.
Field: Water Outlet
Node Name[LINK]
A node name for the water-side condenser outlet must be
provided.
Field:
Water-Cooled Loop Flow Type[LINK]
The type of flow loop should be specified. The two choices
are VariableFlow, in which a Pump:VariableSpeed
must be included in the plant loop, or
ConstantFlow, in which the loop circuit has a
constant flow rate, typically associated with a
Pump:ConstandSpeed object. If the flow type is VariableFlow,
the flow needed to remove the condenser heat energy will be
calculated and requested of the pump. If the flow type is
ConstantFlow, the outlet water temperature will be determined
based on the fixed loop flow rate and heat energy to be
removed. The default type is VariableFlow. Refer to
additional discussion in the Engineering Reference.
Field:
Water Outlet Temperature Schedule Name[LINK]
When the water-cooled loop flow type is “VariableFlow”, the
name of a schedule (Ref: Schedule) that defines the desired
condenser water outlet temperature must be provided. The
schedule may define an outlet temperature that varies through
time.
Field: Water Design Flow
Rate[LINK]
When the water-cooled loop flow type is “ConstantFlow”,
this is the design water flow rate in m\(^{3}\)/s that will be requested
initially. This requested flow will be passed to the loop
simulation, and resulting actual flow will be dependent upon
supply system capabilities (e.g., pump capability). The
design flow rate must always be less than the maximum flow
rate, defined below.
Field: Water Maximum
Flow Rate[LINK]
This numeric field is the maximum water flow rate in m\(^{3}\)/s that will be allowed
through the condenser. When the loop flow type is Variable
Flow, if the calculated flow rate is higher than the maximum
flow rate, an error message will be generated, and the flow
rate will be reset to the maximum flow rate.
Field: Maximum
Water Outlet Temperature[LINK]
This numeric field specifies the maximum allowed water
temperature in degrees C leaving the condenser. The default
value is 55 degrees C.
Field: Minimum
Water Inlet Temperature[LINK]
This numeric field specifies the minimum allowed water
temperature in degrees C entering the compressor rack
condenser. The default value is 10 degrees C. Refer to
additional discussion in the Engineering Reference.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature System”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field:
Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condenser (kg) specified by the
manufacturer, under standard rating conditions.
Field:
Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate receiver (kg) specified by the
manufacturer or system designer, under standard rating
conditions.
Field:
Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate piping (kg) specified by the
system designer, under standard rating conditions.
The following is an example input for a water cooled
condenser.
Refrigeration:Condenser:WaterCooled,
MediumTempCondenser , !- Name
58000. , !- Rated Effective Total Heat Rejection Rate {W}
29.4 , !- Rated Condensing Temperature {C}
0.0 , !- Rated Subcooling Temperature Difference{deltaC}
10.0, !- Rated Water Inlet Temperature {C}
Condenser Inlet Node, !- Water Inlet Node Name
Condenser Outlet Node, !- Water- Outlet Node Name
Variable Flow, !- Water-cooled Loop Flow Type
Cond Outlet Temp Sch, !- Water Outlet Temperature Schedule Name
, !- Water Design Flow Rate {m3/s}
0.003, !- Water Maximum Flow Rate {m3/s}
55., !- Maximum Water Outlet Temperature {C}
, !- Minimum Water Inlet Temperature {C}
, !- End-Use Subcategory
30. , !- Condenser Refrigerant Operating Charge {kg}
65. , !- Condensate Receiver Refrigerant Inventory {kg}
20. ; !- Condensate Piping Refrigerant Inventory {kg}
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:
Zone,Average, Refrigeration System Condenser Heat
Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Transfer Energy
[J]
Zone,Average, Refrigeration System Condenser Total
Recovered Heat Transfer Rate [W] Zone,
Sum, Refrigeration System Condenser Total Recovered Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non
Refrigeration Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Recovered for
Non-Refrigeration Purposes Energy [J]
Zone,Average, Refrigeration System Condenser Defrost
Recovered Heat Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Defrost Recovered Heat
Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Water Mass
Flow Rate [kg/s]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System
Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Total Recovered Heat Transfer Rate [W] HVAC, Sum,
Refrigeration Air Chiller System Condenser Total Recovered
Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Non Refrigeration Recovered Heat Transfer Rate
[W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Defrost Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System
Condenser Fluid Mass Flow Rate [kg/s]
FOR
CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
Refrigeration
System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose.
Refrigeration
System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose for the timestep being
reported.
Refrigeration
System Condenser Non Refrigeration Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating.
Refrigeration
System Condenser Heat Recovered for Non-Refrigeration Purposes
Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating for the
timestep being reported.
Refrigeration
System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration
system..
Refrigeration
System Condenser Heat Energy Recovered for Refrigeration
Defrost Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system for
the timestep being reported.
Refrigeration
System Condenser Water Mass Flow Rate [kg/s][LINK]
This is the mass flow rate of the water used to cool the
condenser in kg/s.
FOR
CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose.
Refrigeration
Air Chiller System Condenser Total Recovered Heat Transfer
Energy [J][LINK]
This is the total heat recovered from the condenser
refrigerant inlet flow for any purpose for the timestep being
reported.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating.
Refrigeration
Air Chiller System Condenser Non Refrigeration Recovered Heat
Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for purposes such as water or air heating for the
timestep being reported.
Refrigeration
Air Chiller System Condenser Defrost Recovered Heat Transfer
Rate [W][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system.
Refrigeration
Chiller System Condenser Heat Energy Recovered for
Refrigeration Defrost Energy [J][LINK]
This is the total heat recovered from the condenser inlet
flow for defrost purposes within the refrigeration system for
the timestep being reported.
Refrigeration
Air Chiller System Condenser Fluid Mass Flow Rate [kg/s][LINK]
This is the mass flow rate of the water used to cool the
condenser in kg/s.
Refrigeration:Condenser:Cascade[LINK]
The refrigeration system requires a single condenser. The
cascade condenser object is one of four options for this
condenser. The cascade condenser is unlike the other condenser
options because it rejects heat to another,
higher-temperature, refrigeration system. That is, the cascade
condenser acts as a heat rejection object for one system, but
acts as a refrigeration load for another system. Therefore,
this object will be referenced twice: first for the system
rejecting heat (see the field Refrigeration Condenser Name for
the object Refrigeration:System), and second for the system
absorbing the heat (see the input for the field Refrigeration
Transfer Load or TransferLoad List Name for the object Refrigeration:System
or the field Cascade Condenser Name or Secondary System Name
for the object Refrigeration:TransferLoadList).
Manufacturer’s data is required for the rated condensing
temperature and the rated approach temperature difference. The
user must also specify the condensing temperature control
type. There are two choices. The user can specify “Fixed” and
the condensing temperature will be held constant at the input
value. The user can specify “Float” if they want the
condensing temperature to be set by other refrigeration loads
served by the higher-temperature system.
The rated heat rejection capacity is not used except as a
rough input value check on the overall system sizing. Optional
input is provided to help the user compare refrigerant
inventories for different systems. These inputs represent the
design values for the refrigerant inventory within the
condenser, within a receiver beneath the condenser, and in the
liquid pipes between the condenser and the refrigerated
cases.
Identifies a particular condenser that rejects heat for a
single refrigeration system. The name must be unique and will
be validated against all the condenser names (ref:
Refrigeration:Condenser:*) in the input file, including names
used for air-cooled, evaporative-cooled, and water-cooled
condensers.
Field: Rated
Condensing Temperature[LINK]
This numeric field provides the rated condensing
temperature (C).
Field:
Rated Approach Temperature Difference[LINK]
This numeric field provides the rated difference (Delta C)
between the saturated condensing temperature for the system
rejecting heat and the saturated evaporating refrigerant
temperature for the system absorbing heat. The default value
is 3.0 C.
Field:
Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection
effect (W). Be sure the rating corresponds to the correct
refrigerant(s). This value is used for system sizing error
checking.
Field:
Condensing Temperature Control Type[LINK]
The type of control used to set the saturated condensing
temperature. Valid choices are Fixed and
Float. If the field is blank,
Fixed will be used. Fixed will hold the
condensing temperature constant at the value specified.
Float will consider the specified input as a
minimum condensing temperature. This value will be compared
to the evaporating temperatures required by other loads on the
higher-temperature refrigeration system, and will use the
lowest temperature required to meet those loads, along with
the Approach Temperature Difference, to set the condensing
temperature.
Field:
Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condenser (kg) specified by the
manufacturer, under standard rating conditions. This
refrigerant is on the side of the condenser rejecting heat,
not on the side of the condenser absorbing the heat.
Field:
Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate receiver (kg) specified by the
manufacturer or system designer, under standard rating
conditions.
Field:
Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the condensate piping (kg) specified by the
system designer, under standard rating conditions.
The following is an example input for a cascade
condenser.
Refrigeration:Condenser:Cascade,
CascadeCondenser1 , !- Name
-4. , !- Rated Condensing Temperature {C}
3. , !- Rated Approach Temperature Difference {DeltaC}
20000.0 , !- Rated Effective Total Heat Rejection Rate {W}
Fixed; !- Condensing Temperature Control Type
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:
Zone,Average, Refrigeration System Condenser Heat
Transfer Rate [W]
Zone,
Sum, Refrigeration System Condenser Heat Transfer Energy
[J]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System
Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser
Heat Transfer Energy [J]
FOR
CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
FOR
CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e.,
compressor energy and refrigeration loads) in Watts.
Refrigeration
Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser
for the timestep being reported.
Refrigeration:GasCooler:AirCooled[LINK]
The transcritical refrigeration system requires a single
gas cooler to reject the system heat. The total heat of
rejection is characterized by a linear relationship between
the difference between the outside dry-bulb and gas cooler
outlet temperatures. The rated gas cooler fan power and fan
speed control type must be specified. If the gas cooler is
not at ground level, the user may specify an air inlet node
name (Ref. OutdoorAir:Node
name). Optional input is provided to help the user track
refrigerant inventories. These inputs represent the design
values for the refrigerant inventory within the gas cooler,
within a receiver, and in the liquid pipes between the gas
cooler and the refrigerated cases.
Identifies a particular gas cooler that rejects heat for a
single refrigeration system. The name must be unique and will
be validated against all the gas cooler names (Ref.
Refrigeration:GasCooler:AirCooled) in the input file.
Field:
Rated Total Heat Rejection Rate Curve Name[LINK]
This field is the name of a curve object defining the gas
cooler heat rejection as a function of the difference between
the gas cooler outlet and entering air temperatures. The curve
should be linear (Curve:Linear). See the Engineering Reference
for more discussion on the curve coefficients.
Field: Gas
Cooler Fan Speed Control Type[LINK]
The type of fan speed control used by the gas cooler fan.
Valid choices are Fixed, FixedLinear, VariableSpeed, and
TwoSpeed. If the field is blank, Fixed will be used. Note
that fan energy consumption for the air-cooled gas cooler is
computed in the same way as that of the air-cooled condenser.
For further information on fan energy calculations, see the
discussion regarding air-cooled condenser fan energy in the
Engineering Reference.
Field: Rated Fan Power[LINK]
This numeric field specifies the rated fan power (W)
specified by the manufacturer, under standard rating
conditions. If this field is blank, the default value of
5000 W will be used
Field: Minimum Fan
Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to
avoid overheating the fan motor or for other reasons. This
numeric field should be between 0. and 1. and has a default
value of 0.2.
Field: Transition
Temperature[LINK]
This is the temperature (C) at which the gas cooler and the
refrigeration system transitions between subcritical and
transcritical operation. If this field is blank, the default
value of 27.0°C will be used.
Field:
Transcritical Approach Temperature[LINK]
This is the temperature difference (C) between the
refrigerant (CO\(_{2}\))
exiting the gas cooler and the air entering the gas cooler
during transcritical operation. If this field is blank, the
default value of 3.0°C will be used.
Field:
Subcritical Temperature Difference[LINK]
This is the temperature difference (C) between the
condensing temperature and the ambient air temperature during
subcritical operation. If this field is blank, the default
value of 10.0°C will be used.
Field: Minimum Condensing
Temperature
This numeric field specifies the minimum condensing
temperature (C) required to maintain stable subcritical
operation. If this field is blank, the default value of
10.0°C will be used.
Field: Air Inlet Node Name
This optional alpha field contains the name of the node
from which the gas cooler draws its outdoor air. If this
field is left blank, the outdoor air dry-bulb temperature
entering the gas cooler is taken directly from the weather
data. If this field is not blank, this node name must also be
specified in an OutdoorAir:Node
object where the height of the node is taken into
consideration when calculating outdoor air temperature from
the weather data. Alternately, the node name may be specified
in an OutdoorAir:NodeList
object where the outdoor air temperature is taken directly
from the weather data.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref. Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
Field:
Gas Cooler Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the gas cooler (kg) specified by the
manufacturer, under standard rating conditions. If this field
is blank, the default value of 0.0 kg will be used.
Field:
Gas Cooler Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the gas cooler receiver (kg) specified by the
manufacturer or system designer, under standard rating
conditions. If this field is blank, the default value of
0.0 kg will be used.
Field:
Gas Cooler Outlet Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant
present within the gas cooling outlet piping (kg) specified by
the system designer, under standard rating conditions. If
this field is blank, the default value of 0.0 kg will be
used.
The following is an example input for an air-cooled gas
cooler.
Refrigeration:GasCooler:AirCooled,
RefrigGasCooler, !- Name
GasCoolerHRCurve, !- Rated Total Heat Rejection Rate Curve Name
Fixed, !- Gas Cooler Fan Speed Control Type
6400, !- Rated Fan Power
0.2, !- Minimum Fan Air Flow Ratio
27.0, !- Transition Temperature
3.0, !- Transcritical Approach Temperature
10.0, !- Subcritical Temperature Difference
10.0, !- Minimum Condensing Temperature
, !- Air Inlet Node Name
RefrigGasCooler, !- End-Use Subcategory
, !- Gas Cooler Refrigerant Operating Charge Inventory
, !- Gas Cooler Receiver Refrigerant Inventory
; !- Gas Cooler Outlet Piping Refrigerant Inventory
Zone,Average, Refrigeration Transcritical System Gas
Cooler Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler
Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Gas
Cooler Fan Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler
Fan Electric Energy [J]
Zone,Average, Refrigeration Transcritical System Gas
Cooler Outlet Temperature [C]
Zone,Average, Refrigeration Transcritical System Gas
Cooler Outlet Pressure [Pa]
Zone,Average, Refrigeration Transcritical System Gas
Cooler Defrost Recovered Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler
Defrost Recovered Heat Transfer Energy [J]
Refrigeration
Transcritical System Gas Cooler Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the gas
cooler in Watts, and includes compressor energy and the
refrigeration load.
Refrigeration
Transcritical System Gas Cooler Heat Transfer Energy [J][LINK]
This output is the total heat transferred from the gas
cooler to the surroundings, in Joules, for the timestep being
reported.
Refrigeration
Transcritical System Gas Cooler Fan Electric Power [W][LINK]
This output is the electric input to the system’s gas
cooler fan(s) in Watts.
Refrigeration
Transcritical System Gas Cooler Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s gas
cooler fan(s) in Joules for the timestep being reported. This
output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Plant
(Ref. Output:Meter
objects).
Refrigeration
Transcritical System Gas Cooler Outlet Temperature [C][LINK]
This output is the temperature (in C) of the refrigerant
exiting the gas cooler.
Refrigeration
Transcritical System Gas Cooler Outlet Pressure [Pa][LINK]
This output is the pressure (in Pa) of the refrigerant
exiting the gas cooler.
Refrigeration
Transcritical System Gas Cooler Defrost Recovered Heat
Transfer Rate [W][LINK]
This is the total heat recovered from the gas cooler inlet
flow for defrost purposes within the refrigeration system.
Refrigeration
Transcritical System Gas Cooler Defrost Recovered Heat
Transfer Energy [J][LINK]
This is the total heat recovered from the gas cooler inlet
flow for defrost purposes within the refrigeration system for
the timestep being reported.
Refrigeration:TransferLoadList[LINK]
A refrigeration system may provide cooling to other,
secondary, systems through either a secondary loop or a
cascade condenser (Ref. Refrigeration:SecondarySystem
and Refrigeration:Condenser:Cascade). If multiple transfer
loads are served by a single primary system, use this list to
group them together for reference by the primary system (see
the field “Refrigeration Transfer Load or TransferLoad List
Name” in the Refrigeration:System
object).
A unique user-assigned name for an instance of a
refrigeration transfer load list. Any reference to this list
by another object will use this name. In particular, the
primary refrigeration system absorbing the heat from all the
loads listed here will use this name to reference those
loads.
Field:
Cascade Condenser Name or Secondary System Name[LINK]
Identifies a cascade condenser or secondary loop that is
cooled, along with the other transfer loads listed here, by a
single system. The name will be validated against the Refrigeration:SecondarySystem
and Refrigeration:Condenser:Cascade
names in the input file (the name will also be compared
against all the other condenser names, but an error will be
issued if it refers to any type of condenser other than a
cascade condenser).
The list is extensible; ten fields are provided in the
IDD.
The following is an example input for a transfer load
list.
Refrigeration:TransferLoadList,
MedTempTransferLoads , !- Name
CascadeCondFrozen, !- Cascade Condenser Name or Secondary System Name
SecondLoopDairy; !- Cascade Condenser Name or Secondary System Name
Refrigeration:SecondarySystem[LINK]
A refrigeration secondary system works in conjunction with
refrigerated cases and walkins (Ref. Refrigeration:SecondarySystem,
Refrigeration:CaseAndWalkInList,
Refrigeration:Case,
and Refrigeration:WalkIn) to simulate the performance of a
secondary loop supermarket refrigeration system. Heat from the
refrigeration loads served by the secondary loop is absorbed
by a primary refrigeration system (ref: Refrigeration:System).
The SecondarySystem object simulates a heat exchanger that is
an evaporator, or refrigeration load, on the primary
refrigeration system.
The inputs for the refrigeration secondary system object
include a name, which is also referenced to identify the load
placed upon the primary refrigeration system. The inputs that
describe the loads placed upon the secondary loop include the
name of a single refrigerated case, the name of a single
walk-in cooler, or a list of cases and walkin coolers. The
circulating fluid type specifies whether or not the secondary
fluid remains in the liquid state throughout the loop (e.g., a
glycol or brine solution) or undergoes a partial phase change
while serving the refrigeration loads (e.g., a CO\(_{2}\) liquid overfeed system).
The circulating fluid name must also be specified and must
correspond to a name used to provide the fluid properties.
If the secondary fluid remains a liquid, the heat exchanger
between the primary and secondary systems functions as an
evaporator on the primary side and chills the circulating
fluid on the secondary side. Inputs that describe the
evaporator performance at rated conditions are used to
calculate the heat exchanger effectiveness. These values
include the rated evaporator capacity (which can be specified
in terms of energy or fluid flow rate), the rated evaporating
temperature, the rated approach temperature difference, and
the rated range temperature difference.
If the secondary fluid undergoes a partial phase change,
the heat exchanger between the primary and secondary systems
functions as an evaporator on the primary side and as a
condenser on the secondary side. The evaporator capacity,
evaporating temperature, and approach temperature difference,
all at full-load design conditions, are input.
The balance of the secondary system object describes the
pumping system. The pumping options include a single constant
speed pump, multiple constant speed pumps, or a variable
frequency-drive pump. The user can also keep track of
distribution piping and receiver shell heat gains.
A unique user-assigned name for an instance of a
refrigeration secondary system. Any reference to this
refrigeration secondary system by another object will use this
name. In particular, the primary refrigeration system
absorbing the heat from this system will use this name to
define that load.
Field:
Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, or walkin, or a particular list
of refrigerated cases and walkins, that are cooled by this
refrigeration secondary system. The name will be validated
against the case, walkin, and CaseAndWalkInList names (ref. Refrigeration:Case,
Refrigeration:WalkIn
and Refrigeration:CaseAndWalkInList) in the input file.
Field: Circulating Fluid
Type[LINK]
Specifies whether the fluid is always liquid (e.g., glycol
solution), or undergoes a partial phase change (e.g., CO\(_{2}\) liquid overfeed system).
The options are “FluidAlwaysLiquid” and
“FluidPhaseChange”.
Field: Circulating Fluid
Name[LINK]
The name of the secondary circulating fluid.
For “FluidAlwaysLiquid”, this name must correspond to
either an ethylene or propylene glycol (ref:
FluidProperties:GlycolConcentration) or to a user-defined
glycol (ref: FluidProperties:Name
and FluidProperties: GlycolConcentration) in the input file.
Note that the corresponding property data, including FluidProperties:Concentration,
FluidProperties:Temperatures,
and FluidProperties:GlycolConcentration
must also be included in the input file and are provided in
GlycolPropertiesRefData.idf for typical ethylene and propylene
glycols.
For “FluidPhaseChange”, the refrigerant used by the
secondary system must be listed in the FluidProperties:Name
object. The corresponding property data must also be supplied
in the input file. Property data for many refrigererants,
including R11, R123, R134A, R12, R22, R404A, R507A, R410A, and
R744, are available in FluidPropertiesRefData.idf.
Field: Evaporator
Capacity[LINK]
For “FluidAlwaysLiquid”, this numeric field should be the
rated heat evaporator capacity (W). Be sure the rating
corresponds to the correct refrigerant and secondary
circulating fluid. If this variable is specified and the rated
evaporator flow rate for secondary fluid is not, then the flow
rate will be calculated. At least one of these two input
variables is required.
For “FluidPhaseChange”, this numeric field should be the
evaporator capacity (W) at full-load design conditions. If
this input is left blank, the capacity will be set to the sum
of the capacities of the cases and walk-ins served by the
secondary loop plus the pump motor load at full-load design
conditions.
Field:
Evaporator Flow Rate for Secondary Fluid[LINK]
For “FluidAlwaysLiquid” systems, this is the rated
evaporator secondary fluid flow rate in m\(^{3}\)/s. If this variable is
specified and the rated evaporator capacity in watts is not,
then the rated capacity will be calculated. At least one of
these two input variables is required.
For “FluidPhaseChange”, this field is not used (see “Phase
Cange Circulating Rate”).
Field:Evaporator
Evaporating Temperature[LINK]
This numeric field provides the evaporating temperature (C)
corresponding to the evaporator capacity. This is the
evaporating temperature on the primary side of the heat
exchanger used to chill or condense the secondary loop
circulating fluid. It is NOT the temperature in any cases or
walkins served by the secondary loop.
Field:
Evaporator Approach Temperature Difference[LINK]
For “FluidAlwaysLiquid”, this numeric field is the rated
temperature difference (DeltaC) between the circulating
secondary fluid leaving the heat exchanger and the heat
exchanger’s evaporating temperature.
For “FluidPhaseChange”, this is the temperature difference
(DeltaC) between the primary refrigerant evaporating and
secondary refrigerant condensing temperatures at full-load
design conditions.
Field:
Evaporator Range Temperature Difference[LINK]
For “FluidAlwaysLiquid”, this numeric field is the rated
temperature difference (DeltaC) between the circulating
secondary fluid entering and leaving the heat exchanger. This
value is not used for “FluidPhaseChange”.
Field: Number of Pumps
in Loop[LINK]
This numeric field provides the integer number of pumps
used to circulate the secondary heat transfer fluid. The
default value is 1. Unless a variable speed pump is specified,
pump energy will be calculated in linear steps to achieve the
necessary flow rate.
Field: Total Pump Flow
Rate[LINK]
This is the secondary fluid circulating flow rate in m\(^{3}\)/s at full-load design
conditions. For “FluidAlwaysLiquid”, if no value is input,
the Evaporator Flow Rate for Secondary Fluid will be used. For
“FluidPhaseChange”, if no value is input, the flow rate will
be calculated using the Evaporator Capacity and the
PhaseChange Circulating Rate.
Field: Total Pump Power[LINK]
This numeric field should be the pump power (W) at
full-load design conditions. Be sure the rating corresponds
to the correct secondary circulating fluid at the design fluid
temperature. EITHER the Total Pump Power OR the Total Pump
Head is required.
Field: Total Pump Head[LINK]
This numeric field should be the design pressure drop, or
head, across the secondary loop (Pa) at full load design
conditions. Be sure the rating corresponds to the correct
secondary circulating fluid at the design fluid temperature.
EITHER the Total Pump Power OR the Total Head is required.
Field: PhaseChange
Circulating Rate[LINK]
This field is not used for “FluidAlwaysLiquid”.
For “FluidPhaseChange”, the Circulating Rate is defined as
the total mass flow at the pump divided by the mass flow rate
of vapor returning to the separator. Values between 2.1 and 3
are common for CO\(_{2}\)
systems and the default is 2.5. If Total Pump Flow Rate is
also defined, the PhaseChange Circulating Rate will only be
used to check whether the two values are consistent.
Field: Pump Drive Type[LINK]
Specifies whether the pump(s) is constant speed or variable
speed. The options are “Constant” and “Variable”. The default
is “Constant”.
Field:
Variable Speed Pump Cubic Curve Name[LINK]
The name of a cubic performance curve
(ref: Performance Curves) that parameterizes the variation of
the variable speed pump power (and the associated load on the
secondary refrigeration load) at off-rated conditions. The
curve should be normalized to have the value of 1.0 at
full-load design conditions. The variable speed pump cubic
curve name is used only for the a pump drive type of
“Variable”.
Field: Pump Motor Heat
to Fluid[LINK]
This choice field determines how much of the pump motor
heat will be added to the circulating secondary fluid. This
represents the motor efficiency for a non-hermetic motor. The
default is 0.85. For a semi-hermetic motor, enter 1.0. The
value entered must be between 0.5 and 1.0.
Field: Sum UA
Distribution Piping[LINK]
This optional field is typically used when trying to
compare the impact of pipe heat gains on system performance,
particularly in comparing a DX system to a secondary system.
Enter the value for secondary loop distribution piping heat
gain (in W/C). That is, sum up the product of the pipe
insulation conductance times the outer piping insulation
surface area. Please see the Engineering Reference for
guidance in calculating this value.
Field:
Distribution Piping Zone Name[LINK]
This optional field is used when trying to determine the
impact of pipe heat gains on system performance, particularly
in comparing a DX system to a secondary system. (If the
previous field, Sum UA Distribution Piping, is blank, this
field will not be used.) Enter the name of the zone where the
Distribution piping is located. The distribution piping heat
gains will be calculated based upon the air temperature within
this zone and will count as a cooling credit for this
zone.
Field: Sum UA
Receiver/Separator Shell[LINK]
This optional field is typically used when trying to
compare the impact of refrigeration component heat gains on
system performance, particularly in comparing a conventional
primary DX system to a secondary system. Enter the value for
receiver/separator heat gain (in W/C). That is, sum up the
product of the tank insulaton conductance times the outer tank
insulation surface area. Please see the Engineering Reference
for guidance in calculating this value.
Field:
Receiver/Separator Zone Name[LINK]
This optional field is used when trying to determine the
impact of refrigeration component heat gains on system
performance, particularly in comparing a conventional primary
DX system to a secondary system. (If the previous field, Sum
UA Receiver/Separator, is blank, this field will not be used.)
Enter the name of the zone where the receiver/separator is
located. The heat gains will be calculated based upon the air
temperature within this zone and will count as a cooling
credit for this zone.
Field:
Evaporator Refrigerant Inventory[LINK]
The secondary loop is chilled by a primary system via a
heat exchanger. This field is the refrigerant inventory on
the cold (primary) side of that heat exchanger, in kg. The
default value is zero.
Field: End-Use
Subcategory[LINK]
This field allows the specification of a user-defined
end-use subcategory (e.g., “Low Temperature Rack”). A new
meter for reporting is created for each unique subcategory
(Ref: Output:Meter
objects). Any text may be used here to further subcategorize
the end-uses in the ABUPS End Uses by Subcategory table and in
the LEED Summary EAp2-4/5 Performance Rating Method Compliance
table. If this field is left blank, the equipment will be
assigned to the “General” end-use subcategory.
The following is an example input for a brine-type
(“FluidAlwaysLiquid”)refrigeration secondary system.
Refrigeration:SecondarySystem,
SecondaryMedLoop, !- Name
MedTempCaseList, !- Refrigerated Case or Walkin or CaseAndWalkInList Name
FluidAlwaysLiquid, !- Circulating Fluid Type
ProGly30Percent, !- Circulating Fluid Name
3.5E4, !- Evaporator Capacity {W}
0.0021, !- Evaporator Flow Rate for Secondary Fluid {M3/s}
-12.6, !- Evaporator Evaporating Temperature {C}
2.7, !- Evaporator Approach Temperature Difference {DeltaC}
4., !- Evaporator Range Temperature Difference {DeltaC}
3, !- Number of Pumps in Loop
.0023, !- Total Pump Flow Rate {M3/s}
, !- Total Pump Power {W}
2.09E5, !- Total Pump Head {Pa}
, !- PhaseChange Circulating Rate
, !- Pump Drive Type
, !- Variable Speed Pump Cubic Curve Name
1.0, !- Pump Motor Heat to Fluid
21., !- Sum UA Distribution Piping {W/C}
SalesFloor, !- Distribution Piping Zone Name
, !- Sum UA Receiver/Separator Shell
, !- Receiver/Separator Zone Name
, !- Evaporator Refrigerant Inventory {kg}
; !- End-Use Subcategory
The following is an example input for a
liquid-overfeed-type (“FluidPhaseChange”) refrigeration
secondary system.
Refrigeration:SecondarySystem,
SecondaryLowLoop, !- Name
LowTempCaseList, !- Refrigerated Case or Walkin or CaseAndWalkInList Name
FluidPhaseChange, !- Circulating Fluid Type
R744, !- Circulating Fluid Name
, !- Evaporator Capacity {W}
, !- Evaporator Flow Rate for Secondary Fluid {M3/s}
-39.2, !- Evaporator Evaporating Temperature {C}
2., !- Evaporator Approach Temperature Difference {DeltaC}
, !- Evaporator Range Temperature Difference {DeltaC}
3, !- Number of Pumps in Loop
, !- Total Pump Flow Rate {M3/s}
, !- Total Pump Power {W}
2.09E5, !- Total Pump Head {Pa}
2.5, !- PhaseChange Circulating Rate
Variable, !- Pump Drive Type
SecondaryVarSpeedPump, !- Variable Speed Pump Cubic Curve Name
1.0, !- Pump Motor Heat to Fluid
10.4, !- Sum UA Distribution Piping {W/C}
SalesFloor, !- Distribution Piping Zone Name
1.4, !- Sum UA Receiver/Separator Shell
BackRoom, !- Receiver/Separator Zone Name
, !- Evaporator Refrigerant Inventory {kg}
; !- End-Use Subcategory
FOR SECONDARY SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average,Refrigeration Secondary Loop Pump Electric
Power [W]
Zone,Sum,Refrigeration Secondary Loop Pump Electric
Energy [J]
Zone,Average,Refrigeration Secondary Loop Load Heat
Transfer Rate [W]
Zone,Sum,Refrigeration Secondary Loop Load Heat
Transfer Energy [J]
Zone,Average,Refrigeration Secondary Loop Total Heat
Transfer Rate [W]
Zone,Sum,Refrigeration Secondary Loop Total Heat
Transfer Energy [J]
Zone,Average,Refrigeration Secondary Loop Estimated
Refrigerant Inventory Mass[kg] Zone,Average,Refrigeration
Secondary Loop Volume Flow Rate [m3/s]
Zone,Average,Refrigeration Secondary Loop Pipe Heat
Gain Rate [W]
Zone,Average,Refrigeration Secondary Loop Pipe Heat
Gain Energy [J]
Zone,Average,Refrigeration Secondary Loop Receiver Heat
Gain Rate [W]
Zone,Average,Refrigeration Secondary Loop Receiver Heat
Gain Energy [J]
FOR SECONDARY SYSTEMS SERVING AIR CHILLERS:
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Pump Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Pump
Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Load Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Load
Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Total Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Total
Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Estimated Refrigerant Inventory Mass[kg]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Volume Flow Rate [m3/s]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Pipe Heat Gain Rate [W]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Pipe Heat Gain Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Receiver Heat Gain Rate [W]
HVAC,Average,Refrigeration Air Chiller Secondary Loop
Receiver Heat Gain Energy [J]
FOR
SECONDARY SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration
Secondary Loop Pump Electric Power [W][LINK]
This output is the total electric power input to the
pump(s) in Watts.
Refrigeration
Secondary Loop Pump Electric Energy [J][LINK]
This is the electricity consumption of the system’s pump(s)
in Joules for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Secondary Loop Load Heat Transfer Rate [W][LINK]
This is the amount of refrigeration provided to the cases
and walkins served by the secondary loop in W.
Refrigeration
Secondary Loop Load Heat Transfer Energy [J][LINK]
This is the amount of refrigeration provided to the cases
and walkins served by the secondary loop in Joules for the
timestep being reported.
Refrigeration
Secondary Loop Total Heat Transfer Rate [W][LINK]
This is the total amount of refrigeration load placed upon
the primary refrigeration system (including loads due to the
cases and walkins plus the loads from the secondary loop pumps
and any energy absorbed by the loop via pipe heat gains) in
W.
Refrigeration
Secondary Loop Total Heat Transfer Energy [J][LINK]
This is the total amount of energy placed upon the primary
refrigeration system by the secondary loop in Joules for the
timestep being reported.
Refrigeration
Secondary Loop Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for
the cases and walkins and the refrigerant circulating through
the loop.
Refrigeration
Secondary Loop Volume Flow Rate [m3/]s[LINK]
This output is the calculated volume flow through the pumps
for this secondary loop.
Refrigeration
Secondary Loop Pipe Heat Gain Rate [W][LINK]
This output is the total heat transferred to the pipes in
Watts.
Refrigeration
Secondary Loop Pipe Heat Gain Energy [J][LINK]
This is the total heat transferred to the pipes in Joules
for the timestep being reported.
Refrigeration
Secondary Loop Receiver Heat Gain Rate [W][LINK]
This output is the total heat transferred to the receiver
in Watts.
Refrigeration
Secondary Loop Receiver Heat Gain Energy [J][LINK]
This is the total heat transferred to the receiver in
Joules for the timestep being reported.
FOR
SECONDARY SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Air Chiller Secondary Loop Pump Electric Power [W][LINK]
This output is the total electric power input to the
pump(s) in Watts.
Refrigeration
Air Chiller Secondary Loop Pump Electric Energy [J][LINK]
This is the electricity consumption of the system’s pump(s)
in Joules for the timestep being reported. This output is also
added to a meter with Resource Type = Electricity, End Use Key
= Refrigeration, Group Key = Plant (Ref. Output:Meter
objects).
Refrigeration
Air Chiller Secondary Loop Load Heat Transfer Rate [W][LINK]
This is the amount of refrigeration provided to the air
chillers served by the secondary loop in W.
Refrigeration
Air Chiller Secondary Loop Load Heat Transfer Energy [J][LINK]
This is the amount of refrigeration provided to the air
chillers served by the secondary loop in Joules for the
timestep being reported.
Refrigeration
Air Chiller Secondary Loop Total Heat Transfer Rate [W][LINK]
This is the total amount of refrigeration load placed upon
the primary refrigeration system (including loads due to the
air chillers plus the loads from the secondary loop pumps and
any energy absorbed by the loop via pipe heat gains) in W.
Refrigeration
Air Chiller Secondary Loop Total Heat Transfer Energy [J][LINK]
This is the total amount of energy placed upon the primary
refrigeration system by the secondary loop in Joules for the
timestep being reported.
Refrigeration
Air Chiller Secondary Loop Estimated Refrigerant Inventory
Mass [kg][LINK]
This output is the sum of the input inventory values for
the air chillers and the refrigerant circulating through the
loop.
Refrigeration
Air Chiller Secondary Loop Volume Flow Rate [m3/]s[LINK]
This output is the calculated volume flow of coolant
through the pumps for this secondary loop.
Refrigeration
Air Chiller Secondary Loop Pipe Heat Gain Rate [W][LINK]
This output is the total heat transferred to the pipes in
Watts.
Refrigeration
Air Chiller Secondary Loop Pipe Heat Gain Energy [J][LINK]
This is the total heat transferred to the pipes in Joules
for the timestep being reported.
Refrigeration
Air Chiller Secondary Loop Receiver Heat Gain Rate [W][LINK]
This output is the total heat transferred to the receiver
in Watts.
Refrigeration
Air Chiller Secondary Loop Receiver Heat Gain Energy [J][LINK]
This is the total heat transferred to the receiver in
Joules for the timestep being reported.
Additional
Refrigeration Outputs Available for Each Zone[LINK]
Multiple refrigeration cases and walkins may be located
within a single zone. Each zone may also exchange heat with
refrigeration system suction piping, secondary loop
distribution piping, and secondary loop receivers. Output
variables have been prepared to sum up the total heat exchange
due to all refrigeration objects within a single zone. The
output variables that start with “Zone
Refrigeration” do not account for refrigeration provided by
refrigeration chiller sets or any piping from systems serving
air chillers. The output variables that start with “Zone
Chillers” account for all the refrigeration system elements
serving air chillers.
Additional
Refrigeration Outputs for Each Zone[LINK]
FOR THE SUM OF ALL COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:
Zone,Average, Refrigeration Zone
Case and Walk In Sensible Cooling Rate [W]
Zone,Sum, Refrigeration Zone
Case and Walk In Sensible Cooling Energy [J]
Zone,Average, Refrigeration Zone
Case and Walk In Heating Rate [W]
Zone,Sum, Refrigeration Zone
Case and Walk In Heating Energy [J]
Zone,Average, Refrigeration Zone
Case and Walk In Total Sensible Cooling Rate [W]
Zone,Sum, Refrigeration Zone
Case and Walk In Total Sensible Cooling Energy [J]
Zone,Average, Refrigeration Zone
Case and Walk In Total Latent Cooling Rate [W]
Zone,Sum, Refrigeration Zone
Case and Walk In Total Latent Cooling Energy [J]
Zone,Sum, Refrigeration Zone
Case and Walk In Total Cooling Energy [J]
Zone,Average,Refrigeration Zone
Case and Walk In Total Cooling Rate [W]
Zone,Average, Refrigeration Zone
Case and Walk In Total Heat Transfer Rate [W]
Zone,Sum, Refrigeration Zone
Case and Walk In Total Heat Transfer Energy [J]
FOR THE SUM OF ALL COOLING SYSTEMS SERVING CHILLERS:
HVAC,Average, Refrigeration Zone
Air Chiller Sensible Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Zone
Air Chiller Sensible Heat Transfer Energy [J]
HVAC,Average, Refrigeration Zone
Air Chiller Latent Cooling Rate [W]
HVAC,Sum, Refrigeration Zone
Air Chiller Latent Cooling Energy [J]
HVAC,Average, Refrigeration Zone
Air Chiller Total Cooling Rate [W]
HVAC,Sum, Refrigeration Zone
Air Chiller Total Cooling Energy [J]
FOR
THE SUM OF ALL COOLING SYSTEMS SERVING CASES AND/OR
WALKINS:[LINK]
Refrigeration
Zone Case and Walk In Total Sensible Cooling Rate [W][LINK]
This output is the total sensible heat transfer between all
refrigeration objects located in the zone in Watts. A negative
value will be reported when the refrigeration objects cool
(that is, remove heat from) the zone.
Refrigeration Zone
Case and Walk In Total Sensible Cooling Energy
[J]
This is the total sensible heat transfer between all
refrigeration objects located in the zone in Joules for for
the timestep being reported. A negative value will be reported
when the refrigeration objects cool (that is, remove heat
from) the zone.
Refrigeration
Zone Case and Walk In Total Latent Cooling Rate [W][LINK]
This output is the total latent heat transfer between all
refrigeration objects located in the zone in Watts. A negative
value will be reported when the refrigeration equipment
provides dehumidification (thereby reducing the zone latent
load).
Refrigeration Zone
Case and Walk In Total Latent Cooling Energy
[J]
This is the total latent heat transfer between all
refrigeration objects located in the zone in Joules for for
the timestep being reported. A negative value will be reported
when the refrigeration equipment provides dehumidification
(thereby reducing the zone latent load).
Refrigeration
Zone Case and Walk In Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer (sensible plus
latent) between all refrigeration objects located in the zone
in Watts. A negative value will be reported when the
refrigeration objects cool (that is, remove heat from) the
zone.
Refrigeration Zone
Case and Walk In Total Heat Transfer Energy
[J]
This is the total heat transfer (sensible plus latent)
between all refrigeration objects located in the zone in
Joules for for the timestep being reported. A negative value
will be reported when the refrigeration objects cool (that is,
remove heat from) the zone.
Refrigeration
Zone Case and Walk In Sensible Cooling Rate [W][LINK]
This output is the total sensible cooling from all
refrigeration objects located in the zone in Watts.
Refrigeration Zone
Case and Walk In Sensible Cooling Energy [J]
This is the total sensible cooling from all refrigeration
objects located in the zone in Joules for for the timestep
being reported.
Refrigeration
Zone Case and Walk In Heating Rate [W][LINK]
This output is the total heating from all refrigeration
objects located in the zone in Watts.
Refrigeration Zone
Case and Walk In Heating Energy [J]
This is the total heating from all refrigeration objects
located in the zone in Joules for for the timestep being
reported.
Refrigeration
Zone Case and Walk In Total Cooling Rate [W][LINK]
This output is the total cooling (sensible plus latent)
from all refrigeration objects located in the zone in
Watts.
Refrigeration Zone
Case and Walk In Total Cooling Energy [J]
This is the total cooling (sensible plus latent) from all
refrigeration objects located in the zone in Joules for for
the timestep being reported.
FOR
THE SUM OF ALL COOLING SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration
Zone Air Chiller Heating Rate [W][LINK]
This output is the total heating from all air chillers
located in the zone in Watts.
Refrigeration Zone
Air Chiller Heating Energy [J]
This is the total heating from all air chillers located in
the zone in Joules for for the timestep being reported.
Refrigeration
Zone Air Chiller Sensible Cooling Rate [W][LINK]
This output is the total sensible cooling from all air
chillers located in the zone in Watts.
Refrigeration Zone
Air Chiller Sensible Cooling Energy [J]
This is the total sensible cooling from all air chillers
located in the zone in Joules for for the timestep being
reported.
Refrigeration
Zone Air Chiller Sensible Heat Transfer Rate [W][LINK]
This output is the total sensible heat transfer from all
air chillers located in the zone in Watts. A negative value
will be reported when the refrigeration objects cool (that is,
remove heat from) the zone.
Refrigeration
Zone Air Chiller Sensible Heat Transfer Energy [J][LINK]
This is the total sensible heat transfer from all air
chillers located in the zone in Joules for for the timestep
being reported. A negative value will be reported when the
refrigeration objects cool (that is, remove heat from) the
zone.
Refrigeration
Zone Air Chiller Latent Cooling Rate [W][LINK]
This output is the total latent cooling from all air
chillers located in the zone in Watts.
Refrigeration Zone
Air Chiller Latent Cooling Energy [J]
This is the total latent cooling from all air chillers
located in the zone in Joules for for the timestep being
reported.
Refrigeration
Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This is the total amount of water removed by all air
chillers located in the zone in kg/s for for the timestep
being reported.
Refrigeration
Zone Air Chiller Total Cooling Rate [W][LINK]
This output is the total cooling (sensible plus latent)
from all air chillers located in the zone in Watts.
Refrigeration Zone
Air Chiller Total Cooling Energy [J]
This is the total cooling (sensible plus latent) from all
air chillers located in the zone in Joules for for the
timestep being reported.
Refrigeration:AirChiller[LINK]
The Refrigeration:AirChiller
object works in conjunction with a refrigeration chiller set,
compressor rack, a refrigeration system, or a refrigeration
secondary system object (Ref.
ZoneHvac:RefrigerationChillerSet, and a Refrigeration:CompressorRack,
Refrigeration:System,
or Refrigeration:SecondarySystem) to simulate the performance
of an air chiller, similar to one found in a refrigerated
warehouse. The air chiller model uses information at rated
conditions along with the zone conditions to determine
performance. Energy use for fans and heaters is modeled based
on inputs for nominal power, schedules, and control type. The
refrigeration chiller model accounts for the sensible and
latent heat exchange with the surrounding environment.
The refrigeration chiller cooler object inputs include a
name, an availability schedule name, the rated cooling
capacity, the rated operating temperature, the rated cooling
source temperature, the rated total heating power and heating
power schedule, the rated fan power and schedules, defrost
type, defrost control type, defrost schedule name, drip-down
schedule name, defrost power, the portion of the defrost
energy used to melt ice (only for temperature termination
control type), and refrigerant inventory.
Chiller coils are rated under multiple conventions. Each
rating is typically based upon a selected fin material and
refrigerant cycle, with correction factors for other materials
or refrigerants. Fields are provided here for those correction
factors. The performance of all chiller coils depends upon the
inlet air temperature, relative humidity, and flow rate.
Multiple methods of expressing this relationship are provided
here to accommodate the way information is provided by
different manufacturers.
A unique user-assigned name for an instance of a
refrigeration chiller. Any reference to this refrigeration
chiller by another object will use this name.
Field:
Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigeration chiller can operate during a given
time period. A schedule value greater than 0 (maximum schedule
value of 1.0 is typically used) indicates that the
refrigeration chiller will operate during a given time period.
A value equal to 0 denotes that the case does not operate
(everything is OFF: refrigeration, fans, lights, anti-sweat,
etc.). Typically the refrigeration chiller will operate
throughout the day (i.e., the schedule will contain 1 for all
time periods); however, refrigeration chillers require
maintenance and/or cleaning and this can be modeled
accordingly using this schedule if desired. If this field is
left blank, the default schedule has a value of 1 for all time
periods.
Field: Capacity Rating
Type[LINK]
The type of capacity rating used for this refrigeration
chiller. Valid choices are UnitLoadFactorSensibleOnly,
CapacityTotalSpecificConditions, EuropeanSC1Standard,
EuropeanSC1NominalWet, EuropeanSC2Standard,
EuropeanSC2NominalWet, EuropeanSC3Standard,
EuropeanSC3NominalWet, EuropeanSC4Standard,
EuropeanSC4NominalWet, EuropeanSC5Standard, and
EuropeanSC5NominalWet. In each case, select the rating option
that corresponds to the expected service conditions. For
example, U.S. manufacturers quote a separate Unit Load Factor
for wet or frosted coils. If the evaporating temperature is
less than 0C, input the frosted coil value. Within the
European convention, select SC1, 2, 3, 4, or 5 depending upon
the expected evaporating temperature. This field is required
and there is no default value. Refer to the Engineering
Reference for further information on these rating types. NOTE:
If the CapacityTotalSpecificConditions rating type is
specified, the input file must include the manufacturer’s coil
capacity correction curve in tabular form using the Table:MultiVariableLookup
object. An example of this may be found in the
RefrigeratedWarehouse.idf example file.
NOTE –
ONLY ONE OF THE FOLLOWING TWO FIELDS IS USED[LINK]
Field: Rated Unit Load
Factor[LINK]
The sensible cooling capacity in watts (W/C) at rated
conditions. The value entered for this field must be greater
than zero, with no default value. This value is only used if
the Capacity Rating Type is UnitLoadFactorSensibleOnly. The
value given must be based upon the difference between the
chiller inlet and outlet air temperatures, not on the
difference between the zone mean temperature and the outlet
air temperature.
Field: Rated Capacity[LINK]
The cooling capacity in watts (W) at rated conditions. The
value entered for this field must be greater than zero, with
no default value. This field is only used if the Capacity
Rating Type is CapacityTotalSpecificConditions,
EuropeanSC1Standard, EuropeanSC1NominalWet,
EuropeanSC2Standard, EuropeanSC2NominalWet,
EuropeanSC3Standard, EuropeanSC3NominalWet,
EuropeanSC4Standard, EuropeanSC4NominalWet,
EuropeanSC5Standard, or EuropeanSC5NominalWet. For
CapacityTotalSpecificConditions, this capacity includes both
sensible and latent at the conditions given in the next two
fields. Note that the European Standard ratings are sensible
only and the European Nominal ratings include latent capacity
as well. The value given here must correspond to the capacity
rating type given previously.
Field: Rated Relative
Humidity[LINK]
This field is ONLY used if the Capacity Rating Type is
CapacityTotalSpecificConditions and represents the relative
humidity at rated conditions, expressed as a percent. The
default is 85.
Field: Rated
Cooling Source Temperature[LINK]
For a DX evaporator coil, enter the saturated evaporating
temperature in ˚C. For a fluid coil, enter the fluid coil
entrance temperature in ˚C. There is no default value. This
number is used, with temperatures for other refrigeration
loads on any one system, to set that system’s minimum suction
pressure or minimum circulating fluid temperature.
Field: Rated
Temperature Difference DT1[LINK]
The rated difference between the air entering the
refrigeration chiller and the cooling source temperature in
˚C. The entered value for this field must be less than 20˚C.
There is no default value.
Field:
Maximum Difference Between Inlet Air and Evaporating
Temperature[LINK]
The maximum difference between the air entering the
refrigeration chiller and the cooling source temperature in °C
used to limit capacity during pull-down. The default is 1.3
times the Rated Temperature Difference DT1.
Field: Coil
Material Correction Factor[LINK]
This field is used to enter the manufacturer’s correction
factor for coil material corresponding to the rating
previously input. The default is 1.0 (dimensionless).
Field:
Refrigerant Correction Factor[LINK]
This field is used to enter the manufacturer’s correction
factor for refrigerant corresponding to the rating previously
input. The default is 1.0 (dimensionless). (Note, the
refrigerant itself is specified for the detailed system or
secondary loop providing the refrigerant to this coil.)
Field: Capacity
Correction Curve Type[LINK]
The type of capacity correction curve used to account for
the impact of the room air conditions on the chiller capacity.
Valid choices are LinearSHR60, QuadraticSHR, European, and
TabularRHxDT1xTRoom. This field will default to LinearSHR60,
unless the CapacityTotalSpecificConditions rating type is
specified, in which case, the TabularRHxDT1xTRoom correction
curve type must be used. Refer to the Engineering Reference
for further information on these curve types. The resulting
correction factor for LinearSHR60, QuadraticSHR, and European
types will be applied to the sensible capacity and must have
output values between 1 and 2. The resulting correction factor
for TabularRHxDT1xTRoom will be applied to the
CapacityTotalSpecificConditions capacity and can have values
between 0.2 and 2. If TabularRHxDT1xTRoom is used, the curve
type within the table must be specified as “Quadratic”.
Field: Capacity
Correction Curve Name[LINK]
The name of the curve object defining the total
refrigerating capacity. For correction curve types LinearSHR60
and QuadraticSHR, the independent variable is the Sensible
Heat Ratio and the output values are between 1.0 and 2.0. For
correction curve type European, EnergyPlus contains built-in
capacity correction curves and specification of a capacity
correction curve name is not required. For correction curve
type TabularRHxDT1xTRoom, enter the name of a Table:MultiVariableLookup
object that gives the total capacity (in W) as a function of
RH, DT1, and Room Temperature; IN THAT ORDER. An example of a
TabularRHxDT1xTRoom correction curve using the
Table:MultiVariableLoopkup object may be found in the
RefrigeratedWarehouse.idf example file.
Field: SHR60 Correction
Factor[LINK]
This field is only used when the capacity correction curve
type is LinearSHR60. It should correspond to the capacity
factor, that is, the total capacity divided by the sensible
capacity corresponding to a Sensible Heat Ratio of 0.6. The
default is 1.48 (dimensionless).
Field: Rated Total
Heating Power[LINK]
The total heating power in watts including drip-pan and any
other heaters (W). This value is required and has no default
value.
Field: Heating
Power Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the
fraction of heater power that operates during a given time
period. A schedule value of zero denotes that all heaters are
off. A schedule value greater than 0 indicates that some
portion of the total heater power will operate during that
time period (maximum schedule value of 1.0 means all heaters
are fully on). If this field is left blank, the default
schedule has a value of 1 for all time periods.
Field: Fan Speed
Control Type[LINK]
The type of fan speed control used by the cooling coil’s
fan(s). Valid choices are Fixed,
FixedLinear, VariableSpeed,
and TwoSpeed. If the field is blank,
Fixed will be used. See the Engineering
Reference for a discussion of this option’s effect on fan
energy consumption.
Field: Rated Fan Power[LINK]
The cooling coil fan power in watts (W). This value has a
default value of 375W. This fan is assumed to run continuously
except during electric, hot brine, or hot gas defrost
periods.
Field: Rated Air Flow[LINK]
The cooling coil fan rated air flow in cubic meters per
second (m\(^{3}\)/s). This
value has no default value and must be input.
Field: Minimum Fan
Air Flow Ratio[LINK]
The minimum fraction of the rated air flow for part-load
fan operation, must be between 0. and 1.0. The default value
is 0.2.
Field: Defrost Type[LINK]
The type of defrost used for this refrigeration chiller.
Valid choices are None, Off-Cycle, HotFluid, and Electric. The
default defrost type is Electric if the field is blank.
HotFluid includes both hot gas and hot brine defrost systems.
Refer to the Engineering Reference for further information on
how the different defrost types are modeled.
Field: Defrost Control
Type[LINK]
The type of defrost control used for this refrigeration
chiller. Valid choices are TimeSchedule and
TemperatureTermination. The default is TimeSchedule if the
field is blank. Refer to the Engineering Reference for further
information on how the different defrost controls are
modeled.
Field: Defrost Schedule
Name[LINK]
The name of the schedule (ref: Schedule) that denotes when
the refrigeration chiller requires defrosting. A schedule
value of 1.0 indicates that defrost can be on during a given
time period. A value equal to 0 denotes that the defrost is
off. Defrost schedules normally repeat the duration and number
of defrost cycles for each day of the year. The refrigeration
chiller manufacturer typically provides this information with
the product literature. If TemperatureTermination control type
is used, the defrost schedule is used for the defrost cycle
start time and the defrost cycle end time is not allowed to
extend beyond the scheduled off time. The use of Compact
Schedules (ref. Schedules) are ideal for this purpose.
Field:
Defrost Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes
whether the refrigeration chiller requires additional time for
draining condensate after the defrost period. A schedule value
of 1.0 indicates that the defrost drip-down period is on
during a given time period. A value equal to 0 denotes that
the defrost drip-down period is over. The refrigeration
chiller manufacturer typically provides this information with
the product literature.
Each defrost drip-down period specified in this schedule
should start at the same time as the corresponding defrost
period specified in the schedule for Defrost Schedule, and the
drip-down schedule defrost period should always be longer than
or equal to the length of the defrost schedule time period.
For example, if the defrost schedule contains a defrost period
from 7:00 to 7:15, you would specify a case defrost drip-down
period from 7:00 to 7:20 if you wanted to model a 5 minute
condensate drip-down period after the regular defrost period.
If no drip-down schedule is entered, then the defrost schedule
(specified for the previous input field) will be used. The use
of Compact Schedules (ref. Schedules) are ideal for this
purpose.
Field: Defrost Power[LINK]
The defrost power in watts. This input is required for
hot-fluid (hot gas or hot brine), or electric defrost types.
Refrigeration chiller manufacturers do not typically provide
information on the heat input for hot gas and hot brine
defrost. Information provided for electric defrost power can
be substituted here for refrigeration chillers using hot-gas
or hot-brine defrost if other information is not available.
Only electric Defrost Types consume electricity during the
defrost period. The entered value for this field must be
greater than or equal to zero.
Field:
Temperature Termination Defrost Fraction to Ice[LINK]
When cooling coils go through a defrost cycle, only a
portion of the defrost energy is actually used to melt the
ice. The rest of the defrost energy goes to increasing the
temperature of the coils themselves and to the refrigeration
chiller environment. The Temperature Termination defrost
control type calculates the end of the defrost cycle that
corresponds to melting all the ice. Therefore, the user must
input this fractional value. The default value is 0.7 for
electric defrost and 0.3 for hot fluid defrost. Refer to the
Engineering Reference for further information on how the
defrost energy control types are modeled.
Field: Vertical Location[LINK]
The vertical location for this refrigeration chiller. Valid
choices are Floor, Middle, and Ceiling. The default is Middle
if the field is blank. The vertical location is used to
transform the mixed zone air temperature to the coil inlet air
temperature. Refer to the Engineering Reference for further
information on how the different vertical locations are
modeled.
Field:
Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant
inventory present in the refrigeration chiller during ordinary
operation. The value is used to produce an estimate of the
total refrigerant present in the refrigeration system. The
value is entered in kg.
The following is an example input for a refrigeration air
chiller.
Refrigeration:AirChiller,
Freezer_1AirChiller_1, !- Name
AvailAllYear, !- Availability Schedule Name
UnitLoadFactorSensibleOnly, !- Capacity Rating Type
10900., !- Rated Unit Load Factor {W/deltaC}
, !- Rated Capacity {W}
, !- Rated Relative Humidity
-26., !- Rated Cooling Source Temperature {C}
8., !- Rated Temperature Difference DT1 {DeltaC}
11., !- Maximum Temperature Difference DT1 {DeltaC}
, !- Material Correction Factor
, !- Refrigerant Correction Factor
LinearSHR60, !- Capacity Correction Curve Type
, !- Capacity Correction Curve Name
1.5, !- SHR60 Correction Factor {dimensionless}
200., !- Rated Total Heating Power {W}
AirChillerDripDownSched1, !- Heating Power Schedule Name
, !- Fan Speed Control Type
375., !- Rated Fan Power {W}
12.4, !- Rated Air Flow {m3/s}
, !- Minimum Fan Air Flow Ratio
Electric, !- Defrost Type
TimeSchedule, !- Defrost Control Type
AirChillerDefrostSched1, !- Defrost Schedule Name
AirChillerDripDownSched1, !- Defrost Drip-Down Schedule Name
55066., !- Defrost Power {W}
, !- Temperature Termination Defrost Fraction to Ice
, !- Vertical Location
; !- Average Refrigerant Charge Inventory {kg}
The following is an example input for a refrigeration air
chiller.
Refrigeration:AirChiller,
Freezer_1AirChiller_1, !- Name
AvailAllYear, !- Availability Schedule Name
UnitLoadFactorSensibleOnly, !- Capacity Rating Type
10900., !- Rated Unit Load Factor {W/deltaC}
, !- Rated Capacity {W}
, !- Rated Relative Humidity
-26., !- Rated Cooling Source Temperature {C}
8., !- Rated Temperature Difference DT1 {DeltaC}
11., !- Maximum Temperature Difference DT1 {DeltaC}
, !- Material Correction Factor
, !- Refrigerant Correction Factor
LinearSHR60, !- Capacity Correction Curve Type
, !- Capacity Correction Curve Name
1.5, !- SHR60 Correction Factor {dimensionless}
200., !- Rated Total Heating Power {W}
AirChillerDripDownSched1, !- Heating Power Schedule Name
, !- Fan Speed Control Type
375., !- Rated Fan Power {W}
12.4, !- Rated Air Flow {m3/s}
, !- Minimum Fan Air Flow Ratio
Electric, !- Defrost Type
TimeSchedule, !- Defrost Control Type
AirChillerDefrostSched1, !- Defrost Schedule Name
AirChillerDripDownSched1, !- Defrost Drip-Down Schedule Name
55066., !- Defrost Power {W}
, !- Temperature Termination Defrost Fraction to Ice
, !- Vertical Location
; !- Average Refrigerant Charge Inventory {kg}
HVAC,Average,Refrigeration Zone
Air Chiller Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Sensible Cooling Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Latent Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Latent Cooling Energy [J]
HVAC,Average, Refrigeration Zone
Air Chiller Water Removed Mass Flow Rate [kg/s]
HVAC,Average,Refrigeration Zone
Air Chiller Total Electric Power [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Total Electric Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Fan Electric Power [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Fan Electric Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Heater Electric Power [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Heater Electric Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Sensible Heat Ratio []
HVAC,Average,Refrigeration Zone
Air Chiller Frost Accumulation Mass [kg]
HVAC,Average,Refrigeration Zone
Air Chiller Zone
Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Zone
Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Zone
Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Zone
Sensible Cooling Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Zone
Heating Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Zone
Heating Energy [J]
Report only for Air Chillers using electric
defrost
HVAC,Average,Refrigeration Zone
Air Chiller Defrost Electric Power [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Defrost Electric Energy [J]
Report for each Zone
exchanging energy with the Air Chiller
HVAC,Average,Refrigeration Zone
Air Chiller Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Sensible Cooling Energy [J]
HVAC,Average, Refrigeration Zone
Air Chiller Heating Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Heating Energy [J]
HVAC,Average, Refrigeration Zone
Air Chiller Latent Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Latent Cooling Energy [J
HVAC,Average,Refrigeration Zone
Air Chiller Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone
Air Chiller Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone
Air Chiller Water Removed Mass Flow Rate [kg/s]
Refrigeration
Zone Air Chiller Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate
of the Air Chiller evaporator coil in Watts.
Refrigeration
Zone Air Chiller Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of
the Air Chiller evaporator coil in Joules over the timestep
being reported. This output is also added to a meter with
Resource Type = EnergyTransfer, End Use Key = Refrigeration,
Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Zone Air Chiller Sensible Cooling Rate [W][LINK]
Refrigeration
Zone Air Chiller Sensible Heat Transfer Rate [W][LINK]
This field is the sensible cooling rate of the Air Chiller
evaporator coil in Watts.
Refrigeration
Zone Air Chiller Sensible Cooling Energy [J][LINK]
Refrigeration
Zone Air Chiller Sensible Heat Transfer Energy [J][LINK]
This field is the sensible cooling of the Air Chiller
evaporator coil in Joules over the timestep being
reported.
Refrigeration
Zone Air Chiller Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of
the Air Chiller evaporator coil in Watts.
Refrigeration
Zone Air Chiller Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the
Air Chiller evaporator coil in Joules over the timestep being
reported.
Refrigeration
Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This field is the latent cooling (dehumidification) of the
Air Chiller evaporator coil in kilograms per second over the
timestep being reported.
Refrigeration
Zone Air Chiller Total Electric Power [W][LINK]
This field is the total electricity (fan, heaters, lights,
and electric defrost) used by the Air Chiller in Watts.
Refrigeration
Zone Air Chiller Total Electric Energy [J][LINK]
This field is the electricity (fan, heaters, lights, and
electric defrost)used by the Refrigeration chiller in Joules
over the timestep being reported.
Refrigeration
Zone Air Chiller Fan Electric Power [W][LINK]
This field is the electric power input to the Air Chiller
fan(s) in Watts.
Refrigeration
Zone Air Chiller Fan Electric Energy [J][LINK]
This field is the electricity consumption of the Air
Chiller fan(s) in Joules over the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Zone Air Chiller Heater Electric Power [W][LINK]
This field is the electric power input to the Air Chiller
heaters in Watts.
Refrigeration
Zone Air Chiller Heater Electric Energy [J][LINK]
This field is the total electricity consumption of the Air
Chiller heaters in Joules over the timestep being reported.
This output is also added to a meter with Resource Type =
Electricity, End Use Key = Refrigeration, Group Key = Building
(Ref. Output:Meter
objects).
Refrigeration
Zone Air Chiller Defrost Electric Power [W][LINK]
This field is the electric power input to the Air Chiller
electric defrost heater(s) in Watts. This output is available
if case defrost type is Electric.
Refrigeration
Zone Air Chiller Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the Air
Chiller electric defrost heater(s) in Joules over the timestep
being reported. This output is also added to a meter with
Resource Type = Electricity, End Use Key = Refrigeration,
Group Key = Building
(Ref. Output:Meter
objects). This output is available if case defrost type is
Electric.
Refrigeration
Zone Air Chiller Sensible Heat Ratio[LINK]
This field is the Sensible Cooling Energy Rate divided by
the Total Cooling Energy Rate.
Refrigeration
Zone Air Chiller Frost Accumulation Mass [kg][LINK]
This field is the total amount of frost present on the coil
during the timestep being reported.
Refrigeration
Zone Air Chiller Zone Total Cooling Rate [W][LINK]
This field is the rate of total cooling delivered to the
zone in Watts. A positive value is reported when the zone is
cooled by the air chiller, otherwise a zero is reported.
Refrigeration
Zone Air Chiller Zone Total Cooling Energy [J][LINK]
This field is the amount of total cooling energy delivered
to the zone in Joules. A positive value is reported when the
zone is cooled by the air chiller, otherwise a zero is
reported.
Refrigeration
Zone Air Chiller Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling delivered to the
zone in Watts. A positive value is reported when the zone is
cooled by the air chiller, otherwise a zero is reported.
Refrigeration
Zone Air Chiller Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling energy
delivered to the zone in Joules. A positive value is reported
when the zone is cooled by the air chiller, otherwise a zero
is reported.
Refrigeration
Zone Air Chiller Zone Heating Rate [W][LINK]
This field is the rate of sensible heating delivered to the
zone in Watts. A positive value is reported when the zone is
heated by the air chiller (typically only occurs during
defrost), otherwise a zero is reported.
Refrigeration
Zone Air Chiller Zone Heating Energy [J][LINK]
This field is the amount of sensible heating energy
delivered to the zone in Joules. A positive value is reported
when the zone is heated by the air chiller (typically only
occurs during defrost), otherwise a zero is reported.
The following output variables are available for each
zone served by any Air Chiller. An output variable
identification is created for each zone exchanging energy with
the Air Chiller. For example if the Air Chiller,
“DairyRefrigeration chiller”, were exchanging energy with the
zone, “SalesArea”, the output variable identification would be
“DairyRefrigeration chillerInZoneSalesArea”.
Refrigeration
Zone Air Chiller Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling delivered to the
zone, net of any auxiliary heat input, in Watts..
Refrigeration
Zone Air Chiller Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling energy, net of
any auxiliary heat input, delivered to the zone in Joules.
Refrigeration
Zone Air Chiller Latent Cooling Rate [W][LINK]
This field is the rate of latent cooling (dehumidification)
delivered to the zone in Watts. A negative value will be
reported when the Air Chiller provides dehumidification
(thereby reducing the zone latent load).
Refrigeration
Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This field is the rate of latent cooling (dehumidification)
delivered to the zone in kg/s. A negative value (or zero) will
be reported when the Air Chiller provides dehumidification
(thereby reducing the zone latent load).
Refrigeration
Zone Air Chiller Latent Cooling Energy [J][LINK]
This field is the amount of latent cooling
(dehumidification) energy delivered to the zone in Joules. A
negative value (or zero) will be reported when the Air Chiller
provides dehumidification (thereby reducing the zone latent
load).
Refrigeration
Zone Air Chiller Total Cooling Rate [W][LINK]
This field is the total rate of cooling, sensible plus
latent, delivered to the zone in Watts.
Refrigeration
Zone Air Chiller Total Cooling Energy [J][LINK]
This field is the total amount of cooling, sensible plus
latent, energy delivered to the zone in Joules.
Refrigeration
Zone Air Chiller Heating Rate [W][LINK]
This field is the rate of net heating due to any auxiliary
or defrost heat input delivered to the zone, in Watts.
Refrigeration
Zone Air Chiller Heating Energy [J][LINK]
This field is the amount of net heating energy due to any
auxiliary heat input, delivered to the zone in Joules.
Group – Refrigeration[LINK]
There are two ways to model a supermarket refrigeration system. The first, and simplest, approach models the combination of compressor(s) and condenser as a single refrigeration compressor rack object. (A list is used to enter multiple case or walk-in names.)
For the first approach, the input objects needed are:
One Refrigeration:CompressorRack object
At least one refrigeration load, which may be any combination of:
Refrigeration:Case or
Refrigeration:WalkIn or
Refrigeration:CaseAndWalkInList objects .
The second approach requires more input objects but also allows the user to model more complex systems. This detailed approach must be used whenever loads are transferred from one system to another, such as with secondary loops, cascade condensers, or mechanical subcoolers. Again lists are used to enter multiple load or compressor names.
For the detailed approach, the input objects needed are:
One Refrigeration:System object
At least one refrigeration load object which may include any combination of:
Refrigeration:Case,
Refrigeration:WalkIn,
Refrigeration:CaseAndWalkInList (may include any combination of cases and walk in cooler names, OR, a list of air chiller names)
Refrigeration:SecondarySystem,
Refrigeration:Condenser:Cascade (as a load, cooling a lower-temperature system) objects,
Refrigeration:TransferLoadList (may include cascade condenser loads and/or secondary loop loads)
Refrigeration:AirChiller
At least one Refrigeration:Compressor object (multiple compressors are entered using a Refrigeration:CompressorList),
One condenser object which may be either:
Refrigeration:Condenser:AirCooled,
Refrigeration:Condenser:EvaporativeCooled,
Refrigeration:Condenser:WaterCooled, or
Refrigeration:Condenser:Cascade (rejecting heat from this system)
The object Refrigeration:Subcooler may optionally be included to describe either a liquid suction or mechanical subcooler.
Output variables are also available to describe the total heat exchange between all refrigeration objects and the zones containing these objects. These variables are described at the end of this section after all the refrigeration objects.
Refrigeration:CompressorRack[LINK]
The refrigeration compressor rack object works in conjunction with the refrigeration case and walkin objects (Ref. Refrigeration:Case and Refrigeration:WalkIn) to simulate the performance of a refrigerated case system. This object models the electric consumption of the rack compressors and the condenser fans. Heat removed from the refrigerated cases, walkins, and compressor/condenser fan heat can be rejected either outdoors or to a zone. Compressor rack waste heat can also be reclaimed for use by an optional air- or water-heating coil (Ref. Coil:Heating:Desuperheater and Coil:WaterHeating:Desuperheater).
If heat is rejected outdoors, condenser cooling can either be accomplished by direct air flow, evaporative water cooling, or a by water-cooled condenser with appropriate plant loop piping. With evaporative cooling, water is sprayed through the air stream to effectively lower the air temperature experienced by the condenser coil as a result of water evaporation. The use of a water-cooled condenser requires the definition of a plant loop to supply cooling to the condenser. Waste heat can be reclaimed and stored using a water storage device.
The inputs for the compressor rack object include a name, the heat rejection location, the compressor rack coefficient of performance (COP) at design conditions, the design condenser fan power, and the type of condenser cooling. The model requires two curve objects to describe performance at off-design conditions. If the condenser is water-cooled, the inlet and outlet node names as well as the water outlet temperature schedule name are required. If the condenser has evaporative cooling, additional inputs for evaporative condenser effectiveness, condenser air flow rate, basin heater parameters, water pump power, water source, and an evaporative cooling availability schedule are available. The names of refrigerated cases and walkins connected to the compressor rack are the final inputs to the model.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigeration compressor rack. Any reference to this compressor rack by another object will use this name.
Field: Heat Rejection Location[LINK]
The location of the compressor rack’s condenser. The compressor rack condenser heat can be directed “Outdoors” to model an outdoor air or water-cooled condenser or “Zone” to model a condenser located in a zone (e.g., a stand-alone packaged refrigerated case with integral condenser located in a conditioned zone). The default for this field is “Outdoors”. If the heat rejection location is “Zone” and no walk-in coolers are served by this compressor rack, then all refrigerated cases connected to this compressor rack must be located in the same zone. If however, walk-in coolers are also served by this compressor rack, then the heat rejection zone name must be specified (see Heat Rejection Zone Name field below) and cases and walk-ins can be located in multiple zones.
NOTE: When modeling a heat reclaim coil, the heat rejection location must be “Outdoors”. If the heat rejection location is “Zone”, the total amount of waste heat available for reclaim (e.g., by a desuperheater heating coil) is set to zero by this compressor rack object and the simulation proceeds.
Field: Design Compressor Rack COP[LINK]
The coefficient of performance (COP) for the compressor rack at design conditions (compressors only, excluding condenser fan power). This value must be greater than zero, with a default value of 2.0 if this field is left blank. This value should represent the compressor rack COP corresponding to the lowest evaporating temperature of any case or walkin served by the rack.
Field: Compressor Rack COP Function of Temperature Curve Name[LINK]
The name of the curve object defining the change in compressor rack COP as a function of the temperature of air entering the condenser. The curve object will be evaluated using the zone air dry-bulb temperature when rack heat rejection location equals “Zone” and the outdoor air dry-bulb temperature when rack heat rejection location equals “Outdoors” and the condenser type is air-cooled. As explained below, if the condenser is cooled by evaporative or water loop cooling, the curve object is evaluated using an effective temperature. The output from this curve is multiplied by the design compressor rack COP to yield the actual COP at the specific air temperature entering the condenser. This curve must be cubic or quadratic (Curve:Cubic or Curve:Quadratic), and should be normalized to 1.0 at the condenser entering air temperature at which the design compressor rack COP occurs. This curve should represent the compressor rack COP corresponding to the lowest evaporating temperature of any case served by the rack.
Field: Design Condenser Fan Power[LINK]
This field defines the design power for the condenser fan(s) in Watts. This field is applicable for air or evaporative cooling only. If the condenser is water-cooled, the fan power is captured in the cooling object (e.g., cooling tower). If applicable, this value must be greater than 0.0, with a default value of 250 Watts if this field is left blank.
Field: Condenser Fan Power Function of Temperature Curve Name[LINK]
This field is the name of the curve object defining the change in condenser fan power as a function of the temperature of air entering the condenser. This curve is used to simulate the modulation of air flow by the condenser fans (e.g., staging, multi-speed, or variable speed) as a function of temperature. The curve object will be evaluated using the zone air dry-bulb temperature when rack heat rejection location equals “Zone” and the outdoor air dry-bulb temperature when rack heat rejection location equals “Outdoors” and the condenser type is air-cooled. As explained below, if the condenser is cooled by evaporative cooling, the curve object is evaluated using an effective temperature. The output from this curve is multiplied by the design condenser fan power to yield the actual fan power at the specific air temperature entering the condenser. This curve must be cubic or quadratic (Curve:Cubic or Curve:Quadratic), and should be normalized to 1.0 at the condenser entering air temperature at which the design condenser fan power occurs. The actual condenser fan power is not allowed to exceed the design condenser fan power defined in the previous input field or go below zero (i.e., the output of the curve object is limited to values from 0.0 to 1.0). If this field is left blank, then the model assumes the condenser fan power is at the design power level when any of the refrigerated cases connected to this rack are operating.
Field: Condenser Type[LINK]
When the heat rejection location is “Outdoors”, the condenser may be either cooled by dry air by specifying “AirCooled”, by wet evaporative cooling by specifying “EvaporativelyCooled”, or by a water loop by specifying “WaterCooled”. If the condenser type is “WaterCooled”, then a plant cooling loop will need to be defined using other EnergyPlus objects, e.g., plant loop, pump, cooling tower, etc. The default value is “AirCooled”.
Field: Water-cooled Condenser Inlet Node Name[LINK]
When the condenser type is “WaterCooled”, a node name for the water-side condenser inlet must be provided.
Field: Water-cooled Condenser Outlet Node Name[LINK]
When the condenser type is “WaterCooled”, a node name for the water-side condenser outlet must be provided.
Field: Water-cooled Loop Flow Type[LINK]
When the condenser type is “WaterCooled”, the type of flow loop should be specified. The two choices are VariableFlow, in which a Pump:VariableSpeed needs to be included in the plant loop, or ConstantFlow, in which the loop circuit has a constant flow rate, typically associated with a Pump:ConstantSpeed object. If the flow type is VariableFlow, the flow needed to remove the condenser heat energy will be calculated and requested of the pump. If the flow type is Constant Flow, the outlet water temperature will be determined based on the fixed loop flow rate and heat energy to be removed. The default type is VariableFlow. Refer to additional discussion in the Engineering Reference.
Field: Water-cooled Condenser Outlet Temperature Schedule Name[LINK]
When the condenser type is “WaterCooled”, and when the water-cooled loop flow type is “Variable Flow”, the name of a schedule (Ref: Schedule) that defines the desired condenser water outlet temperature must be provided. The schedule may define an outlet temperature that varies through time.
Field: Water-cooled Condenser Design Flow Rate[LINK]
When the condenser type is “WaterCooled”, and when the water-cooled loop flow type is “Constant Flow”, this is the design water flow rate in m\(^{3}\)/s that will be requested initially. This requested flow will be passed to the loop simulation, and resulting actual flow will be dependent upon supply system capabilities (e.g., pump capability). The design flow rate must always be less than the maximum flow rate, defined below.
Field: Water-cooled Condenser Maximum Flow Rate[LINK]
When the condenser type is “Water Cooled”, this is the maximum water flow rate in m\(^{3}\)/s that will be allowed through the condenser. When the loop flow type is Variable Flow, if the calculated flow rate is higher than the maximum flow rate, an error message will be generated, and the flow rate will be reset to the maximum flow rate.
Field: Water-cooled Condenser Maximum Water Outlet Temperature[LINK]
When the condenser type is “WaterCooled”, this field specifies the maximum allowed water temperature in degrees C leaving the compressor rack condenser. The default value is 55 degrees C.
Field: Water-cooled Condenser Minimum Water Inlet Temperature[LINK]
When the condenser type is “WaterCooled”, this field specifies the minimum allowed water temperature in degrees C entering the compressor rack condenser. The default value is 10 degrees C. Refer to additional discussion in the Engineering Reference.
Field: Evaporative Condenser Availability Schedule Name[LINK]
When the condenser type is “EvaporativelyCooled”, the name of the optional schedule (Ref: Schedule) that specifies the time periods that evaporative cooling is available/unavailable. In some colder climates, evaporative cooling is periodically discontinued and the basin sumps drained to avoid freezing. In these times, the condenser runs as a typical dry air cooled condenser, and related evaporative cooling systems (e.g., water pump, basin heaters) do not operate. Use of this optional schedule permits modeling of planned, seasonal interruptions of evaporative cooling. All schedule values must be greater than or equal to zero. Typically, an ON/OFF schedule type is used with values being either 0 or 1. A schedule value of 1 indicates that evaporative cooling is available during the defined time period, and a value of 0 denotes that evaporative cooling is not available during the defined time period. If the schedule name is omitted (blank) and Condenser Type = “Evap Cooled”, then the model assumes that evaporative cooling of the condenser is available for the entire simulation period.
Field: Evaporative Condenser Effectiveness[LINK]
When the condenser type is “EvaporativelyCooled”, this field specifies the effectiveness of the evaporative system in modifying the temperature of the air entering the condenser coil. The resulting effective temperature is determined as
\[{T_{effective}} = {T_{owb}} + (1 - \varepsilon )*[{T_{odb}} - {T_{owb}}]\]
where:
\({T_{effective}}\) = effective dry-bulb temperature of air entering the condenser cooling coil (°C)
\({T_{owb}}\) = outdoor air wet-bulb temperature (°C)
\({T_{odb}}\) = outdoor air dry-bulb temperature (°C)
\(\varepsilon\) = evaporative condenser effectiveness.
The resulting condenser inlet air temperature is used by the Compressor Rack COP as a Function of Temperature Curve and the Condenser Fan Power as a Function of Temperature Curve. The default value for this field is 0.9, although valid entries can range from 0.0 to 1.0.
If the two function-of-temperature curves (i.e., Compressor Rack COP as a Function of Temperature Curve and Condenser Fan Power as a Function of Temperature Curve) are based on wet-bulb temperature rather than dry-bulb temperature, the evaporative condenser effectiveness should be set to 1.0 for consistency.
Field: Evaporative Condenser Air Flow Rate[LINK]
When the condenser type is “EvaporativelyCooled”, the air volume flow rate, in m\(^{3}\)per second, entering the evaporative condenser. This value is used to calculate the amount of water evaporated when evaporatively cooling the condenser inlet air. The value for this field must be greater than zero. This input field is also autocalculatable, equivalent to 0.000144 m\(^{3}\)/s per watt of total cooling capacity [850 cfm/ton] where the total cooling capacity is the sum of the rated total cooling capacities for the refrigerated cases connected to this compressor rack (Ref. Refrigeration:Case).
Field: Basin Heater Capacity[LINK]
When the condenser type is “EvaporativelyCooled”, this field defines the power level of the basin heater, if applicable, used to avoid water freezing in an outdoor evaporative cooler basin. This numeric field contains the capacity of the electric basin heater in Watts per degree Kelvin. This field is used in conjunction with the Basin Heater Set Point Temperature described in the following field. The basin heater electric power is equal to this field multiplied by the difference between the basin heater set point temperature and the dry-bulb temperature of the condenser coil inlet air. The basin heater only operates when the condenser fan is off (i.e., no compressor heat rejection). The basin heater capacity must be greater than or equal to zero, with a default value of 200 W/K if this field is left blank.
Field: Basin Heater Setpoint Temperature[LINK]
When the condenser type is “EvaporativelyCooled”, this numeric field contains the set point temperature (°C) for the basin heater described in the previous field. The basin heater is active when the outdoor air dry-bulb temperature falls below this set point temperature, as long as the condenser fan is off. The default value is 2°C if this field is left blank.
Field: Design Evaporative Condenser Water Pump Power[LINK]
When the condenser type is “EvaporativelyCooled”, the rated power of the evaporative condenser water pump in Watts. This value is used to calculate the power required to pump the water used to evaporatively cool the condenser inlet air. The value for this field must be greater than or equal to 0, with a default value of 1000 Watts if this field is left blank. This input field is also autocalculatable, equivalent to 0.004266 W per watt [15 W/ton] of total cooling capacity where the total cooling capacity is the sum of the rated total cooling capacities for the refrigerated cases and walk-ins connected to this compressor rack (Ref. Refrigeration:Case and Refrigeration:WalkIn)).
Field: Evaporative Water Supply Tank Name[LINK]
When the condenser type is “EvaporativelyCooled”, this field is used to define where the compressor rack obtains water used for evaporative cooling of its condenser. If this field is left blank, the unit will obtain water directly from the mains (Ref. Water Mains Temperatures). If the name of a Water Storage Tank object is used here, then the unit will obtain its water from that tank.
Field: Condenser Air Inlet Node Name[LINK]
This optional alpha field contains the name of the node from which the outdoor compressor rack condenser draws its outdoor air. This field is applicable only when the heat rejection location is “Outdoors” (if the heat rejection location is “Zone”, this field is disregarded). If this field is left blank, the outdoor air temperature entering the condenser (dry-bulb or wet-bulb) is taken directly from the weather data. If this field is not blank, this node name must also be specified in an OutdoorAir:Node object where the height of the node is taken into consideration when calculating outdoor air temperature from the weather data. Alternately, the node name may be specified in an OutdoorAir:NodeList object where the outdoor air temperature is taken directly from the weather data.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Refrigeration Case Name or WalkIn Name or CaseAndWalkInList Name[LINK]
This alpha field is the name of a single refrigerated case, a single walk in cooler, the name of a CaseAndWalkInList for multiple refrigerated cases and/or walk-ins, the name of a refrigeration chiller, or the name of a CaseAndWalkInList for multiple refrigeration chillers connected to this compressor rack. Note that if a CaseAndWalkInList contains the name(s) of refrigeration chillers, it CANNOT have the name(s) or any refrigerated cases or walkins . This field is required.
Field: Heat Rejection Zone Name[LINK]
If the Heat Rejection Location is “Zone” and any walk-in coolers are connected to this compressor rack, then this field is required. The compressor rack heat rejection will impact the air heat balance in this zone.
The following is an example input for a Refrigeration Compressor Rack with water cooled condenser.
Outputs[LINK]
If Condenser Type = Water Cooled:
System,Average, Refrigeration Compressor Rack Condenser Refrigerant Mass Flow Rate [kg/s]
System,Average, Refrigeration Compressor Rack Condenser Heat Transfer Rate [W]
System,Sum, Refrigeration Compressor Rack Condenser Heat Transfer Energy [J]
IF THE RACK SERVES CASES AND/OR WALKINS:
Zone,Average, Refrigeration Compressor Rack Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Condenser Fan Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Condenser Fan Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Total Heat Transfer Rate [W]
Zone,Sum, Refrigeration Compressor Rack Total Heat Transfer Energy [J]
Zone,Average, Refrigeration Compressor Rack COP [W/W]
If Condenser Type = Evap Cooled:
Zone,Average, Refrigeration Compressor Rack Evaporative Condenser Pump Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Evaporative Condenser Pump Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Evaporative Condenser Basin Heater Electric Power [W]
Zone,Sum, Refrigeration Compressor Rack Evaporative Condenser Basin Heater Electric Energy [J]
Zone,Average, Refrigeration Compressor Rack Evaporative Condenser Water Volume Flow Rate [m\(^{3}\)/s]
Zone,Sum, Refrigeration Compressor Rack Evaporative Condenser Water Volume [m\(^{3}\)]
If Heat Rejection Location = Zone:
Zone,Average, Refrigeration Compressor Rack Zone Sensible Heating Rate [W]
Zone,Sum,Refrigeration Compressor Rack Zone Sensible Heating Energy [J]
Zone,Average, Refrigeration Compressor Rack Return Air Sensible Heating Rate [W]
Zone,Sum,Refrigeration Compressor Rack Return Air Sensible Heating Energy [J]
IF THE RACK SERVES REFRIGERATION CHILLERS
HVAC,Average, Refrigeration Air Chiller Compressor Rack Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Compressor Runtime Fraction []
HVAC,Average, Refrigeration Air Chiller Compressor Rack Condenser Fan Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Condenser Fan Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack Total Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Total Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack COP [W/W]
If Condenser Type = Evap Cooled:
HVAC,Average, Refrigeration Air Chiller Compressor Rack Evaporative Condenser Pump Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Evaporative Condenser Pump Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack Evaporative Condenser Basin Heater Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Electric PowerRefrigeration Air Chiller Compressor Rack Evaporative Condenser Basin Heater Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack Evaporative Condenser Water Volume Flow Rate [m3/s]
HVAC,Sum, Refrigeration Air Chiller Compressor Rack Evaporative Condenser Water Volume [m3]
If Heat Rejection Location = Zone:
HVAC,Average, Refrigeration Air Chiller Compressor Rack Zone Sensible Heating Rate [W]
HVAC,Sum,Refrigeration Air Chiller Compressor Rack Zone Sensible Heating Energy [J]
HVAC,Average, Refrigeration Air Chiller Compressor Rack Return Air Sensible Heating Rate [W]
HVAC,Sum,Refrigeration Air Chiller Compressor Rack Return Air Sensible Heating Energy [J]
Refrigeration Compressor Rack Condenser Mass Flow Rate [kg/s][LINK]
When condenser type is Water Cooled, this is the mass flow rate of water flowing through the water cooled condenser.
Refrigeration Compressor Rack Condenser Heat Transfer Rate [W][LINK]
When condenser type is Water Cooled, this is the total heat transfer across the condenser (i.e., compressor energy and case cooling).
Refrigeration Compressor Rack Condenser Heat Transfer Energy [J][LINK]
When condenser type is Water Cooled, this is the total heat energy flowing across the condenser for the timestep being reported.
IF THE RACK SERVES CASES AND OR WALKINS:[LINK]
Refrigeration Compressor Rack Electric Power [W][LINK]
This output is the electric power input to the rack compressor(s) in Watts.
Refrigeration Compressor Rack Electric Energy [J][LINK]
This is the electricity consumption of the rack compressor(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Compressor Runtime Fraction [][LINK]
This is the runtime operating ratio for the compressor.
Refrigeration Compressor Rack Condenser Fan Electric Power [W][LINK]
This output is the electric input to the rack condenser fan(s) in Watts.
Refrigeration Compressor Rack Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the rack condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Compressor Rack Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the refrigeration compressor rack in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases and walk-ins that are connected to this rack. This value does not include compressor or condenser fan heat.
Refrigeration Compressor Rack Total Heat Transfer Energy [J][LINK]
This is the total heat transfer of the refrigeration compressor rack in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Compressor Rack COP [W/W][LINK]
This field is the refrigeration compressor rack coefficient of performance. It is the actual compressor rack COP for the timestep being reported, accounting for the COP variation as a function of temperature. It is calculated as the Design Compressor Rack COP times the Compressor Rack COP as a Function of Temperature Curve evaluated at the effective condenser entering air temperature for the timestep being reported.
Refrigeration Compressor Rack Evaporative Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water pump used with evaporative cooling of the compressor rack condenser.
Refrigeration Compressor Rack Evaporative Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water pump used with evaporative cooling of the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Compressor Rack Evaporative Condenser Basin Heater Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water heater in the basin of the evaporative system used to cool the compressor rack condenser.
Refrigeration Compressor Rack Evaporative Condenser Basin Heater Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water heater used to prevent freezing of the evaporative cooling system for the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Compressor Rack Evaporative Condenser Water Volume Flow Rate [m3/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while providing evaporative cooling of the compressor rack condenser.
Refrigeration Compressor Rack Evaporative Condenser Water Volume [m3][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing evaporative cooling of the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Water, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Compressor Rack Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating in Watts provided to the zone by condenser waste heat rejection, which impacts the zone air heat balance.
Refrigeration Compressor Rack Zone Sensible Heating Energy [J][LINK]
This field is the sensible heating energy in Joules provided to the zone by condenser waste heat rejection for the timestep being reported.
Refrigeration Compressor Rack Return Air Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating in Watts provided by condenser waste heat rejection to the HVAC return air (zone return air path outlet node), which impacts the HVAC return air temperature. If the HVAC system is off for a simulation timestep (no return air mass flow), then this sensible heating is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Compressor Rack Return Air Sensible Heating Energy [J][LINK]
This field is the sensible heating energy in Joules provided by condenser waste heat rejection to the HVAC return air (zone return air path outlet node) for the timestep being reported. If the HVAC system is off for a simulation timestep (no return air mass flow), then this sensible heating is actually provided to the zone air instead (even though a non-zero value is reported here).
IF THE RACK SERVES CHILLERS[LINK]
Refrigeration Air Chiller Compressor Rack Electric Power [W][LINK]
This output is the electric power input to the rack compressor(s) in Watts.
Refrigeration Air Chiller Compressor Rack Electric Energy [J][LINK]
This is the electricity consumption of the rack compressor(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Compressor Runtime Fraction [][LINK]
This is the runtime fraction for the compressor serving air chillers.
Refrigeration Air Chiller Compressor Rack Condenser Fan Electric Power [W][LINK]
This output is the electric input to the rack condenser fan(s) in Watts.
Refrigeration Air Chiller Compressor Rack Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the rack condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller Compressor Rack Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the refrigeration compressor rack in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases and walk-ins that are connected to this rack. This value does not include compressor or condenser fan heat.
Refrigeration Air Chiller Compressor Rack Total Heat Transfer Energy [J][LINK]
This is the total heat transfer of the refrigeration compressor rack in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller Compressor Rack COP [W/W][LINK]
This field is the refrigeration compressor rack coefficient of performance. It is the actual compressor rack COP for the timestep being reported, accounting for the COP variation as a function of temperature. It is calculated as the Design Compressor Rack COP times the Compressor Rack COP as a Function of Temperature Curve evaluated at the effective condenser entering air temperature for the timestep being reported.
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water pump used with evaporative cooling of the compressor rack condenser.
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water pump used with evaporative cooling of the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Basin Heater Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water heater in the basin of the evaporative system used to cool the compressor rack condenser.
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Basin Heater Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water heater used to prevent freezing of the evaporative cooling system for the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Water Volume Flow Rate [m\(^{3}\)/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while providing evaporative cooling of the compressor rack condenser.
Refrigeration Air Chiller Compressor Rack Evaporative Condenser Water Volume [m\(^{3}\)][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing evaporative cooling of the compressor rack condenser for the timestep being reported. This output is also added to a meter with Resource Type = Water, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Air Chiller Compressor Rack Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating in Watts provided to the zone by condenser waste heat rejection, which impacts the zone air heat balance.
Refrigeration Air Chiller Compressor Rack Zone Sensible Heating Energy [J][LINK]
This field is the sensible heating energy in Joules provided to the zone by condenser waste heat rejection for the timestep being reported.
Refrigeration Air Chiller Compressor Rack Return Air Sensible Heating Energy [J][LINK]
Refrigeration Air Chiller Compressor Rack Return Air Sensible Heating Rate [W][LINK]
These are the sensible heating energy, in Joules or Watts, provided to the HVAC system return air node by condenser heat rejection at the compressor rack.
Refrigeration:Case[LINK]
The Refrigeration Case object works in conjunction with a compressor rack, a refrigeration system, or a secondary loop object (Refrigeration:CompressorRack, Refrigeration:System, or Refrigeration:SecondarySystem) to simulate the performance of a refrigerated case system. The refrigerated case model uses performance information at rated conditions along with performance curves for latent case credits and defrost heat load to determine performance at off-rated conditions. Energy use for lights, fans and anti-sweat heaters is modeled based on inputs for nominal power, schedules, and control type. The refrigerated case model accounts for the sensible and latent heat exchange with the surrounding environment (termed “case credits”) which impacts the temperature and humidity in the zone where the case is located.
A dataset has been provided containing refrigerated case input data for a large number of refrigerated cases from multiple manufacturers. See RefrigerationCases.idf.
The Refrigeration Case object inputs include a case name, an availability schedule name, the zone name for the location of the case, and the temperature and relative humidity of the ambient (zone) air surrounding the refrigerated case at the rating conditions for case performance. Additional inputs include the total cooling capacity, latent heat ratio, and run time fraction of the refrigerated case at rated conditions. The case length and operating temperature (average temperature of air/products within the case) must also be specified.
The refrigerated case model requires two curves to describe performance at off-rated conditions (i.e., at different zone temperature and humidity levels): the latent case credit curve and the defrost energy correction curve. The user must enter cubic performance curves with the independent variable being user selectable (case temperature, zone relative humidity, or zone dewpoint temperature).
The user can select from eight case defrost types, with additional inputs being required depending on the type selected. The user must enter a defrost schedule (unless Case Defrost Type = None), and an optional defrost drip-down schedule can be specified to allow additional time for melted frost to drain from the cooling coil following the regular defrost period.
Inputs are required for case fans, lights, and anti-sweat heaters. Case lighting can be controlled by the user through entering a schedule. The case fans operate whenever the cooling coil is operating and during defrost periods for certain case defrost types. Anti-sweat heater power can be controlled by several methods which are user selectable. The model assumes that the fans are contained within the thermal envelope of the case and provide a direct heat load on the case cooling coil. For lighting and anti-sweat heaters, the user can specify the fraction of their respective heat loads that directly impact the case cooling coil (with the remainder of their heat load impacting the surrounding zone air).
The user has the option of specifying a case restocking schedule and a schedule for modifying the case credits if needed. Finally, the user can specify the under case HVAC return air fraction which determines the portion of the case credits that directly impact the HVAC return air conditions (with the remainder of the case credits impacting the zone sensible and latent loads).
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigerated case. Any reference to this case by another object will use this name.
Field: Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigerated case can operate during a given time period. A schedule value greater than 0 (maximum schedule value of 1.0 is typically used) indicates that the case will operate during a given time period. A value equal to 0 denotes that the case does not operate (everything is OFF: refrigeration, fans, lights, anti-sweat, etc.). Typically the refrigerated case will operate throughout the day (i.e., the schedule will contain 1 for all time periods); however, cases require maintenance and/or cleaning and this can be modeled accordingly using this schedule if desired. If this field is left blank, the case is assumed to be available at all time periods.
Field: Zone Name[LINK]
The name of the zone where the refrigerated case is located. The refrigerated case will impact the air heat balance in this zone. When modeling multiple refrigerated cases connected to a single compressor rack where the condenser heat is rejected to the zone (ref: Refrigeration:CompressorRack), all of the refrigerated cases connected to that compressor rack must be located in the same zone.
Field: Rated Ambient Temperature[LINK]
Dry-bulb temperature of the ambient (zone) air surrounding the refrigerated case at the rating conditions for refrigerated case performance. The default value for this field is 23.9˚C (75˚F). This temperature must be greater than 0˚C and greater than the case operating temperature.
Field: Rated Ambient Relative Humidity[LINK]
Relative humidity of the ambient (zone) air surrounding the refrigerated case at the rating conditions for refrigerated case performance. The default value for this field is 55% RH.
Field: Rated Total Cooling Capacity per Unit Length[LINK]
The total, full load cooling capacity (sensible plus latent) in watts per unit length of refrigerated case (W/m) at rated conditions (i.e., at the Rated Ambient Temperature, Rated Ambient Relative Humidity, Case Operating Temperature, and with the Standard Case Fan Power per Unit Length and the Standard Case Lighting Power per Unit Length). The value entered for this field must be greater than zero, with a default value of 1900 W/m if the field is blank.
Field: Rated Latent Heat Ratio[LINK]
The latent heat ratio (LHR = latent capacity divided by total cooling capacity) of the refrigerated case at rated conditions (i.e., at the Rated Ambient Temperature, Rated Ambient Relative Humidity, Case Operating Temperature, and with the Standard Case Fan Power per Unit Length and the Standard Case Lighting Power per Unit Length). The value for this field can range from zero to 1.0, with a default value of 0.3 if the field is blank.
Field: Rated Runtime Fraction[LINK]
The runtime fraction of the refrigerated case at rated conditions (i.e., at the Rated Ambient Temperature, Rated Ambient Relative Humidity, and Case Operating Temperature). Even at rated conditions, refrigerated cases typically include additional cooling capacity to account for product stocking and recovery from defrost. The rated runtime fraction for refrigerated cases typically ranges from 0.8 to 0.9. The entered value for this field must be greater than 0.0 and less than or equal to 1.0, and the default value is 0.85 if the field is blank.
Field: Case Length[LINK]
The length of the refrigerated case in meters. The entered value for this field must be greater than 0.0, and the default value is 3 meters if the field is blank.
Field: Case Operating Temperature[LINK]
The average temperature of the air and products within the refrigerated case in ˚C. The refrigerated case manufacturer typically provides this information in the product literature. Typical operating temperatures for medium temperature cases are 1.6˚C to 7.2˚C (35˚F to 45˚F). Typical operating temperatures for low temperatures cases are -28.9˚C to -17.8˚C (-20˚F to 0˚F). The entered value for this field must be less than 20˚C and lower than the Rated Ambient Temperature. The default value is 1.1˚C if the field is blank.
Field: Latent Case Credit Curve Type[LINK]
This alpha field defines the form of the curve used to modify the latent case credits (latent heat removed from the zone where the refrigerated case is located) at off-rated conditions. The valid choices for this field are:
This method defines the variation in latent case credits as a cubic function of Case Operating Temperature. The result from the cubic curve is multiplied by the difference between the rated ambient relative humidity and the actual zone relative humidity, and one minus this value is multiplied by the Rated LHR to give the operating LHR at the actual zone humidity condition. (Representative cooefficient values for single-shelf horizontal and multi-shelf vertical display cases are given in the EnergyPlus Engineering Reference.)
This method defines the variation in latent case credits as a cubic function of ambient (zone) air relative humidity.
This method defines the variation in latent case credits as a cubic function of ambient (zone) air dewpoint temperature.
The default curve type is the Case Temperature Method. Refer to the Engineering Reference for further information on how latent case credits are modeled.
Field: Latent Case Credit Curve Name[LINK]
The name of a cubic performance curve (ref: Performance Curves) that parameterizes the variation of the latent case credits at off-rated conditions. The curve should be normalized to have a value of 1.0 at the rated ambient air conditions defined above.
Field: Standard Case Fan Power per Unit Length[LINK]
The total standard fan power in Watts per unit length of refrigerated case (W/m). This value represents the fan power included in the field Rated Total Cooling Capacity per Unit Length, and is used to determine the sensible case credits. The entered value for this field must be greater than or equal to zero, and the default value is 75.0 W/m if the field is blank.
Field: Operating Case Fan Power per Unit Length[LINK]
The total operating fan power in Watts per unit length of refrigerated case (W/m). Enter the actual power for the installed fans. The entered value for this field must be greater than or equal to zero, and the value is set equal to the standard case fan powers if the field is blank.
Field: Standard Case Lighting Power per Unit Length[LINK]
The total standard lighting power in Watts per unit length of refrigerated case (W/m). This value should represent the lighting power provided by the case manufacturer and included in the “Rated Total Cooling Capacity per Unit Length” field and is used to determine the sensible case credits. For cases where the manufacturer does not include the lights in the Rated Total Cooling Capacity, this value should be zero (0.0). The entered value for this field must be greater than or equal to zero, and the default value is 90.0 W/m if the field is blank.
Field: Installed Case Lighting Power per Unit Length[LINK]
The total installed lighting power in Watts per unit length of refrigerated case (W/m). Enter the actual power for the installed lights. This number may be greater or less than the standard lighting power value, depending upon the manufacturer’s practice in specifying the case rated cooling capacity and whether or not energy-efficient lights are being modeled. The next field (i.e. Case Lighting Schedule Name) may be used to specify the name of a schedule that contains the fraction of the Installed Case Lighting Power per Unit Length to be modeled for each timestep of the simulation period. The entered value for this field must be greater than or equal to zero, and the value is set equal to the standard case lighting power if the field is blank.
Field: Case Lighting Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of installed refrigerated case lights that operate during a given time period. A schedule value greater than 0 indicates that the lights will operate during that time period (maximum schedule value of 1.0 means lights are fully on at the Installed Case Lighting Power per Unit Length level). A schedule value of zero denotes that the lights are off. The refrigerated case lights will typically operate only when the store is open for business and can be scheduled off as desired via this schedule. If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Fraction of Lighting Energy To Case[LINK]
The fraction of the lighting energy that directly contributes to the case heat load. The remainder of the lighting energy (1 – fraction) is a heating load to the zone where the case is located. This field can be used to model lighting ballasts and bulbs located outside the air curtain of the refrigerated case. The value for this field can range from zero to 1.0, with a default value of 1.0 if the field is blank.
Field: Case Anti-Sweat Heater Power per Unit Length[LINK]
The electric anti-sweat heater power in watts per unit length of refrigerated case (W/m). The entered value for this field must be greater than or equal to zero, and the default value is 0 W/m if the field is blank.
Field: Minimum Anti-Sweat Heater Power per Unit Length[LINK]
The minimum electric anti-sweat heater power in watts per unit length of refrigerated case (W/m). Anti-sweat heater power will remain at or above this value for anti-sweat heater control types linear, dewpoint method, or heat balance method. Other anti-sweat heater control types disregard this field. The entered value for this field must be greater than or equal to zero, and the default value is 0 W/m if the field is blank.
Field: Anti-Sweat Heater Control Type[LINK]
The type of anti-sweat heater control used for this refrigerated case. Valid choices are None, Constant, Linear, DewpointMethod, or HeatBalanceMethod. The default is None if the field is blank. Refer to the Engineering Reference for further information on how the different anti-sweat heater controls are modeled.
Field: Humidity at Zero Anti-Sweat Heater Energy[LINK]
The value of this numeric field is only used when the Linear anti-sweat heater control type is selected. Enter the zone relative humidity where anti-sweat heater energy use is zero. Negative values for relative humidity may be entered. Other anti-sweat heater control types disregard this field. The value entered for this field must be less than the Rated Ambient Relative Humidity specified above. The default for this field is -10.0.
Field: Case Height[LINK]
The value of this numeric field is used when Heat Balance Method anti-sweat heater control is selected. Enter the case height in meters. Other anti-sweat heater control types disregard this field. The entered value for this field must be greater than zero when Heat Balance Method anti-sweat heater control is selected, and the default value is 1.5 meters if the field is blank.
Field: Fraction of Anti-Sweat Heater Energy To Case[LINK]
This value denotes the fraction of anti-sweat heater energy that results in a direct heat load to the refrigerated case. The remainder of the anti-sweat heater energy (1-fraction) is a heating load to the zone where the refrigerated case is located. The value for this field can range from zero to 1.0, with a default value of 1.0 if the field is blank.
Field: Case Defrost Power per Unit Length[LINK]
The defrost power in watts per unit length of refrigerated case (W/m). This input is required for hot-gas, hot-fluid, or electric defrost types and is used to evaluate the load on the case as well as power or heat consumption. Refrigerated case manufacturers do not typically provide information on the heat input for hot-gas and hot-fluid defrost. Information provided for electric defrost power can be substituted here for refrigerated cases using hot-gas or hot-fluid defrost if other information is not available. Only electric Case Defrost Types consume electricity during the defrost period. The entered value for this field must be greater than or equal to zero, and the default value is 0 W/m if the field is blank.
Field: Case Defrost Type[LINK]
The type of defrost used for this refrigerated case. Valid choices are None, OffCycle, HotGas, HotGaswithTemperatureTermination, Electric, ElectricwithTemperatureTermination, HotFluid, and HotFluidwithTemperatureTermination. The default defrost type is OffCycle if the field is blank. Refer to the Engineering Reference for further information on how the different case defrost types are modeled. In particular, hot-fluid defrost systems may be effective with much shorter defrost times than other systems, which should be reflected in the defrost and drip-down schedules.
Field: Case Defrost Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigerated case requires defrosting. A schedule value of 1.0 indicates that defrost will be on during a given time period. A value equal to 0 denotes that the defrost is off. Defrost schedules normally repeat the duration and number of defrost cycles for each day of the year. The refrigerated case manufacturer typically provides this information with the product literature. The use of Compact Schedules (ref. Schedules) are ideal for this purpose. In a typical supermarket with many cases, it is important to diversify the defrost schedules in order to avoid large swings in the load placed upon the remainder of the refrigeration system.
Field: Case Defrost Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigerated case requires additional time for draining condensate after the defrost period. A schedule value of 1.0 indicates that the defrost drip-down period is on during a given time period. A value equal to 0 denotes that the defrost drip-down period is over. The refrigerated case manufacturer typically provides this information with the product literature.
Each defrost drip-down period specified in this schedule should start at the same time as the corresponding defrost period specified in the schedule for Case Defrost Schedule, and the drip-down schedule defrost period should always be longer than or equal to the length of the defrost schedule time period. For example, if the case defrost schedule contains a defrost period from 7:00 to 7:15, you would specify a case defrost drip-down period from 7:00 to 7:20 if you wanted to model a 5 minute condensate drip-down period after the regular defrost period. If no drip-down schedule is entered, then the case defrost schedule (specified for the previous input field) will be used. The use of Compact Schedules (ref. Schedules) are ideal for this purpose.
Field: Defrost Energy Correction Curve Type[LINK]
This alpha field defines the form of the correction curve used to modify the defrost energy use (and the associated load on the case cooling coil) at off-rated conditions. The valid choices for this field are:
This choice specifies that a defrost energy correction curve will not be used.
This method defines the variation in defrost energy as a cubic function of Case Operating Temperature. The result from the cubic curve is multiplied by the difference between the rated ambient relative humidity and the actual zone relative humidity, and one minus this value is multiplied by the Case Defrost Power to give the (average) operating defrost power at the actual zone humidity condition. (Representative cooefficient values for single-shelf horizontal and multi-shelf vertical display cases are given in the EnergyPlus Engineering Reference.)
This method defines the variation in defrost energy as a cubic function of ambient (zone) air relative humidity.
This method defines the variation in defrost energy as a cubic function of ambient (zone) air dewpoint temperature.
The default curve type is None. The methods described here (e.g. Case Temperature, Relative Humidity, and Dewpoint) are applicable only to Electric with Temperature Termination, Hot-Gas with Temperature Termination, and Hot-Brine with Temperature Termination case defrost types. Refer to the Engineering Reference for further information on how the defrost energy correction types are modeled.
Field: Defrost Energy Correction Curve Name[LINK]
The name of a cubic performance curve (ref: Performance Curves) that parameterizes the variation of the defrost energy (and the associated load on the case cooling coil) at off-rated conditions. The curve should be normalized to have the value of 1.0 at the rated ambient air conditions defined above. The defrost energy correction curve name is used only for the Electric with Temperature Termination, Hot-Gas with Temperature Termination, and Hot-Brine with Temperature Termination case defrost types.
Field: Under Case HVAC Return Air Fraction[LINK]
This field denotes the fraction of HVAC system (air loop) return air that passes beneath the refrigerated case, if any. At times it is necessary to design HVAC systems with under case returns to avoid overcooling the area around the refrigerated case, thus providing a more comfortable environment for the zone occupants. This return air fraction affects the portion of the case credits (sensible and latent) that are applied to the air returning to the HVAC system, while the remainder of the case credits directly impacts the zone air heat balance. Refer to the Engineering Reference for further information on how this is modeled. The sum of the Under Case HVAC Return Air Fractions for all refrigerated cases located in a single zone must be less than or equal to 1.0. The value for this field can range from zero to 1.0, with a default value of 0 if the field is blank. The return air node name may be specified below.
Field: Refrigerated Case Restocking Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigerated case is being restocked with product. The schedule should contain values in units of Watts per unit length of refrigerated case (W/m). This field can be used to denote the additional load imposed on the refrigerated case from stocking the case with product that is warmer than the refrigerated case temperature. This information is difficult to find and may require additional research for proper modeling; however, this schedule is available for this purpose if desired. If restocking of the refrigerated case will not be simulated, enter a schedule with values of zero for all time periods or leave this field blank.
Field: Case Credit Fraction Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes a fraction of both the sensible and latent case credits to be applied to the zone and/or the HVAC system return air. Schedule values must be from 0 to 1. This allows correction of the case credits for various refrigerated case types. For instance, if glass door refrigerated display cases are installed in a store that is operated 12 hours per day, then the doors will remain closed during the unoccupied times and would therefore reduce the sensible and latent case credits during the unoccupied time. Leaving this field blank will result in no case credit fraction being applied during the simulation.
Field: Design Evaporator Temperature or Brine Inlet Temperature[LINK]
The value of this numeric field is used only with the detailed refrigeration system and is not read for the compressor-rack system. For the refrigeration system, it is used to evaluate compressor performance and is also used when the evaporator pressure and temperature are allowed to float at loads less than the design load. If the case is cooled by a secondary system (ref: Refrigeration:SecondarySystem), this value is the brine inlet temperature. The minimum value is -70C and the maximum value is 40C. The default value is 5C less than the case temperature.
Field: Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant inventory present in the refrigerated case during ordinary operation. The value is used to produce an estimate of the total refrigerant present in the refrigeration system. The value is entered in kg/m.
Field: Under Case HVAC Return Air Node Name[LINK]
Name of the return air node for this case. If left blank, it defaults to the first return air node for this zone.
The following is an example input for a refrigerated case.
Outputs[LINK]
Zone,Average,Refrigeration Case Evaporator Total Cooling Rate [W]
Zone,Sum,Refrigeration Case Evaporator Total Cooling Energy [J]
Zone,Average,Refrigeration Case Evaporator Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Case Evaporator Sensible Cooling Energy [J]
Zone,Average, Refrigeration Case Evaporator Latent Cooling Rate [W]
Zone,Sum, Refrigeration Case Evaporator Latent Cooling Energy [J]
Zone,Average,Refrigeration Case Zone Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Case Zone Sensible Cooling Energy [J]
Zone,Average,Refrigeration Case Zone Sensible Heating Rate [W]
Zone,Sum,Refrigeration Case Zone Sensible Heating Energy [J]
Zone,Average,Refrigeration Case Zone Latent Rate [W]
Zone,Sum,Refrigeration Case Zone Latent Energy [J]
Zone,Average,Refrigeration Case Return Air Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Case Return Air Sensible Cooling Energy [J]
Zone,Average,Refrigeration Case Return Air Sensible Heating Rate [W]
Zone,Sum,Refrigeration Case Return Air Sensible Heating Energy [J]
Zone,Average,Refrigeration Case Return Air Latent Rate [W]
Zone,Sum,Refrigeration Case Return Air Latent Energy [J]
Zone,Average,Refrigeration Case Evaporator Fan Electric Power [W]
Zone,Sum,Refrigeration Case Evaporator Fan Electric Energy [J]
Zone,Average,Refrigeration Case Lighting Electric Power [W]
Zone,Sum,Refrigeration Case Lighting Electric Energy [J]
Zone,Average,Refrigeration Case Latent Credit Curve Value []
If case defrost type is Electric, Hot-Gas, or Hot-Brine with Temperature Termination
If anti-sweat heater control type is not equal to None:
Zone,Average,Refrigeration Case Anti Sweat Electric Power [W]
Zone,Sum,Refrigeration Case Anti Sweat Electric Energy [J]
If case defrost type is Electric or Electric with Temperature Termination:
Zone,Average,Refrigeration Case Defrost Electric Power [W]
Zone,Sum,Refrigeration Case Defrost Electric Energy [J]
Refrigeration Case Evaporator Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate of the refrigerated case evaporator coil in Watts.
Refrigeration Case Evaporator Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of the refrigerated case evaporator coil in Joules over the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Case Evaporator Sensible Cooling Rate [W][LINK]
This field is the sensible cooling rate of the refrigerated case evaporator coil in Watts.
Refrigeration Case Evaporator Sensible Cooling Energy [J][LINK]
This field is the sensible cooling of the refrigerated case evaporator coil in Joules over the timestep being reported.
Refrigeration Case Evaporator Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of the refrigerated case evaporator coil in Watts.
Refrigeration Case Evaporator Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the refrigerated case evaporator coil in Joules over the timestep being reported.
Refrigeration Case Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits delivered to the zone in Watts. If an under case return duct is simulated, only a portion of the sensible case credits are applied to the zone. A positive value is reported when the zone is cooled by sensible case credits, otherwise a zero is reported.
Refrigeration Case Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit energy delivered to the zone in Joules. If an under case return duct is simulated, only a portion of the sensible case credits are applied to the zone. A positive value is reported when the zone is cooled by sensible case credits, otherwise a zero is reported.
Refrigeration Case Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits delivered to the zone in Watts. If an under case return duct is simulated, only a portion of the sensible case credits are applied to the zone. A positive value is reported when the zone is heated by sensible case credits, otherwise a zero is reported.
Refrigeration Case Zone Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit energy delivered to the zone in Joules. If an under case return duct is simulated, only a portion of the sensible case credits are applied to the zone. A positive value is reported when the zone is heated by sensible case credits, otherwise a zero is reported.
Refrigeration Case Zone Latent Rate [W][LINK]
This field is the rate of latent cooling (dehumidification) case credits delivered to the zone in Watts. If an under case return duct is simulated, only a portion of the latent case credits are applied to the zone. A negative value (or zero) will be reported when the refrigerated case provides dehumidification (thereby reducing the zone latent load).
Refrigeration Case Zone Latent Energy [J][LINK]
This field is the amount of latent cooling (dehumidification) case credit energy delivered to the zone in Joules. If an under case return duct is simulated, only a portion of the latent case credits are applied to the zone. A negative value (or zero) will be reported when the refrigerated case provides dehumidification (thereby reducing the zone latent load).
Refrigeration Case Return Air Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits delivered to the return air duct (zone return air node) in Watts. If an under case return duct is simulated, a portion of the sensible case credits are applied to the HVAC (zone) return air. A positive value is reported when the return air is cooled by sensible case credits, otherwise a zero is reported. If the HVAC system is off for a simulation timestep (no return air mass flow), then this sensible cooling is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Case Return Air Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit energy delivered to the return air duct (zone return air node) in Joules. If an under case return duct is simulated, a portion of the sensible case credits are applied to the HVAC (zone) return air. A positive value is reported when the return air is cooled by sensible case credits, otherwise a zero is reported. If the HVAC system is off for a simulation timestep (no return air mass flow), then this sensible cooling is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Case Return Air Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits delivered to the return air duct (zone return air node) in Watts. If an under case return duct is simulated, a portion of the sensible case credits are applied to the HVAC (zone) return air. A positive value is reported when the return air is heated by sensible case credits, otherwise a zero is reported. If the HVAC system is off for a simulation timestep (no return air mass flow), then this sensible heating is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Case Return Air Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit energy delivered to the return air duct (thereby reducing the zone latent load). If the HVAC system is off for a simulation timestep (no return air mass flow), then this latent energy is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Case Return Air Latent Energy [J][LINK]
Refrigeration Case Return Air Latent Rate [W][LINK]
These are the amount of latent cooling (dehumidification) case credit energy delivered to the return air duct (zone return air node) in Joules or Watts. If an under case return duct is simulated, only a portion of the latent case credits are applied to the HVAC (zone) return air. A negative value (or zero) will be reported since the refrigerated case provides dehumidification (thereby reducing the zone latent load). If the HVAC system is off for a simulation timestep (no return air mass flow), then this latent energy is actually provided to the zone air instead (even though a non-zero value is reported here).
Refrigeration Case Evaporator Fan Electric Power [W][LINK]
This field is the electric power input to the refrigerated case fan(s) in Watts.
Refrigeration Case Evaporator Fan Electric Energy [J][LINK]
This field is the electricity consumption of the refrigerated case fan(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Case Lighting Electric Power [W][LINK]
This field is the electric power input to the refrigerated case lights in Watts.
Refrigeration Case Lighting Electric Energy [J][LINK]
This field is the electricity consumption of the refrigerated case lights in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Case Defrost Energy Correction Curve Value[LINK]
This field is the output of the Defrost Energy Correction Curve which denotes the variation in defrost energy at off-rated conditions. The output of the defrost energy correction curve directly impacts the energy used during the defrost time period. It does not, however, impact the duration of the defrost period. This output is available only for Electric with Temperature Termination, Hot-Gas with Temperature Termination, or Hot-Brine with Temperature Termination case defrost types.
Refrigeration Case Latent Credit Curve Value [][LINK]
This field is the output of the Latent Case Credit Curve which denotes the variation in latent case credits at off-rated conditions. The output of the latent case credit curve directly impacts the amount of frost formation on the refrigerated case evaporator coil and the requirement for defrost.
Refrigeration Case Anti Sweat Electric Power [W][LINK]
This field is the electric power input to the refrigerated case anti-sweat heater in Watts. This output is available unless anti-sweat heater control type is specified as NONE.
Refrigeration Case Anti Sweat Electric Energy [J][LINK]
This field is the total electricity consumption of the refrigerated case anti-sweat heater in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects). This output is available unless anti-sweat heater control type is specified as NONE.
Refrigeration Case Defrost Electric Power [W][LINK]
This field is the electric power input to the refrigerated case electric defrost heater(s) in Watts. This output is available if case defrost type is Electric or Electric with Temperature Termination.
Refrigeration Case Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the refrigerated case electric defrost heater(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects). This output is available if case defrost type is Electric or Electric with Temperature Termination.
Refrigeration:CaseAndWalkInList[LINK]
This object provides a list of all the refrigerated cases and/or walk in coolers cooled by a single refrigeration system (ref: Refrigeraion:CompressorRack and Refrigeration:System). This list is extensible. Note that the names of all cases, walk-ins,air chillers, and caseandwalkinlists must be unique. That is, you cannot give a list the same name as one of the cases. Similarly, a walkin cannot have the same name as a case.This list may contain a combination of case and walk-in names OR a list of air chiller names. Air chillers may not be included in any list that also includes cases or walk-ins.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a CaseAndWalkInList. Any reference to this list by another object will use this name.
Field: Case or WalkIn or Air Chiller <x> Name[LINK]
Identifies a particular refrigerated case or walk-in. The name will be validated against the Refrigeration Case, Refrigeration WalkIn, and Air Chiller names (ref: Refrigeration:Case, Refrigeration:WalkIn, and Refrigeration:AirChiller) in the input file. Up to 20 are provided in the IDD; this object is extensible.
The following is an example input for a CaseAndWalkInList.
Refrigeration:WalkIn[LINK]
The Refrigeration WalkIn object works in conjunction with a compressor rack, a refrigeration system, or a refrigeration secondary system object (Ref. Refrigeration:CompressorRack, Refrigeration:System, or Refrigeration:SecondarySystem) to simulate the performance of a walk-in cooler. The walk-in cooler model uses information at rated conditions along with input descriptions for heat transfer surfaces facing multiple zones to determine performance. Energy use for lights, fans, and floor and anti-sweat heaters is modeled based on inputs for nominal power, schedules, and control type. The walk-in cooler model accounts for the sensible and latent heat exchange with the surrounding environment (termed “case credits”) which impacts the temperature and humidity in each zone adjacent to the walk-in.
The walk-in cooler object inputs include a name, an availability schedule name, the rated cooling capacity, the rated operating temperature, the rated cooling source temperature, the rated total heating power and heating power schedule, the rated fan and lighting power and schedules, defrost type, defrost control type, defrost schedule name, drip-down schedule name, defrost power, the portion of the defrost energy used to melt ice (only for temperature termination control type), restocking schedule, refrigerant inventory, and the floor area and U-value.
For each zone adjacent to the walk-in, the user must input the zone name and the insulated surface area and U-value facing that zone. The user must also specify, for two types of doors, the door area, height, U-value, door opening schedule name, and any door opening protection.
Under case HVAC return air fraction, available for refrigerated cases, is not available for walk-in coolers.
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigerated walk-in. Any reference to this walk-in by another object will use this name.
Field: Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the walk in can operate during a given time period. A schedule value greater than 0 (maximum schedule value of 1.0 is typically used) indicates that the walkin will operate during a given time period. A value equal to 0 denotes that the case does not operate (everything is OFF: refrigeration, fans, lights, anti-sweat, etc.). Typically the walkin will operate throughout the day (i.e., the schedule will contain 1 for all time periods); however, walkins require maintenance and/or cleaning and this can be modeled accordingly using this schedule if desired. If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Rated Coil Cooling Capacity[LINK]
The total, full load cooling capacity (sensible plus latent) in watts (W) at rated conditions The value entered for this field must be greater than zero, with no default value.
Field: Operating Temperature[LINK]
The rated average temperature of the air and products within the walk-in cooler in ˚C. The entered value for this field must be less than 20˚C. There is no default value.
Field: Rated Cooling Source Temperature[LINK]
For a DX evaporator coil, enter the saturated evaporating temperature in ˚C. For a fluid coil, enter the fluid coil entrance temperature in ˚C. There is no default value. This number is used, with temperatures for other refrigeration loads on any one system, to set that system’s minimum suction pressure or minimum circulating fluid temperature. (This value is not used if the walkin is cooled by a compressor rack object.)
Field: Rated Total Heating Power[LINK]
The total heating power in watts including all anti-sweat, door, drip-pan, and floor heaters (W). This value is required and has no default value.
Field: Heating Power Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of heater power that operates during a given time period. A schedule value of zero denotes that all heaters are off. A schedule value greater than 0 indicates that some portion of the total heater power will operate during that time period (maximum schedule value of 1.0 means all heaters are fully on). For example, if door and floor heaters represent 50% of the total heater power and are on all the time, the minimum schedule value would be 0.5. If anti-sweat heaters represent 40% of the total heater power and are only on during certain hours, the schedule value during those hours would be increased by 0.4. If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Rated Cooling Coil Fan Power[LINK]
The cooling coil fan power in watts (W). This value has a default value of 375W. This fan is assumed to run continuously except during electric, hot brine, or hot gas defrost periods.
Field: Rated Circulation Fan Power[LINK]
The circulation fan power in watts (W). This value has a default value of 0 W. This fan is assumed to run continuously.
Field: Rated Total Lighting Power[LINK]
The total lighting power in watts including both display and task lighting (W). This value is required and has no default value.
Field: Lighting Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of walk-in lights that operate during a given time period. A schedule value greater than 0 indicates that the lights will operate during that time period (maximum schedule value of 1.0 means lights are fully on). A schedule value of zero denotes that the lights are off. If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Defrost Type[LINK]
The type of defrost used for this walk-in. Valid choices are None, Off-Cycle, HotFluid, and Electric. The default defrost type is Electric if the field is blank. HotFluid includes both hot gas and hot brine defrost systems. Refer to the Engineering Reference for further information on how the different defrost types are modeled.
Field: Defrost Control Type[LINK]
The type of defrost control used for this walkin. Valid choices are TimeSchedule and TemperatureTermination. The default is TimeSchedule if the field is blank. Refer to the Engineering Reference for further information on how the different defrost controls are modeled.
Field: Defrost Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes when the walkin requires defrosting. A schedule value of 1.0 indicates that defrost will be on during a given time period if the defrost control type is “TimeSchedule”. For the TemperatureTermination defrost control type, the defrost will start with the schedule value changes from 0 to 1, but will end when the ice is melted. A value equal to 0 denotes that the defrost is off. Defrost schedules normally repeat the duration and number of defrost cycles for each day of the year. The walkin manufacturer typically provides this information with the product literature. If TemperatureTermination control type is used, the defrost schedule is used for the defrost cycle start time and the defrost cycle end time is not allowed to extend beyond the scheduled off time. The use of Compact Schedules (ref. Schedules) are ideal for this purpose.
Field: Defrost Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the walkin requires additional time for draining condensate after the defrost period. A schedule value of 1.0 indicates that the defrost drip-down period is on during a given time period. A value equal to 0 denotes that the defrost drip-down period is over. The walkin manufacturer typically provides this information with the product literature.
Each defrost drip-down period specified in this schedule should start at the same time as the corresponding defrost period specified in the schedule for Defrost Schedule, and the drip-down schedule defrost period should always be longer than or equal to the length of the defrost schedule time period. For example, if the defrost schedule contains a defrost period from 7:00 to 7:15, you would specify a case defrost drip-down period from 7:00 to 7:20 if you wanted to model a 5 minute condensate drip-down period after the regular defrost period. If no drip-down schedule is entered, then the defrost schedule (specified for the previous input field) will be used. The use of Compact Schedules (ref. Schedules) are ideal for this purpose.
Field: Defrost Power[LINK]
The defrost power in watts. This input is required for hot-fluid (hot gas or hot brine), or electric defrost types. Walkin manufacturers do not typically provide information on the heat input for hot gas and hot brine defrost. Information provided for electric defrost power can be substituted here for walkins using hot-gas or hot-brine defrost if other information is not available. Only electric Defrost Types consume electricity during the defrost period. The entered value for this field must be greater than or equal to zero.
Field: Temperature Termination Defrost Fraction to Ice[LINK]
When cooling coils go through a defrost cycle, only a portion of the defrost energy is actually used to melt the ice. The rest of the defrost energy goes to increasing the temperature of the coils themselves and to the walkin environment. The Temperature Termination defrost control type calculates the end of the defrost cycle that corresponds to melting all the ice. Therefore, the user must input this fractional value. The default value is 0.7 for electric defrost and 0.3 for hot fluid defrost. Refer to the Engineering Reference for further information on how the defrost energy control types are modeled.
Field: Restocking Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the walkin is being restocked with product. The schedule should contain values in units of Watts (note this is different from the restocking schedule values for cases that are entered per unit length). This field can be used to denote the additional load imposed on the walkin from stocking the walkin with product that is warmer than the walkin temperature. This information is difficult to find and may required additional research for proper modeling; however, this schedule is available for this purpose if desired. If restocking of the refrigerated walkin will not be simulated, enter a schedule with values of zero for all time periods or leave this field blank.
Field: Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant inventory present in the walkin during ordinary operation. The value is used to produce an estimate of the total refrigerant present in the refrigeration system. The value is entered in kg.
Field: Insulated Floor Surface Area[LINK]
The floor area in square meters. This value is required and has no default value.
Field: Insulated Floor U-Value[LINK]
The floor themal transmittance (in W/m\(^{2}\)-K). This value has a default value of 0.3154. (This corresponds to R18 in Archaic American Insulation Units. To convert other R-values to thermal transmittance, divide 5.678 by the R-value. For example, R15 is 0.3785 W/m\(^{2}\)-K and R5 is 1.136 W/m\(^{2}\)-K.)
THE REMAINING 12 FIELDS FOR THE WALK-IN COOLER MUST BE REPEATED FOR EACH ZONE WHICH IS IN CONTACT WITH A WALK-IN WALL, CEILING, OR DOOR. The IDD includes fields for 3 zones, but can be extended by repeating the last 12 values in the object.
Field: Zone <x> Name[LINK]
The name of a zone adjoining the walkin. The walkin will impact the air heat balance in this zone. This zone must represent a conditioned space, that is, it must appear in a ZoneHVAC:EquipmentConnections object.
Field: Total Insulated Surface Area Facing Zone <x>[LINK]
The total surface area (walls and ceilings) facing this particular zone in square meters. This value is required and has no default value.
Field: Insulated Surface U-Value Facing Zone <x>[LINK]
The surface (walls and ceilings) themal transmittance (in W/m\(^{2}\)-K). This value has a default value of 0.3154. (This corresponds to R18 in Archaic American Insulation Units. To convert other R-values to thermal transmittance, divide 5.678 by the R-value. For example, R15 is 0.3785 W/m\(^{2}\)-K and R5 is 1.136 W/m\(^{2}\)-K.)
Field: Area of Glass Reach In Doors Facing Zone <x>[LINK]
The total area of glass doors facing this particular zone in square meters. The default is 0.0.
Field: Height of Glass Reach In Doors Facing Zone <x>[LINK]
The glass reach in door height in meters. The default is 1.5.
Field: Glass Reach In Door U-Value Facing Zone <x>[LINK]
The glass door themal transmittance (in W/m\(^{2}\)-K). This field has a default value of 1.136. (This corresponds to R5 in Archaic American Insulation Units.)
Field: Glass Reach In Door Opening Schedule Name Facing Zone <x>[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of time glass doors are open during a given time period. The schedule values should be between 0 and 1.0. If no schedule is specified, the doors are assumed to be open 5% of the time (corresponding to a schedule value of 0.05).
Field: Area of Stocking Doors Facing Zone <x>[LINK]
The total area of stock doors facing this particular zone in square meters. The default is 0.0.
Field: Height of Stocking Doors Facing Zone <x>[LINK]
The stocking door height in meters. The default is 2.0.
Field: Stocking Door U-Value Facing Zone <x>[LINK]
The stocking door themal transmittance (in W/m\(^{2}\)-K). This value has a default value of 0.3785. (This corresponds to R15 in Archaic American Insulation Units.)
Field: Stocking Door Opening Schedule Name Facing Zone <x>[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of time stocking doors are open during a given time period. The schedule values should be between 0 and 1.0. If no schedule is specified, the doors are assumed to be open 5% of the time (corresponding to a schedule value of 0.05).
Field: Stocking Door Opening Protection Type Facing Zone <x>[LINK]
The type of stocking door opening protection used for this walkin. Valid choices are None, AirCurtain, and StripCurtain. The default is AirCurtain if the field is blank. Use the type, StripCurtain, for both hanging strips and airlock vestibules. Refer to the Engineering Reference for further information on how the door protection types are modeled.
The following is an example input for a refrigeration walkin.
Refrigeration Case and WalkIn Outputs[LINK]
Zone,Average,Refrigeration Walk In Evaporator Total Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Total Cooling Energy [J]
Zone,Average,Refrigeration Walk In Evaporator Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Sensible Cooling Energy [J]
Zone,Average,Refrigeration Walk In Evaporator Latent Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Evaporator Latent Cooling Energy [J]
Zone,Average,Refrigeration Walk In Ancillary Electric Power [W]
Zone,Sum,Refrigeration Walk In Ancillary Electric Energy [J]
Zone,Average,Refrigeration Walk In Fan Electric Power [W]
Zone,Sum,Refrigeration Walk In Fan Electric Energy [J]
Zone,Average,Refrigeration Walk In Lighting Electric Power [W]
Zone,Sum,Refrigeration Walk In Lighting Electric Energy [J]
Zone,Average,Refrigeration Walk In Heater Electric Power [W]
Zone,Sum,Refrigeration Walk In Heater Electric Energy [J]
Report only for WalkIns using electric defrost
Zone,Average,Refrigeration Walk In Defrost Electric Power [W]
Zone,Sum,Refrigeration Walk In Defrost Electric Energy [J]
Report for each Zone exchanging energy with the WalkIn
Zone,Average,Refrigeration Walk In Zone Sensible Cooling Rate [W]
Zone,Sum,Refrigeration Walk In Zone Sensible Cooling Energy [J]
Zone,Average, Zone,Average,Refrigeration Walk In Zone Sensible Heating Rate [W]
Zone,Sum,Refrigeration Walk In Zone Sensible Heating Energy [J]
Zone,Average,Zone,Average,Refrigeration Walk In Zone Latent Rate [W]
Zone,Sum,Refrigeration Walk In Zone Latent Energy [J]
Refrigeration Walk In Evaporator Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate of the WalkIn evaporator coil in Watts.
Refrigeration Walk In Evaporator Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of the WalkIn evaporator coil in Joules over the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Walk In Evaporator Sensible Cooling Rate [W][LINK]
This field is the sensible cooling rate of the WalkIn evaporator coil in Watts.
Refrigeration Walk In Evaporator Sensible Cooling Energy [J][LINK]
This field is the sensible cooling of the WalkIn evaporator coil in Joules over the timestep being reported.
Refrigeration Walk In Evaporator Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of the WalkIn evaporator coil in Watts.
Refrigeration Walk In Evaporator Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the WalkIn evaporator coil in Joules over the timestep being reported.
Refrigeration Walk In Ancillary Electric Power [W][LINK]
This field is the total electricity (fan, heaters, lights, and electric defrost) used by the walkin in Watts.
Refrigeration Walk In Ancillary Electric Energy [J][LINK]
This field is the electricity (fan, heaters, lights, and electric defrost)used by the WalkIn in Joules over the timestep being reported.
Refrigeration Walk In Fan Electric Power [W][LINK]
This field is the electric power input to the WalkIn fan(s) in Watts.
Refrigeration Walk In Fan Electric Energy [J][LINK]
This field is the electricity consumption of the WalkIn fan(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Walk In Lighting Electric Power [W][LINK]
This field is the electric power input to the WalkIn lights in Watts.
Refrigeration Walk In Lighting Electric Energy [J][LINK]
This field is the electricity consumption of the WalkIn lights in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Walk In Heater Electric Power [W][LINK]
This field is the electric power input to the WalkIn heaters in Watts.
Refrigeration Walk In Heater Electric Energy [J][LINK]
This field is the total electricity consumption of the WalkIn heaters in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Walk In Defrost Electric Power [W][LINK]
This field is the electric power input to the WalkIn electric defrost heater(s) in Watts. This output is available if case defrost type is Electric.
Refrigeration Walk In Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the WalkIn electric defrost heater(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects). This output is available if case defrost type is Electric.
The following output variables are available for each zone adjacent to the walkin. An output variable identification is created for each zone exchanging energy with the walkin. For example if the walkin, “DairyWalkIn”, were exchanging energy with the zone, “SalesArea”, the output variable identification would be “DairyWalkInInZoneSalesArea”.
Refrigeration Walk In Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling case credits delivered to the zone in Watts. A positive value is reported when the zone is cooled by sensible case credits, otherwise a zero is reported.
Refrigeration Walk In Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling case credit energy delivered to the zone in Joules. A positive value is reported when the zone is cooled by sensible case credits, otherwise a zero is reported.
Refrigeration Walk In Zone Sensible Heating Rate [W][LINK]
This field is the rate of sensible heating case credits delivered to the zone in Watts. A positive value is reported when the zone is heated by sensible case credits, otherwise a zero is reported.
Refrigeration Walk In Zone Sensible Heating Energy [J][LINK]
This field is the amount of sensible heating case credit energy delivered to the zone in Joules. A positive value is reported when the zone is heated by sensible case credits, otherwise a zero is reported.
Refrigeration Walk In Zone Latent Rate [W][LINK]
This field is the rate of latent cooling (dehumidification) case credits delivered to the zone in Watts. A negative value (or zero) will be reported when the WalkIn provides dehumidification (thereby reducing the zone latent load).
Refrigeration Walk In Zone Latent Energy [J][LINK]
This field is the amount of latent cooling (dehumidification) case credit energy delivered to the zone in Joules. A negative value (or zero) will be reported when the WalkIn provides dehumidification (thereby reducing the zone latent load).
Refrigeration:System[LINK]
The refrigeration system object simulates the performance of a supermarket refrigeration system when used along with other objects to define the refrigeration load(s), the compressor(s), and the condenser.
At least one refrigeration load object must be defined which may be one of four types of load, a refrigerated case, a walk-in cooler, a chiller providing refrigeration to a secondary loop, or a cascade condenser which absorbs heat rejected by a lower-temperature system (Ref. Refrigeration:Case, Refrigeration:WalkIn, Refrigeration:SecondarySystem, and Refrigeration:Condenser:Cascade) If multiple loads are served by the same system , the user should use one or both of the list objects available to assign loads to the system. The first list includes all cases and walkins cooled directly by this system (Ref. Refrigeration:CaseAndWalkInList). The second list includes any ‘transfer’ loads, that is refrigeration loads borne by this system that are transferred from another refrigeration system via either a secondary loop chiller or a cascade condenser (Ref. Refrigeration:TransferLoadList, see the Engineering Reference for more information about these types of systems).
The refrigeration system object is capable of modeling both single-stage and two-stage compression refrigeration systems. The name of at least one compressor must be defined and a list object is available if the system is served by more than one compressor (Ref. Refrigeration:Compressor and Refrigeration:CompressorList).
Heat is rejected outdoors in a condenser by direct air flow, evaporative water cooling, by a water-cooled condenser with appropriate plant loop piping, or to a cascade condenser cooled by another refrigeration system(ref: Refrigeration:Condenser:AirCooled, Refrigeration:Condenser:EvaporativeCooled, Refrigeration:Condenser:WaterCooled, Refrigeration:Condenser:Cascade). With evaporative cooling, water is sprayed through the air stream to effectively lower the air temperature experienced by the condenser coil as a result of water evaporation. The use of a water-cooled condenser requires the definition of a plant loop to supply cooling to the condenser. If a cascade condenser is specified, the refrigeration system absorbing the rejected heat must also be defined.
The refrigeration system may also include a liquid suction and/or mechanical subcooler (Ref. Refrigeration:Subcooler).
The system object coordinates the energy flows between the other refrigeration objects and is used to set system parameters. Compressor waste heat can also be reclaimed for use by an optional air- or water-heating coil (Ref. Coil:Heating:Desuperheater and Coil:WaterHeating:Desuperheater).
The inputs for the refrigeration system object, in addition to the names of the other refrigeration objects described above, include a name for this system, the minimum condensing temperature, the refrigeration system working fluid, and the type of saturated suction temperature control. Optional input fields are also provided for users seeking to keep track of refrigerant inventory and suction pipe heat gains.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigeration system. Any reference to this refrigeration system by another object will use this name.
Field: Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, a single walkin, single air chiller, or a particular list of refrigerated cases and walkins or air chillers, that is cooled by this refrigeration system. The name will be validated against the case, walkin, air chiller and CaseAndWalkInList names (ref: Refrigeration:Case, Refrigeration:WalkIn, Refrigeration:AirChiller, and Refrigeration:CaseAndWalkInList) in the input file. Only cases and walkins or air chillers served directly by the system should be included in this list. Any cases, walkins, or air chillers served indirectly via a secondary loop should NOT be included in this list. Note that any system that serves an air chiller cannot also serve a case or walkin.
Field: Refrigeration Transfer Load or TransferLoad List Name[LINK]
Identifies a single SecondarySystem, a single Cascade Condenser, OR or a list of Transfer Loads (where the list is comprised of SecondarySystems and/or Cascade Condensers) that are cooled by this refrigeration system. The name will be validated against the secondary system, cascade condenser, and TransferLoad list names (ref: Refrigeration:SecondarySystem, Refrigeration:Condenser:Cascade, and Refrigeration:TransferLoadList) in the input file. Only secondary systems and cascade condensers served directly by the system should be included in this list. (NOTE – this entry is for a cascade condenser cooled by this system, not a condenser absorbing heat rejected by this system.)
Field: Condenser Name[LINK]
The name of the condenser that is used to reject heat from this refrigeration system. The name will be validated against the condenser names (ref: Refrigeration:Condenser:AirCooled, Refrigeration:Condenser:WaterCooled, Refrigeration:Condenser:EvaporativeCooled, and Refrigeration:Condenser:Cascade) in the input file.
Field:Compressor or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of compressors, that provide cooling energy to this refrigeration system. The name will be validated against the compressor list names (ref: List:Refrigeration:Compressors) in the input file. If the refrigeration systems contains two stages of compression, this field identifies the low-stage compressors connected to the two-stage system.
Field: Minimum Condensing Temperature[LINK]
This numeric field specifies the minimum condensing temperature (C), which is usually determined by the temperature required to maintain acceptable thermal expansion valve performance.
Field: Refrigeration System Working Fluid Type[LINK]
The type of refrigerant used by the system. Valid choices are R11, R123, R134A, R12, R22, R404A, R507A, or R410A. This name will be validated against Fluid Names (ref: Fluid Properties section) in the input file. Note that the corresponding property data, available in FluidPropertiesRefData.idf, must by supplied in the input file.
Field: Suction Temperature Control Type[LINK]
The type of saturated suction temperature control used by the system. Valid choices are FloatSuctionTemperature and ConstantSuctionTemperature. If the field is blank, the default will be ConstantSuctionTemperature. See the Engineering Reference section, Variable Evaporator Temperature, for a discussion of this option.
Field: Mechanical Subcooler Name[LINK]
This optional field identifies a mechanical subcooler that absorbs heat from this refrigeration system. This field should not be used for a mechanical subcooler that absorbs heat from another system. The name will be validated against the subcooler names (ref: Refrigeration:Subcooler) in the input file.
Field: Liquid Suction Heat Exchanger Subcooler Name[LINK]
This optional field Identifies a particular liquid suction heat exchanger (LSHX) subcooler present in this refrigeration system. The name will be validated against the subcooler names (ref: Refrigeration:Subcooler) in the input file.
Field: Sum UA Suction Piping[LINK]
This optional field is typically used when trying to determine the impact of pipe heat gains on system performance and zone heat balance, particularly in comparing a DX system to a secondary system. Enter the value for suction piping heat gain (in W/C). That is, sum up the product of the pipe wall insulation conductance times the outer surface area of the pipe insulation. Please see the Engineering Reference for guidance in calculating this value. If the Sum UA Suction Piping is entered, the Suction Piping Zone Name is also required.
Field: Suction Piping Zone Name[LINK]
This optional field is typically used when trying to determine the impact of pipe heat gains on system performance, particularly in comparing a DX system to a secondary system. (If the previous field, Sum UA Suction Piping, is blank, this field will not be used.) Enter the name of the zone where the suction piping is located. The suction piping heat gains will be calculated based upon the air temperature within this zone. The heat balance of this zone will also be affected by the piping heat exchange. Additional output variables are described at the end of this “Group-Refrigeration” section for the total impact of refrigeration on zones, including suction pipe heat exchange.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Number of Compressor Stages[LINK]
This field determines whether the refrigeration system contains one or two stages of compression. In this field, enter either “1” for single-stage compression systems or “2” for two-stage compression systems. If two stages of compression are selected, then an intercooler will be used between the compressor stages to cool the discharge of the low-stage compressors. The default value is “1”.
Field: Intercooler Type[LINK]
This field determines the type of intercooler which is used for two-stage compression systems. Valid choices for this field include “None”, “Flash Intercooler” or “Shell-and-Coil Intercooler”. Single-stage systems require “None” while two-stage systems require either “Flash Intercooler” or “Shell-and-Coil Intercooler”. The default selection is “None”, corresponding to a single-stage compression system.
Field: Shell-and-Coil Intercooler Effectiveness[LINK]
When a shell-and-coil intercooler is selected for two-stage compression systems, this field allows the specification of the shell-and-coil intercooler effectiveness. Values in this field will only be valid if “Shell-and-Coil Intercooler” is selected in the “Intercooler Type” field above. The valid range of values for this field is between 0.0 and 1.0. A default value of 0.80 will be used if none is specified.
Field: High-Stage Compressor or CompressorList Name[LINK]
Identifies a single compressor, or a particular list of compressors, that comprise the high-stage compression of a two-stage compression refrigeration system. The name will be validated against the compressor list names (ref: List:Refrigeration:Compressors) in the input file. Names in this field are only valid if two compressor stages have been specified in the “Number of Compressor Stages” field above.
The following is an example input for a single-stage compression refrigeration system.
The following is an example input for a two-stage compression refrigeration system.
Outputs[LINK]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Total Compressor Electric Power [W]
Zone,Sum, Refrigeration System Total Compressor Electric Energy [J]
Zone,Average, Refrigeration System Average Compressor COP [W/W]
Zone,Average, Refrigeration System Total Compressor Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Compressor Heat Transfer Energy [J]
Zone,Average, Refrigeration System Total Cases and Walk Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Cases and Walk Ins Heat Transfer Energy [J]
Zone,Average, Refrigeration System Total Transferred Load Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Total Transferred Load Heat Transfer Energy [J]
Zone,Average, Refrigeration System Total Suction Pipe Heat Gain Rate [W]
Zone,Sum, Refrigeration System Total Suction Pipe Heat Gain Energy [J]
Zone,Average, Refrigeration System Net Rejected Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Net Rejected Heat Transfer Energy [J]
Zone,Average,Refrigeration System Estimated Refrigerant Inventory Mass [kg]
Zone,Average, Refrigeration System Liquid Suction Subcooler Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Liquid Suction Subcooler Heat Transfer Energy [J]
Zone,Average, Refrigeration System Estimated Refrigerant Inventory [kg]
Zone,Average, Refrigeration System Estimated Refrigerant Mass Flow Rate [kg/s]
Zone,Average, Refrigeration System Condensing Temperature [C]’
Zone,Average, Refrigeration System Evaporating Temperature [C]
Zone,Average, Refrigeration System Suction Pipe Suction Temperature [C]
Zone,Average, Refrigeration System Thermostatic Expansion Valve Liquid Temperature [C]
Zone,Average, Refrigeration System Estimated High Stage Refrigerant Mass Flow Rate [kg/s]
Zone,Sum,Refrigeration System Total High Stage Compressor Electric Energy [J]
Zone,Average,Refrigeration System Total High Stage Compressor Electric Power [W]
Zone,Sum,Refrigeration System Total High Stage Compressor Heat Transfer Energy [J]
Zone,Average,Refrigeration System Total High Stage Compressor Heat Transfer Rate [W]
Zone,Sum,Refrigeration System Total Low and High Stage Compressor Electric Energy [J]
Zone,Sum,Refrigeration System Total Low Stage Compressor Electric Energy [J]
Zone,Average,Refrigeration System Total Low Stage Compressor Electric Power [W]
Zone,Sum,Refrigeration System Total Low Stage Compressor Heat Transfer Energy [J]
Zone,Average,Refrigeration System Total Low Stage Compressor Heat Transfer Rate [W]
Zone,Average,Refrigeration System Estimated Low Stage Refrigerant Mass Flow Rate [kg/s]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System Total Compressor Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller System Total Compressor Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System Average Compressor COP [W/W]
HVAC,Average, Refrigeration Air Chiller System Total Compressor Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Compressor Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total Air Chiller Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Case and Walk In Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total Transferred Load Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Transferred Load Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Total Suction Pipe Heat Gain Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Suction Pipe Heat Gain Energy [J]
HVAC,Average, Refrigeration Air Chiller System Net Rejected Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Net Rejected Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Liquid Suction Subcooler Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Liquid Suction Subcooler Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Estimated Refrigerant Inventory Mass [kg]
HVAC,Average, Refrigeration Air Chiller System Estimated Refrigerant Mass Flow Rate [kg/s]
HVAC,Average,Refrigeration Air Chiller System Intercooler Temperature [C]
HVAC,Average,Refrigeration Air Chiller System Intercooler Pressure [Pa]
HVAC,Average, Refrigeration Air Chiller System Condensing Temperature [C]’
HVAC,Average, Refrigeration Air Chiller System Evaporating Temperature [C]
HVAC,Average, Refrigeration Air Chiller System Suction Temperature [C]
HVAC,Average, Refrigeration Air Chiller System TXV Liquid Temperature [C]
HVAC,Average,Refrigeration Air Chiller System Estimated High Stage Refrigerant Mass Flow Rate [kg/s]
HVAC,Sum,Refrigeration Air Chiller System Total High Stage Compressor Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total High Stage Compressor Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller System Total High Stage Compressor Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total High Stage Compressor Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Air Chiller System Total Low and High Stage Compressor Electric Energy [J]
HVAC,Sum,Refrigeration Air Chiller System Total Low Stage Compressor Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total Low Stage Compressor Electric Power [W]
HVAC,Sum, Refrigeration Air Chiller System Total Low Stage Compressor Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller System Total Low Stage Compressor Heat Transfer Rate [W]
HVAC,Average,Refrigeration Air Chiller System Estimated Low Stage Refrigerant Mass Flow Rate [kg/s]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES AND/OR WALKINS[LINK]
Refrigeration System Total Compressor Electric Power [W][LINK]
This output is the total electric power input to the system compressor(s) in Watts.
Refrigeration System Total Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration System Total Low Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s low-stage compressor(s) in Watts. This output is valid only for two-stage compression systems.
Refrigeration System Total Low Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s low-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration System Total High Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s high-stage compressor(s) in Watts. This output is valid only for two-stage compression systems.
Refrigeration System Total High Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s high-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration System Total Low and High Stage Compressor Electric Energy [J][LINK]
This is the total electricity consumption of the system’s low- and high-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration System Average Compressor COP [W/W][LINK]
This output is the system average compressor COP, the total refrigeration effect divided by the total power to the compressors.
Refrigeration System Total Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the Refrigeration Compressor rack in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value.
Refrigeration System Total Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the Refrigeration Compressor rack in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration System Total Low Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the low-stage compressors in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value. This output is valid only for two-stage compression systems.
Refrigeration System Total Low Stage Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the low-stage compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration System Total High Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the high-stage compressors in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value. This output is valid only for two-stage compression systems.
Refrigeration System Total High Stage Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the high-stage compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration System Total Cases and Walk Ins Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the refrigerated cases and walk-ins served directly by this system in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases and walk-ins that are connected directly to this system. This value does not include compressor or condenser fan heat or the heat transfer for cases and walk-ins served by any connected secondary systems.
Refrigeration System Total Cases and Walk Ins Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the refrigerated cases and walk-ins served directly by this system in Joules. It is the sum of all of the heat transfered for the refrigerated cases and walk-ins that are connected directly to this system. This value does not include compressor or condenser fan heat or the heat transfer for cases and walk-ins served by any connected secondary systems.
Refrigeration System Total Transferred Load Heat Transfer Rate [W][LINK]
This output is the sum of the heat transfer rates for any secondary loops, cascade condensers, and mechanical subcoolers cooled by this system, minus the benefit of any mechanical subcooler providing cooling to this system in Watts. Therefore, if the only transfer load between two systems is a mechanical subcooler, the same amount will show as a negative value for the system receiving the cooling effect and as a positive number for the system serving that cooling load. It also includes the pump energy for any secondary loops and the compressor energy for any cascade condenser systems that are cooled by this system. (See the Engineering Reference for more details about the loads placed by secondary systems upon the primary system.)
Refrigeration System Total Transferred Load Heat Transfer Energy [J][LINK]
This output is the sum of the heat transfered for any secondary loops, cascade condensers, and mechanical subcoolers cooled by this system, minus the benefit of any mechanical subcooler providing cooling to this system in Joules. Therefore, if the only transfer load between two systems is a mechanical subcooler, the same amount will show as a negative value for the system receiving the cooling effect and as a positive number for the system serving that cooling load. It also includes the pump energy for any secondary loops and the compressor energy for any cascade condenser systems that are cooled by this system. (See the Engineering Reference for more details about the loads placed by secondary systems upon the primary system.)
Refrigeration System Total Suction Pipe Heat Gain Rate [W][LINK]
This output is the total heat transfer rate for suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the suction piping heat gain characteristics in the input.
Refrigeration System Total Suction Pipe Heat Gain Energy [J][LINK]
This output is the total heat transfer rate for suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the suction piping heat gain characteristics in the input.
Refrigeration System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to the system condenser in Watts. It does not include system heat rejection that has been recovered for useful purposes. However, if a water-cooled condenser was used to provide heat to a separate water loop, the energy transferred to that loop is included here.
Refrigeration System Net Rejected Heat Transfer Energy [J][LINK]
This output is the total heat rejected by this system to the system condenser in Joules for the timestep being reported. It does not include system heat rejection that has been recovered for useful purposes. However, if a water-cooled condenser was used to provide heat to a separate water loop, the energy transferred to that loop is included here.
Refrigeration System Liquid Suction Subcooler Heat Transfer Rate [W][LINK]
This output is the total heat transferred from the liquid condensate before the thermal expansion valve to the suction gas.
Refrigeration System Liquid Suction Subcooler Heat Transfer Energy [J][LINK]
This output is the total heat transferred from the liquid condensate before the thermal expansion valve to the suction gas.
Refrigeration System Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for the condenser, receiver, cases, and liquid pipes that are a part of this system.
Refrigeration System Estimated Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the compressors for this system.
Refrigeration System Estimated Low Stage Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the low-stage compressors for this system. This output is valid only for two-stage compression systems.
Refrigeration System Estimated High Stage Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the high-stage compressors for this system. This output is valid only for two-stage compression systems.
Refrigeration System Intercooler Temperature [C][LINK]
This is the saturation temperature in the intercooler. This output is valid only for two-stage compression systems.
Refrigeration System Intercooler Pressure [Pa][LINK]
This is the saturation pressure in the intercooler. This output is valid only for two-stage compression systems.
Refrigeration System Condensing Temperature [C][LINK]
This is the saturated condensing temperature.
Refrigeration System Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature.
Refrigeration System Suction Pipe Suction Temperature [C][LINK]
This is the temperature at the compressor inlet including superheat after the cases and superheat from any liquid suction heat exchangers.
Refrigeration System Thermostatic Expansion Valve Liquid Temperature [C][LINK]
This is the temperature entering the thermal expansion valve before the cases, equal to the condensing temperature minus any subcooling included in the condenser or provided by mechanical and/or liquid suction heat exchanger subcoolers.
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR CHILLERS[LINK]
Refrigeration Air Chiller System Total Compressor Electric Power [W][LINK]
This output is the total electric power input to the system compressor(s) in Watts.
Refrigeration Chiller System Total Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Total Low Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s low-stage compressor(s) in Watts. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total Low Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s low-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total High Stage Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s high-stage compressor(s) in Watts. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total High Stage Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s high-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total Low and High Stage Compressor Electric Energy [J][LINK]
This is the total electricity consumption of the system’s low- and high-stage compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Average Compressor COP [W/W][LINK]
This output is the system average compressor COP, the total refrigeration effect divided by the total power to the compressors
Refrigeration Air Chiller System Total Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the Refrigeration Compressor rack in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value.
Refrigeration Air Chiller System Total Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the Refrigeration Compressor rack in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Total Low Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the low-stage compressors in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total Low Stage Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the low-stage compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total High Stage Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the high-stage compressors in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases, walk-ins, secondary loops, cascade condensers, and mechanical subcoolers that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total High Stage Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the high-stage compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects). This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Total Air Chiller Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the refrigerated cases and walk-ins served directly by this system in Watts. It is the sum of all of the heat transfer rates for the refrigerated cases and walk-ins that are connected directly to this system. This value does not include compressor or condenser fan heat or the heat transfer for cases and walk-ins served by any connected secondary systems.
Refrigeration Air Chiller System Total Case and Walk In Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the refrigerated cases and walk-ins served directly by this system in Joules. It is the sum of all of the heat transfered for the refrigerated cases and walk-ins that are connected directly to this system. This value does not include compressor or condenser fan heat or the heat transfer for cases and walk-ins served by any connected secondary systems.
Refrigeration Air Chiller System Total Transferred Load Heat Transfer Rate [W][LINK]
This output is the sum of the heat transfer rates for any secondary loops, cascade condensers, and mechanical subcoolers cooled by this system, minus the benefit of any mechanical subcooler providing cooling to this system in Watts. Therefore, if the only transfer load between two systems is a mechanical subcooler, the same amount will show as a negative value for the system receiving the cooling effect and as a positive number for the system serving that cooling load. It also includes the pump energy for any secondary loops and the compressor energy for any cascade condenser systems that are cooled by this system. (See the Engineering Reference for more details about the loads placed by secondary systems upon the primary system.)
Refrigeration Air Chiller System Total Transferred Load Heat Transfer Energy [J][LINK]
This output is the sum of the heat transfered for any secondary loops, cascade condensers, and mechanical subcoolers cooled by this system, minus the benefit of any mechanical subcooler providing cooling to this system in Joules. Therefore, if the only transfer load between two systems is a mechanical subcooler, the same amount will show as a negative value for the system receiving the cooling effect and as a positive number for the system serving that cooling load. It also includes the pump energy for any secondary loops and the compressor energy for any cascade condenser systems that are cooled by this system. (See the Engineering Reference for more details about the loads placed by secondary systems upon the primary system.)
Refrigeration Air Chiller System Total Suction Pipe Heat Gain Rate [W][LINK]
This output is the total heat transfer rate for suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the suction piping heat gain characteristics in the input.
Refrigeration Air Chiller System Total Suction Pipe Heat Gain Energy [J][LINK]
This output is the total heat transfer rate for suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the suction piping heat gain characteristics in the input.
Refrigeration Air Chiller System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to the system condenser in Watts. It does not include system heat rejection that has been recovered for useful purposes. However, if a water-cooled condenser was used to provide heat to a separate water loop, the energy transferred to that loop is included here.
Refrigeration Air Chiller System Net Rejected Heat Transfer Energy [J][LINK]
This output is the total heat rejected by this system to the system condenser in Joules for the timestep being reported. It does not include system heat rejection that has been recovered for useful purposes. However, if a water-cooled condenser was used to provide heat to a separate water loop, the energy transferred to that loop is included here.
Refrigeration Air Chiller System Liquid Suction Subcooler Heat Transfer Rate [W][LINK]
This output is the total heat transferred from the liquid condensate before the thermal expansion valve to the suction gas.
Refrigeration Air Chiller System Liquid Suction Subcooler Heat Transfer Energy [J][LINK]
This output is the total heat transferred from the liquid condensate before the thermal expansion valve to the suction gas.
Refrigeration Air Chiller System Mechanical Subcooler Heat Transfer Energy [J][LINK]
Refrigeration Air Chiller System Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for the condenser, receiver, cases, and liquid pipes that are a part of this system.
Refrigeration Air Chiller System Estimated Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the compressors for this system.
Refrigeration Air Chiller System Estimated Low Stage Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the low-stage compressors for this system. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Estimated High Stage Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow through the high-stage compressors for this system. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Intercooler Temperature [C][LINK]
This is the saturation temperature in the intercooler. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Intercooler Pressure [Pa][LINK]
This is the saturation pressure in the intercooler. This output is valid only for two-stage compression systems.
Refrigeration Air Chiller System Condensing Temperature [C][LINK]
This is the saturated condensing temperature.
Refrigeration Air Chiller System Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature.
Refrigeration Air Chiller System Suction Temperature [C][LINK]
This is the temperature at the compressor inlet including superheat after the cases and superheat from any liquid suction heat exchangers.
Refrigeration Air Chiller System TXV Liquid Temperature [C][LINK]
This is the temperature entering the thermal expansion valve before the cases, equal to the condensing temperature minus any subcooling included in the condenser or provided by mechanical and/or liquid suction heat exchanger subcoolers.
Refrigeration:TranscriticalSystem[LINK]
The Refrigeration:TranscriticalSystem object allows users to model detailed transcritical carbon dioxide (CO\(_{2}\)) booster refrigeration systems used in supermarkets. The object allows for modeling either a single stage system with medium-temperature loads or a two stage system with both medium- and low-temperature loads.
The input objects required to model a detailed transcritical CO\(_{2}\) refrigeration system include the following:
One Refrigeration:TranscriticalSystem object,
At least one refrigeration load object which may include any combination of the following:
Refrigeration:Case,
Refrigeration:WalkIn,
Refrigeration:CaseAndWalkInList (may include both cases and/or walk-in cooler names),
At least one Refrigeration:Compressor object (multiple compressors are entered using a Refrigeration:CompressorList),
One Refrigeration:GasCooler:AirCooled object,
Output variables are available to describe the total heat exchange between all the refrigeration objects and the zones containing these objects. These variables are described at the end of this section.
At least one refrigeration load object must be defined which may be one of two types of loads, including a refrigerated display case and a walk-in cooler, (Ref. Refrigeration:Case, and Refrigeration:WalkIn). If multiple loads are served by the same system, the user should use the refrigerated case and walk-in list object available to assign all cases and walk-ins cooled directly by this system (Ref. Refrigeration:CaseAndWalkInList).
The name of at least one compressor must be defined and a list object is available if the system is served by more than one compressor (Ref. Refrigeration:Compressor and Refrigeration:CompressorList).
Heat is rejected to the outdoors via an air-cooled gas cooler (Ref. Refrigeration:GasCooler:AirCooled).
The Refrigeration:TranscriticalSystem object coordinates the energy flows between the other refrigeration objects and is used to set system parameters.
The inputs for the refrigeration system object, in addition to the names of the other refrigeration objects described above, include a name for this system, the receiver pressure, the subcooler effectiveness, and the refrigeration system working fluid. Optional input fields are also provided for users seeking to keep track of suction pipe heat gains.
A detailed description of the transcritical CO\(_{2}\) booster refrigeration system may be found in the Refrigeration section of the Engineering Reference.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a transcritical CO\(_{2}\) refrigeration system. Any reference to this refrigeration system by another object will use this name.
Field: System Type[LINK]
Identifies the transcritical CO\(_{2}\) refrigeration system as either a single-stage system with only medium-temperature loads, or a two-stage system with both medium- and low-temperature loads. Valid choices are: SingleStage for single stage systems or TwoStage for two stage systems.
Field: Medium Temperature Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, a single walk-in, or a particular list of refrigerated cases and walk-ins, that is cooled by the medium-temperature stage of the refrigeration system. The name will be validated against the case, walk-in, and CaseAndWalkInList names (Ref. Refrigeration:Case, Refrigeration:WalkIn, and Refrigeration:CaseAndWalkInList) in the input file. Only medium temperature cases and walk-ins served directly by the system should be included in this list. Note that this entry is required for both single-stage and two-stage systems.
Field: Low Temperature Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, a single walk-in, or a particular list of refrigerated cases and walk-ins, that is cooled by the low-temperature stage of the refrigeration system. The name will be validated against the case, walk-in, and CaseAndWalkInList names (Ref. Refrigeration:Case, Refrigeration:WalkIn, and Refrigeration:CaseAndWalkInList) in the input file. Only low temperature cases and walk-ins served directly by the system should be included in this list. Note that this entry is valid only for two-stage systems.
Field: Refrigeration Gas Cooler Name[LINK]
The name of the gas cooler that is used to reject heat from the transcritical refrigeration system. The name will be validated against the gas cooler names (Ref. Refrigeration:GasCooler:AirCooled) in the input file.
Field: High Pressure Compressor or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of compressors, that provides compression for a single-stage system or the high pressure stage of a two-stage system. The name will be validated against the compressor list names (Ref. List:Refrigeration:Compressors) in the input file. Note that this entry is required for both single-stage and two-stage systems.
Field: Low Pressure Compressor or Compressor List Name[LINK]
Identifies a single compressor, or a particular list of compressors, that provides compression for the low pressure stage of a two-stage system. The name will be validated against the compressor list names (Ref. List:Refrigeration:Compressors) in the input file. Note that this entry is valid only for two-stage systems.
Field: Receiver Pressure[LINK]
This numeric field specifies the refrigerant pressure (Pa) in the receiver. The default value for the receiver pressure is 4.0 × 10\(^{6}\) Pa.
Field: Subcooler Effectiveness[LINK]
This numeric field specifies the heat exchanger effectiveness of the subcooler. The default value for the subcooler effectiveness is 0.4.
Field: Refrigeration System Working Fluid Type[LINK]
The type of refrigerant used by the system. It is assumed that carbon dioxide will be the refrigerant used in the transcritical CO\(_{2}\) refrigeration system. However, the user must specify the name used in the input file which refers to carbon dioxide. This name will be validated against Fluid Names (Ref. Fluid Properties section) in the input file. Note that the corresponding property data for carbon dioxide (R744), available in FluidPropertiesRefData.idf, must be supplied in the input file.
Field: Sum UA Suction Piping for Medium Temperature Loads[LINK]
This optional field is typically used to determine the impact of pipe heat gains on system performance and zone heat balance. Enter the value for suction piping heat gain (in W/C) for the medium-temperature suction line, i.e., sum up the product of the pipe wall insulation conductance times the outer surface area of the pipe insulation. Please see the Engineering Reference for guidance in calculating this value. If the Sum UA Suction Piping for Medium Temperature Loads is entered, the Medium Temperature Suction Piping Zone Name is also required.
Field: Medium Temperature Suction Piping Zone Name[LINK]
This optional field is typically used to determine the impact of pipe heat gains on system performance. If the previous field, Sum UA Suction Piping for Medium Temperature Loads, is blank, this field will not be used. Enter the name of the zone where the medium-temperature suction piping is located. The suction piping heat gains will be calculated based upon the air temperature within this zone. The heat balance of this zone will also be affected by the piping heat exchange. Additional output variables are described at the end of this section for the total impact of refrigeration on zones, including suction pipe heat exchange.
Field: Sum UA Suction Piping for Low Temperature Loads[LINK]
This optional field is typically used to determine the impact of pipe heat gains on system performance and zone heat balance. Enter the value for suction piping heat gain (in W/C) for the low-temperature suction line, i.e., sum up the product of the pipe wall insulation conductance times the outer surface area of the pipe insulation. Please see the Engineering Reference for guidance in calculating this value. If the Sum UA Suction Piping for Low Temperature Loads is entered, the Low Temperature Suction Piping Zone Name is also required. Note that this entry is valid only for two-stage systems.
Field: Low Temperature Suction Piping Zone Name[LINK]
This optional field is typically used to determine the impact of pipe heat gains on system performance. If the previous field, Sum UA Suction Piping for Low Temperature Loads, is blank, this field will not be used. Enter the name of the zone where the low-temperature suction piping is located. The suction piping heat gains will be calculated based upon the air temperature within this zone. The heat balance of this zone will also be affected by the piping heat exchange. Additional output variables are described at the end of this section for the total impact of refrigeration on zones, including suction pipe heat exchange. Note that this entry is valid only for two-stage systems.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Medium Temperature System”). A new meter for reporting is created for each unique subcategory (Ref. Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
The following is an example input for a transcritical CO\(_{2}\) refrigeration system.
Outputs[LINK]
Zone,Average, Refrigeration Transcritical System Total High Pressure Compressor Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Total High Pressure Compressor Electric Energy [J]
Zone,Average, Refrigeration Transcritical System Low Pressure Compressor Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Low Pressure Compressor Electric Energy [J]
Zone,Sum, Refrigeration Transcritical System Total Compressor Electric Energy [J]
Zone,Average, Refrigeration Transcritical System Average COP [W/W]
Zone,Average, Refrigeration Transcritical System Medium Temperature Cases and Walk Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Medium Temperature Cases and Walk Ins Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Low Temperature Cases and Walk Ins Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low Temperature Cases and Walk Ins Heat Transfer Energy [J]
Zone,Sum, Refrigeration Transcritical System Total Cases and Walk Ins Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Medium Temperature Suction Pipe Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Medium Temperature Suction Pipe Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Low Temperature Suction Pipe Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low Temperature Suction Pipe Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System High Pressure Compressor Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System High Pressure Compressor Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Low Pressure Compressor Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Low Pressure Compressor Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Net Rejected Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Net Rejected Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Estimated Refrigerant Inventory Mass [kg]
Zone,Average, Refrigeration Transcritical System Refrigerant Mass Flow Rate [kg/s]
Zone,Average, Refrigeration Transcritical System Medium Temperature Evaporating Temperature [C]
Zone,Average, Refrigeration Transcritical System Medium Temperature Suction Temperature [C]
Zone,Average, Refrigeration Transcritical System Low Temperature Evaporating Temperature [C]
Zone,Average, Refrigeration Transcritical System Low Temperature Suction Temperature [C]
Refrigeration Transcritical System Total High Pressure Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s high pressure compressor(s) in Watts.
Refrigeration Transcritical System Total High Pressure Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s high pressure compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Transcritical System Low Pressure Compressor Electric Power [W][LINK]
This output is the total electric power input to the system’s low pressure compressor(s) in Watts.
Refrigeration Transcritical System Low Pressure Compressor Electric Energy [J][LINK]
This is the electricity consumption of the system’s low pressure compressor(s) in Joules for the timestep being reported. The individual consumption for each compressor is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Transcritical System Total Compressor Electric Energy [J][LINK]
This output is the total electric power input to all of the system’s compressor(s) in Watts.
Refrigeration Transcritical System Average COP [W/W][LINK]
This output is the system average compressor COP, which is the total refrigeration effect divided by the total power to all of the compressors.
Refrigeration Transcritical System Medium Temperature Cases and Walk Ins Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the medium temperature refrigerated cases and walk-ins served directly by this system in Watts. It is the sum of all of the heat transfer rates for the medium temperature refrigerated cases and walk-ins that are connected directly to this system.
Refrigeration Transcritical System Medium Temperature Cases and Walk Ins Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the medium temperature refrigerated cases and walk-ins served directly by this system in Joules. It is the sum of all of the heat transferred for the medium temperature refrigerated cases and walk-ins that are connected directly to this system.
Refrigeration Transcritical System Low Temperature Cases and Walk Ins Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the low temperature refrigerated cases and walk-ins served directly by this system in Watts. It is the sum of all of the heat transfer rates for the low temperature refrigerated cases and walk-ins that are connected directly to this system.
Refrigeration Transcritical System Low Temperature Cases and Walk Ins Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from the low temperature refrigerated cases and walk-ins served directly by this system in Joules. It is the sum of all of the heat transferred for the low temperature refrigerated cases and walk-ins that are connected directly to this system.
Refrigeration Transcritical System Total Cases and Walk Ins Heat Transfer Energy [J][LINK]
This output is the total heat transfer energy from all the low- and medium-temperature refrigerated cases and walk-ins served directly by this system in Joules. It is the sum of all of the heat transferred for all the refrigerated cases and walk-ins that are connected directly to this system.
Refrigeration Transcritical System Medium Temperature Suction Pipe Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate for the medium-temperature suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the medium-temperature suction piping heat gain characteristics in the input.
Refrigeration Transcritical System Medium Temperature Suction Pipe Heat Transfer Energy [J][LINK]
This output is the total heat transfer rate for the medium-temperature suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the medium-temperature suction piping heat gain characteristics in the input.
Refrigeration Transcritical System Low Temperature Suction Pipe Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate for the low-temperature suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the low-temperature suction piping heat gain characteristics in the input.
Refrigeration Transcritical System Low Temperature Suction Pipe Heat Transfer Energy [J][LINK]
This output is the total heat transfer rate for the low-temperature suction piping served by this system in Watts. Note this is an optional input, and is only available if the user has described the low-temperature suction piping heat gain characteristics in the input.
Refrigeration Transcritical System High Pressure Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the high pressure Compressors in Watts. It is the sum of all of the heat transfer rates for the low- and medium-temperature refrigerated cases and walk-ins as well as the low pressure compressors that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value.
Refrigeration Transcritical System High Pressure Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the high pressure compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Transcritical System Low Pressure Compressor Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate of the low pressure Compressors in Watts. It is the sum of all of the heat transfer rates for the low temperature refrigerated cases and walk-ins that are cooled by this system. This value does not include compressor or condenser fan heat. If specified as in input value, the suction pipe heat gains are included in this value.
Refrigeration Transcritical System Low Pressure Compressor Heat Transfer Energy [J][LINK]
This is the total heat transfer of the low pressure compressors in Joules for the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Transcritical System Net Rejected Heat Transfer Rate [W][LINK]
This output is the total heat rejected by this system to the system gas cooler in Watts. It does not include system heat rejection that has been recovered for useful purposes.
Refrigeration Transcritical System Net Rejected Heat Transfer Energy [J][LINK]
This output is the total heat rejected by this system to the system gas cooler in Joules for the timestep being reported. It does not include system heat rejection that has been recovered for useful purposes.
Refrigeration Transcritical System Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input refrigerant inventory values for the gas cooler, receiver, cases, and liquid pipes that are a part of this system.
Refrigeration Transcritical System Refrigerant Mass Flow Rate [kg/s][LINK]
This output is the calculated refrigerant mass flow rate through the high pressure compressors for this system.
Refrigeration Transcritical System Medium Temperature Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature for the medium temperature loads.
Refrigeration Transcritical System Medium Temperature Suction Temperature [C][LINK]
This is the temperature at the high pressure compressor inlet including superheat after the display cases and superheat from the suction line heat exchanger.
Refrigeration Transcritical System Low Temperature Evaporating Temperature [C][LINK]
This is the saturated evaporating temperature for the low-temperature loads.
Refrigeration Transcritical System Low Temperature Suction Temperature [C][LINK]
This is the temperature at the low pressure compressor inlet including superheat after the display cases.
Refrigeration:Compressor[LINK]
The compressors are described here using manufacturer’s data for curves that provide the efficiency, cooling capacity, and power consumption. The corresponding rated values for cycle superheat and subcooling are also required.
A dataset has been provided containing the compressor rating data, including the performance curve inputs, for a large number of compressors. See RefrigerationCompressorCurves.idf.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a compressor. Any reference to this compressor by another object will use this name.
Field: Refrigeration Compressor Power Curve Name[LINK]
This required field provides the name of the curve object that describes the compressor power as a function of the evaporating and condensing temperatures, as specified in ARI 540. The curve is of the bicubic form(ref: Curve:Bicubic). However, the input order for the Energy Plus bicubic curve does not match the ARI 540 standard order. When this curve is entered, the user should use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum evaporating temperature and N12 is the Maximum evaporating temperature.
N13 is the the Minimum condensing temperature and N14 is the Maximum condensing temperature
Field: Refrigeration Compressor Capacity Curve Name[LINK]
This required field provides the name of the curve object that describes the compressor cooling capacity as a function of the evaporating and condensing temperatures, as specified in ARI 540. The curve is of the bicubic form(ref: Curve:Bicubic). However, the input order for the Energy Plus bicubic curve does not match the ARI 540 standard order. When this curve is entered, the user should use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum evaporating temperature and N12 is Maximum evaporating temperature.
N13 is the Minimum condensing temperature and N14 is the Maximum condensing temperature
Field: Rated Superheat[LINK]
Some manufacturers specify a constant return gas temperature while others specify a constant superheat (the difference between the saturated evaporating temperature and the actual return gas temperature). Use this field for compressors that provide their rated superheat. (Do NOT use both this field and the Rated Return Gas Temperature field.) The rated superheat is specified in units of delta C.
Field: Rated Return Gas Temperature[LINK]
Some manufacturers specify a constant return gas temperature ( which may also be called the Rated Suction Temperature) while others specify a constant superheat. Use this field for compressors that provide their rated return gas temperature. (Do NOT use both this field and the Rated Superheat field.) The rated return gas temperature is specified in units of C.
Field: Rated Liquid Temperature[LINK]
Some compressor manufactures rate their equipment according to a constant subcooling (the difference between the saturated condensing temperature and the actual liquid temperature entering the thermal expansion valve before the refrigeration load). Other manufacturers specify a constant liquid temperature.Use this field if the manufacturer specifies the rated liquid temperature. (Do NOT use both this field and the Rated Subcooling field.) The units for this field are degrees C.
Field: Rated Subcooling[LINK]
Some compressor manufactures rate their equipment according to a constant subcooling (the difference between the saturated condensing temperature and the actual liquid temperature entering the thermal expansion valve before the refrigeration load). Other manufacturers specify a constant liquid temperature.Use this field if the manufacturer specifies the rated subcooling. (Do NOT use both this field and the Rated Liquid Temperature field.) The units for this field are delta C.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature System”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Mode-of-Operation[LINK]
The type of mode of operation. Valid choices are Subcritical and Transcritical. If this input field is blank, the default will be Subcritical. If Transcritical is selected as mode of operation, the next two input fields are required to model transcritical cycle operation electric power consumption and cooling capacity.
Field: Transcritical-Compressor-Power-Curve-Name[LINK]
This field is the name of the curve object that describes the transcritical operation compressor power as a function of the saturated suction temperature and the gas cooler pressure. The curve is of the bicubic form(ref: Curve:Bicubic). However, the input order of the coefficients for the EnergyPlus bicubic curve does not match the ARI 540 standard order. When this curve is entered, the user should use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum saturated suction temperature.
N12 is the Maximum saturated suction temperature.
N13 is the the Minimum gas cooler pressure and N14 is the Maximum gas cooler pressure.
If Transcritical is selected as Mode of Operation, then this input field is required.
Field: Transcritical-Compressor-Capacity-Curve-Name[LINK]
This field is the name of the curve object that describes the transcritical compressor operation cooling capacity as a function of the saturated suction temperature and the gas cooler outlet enthalpy. The curve is of the bicubic form(ref: Curve:Bicubic). However, the input order of the coefficients for the EnergyPlus bicubic curve does not match the ARI 540 standard order. When this curve is entered, the user should use the following assignments:
N1 is ARI C1 and N2 is ARI C2.
N3 is ARI C4 and N4 is ARI C3.
N5 is ARI C6 and N6 is ARI C5,
N7 is ARI C7.
N8 is ARI C10, N9 is ARI C8, and N10 is ARI C9.
N11 is the Minimum saturated suction temperature.
N12 is the Maximum saturated suction temperature.
N13 is the the Minimum gas cooler outlet enthalpy and N14 is the Maximum gas cooler outlet enthalpy.
If Transcritical is selected as Mode of Operation, then this input field is required.
The following is an example input for a refrigeration compressor.
Outputs[LINK]
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES AND/OR WALKINS:
Zone,Average,Refrigeration Compressor Electric Power [W]
Zone,Sum,Refrigeration Compressor Electric Energy [J]
Zone,Average,Refrigeration Compressor Heat Transfer Rate [W]
Zone,Sum,Refrigeration Compressor Heat Transfer Energy [J]
Zone,Sum,Refrigeration Compressor Run Time Fraction []
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR CHILLERS:
HVAC,Average,Refrigeration Air Chiller System Compressor Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller System Compressor Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller System Compressor Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller System Compressor Heat Transfer Energy [J]
HVAC,Average,Refrigeration Chiller Compressor Run TimeFraction []
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE CASES AND/OR WALKINS[LINK]
Refrigeration Compressor Electric Power [W][LINK]
This output is the electric power input to the compressor in Watts.
Refrigeration Compressor Electric Energy [J][LINK]
This is the electric energy consumed by the compressor in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Compressor Heat Transfer Rate [W][LINK]
This output is the heat removed from the refrigerated cases by the compressor in Watts.
Refrigeration Compressor Heat Transfer Energy [J][LINK]
This is the heat removed from the refrigerated cases by the compressor in Joules for the timestep being reported.
Refrigeration Compressor Run Time Fraction [][LINK]
This is the fraction of the time step when the compressor ran to meet the load. It is a value between 0.0 and 1.0.
THE FOLLOWING OUTPUTS ARE AVAILABLE FOR SYSTEMS THAT SERVE AIR CHILLERS[LINK]
Refrigeration Air Chiller System Compressor Electric Power [W][LINK]
This output is the electric power input to the compressor in Watts.
Refrigeration Air Chiller System Compressor Electric Energy [J][LINK]
This is the electric energy consumed by the compressor in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Compressor Heat Transfer Rate [W][LINK]
This output is the heat removed from the refrigerated cases by the compressor in Watts.
Refrigeration Air Chiller System Compressor Heat Transfer Energy [J][LINK]
This is the heat removed from the refrigerated cases by the compressor in Joules for the timestep being reported.
Refrigeration Chiller Compressor Run Time Fraction [][LINK]
This is the fraction of the time step when the compressor ran to meet the load. It is a value between 0.0 and 1.0.
Refrigeration:CompressorList[LINK]
This object provides a list of all the compressors included within a single refrigeration system (Ref: Refrigeration:System). Each list must contain at least one compressor. The order in which the individual compressors are listed here will be the order in which the compressors are dispatched to meet the system load. That is, at very low loads, only compressor #1 will be operating. As the load increases, the first two compressors will be operating, and so on. This list is extensible.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a compressor list. Any reference to this compressor list by another object will use this name. The compressor list cannot have the same name as any individual compressor.
Field: Refrigeration Compressor <x> Name[LINK]
Identifies a particular compressor that works in conjunction with the other compressors on this list to provides cooling to a single refrigeration system. The name will be validated against the compressor names (ref: Refrigeration:Compressor) in the input file. Up to 20 are available in the IDD; this object is extensible.
The following is an example input for a compressor list.
Refrigeration:Subcooler[LINK]
Two types of subcoolers are modeled by the detailed refrigeration system. As described in the Engineering Reference, the liquid suction heat exchanger uses cool suction gas to subcool the hot condensate after it leaves the condenser and before it reaches the thermal expansion valve. For the liquid suction heat exchanger, both the source and sink of energy are located within the same refrigeration system. In contrast, a mechanical subcooler is used to transfer cooling capacity from one refrigeration system to another. The mechanical subcooler is listed as a part of the system for which the condensate is cooled. However, the input data for the mechanical subcooler includes a field that identifies the system that provides the cooling capacity.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a subcooler. Any reference to this subcooler by another object will use this name.
Field: Subcooler Type[LINK]
The type of subcooler. Valid choices are Mechanical and LiquidSuction. If the field is blank, the default will be LiquidSuction.
Field: Liquid Suction Design Subcooling Temperature Difference[LINK]
This numeric field is the design subcooling temperature difference (DeltaC) for a liquid suction heat exchanger and should be blank for a mechanical subcooler.
Field: Design Liquid Inlet Temperature[LINK]
This numeric field is the design inlet temperature (C) for the hot liquid entering a liquid suction heat exchanger and should be blank for a mechanical subcooler.
Field: Design Vapor Inlet Temperature[LINK]
This numeric field is the design inlet temperature (C) for the cool vapor entering a liquid suction heat exchanger and should be blank for a mechanical subcooler.
Field: Capacity-Providing System[LINK]
This field is the name of the refrigeration system object that provides the cooling capacity for the mechanical subcooler (ref: Refrigeration:System Name). This field should be blank for a liquid suction heat exchanger.
Field: Outlet Control Temperature[LINK]
This numeric field is the controlled outlet temperature (C) for subcooled liquid exiting a mechanical subcooler. This field should be blank for a liquid suction heat exchanger.
The following is example input for both liquid suction and mechanical subcoolers.
! Mechanical Subcooler (uses Med Temp System to cool low temp liquid to 10C)
Outputs[LINK]
FOR SUBCOOLERS ON SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Mechanical Subcooler Heat Transfer Rate [W]
Zone,Sum, Refrigeration System Mechanical Subcooler Heat Transfer Energy [J]
FOR SUBCOOLERS ON SYSTEMS SERVING AIR CHILLERS:
Zone,Average, Refrigeration Air Chiller System Mechanical Subcooler Heat Transfer Rate [W]
Zone,Sum, Refrigeration Air Chiller System Mechanical Subcooler Heat Transfer Energy [J]
FOR SUBCOOLERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration System Mechanical Subcooler Heat Transfer Rate [W][LINK]
This output is the cooling energy transferred from one system’s compressor group to the refrigerant leaving the condenser for another refrigeration system in Watts.
Refrigeration System Mechanical Subcooler Heat Transfer Energy [J][LINK]
This output is the cooling energy transferred from one system’s compressor group to the refrigerant leaving the condenser for another refrigeration system in Joules.
FOR SUBCOOLERS ON SYSTEMS SERVING AIR CHILLERS[LINK]
Refrigeration Air Chiller System Mechanical Subcooler Heat Transfer Rate [W][LINK]
This output is the cooling energy transferred from one system’s compressor group to the refrigerant leaving the condenser for another refrigeration system in Watts.
Refrigeration Air Chiller System Mechanical Subcooler Heat Transfer Energy [J][LINK]
This output is the cooling energy transferred from one system’s compressor group to the refrigerant leaving the condenser for another refrigeration system in Joules.
Refrigeration:Condenser:AirCooled[LINK]
The refrigeration system requires a single condenser to reject the system heat. The air cooled condenser object is one of four options for this condenser. In an air-cooled condenser, the total heat of rejection is characterized by a linear relationship between the difference between the inlet air (usually the outside drybulb) and condensing temperatures. This curve is commonly found in the condenser manufacturers’ literature. This rating curve, which corresponds to ARI 460 standards, also has an associated rated value for subcooling that should be entered. The rated condenser fan power and fan speed control type must be specified. If the condenser is not at ground level, the user may specify an air inlet node name (ref: OutdoorAir:Node name). If the condenser is located inside a conditioned zone, the zone name may be specified(ref: bbbZoneNamebbb). Optional input is provided to help the user compare refrigerant inventories for different systems. These inputs represent the design values for the refrigerant inventory within the condenser, within a receiver beneath the condenser, and in the liquid pipes between the condenser and the refrigerated cases.
Inputs[LINK]
Field: Name[LINK]
Identifies a particular condenser that rejects heat for a one or more refrigeration system(s). The name must be unique and will be validated against all the condenser names (ref: Refrigeration:Condenser:*) in the input file, including names used for evaporative-cooled, water-cooled, and cascade-cooled condensers.
Field: Rated Effective Total Heat Rejection Rate Curve Name[LINK]
This field is the name of a curve object defining the condenser heat rejection as a function of the difference between the condensing and entering air temperatures. The curve should be linear (Curve:Linear). See the Engineering Reference for more discussion on the curve coefficients.
Field: Rated Subcooling Temperature Difference[LINK]
This numeric field specifies the rated subcooling (DeltaC) specified by the manufacturer, consistent with the heat rejection curve rating data.
Field: Condenser Fan Speed Control Type[LINK]
The type of fan speed control used by the condenser fan. Valid choices are Fixed, FixedLinear, VariableSpeed, and TwoSpeed. If the field is blank, Fixed will be used. See the Engineering Reference for a discussion of this option’s effect on fan energy consumption.
Field: Rated Fan Power[LINK]
This numeric field specifies the rated fan power (W) specified by the manufacturer, under standard rating conditions.
Field: Minimum Fan Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to avoid overheating the fan motor or for other reasons. This numeric field should be between 0. and 1. and has a default value of 0.2.
Field: Air Inlet Node Name or Zone Name[LINK]
This optional alpha field contains the name of the node from which the condenser draws its outdoor air or the name of the conditioned zone where the condenser is located. If this field is left blank, the outdoor air drybulb temperature entering the condenser is taken directly from the weather data. If this field is not blank and an outdoor air node name is entered, this node name must also be specified in an OutdoorAir:Node object where the height of the node is taken into consideration when calculating outdoor air temperature from the weather data. Alternately, the node name may be specified in an OutdoorAir:NodeList object where the outdoor air temperature is taken directly from the weather data. If a zone name is entered, the temperature of that zone is used.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condenser (kg) specified by the manufacturer, under standard rating conditions.
Field: Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate receiver (kg) specified by the manufacturer or system designer, under standard rating conditions.
Field: Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate piping (kg) specified by the system designer, under standard rating conditions.
The following is an example input for an air-cooled condenser.
Outputs[LINK]
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Condenser Fan Electric Power [W]
Zone, Sum, Refrigeration System Condenser Fan Electric Energy [J]
Zone,Average, Refrigeration System Condenser Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Total Recovered Heat Transfer Rate [W] Zone, Sum, Refrigeration System Condenser Total Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Recovered for Non-Refrigeration Purposes Energy [J]
Zone,Average, Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Defrost Recovered Heat Transfer Energy [J]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration System Condenser Fan Electric Power [W]
HVAC, Sum, Refrigeration System Condenser Fan Electric Consumption [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W] HVAC, Sum, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Energy [J]
FOR CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser fan(s) in Watts.
Refrigeration System Condenser Fan Electric Consumption [J][LINK]
This is the electricity consumption of the system’s condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration load minus any heat recovered for defrost or other purposes).
Refrigeration System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported (i.e., compressor energy and refrigeration load minus any heat recovered for defrost or other purposes).
Refrigeration System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for all purposes including defrost and water or air heating.
Refrigeration System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for all purposes including defrost and water or air heating for the timestep being reported.
Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating.
Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system.
Refrigeration System Condenser Defrost Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
FOR CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Air Chiller System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser fan(s) in Watts.
Refrigeration Air Chiller System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration load minus any heat recovered for defrost or other purposes).
Refrigeration Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported (i.e., compressor energy and refrigeration load minus any heat recovered for defrost or other purposes).
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for all purposes including defrost and water or air heating.
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for all purposes including defrost and water or air heating for the timestep being reported.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system.
Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration:Condenser:EvaporativeCooled[LINK]
Each refrigeration system requires a single condenser. The evaporative cooled condenser object is one of four options for this condenser. In an evaporative-cooled condenser, the total heat of rejection is characterized by a four-factor relationship between the condensing temperature and the difference between the outside wetbulb and condensing temperatures. This curve must be developed by regression from the condenser manufacturers’ literature. This rating curve, which is based upon rated data taken according to ARI 460 standards, also has an associated rated value for subcooling that should be entered. The rated condenser fan power and fan speed control type must be specified. If the condenser is not at ground level, the user may specify an air inlet node name (ref: OutdoorAir:Node name). Optional input is provided to help the user compare refrigerant inventories for different systems. These input represent the design values for the refrigerant inventory within the condenser, within a receiver beneath the condenser, and in the liquid pipes between the condenser and the refrigerated cases.
Additional inputs are needed for basin heater parameters, water pump power, and water source. An evaporative cooling availability schedule is available.
Inputs[LINK]
Field: Name[LINK]
Identifies a particular condenser that rejects heat for a one or more refrigeration system(s). The name must be unique and will be validated against all the condenser names (ref: Refrigeration:Condenser:*) in the input file, including names used for air-cooled, water-cooled and cascade-cooled condensers.
Field: Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection effect (W) at standard rating conditions per ARI 490. Be sure the rating corresponds to the correct refrigerant.
Field: Rated Subcooling Temperature Difference[LINK]
This numeric field specifies the rated subcooling (DeltaC) specified by the manufacturer, consistent with the rated value for total heat rejection.
Field: Fan Speed Control Type[LINK]
The type of fan speed control used by the condenser fan. Valid choices are Fixed, FixedLinear, VariableSpeed, and TwoSpeed. If the field is blank, Fixed will be used. See the Engineering Reference for a discussion of this option’s effect on fan energy consumption.
Field: Rated Fan Power[LINK]
This numeric field specifies the rated fan power (W) specified by the manufacturer, under standard rating conditions.
Field: Minimum Fan Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to avoid overheating the fan motor or for other reasons. This numeric field has a minimum value of 0. and a default value of 0.2.
Field: Approach Temperature Constant Term[LINK]
As described in the Engineering Reference (ref Refrigeration:Condenser:Evaporative), the heat rejection capacity factor is specified according to the form (where Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A1 and has a default value of 6.63, a minimum of 0. and a maximum of 20. (C)
Field: Approach Temperature Coefficient 2[LINK]
As described in the Engineering Reference (ref Refrigeration:Condenser:Evaporative), the heat rejection capacity factor is specified according to the form (where Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A2 and has a default value of 0.468, a minimum of 0, and a maximum of 20 (C).
Field: Approach Temperature Coefficient 3[LINK]
As described in the Engineering Reference (ref Refrigeration:Condenser:Evaporative), the heat rejection capacity factor is specified according to the form (where Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) +(1 + A4)(Twb)
This numeric field is the value for A3 and has a default value of 17.93, a minimum of 0, and a maximum of 30 (C).
Field: Approach Temperature Coefficient 4[LINK]
As described in the Engineering Reference (ref Refrigeration:Condenser:Evaporative), the heat rejection capacity factor is specified according to the form (where Twetbulb and Tcondense are in C):
Tcondense = A1 + A2(hrcf) + A3/(hrcf) + (1 + A4)(Twb)
This numeric field is the value for A4 and has a default value of -0.322, a minimum of -20., and a maximum of 20 (dimensionless).
Field: Minimum Capacity Factor[LINK]
This numeric field is the minimum heat rejection capacity factor in the manufacturer’s data used to develop the equation described in the preceding four fields. The default value is 0.5.
Field: Maximum Capacity Factor[LINK]
This numeric field is the maximum heat rejection capacity factor in the manufacturer’s data used to develop the equation described in the preceding four fields. The default value is 5.0.
Field: Air Inlet Node Name[LINK]
This optional alpha field contains the name of the node from which the condenser draws its outdoor air. If this field is left blank, the outdoor air drybulb temperature entering the condenser is taken directly from the weather data. If this field is not blank, this node name must also be specified in an OutdoorAir:Node object where the height of the node is taken into consideration when calculating outdoor air temperature from the weather data. Alternately, the node name may be specified in an OutdoorAir:NodeList object where the outdoor air temperature is taken directly from the weather data.
Field: Rated Air Flow Rate[LINK]
The air volume flow rate, in m\(^{3}\)per second, entering the evaporative condenser. This value is used to calculate the amount of water evaporated when evaporatively cooling the condenser inlet air. The value for this field must be greater than zero. This input field is also autocalculatable, equivalent to 0.000144 m\(^{3}\)/s per watt of total cooling capacity [850 cfm/ton] where the total cooling capacity is the total heat of rejection.
Field: Basin Heater Capacity[LINK]
This field defines the power level of the basin heater, if applicable, used to avoid water freezing in an outdoor evaporative cooler basin. This numeric field contains the capacity of the electric basin heater in Watts per degree C. This field is used in conjunction with the Basin Heater Set Point Temperature described in the following field. The basin heater electric power is equal to this field multiplied by the difference between the basin heater set point temperature and the dry-bulb temperature of the condenser coil inlet air. The basin heater only operates when the condenser fan is off (i.e., no compressor heat rejection). The basin heater capacity must be greater than or equal to zero, with a default value of 200 W/C if this field is left blank.
Field: Basin Heater Setpoint Temperature[LINK]
This numeric field contains the set point temperature (°C) for the basin heater described in the previous field. The basin heater is active when the outdoor air dry-bulb temperature falls below this set point temperature, as long as the condenser fan is off. The default value is 2°C if this field is left blank.
Field: Rated Water Pump Power[LINK]
The rated power of the evaporative condenser water pump in Watts. This value is used to calculate the power required to pump the water used to evaporatively cool the condenser inlet air. The value for this field must be greater than or equal to 0, with a default value of 1000 Watts if this field is left blank. This input field is also autocalculatable, equivalent to 0.004266 W per Watt [15 W/ton] of total cooling capacity.
Field: Evaporative Water Supply Tank Name[LINK]
This field is used to define where the condenser obtains water used for evaporative cooling. If this field is left blank, the unit will obtain water directly from the mains (Ref. Water Mains Temperatures). If the name of a Water Storage Tank object is used here, then the unit will obtain its water from that tank.
Field: Evaporative Condenser Availability Schedule Name[LINK]
For evaporative cooled condensers, the name of the optional schedule (Ref: Schedule) that specifies the time periods that evaporative cooling is available/unavailable. In some colder climates, evaporative cooling is periodically discontinued and the basin sumps drained to avoid freezing and to avoid ice formation on the condenser. In these times, the condenser runs as a typical dry air cooled condenser, and related evaporative cooling systems (e.g., water pump, basin heaters) do not operate. Use of this optional schedule permits modeling of planned, seasonal interruptions of evaporative cooling. All schedule values must be greater than or equal to zero. Typically, an ON/OFF schedule type is used with values being either 0 or 1. A schedule value of 1 indicates that evaporative cooling is available during the defined time period, and a value of 0 denotes that evaporative cooling is not available during the defined time period. If the schedule name is omitted (blank), then the model assumes that evaporative cooling of the condenser is available for the entire simulation period. Note: the use of this schedule is the correct way to model an evaporative condenser in a climate subject to freezing weather. However, because some users will take a single model description and run it for a multiple climates, the code also includes an automatic switch from wet to dry operation, as described in the Engineering Reference.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condenser (kg) specified by the manufacturer, under standard rating conditions.
Field: Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate receiver (kg) specified by the manufacturer or system designer, under standard rating conditions.
Field: Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate piping (kg) specified by the system designer, under standard rating conditions.
The following is an example input for an evaporative condenser
Outputs[LINK]
Zone,Average, Refrigeration System Condenser Fan Electric Power [W]
Zone, Sum, Refrigeration System Condenser Fan Electric Consumption [J]
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Condenser Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Total Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Total Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Defrost Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Pump Electric Power [W]
Zone, Sum, Refrigeration System Condenser Pump Electric Energy [J]
Zone,Average, Refrigeration System Condenser Basin Heater Electric Power [W]
Zone, Sum, Refrigeration System Condenser Basin Heater Electric Energy [J]
Zone,Average, Refrigeration System Condenser Evaporated Water Volume Flow Rate [m3/s]
Zone, Sum, Refrigeration System Condenser Evaporated Water Volume [m3]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Pump Electric Power [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Pump Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Basin Heater Electric Power [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Basin Heater Electric Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Evaporated Water Volume Flow Rate [m3/s]
HVAC, Sum, Refrigeration Air Chiller System Condenser Evaporated Water Volume [m3]
FOR CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser fan(s) in Watts.
Refrigeration System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
Refrigeration System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose.
Refrigeration System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose for the timestep being reported.
Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for purposes such as water or air heating.
Refrigeration System Condenser Heat Recovered for Non-Refrigeration Purposes Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for defrost purposes within the refrigeration system..
Refrigeration System Condenser Defrost Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration System Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water pump used with evaporative cooling of the condenser.
Refrigeration System Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water pump used with evaporative cooling of the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration System Condenser Basin Heater Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water heater in the basin of the evaporative system used to cool the condenser.
Refrigeration System Condenser Basin Heater Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water heater used to prevent freezing of the evaporative cooling system for the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration System Condenser Evaporated Water Volume Flow Rate [m\(^{3}\)/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while providing evaporative cooling of the condenser.
Refrigeration System Condenser Evaporated Water Volume [m\(^{3}\)][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing evaporative cooling of the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Water, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
FOR CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Air Chiller System Condenser Fan Electric Power [W][LINK]
This output is the electric input to the system’s condenser fan(s) in Watts.
Refrigeration Air Chiller System Condenser Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s condenser fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose.
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose for the timestep being reported.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for purposes such as water or air heating.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for defrost purposes within the refrigeration system.
Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration Air Chiller System Condenser Pump Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water pump used with evaporative cooling of the condenser.
Refrigeration Air Chiller System Condenser Pump Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water pump used with evaporative cooling of the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Air Chiller System Condenser Basin Heater Electric Power [W][LINK]
This is the electrical power requirement in Watts for the timestep being reported for the water heater in the basin of the evaporative system used to cool the condenser.
Refrigeration Air Chiller System Condenser Basin Heater Electric Energy [J][LINK]
This is the electricity consumption in Joules of the water heater used to prevent freezing of the evaporative cooling system for the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration Air Chiller System Condenser Evaporated Water Volume Flow Rate [m3/s][LINK]
The volumetric flow rate in m\(^{3}\)/s of water consumed while providing evaporative cooling of the condenser.
Refrigeration Air Chiller System Condenser Evaporated Water Volume [m3][LINK]
This is the water consumed by evaporation in m\(^{3}\) while providing evaporative cooling of the condenser for the timestep being reported. This output is also added to a meter with Resource Type = Water, End Use Key = Refrigeration, Group Key = Plant. Use of an optional subkey category is also available, with default to the General end-use subcategory (Ref. Output:Meter objects).
Refrigeration:Condenser:WaterCooled[LINK]
The refrigeration system requires a single condenser. The water cooled condenser object is one of four options for this condenser. Manufacturer’s data is required for the rated total heat rejection, the rated condensing temperature, and the rated leaving liquid refrigerant temperature, all per ARI 450. These values are used to calculate the subcooling included in the rated capacity. The inlet and outlet node names as well as the water outlet temperature schedule name are required. Optional input is provided to help the user compare refrigerant inventories for different systems. These input represent the design values for the refrigerant inventory within the condenser, within a receiver beneath the condenser, and in the liquid pipes between the condenser and the refrigerated cases.
Inputs[LINK]
Field: Name[LINK]
Identifies a particular condenser that rejects heat for one or more refrigeration system(s). The name must be unique and will be validated against all the condenser names (ref: Refrigeration:Condenser) in the input file, including names used for air-cooled, evaporative-cooled, and cascade-cooled condensers.
Field: Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection effect (W) at standard rating conditions per ARI 450. Be sure the rating corresponds to the correct refrigerant.
Field: Rated Condensing Temperature[LINK]
This numeric field provides the rated condensing temperature (C) corresponding to the rated heat rejection capacity.
Field: Rated Subcooling Temperature Difference[LINK]
This numeric field provides the rated liquid refrigerant subcooling (DeltaC) corresponding to the rated heat rejection capacity. Note this is equal to the difference between the saturated condensing temperature and the leaving liquid refrigerant temperature.
Field: Rated Water Inlet Temperature[LINK]
This numeric field provides the rated water inlet temperature (C) corresponding to the rated heat rejection capacity at the rated condensing temperature.
Field: Water Inlet Node Name[LINK]
A node name for the water-side condenser inlet must be provided.
Field: Water Outlet Node Name[LINK]
A node name for the water-side condenser outlet must be provided.
Field: Water-Cooled Loop Flow Type[LINK]
The type of flow loop should be specified. The two choices are VariableFlow, in which a Pump:VariableSpeed must be included in the plant loop, or ConstantFlow, in which the loop circuit has a constant flow rate, typically associated with a Pump:ConstandSpeed object. If the flow type is VariableFlow, the flow needed to remove the condenser heat energy will be calculated and requested of the pump. If the flow type is ConstantFlow, the outlet water temperature will be determined based on the fixed loop flow rate and heat energy to be removed. The default type is VariableFlow. Refer to additional discussion in the Engineering Reference.
Field: Water Outlet Temperature Schedule Name[LINK]
When the water-cooled loop flow type is “VariableFlow”, the name of a schedule (Ref: Schedule) that defines the desired condenser water outlet temperature must be provided. The schedule may define an outlet temperature that varies through time.
Field: Water Design Flow Rate[LINK]
When the water-cooled loop flow type is “ConstantFlow”, this is the design water flow rate in m\(^{3}\)/s that will be requested initially. This requested flow will be passed to the loop simulation, and resulting actual flow will be dependent upon supply system capabilities (e.g., pump capability). The design flow rate must always be less than the maximum flow rate, defined below.
Field: Water Maximum Flow Rate[LINK]
This numeric field is the maximum water flow rate in m\(^{3}\)/s that will be allowed through the condenser. When the loop flow type is Variable Flow, if the calculated flow rate is higher than the maximum flow rate, an error message will be generated, and the flow rate will be reset to the maximum flow rate.
Field: Maximum Water Outlet Temperature[LINK]
This numeric field specifies the maximum allowed water temperature in degrees C leaving the condenser. The default value is 55 degrees C.
Field: Minimum Water Inlet Temperature[LINK]
This numeric field specifies the minimum allowed water temperature in degrees C entering the compressor rack condenser. The default value is 10 degrees C. Refer to additional discussion in the Engineering Reference.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature System”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condenser (kg) specified by the manufacturer, under standard rating conditions.
Field: Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate receiver (kg) specified by the manufacturer or system designer, under standard rating conditions.
Field: Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate piping (kg) specified by the system designer, under standard rating conditions.
The following is an example input for a water cooled condenser.
Outputs[LINK]
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Condenser Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Total Recovered Heat Transfer Rate [W] Zone, Sum, Refrigeration System Condenser Total Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Recovered for Non-Refrigeration Purposes Energy [J]
Zone,Average, Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Defrost Recovered Heat Transfer Energy [J]
Zone,Average, Refrigeration System Condenser Water Mass Flow Rate [kg/s]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W] HVAC, Sum, Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Energy [J]
HVAC,Average, Refrigeration Air Chiller System Condenser Fluid Mass Flow Rate [kg/s]
FOR CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
Refrigeration System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose.
Refrigeration System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose for the timestep being reported.
Refrigeration System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating.
Refrigeration System Condenser Heat Recovered for Non-Refrigeration Purposes Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system..
Refrigeration System Condenser Heat Energy Recovered for Refrigeration Defrost Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration System Condenser Water Mass Flow Rate [kg/s][LINK]
This is the mass flow rate of the water used to cool the condenser in kg/s.
FOR CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose.
Refrigeration Air Chiller System Condenser Total Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser refrigerant inlet flow for any purpose for the timestep being reported.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating.
Refrigeration Air Chiller System Condenser Non Refrigeration Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for purposes such as water or air heating for the timestep being reported.
Refrigeration Air Chiller System Condenser Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system.
Refrigeration Chiller System Condenser Heat Energy Recovered for Refrigeration Defrost Energy [J][LINK]
This is the total heat recovered from the condenser inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration Air Chiller System Condenser Fluid Mass Flow Rate [kg/s][LINK]
This is the mass flow rate of the water used to cool the condenser in kg/s.
Refrigeration:Condenser:Cascade[LINK]
The refrigeration system requires a single condenser. The cascade condenser object is one of four options for this condenser. The cascade condenser is unlike the other condenser options because it rejects heat to another, higher-temperature, refrigeration system. That is, the cascade condenser acts as a heat rejection object for one system, but acts as a refrigeration load for another system. Therefore, this object will be referenced twice: first for the system rejecting heat (see the field Refrigeration Condenser Name for the object Refrigeration:System), and second for the system absorbing the heat (see the input for the field Refrigeration Transfer Load or TransferLoad List Name for the object Refrigeration:System or the field Cascade Condenser Name or Secondary System Name for the object Refrigeration:TransferLoadList).
Manufacturer’s data is required for the rated condensing temperature and the rated approach temperature difference. The user must also specify the condensing temperature control type. There are two choices. The user can specify “Fixed” and the condensing temperature will be held constant at the input value. The user can specify “Float” if they want the condensing temperature to be set by other refrigeration loads served by the higher-temperature system.
The rated heat rejection capacity is not used except as a rough input value check on the overall system sizing. Optional input is provided to help the user compare refrigerant inventories for different systems. These inputs represent the design values for the refrigerant inventory within the condenser, within a receiver beneath the condenser, and in the liquid pipes between the condenser and the refrigerated cases.
Inputs[LINK]
Field: Name[LINK]
Identifies a particular condenser that rejects heat for a single refrigeration system. The name must be unique and will be validated against all the condenser names (ref: Refrigeration:Condenser:*) in the input file, including names used for air-cooled, evaporative-cooled, and water-cooled condensers.
Field: Rated Condensing Temperature[LINK]
This numeric field provides the rated condensing temperature (C).
Field: Rated Approach Temperature Difference[LINK]
This numeric field provides the rated difference (Delta C) between the saturated condensing temperature for the system rejecting heat and the saturated evaporating refrigerant temperature for the system absorbing heat. The default value is 3.0 C.
Field: Rated Effective Total Heat Rejection Rate[LINK]
This numeric field should be the rated heat rejection effect (W). Be sure the rating corresponds to the correct refrigerant(s). This value is used for system sizing error checking.
Field: Condensing Temperature Control Type[LINK]
The type of control used to set the saturated condensing temperature. Valid choices are Fixed and Float. If the field is blank, Fixed will be used. Fixed will hold the condensing temperature constant at the value specified. Float will consider the specified input as a minimum condensing temperature. This value will be compared to the evaporating temperatures required by other loads on the higher-temperature refrigeration system, and will use the lowest temperature required to meet those loads, along with the Approach Temperature Difference, to set the condensing temperature.
Field: Condenser Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condenser (kg) specified by the manufacturer, under standard rating conditions. This refrigerant is on the side of the condenser rejecting heat, not on the side of the condenser absorbing the heat.
Field: Condensate Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate receiver (kg) specified by the manufacturer or system designer, under standard rating conditions.
Field: Condensate Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the condensate piping (kg) specified by the system designer, under standard rating conditions.
The following is an example input for a cascade condenser.
Outputs[LINK]
FOR CONDENSERS COOLING SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration System Condenser Heat Transfer Rate [W]
Zone, Sum, Refrigeration System Condenser Heat Transfer Energy [J]
FOR CONDENSERS COOLING SYSTEMS SERVING AIR CHILLERS:
HVAC,Average, Refrigeration Air Chiller System Condenser Heat Transfer Rate [W]
HVAC, Sum, Refrigeration Air Chiller System Condenser Heat Transfer Energy [J]
FOR CONDENSERS ON SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
FOR CONDENSERS ON SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Air Chiller System Condenser Heat Transfer Rate [W][LINK]
This is the total heat transfer across the condenser (i.e., compressor energy and refrigeration loads) in Watts.
Refrigeration Air Chiller System Condenser Heat Transfer Energy [J][LINK]
This is the total heat energy flowing across the condenser for the timestep being reported.
Refrigeration:GasCooler:AirCooled[LINK]
The transcritical refrigeration system requires a single gas cooler to reject the system heat. The total heat of rejection is characterized by a linear relationship between the difference between the outside dry-bulb and gas cooler outlet temperatures. The rated gas cooler fan power and fan speed control type must be specified. If the gas cooler is not at ground level, the user may specify an air inlet node name (Ref. OutdoorAir:Node name). Optional input is provided to help the user track refrigerant inventories. These inputs represent the design values for the refrigerant inventory within the gas cooler, within a receiver, and in the liquid pipes between the gas cooler and the refrigerated cases.
Inputs[LINK]
Field: Name[LINK]
Identifies a particular gas cooler that rejects heat for a single refrigeration system. The name must be unique and will be validated against all the gas cooler names (Ref. Refrigeration:GasCooler:AirCooled) in the input file.
Field: Rated Total Heat Rejection Rate Curve Name[LINK]
This field is the name of a curve object defining the gas cooler heat rejection as a function of the difference between the gas cooler outlet and entering air temperatures. The curve should be linear (Curve:Linear). See the Engineering Reference for more discussion on the curve coefficients.
Field: Gas Cooler Fan Speed Control Type[LINK]
The type of fan speed control used by the gas cooler fan. Valid choices are Fixed, FixedLinear, VariableSpeed, and TwoSpeed. If the field is blank, Fixed will be used. Note that fan energy consumption for the air-cooled gas cooler is computed in the same way as that of the air-cooled condenser. For further information on fan energy calculations, see the discussion regarding air-cooled condenser fan energy in the Engineering Reference.
Field: Rated Fan Power[LINK]
This numeric field specifies the rated fan power (W) specified by the manufacturer, under standard rating conditions. If this field is blank, the default value of 5000 W will be used
Field: Minimum Fan Air Flow Ratio[LINK]
Fan controls often include a minimum air flow ratio to avoid overheating the fan motor or for other reasons. This numeric field should be between 0. and 1. and has a default value of 0.2.
Field: Transition Temperature[LINK]
This is the temperature (C) at which the gas cooler and the refrigeration system transitions between subcritical and transcritical operation. If this field is blank, the default value of 27.0°C will be used.
Field: Transcritical Approach Temperature[LINK]
This is the temperature difference (C) between the refrigerant (CO\(_{2}\)) exiting the gas cooler and the air entering the gas cooler during transcritical operation. If this field is blank, the default value of 3.0°C will be used.
Field: Subcritical Temperature Difference[LINK]
This is the temperature difference (C) between the condensing temperature and the ambient air temperature during subcritical operation. If this field is blank, the default value of 10.0°C will be used.
Field: Minimum Condensing Temperature
This numeric field specifies the minimum condensing temperature (C) required to maintain stable subcritical operation. If this field is blank, the default value of 10.0°C will be used.
Field: Air Inlet Node Name
This optional alpha field contains the name of the node from which the gas cooler draws its outdoor air. If this field is left blank, the outdoor air dry-bulb temperature entering the gas cooler is taken directly from the weather data. If this field is not blank, this node name must also be specified in an OutdoorAir:Node object where the height of the node is taken into consideration when calculating outdoor air temperature from the weather data. Alternately, the node name may be specified in an OutdoorAir:NodeList object where the outdoor air temperature is taken directly from the weather data.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref. Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
Field: Gas Cooler Refrigerant Operating Charge Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the gas cooler (kg) specified by the manufacturer, under standard rating conditions. If this field is blank, the default value of 0.0 kg will be used.
Field: Gas Cooler Receiver Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the gas cooler receiver (kg) specified by the manufacturer or system designer, under standard rating conditions. If this field is blank, the default value of 0.0 kg will be used.
Field: Gas Cooler Outlet Piping Refrigerant Inventory[LINK]
This numeric field specifies the amount of refrigerant present within the gas cooling outlet piping (kg) specified by the system designer, under standard rating conditions. If this field is blank, the default value of 0.0 kg will be used.
The following is an example input for an air-cooled gas cooler.
Outputs[LINK]
Zone,Average, Refrigeration Transcritical System Gas Cooler Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler Heat Transfer Energy [J]
Zone,Average, Refrigeration Transcritical System Gas Cooler Fan Electric Power [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler Fan Electric Energy [J]
Zone,Average, Refrigeration Transcritical System Gas Cooler Outlet Temperature [C]
Zone,Average, Refrigeration Transcritical System Gas Cooler Outlet Pressure [Pa]
Zone,Average, Refrigeration Transcritical System Gas Cooler Defrost Recovered Heat Transfer Rate [W]
Zone,Sum, Refrigeration Transcritical System Gas Cooler Defrost Recovered Heat Transfer Energy [J]
Refrigeration Transcritical System Gas Cooler Heat Transfer Rate [W][LINK]
This output is the total heat transfer rate from the gas cooler in Watts, and includes compressor energy and the refrigeration load.
Refrigeration Transcritical System Gas Cooler Heat Transfer Energy [J][LINK]
This output is the total heat transferred from the gas cooler to the surroundings, in Joules, for the timestep being reported.
Refrigeration Transcritical System Gas Cooler Fan Electric Power [W][LINK]
This output is the electric input to the system’s gas cooler fan(s) in Watts.
Refrigeration Transcritical System Gas Cooler Fan Electric Energy [J][LINK]
This is the electricity consumption of the system’s gas cooler fan(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Transcritical System Gas Cooler Outlet Temperature [C][LINK]
This output is the temperature (in C) of the refrigerant exiting the gas cooler.
Refrigeration Transcritical System Gas Cooler Outlet Pressure [Pa][LINK]
This output is the pressure (in Pa) of the refrigerant exiting the gas cooler.
Refrigeration Transcritical System Gas Cooler Defrost Recovered Heat Transfer Rate [W][LINK]
This is the total heat recovered from the gas cooler inlet flow for defrost purposes within the refrigeration system.
Refrigeration Transcritical System Gas Cooler Defrost Recovered Heat Transfer Energy [J][LINK]
This is the total heat recovered from the gas cooler inlet flow for defrost purposes within the refrigeration system for the timestep being reported.
Refrigeration:TransferLoadList[LINK]
A refrigeration system may provide cooling to other, secondary, systems through either a secondary loop or a cascade condenser (Ref. Refrigeration:SecondarySystem and Refrigeration:Condenser:Cascade). If multiple transfer loads are served by a single primary system, use this list to group them together for reference by the primary system (see the field “Refrigeration Transfer Load or TransferLoad List Name” in the Refrigeration:System object).
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigeration transfer load list. Any reference to this list by another object will use this name. In particular, the primary refrigeration system absorbing the heat from all the loads listed here will use this name to reference those loads.
Field: Cascade Condenser Name or Secondary System Name[LINK]
Identifies a cascade condenser or secondary loop that is cooled, along with the other transfer loads listed here, by a single system. The name will be validated against the Refrigeration:SecondarySystem and Refrigeration:Condenser:Cascade names in the input file (the name will also be compared against all the other condenser names, but an error will be issued if it refers to any type of condenser other than a cascade condenser).
The list is extensible; ten fields are provided in the IDD.
The following is an example input for a transfer load list.
Refrigeration:SecondarySystem[LINK]
A refrigeration secondary system works in conjunction with refrigerated cases and walkins (Ref. Refrigeration:SecondarySystem, Refrigeration:CaseAndWalkInList, Refrigeration:Case, and Refrigeration:WalkIn) to simulate the performance of a secondary loop supermarket refrigeration system. Heat from the refrigeration loads served by the secondary loop is absorbed by a primary refrigeration system (ref: Refrigeration:System). The SecondarySystem object simulates a heat exchanger that is an evaporator, or refrigeration load, on the primary refrigeration system.
The inputs for the refrigeration secondary system object include a name, which is also referenced to identify the load placed upon the primary refrigeration system. The inputs that describe the loads placed upon the secondary loop include the name of a single refrigerated case, the name of a single walk-in cooler, or a list of cases and walkin coolers. The circulating fluid type specifies whether or not the secondary fluid remains in the liquid state throughout the loop (e.g., a glycol or brine solution) or undergoes a partial phase change while serving the refrigeration loads (e.g., a CO\(_{2}\) liquid overfeed system). The circulating fluid name must also be specified and must correspond to a name used to provide the fluid properties.
If the secondary fluid remains a liquid, the heat exchanger between the primary and secondary systems functions as an evaporator on the primary side and chills the circulating fluid on the secondary side. Inputs that describe the evaporator performance at rated conditions are used to calculate the heat exchanger effectiveness. These values include the rated evaporator capacity (which can be specified in terms of energy or fluid flow rate), the rated evaporating temperature, the rated approach temperature difference, and the rated range temperature difference.
If the secondary fluid undergoes a partial phase change, the heat exchanger between the primary and secondary systems functions as an evaporator on the primary side and as a condenser on the secondary side. The evaporator capacity, evaporating temperature, and approach temperature difference, all at full-load design conditions, are input.
The balance of the secondary system object describes the pumping system. The pumping options include a single constant speed pump, multiple constant speed pumps, or a variable frequency-drive pump. The user can also keep track of distribution piping and receiver shell heat gains.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigeration secondary system. Any reference to this refrigeration secondary system by another object will use this name. In particular, the primary refrigeration system absorbing the heat from this system will use this name to define that load.
Field: Refrigerated Case or WalkIn or CaseAndWalkInList Name[LINK]
Identifies a single case, or walkin, or a particular list of refrigerated cases and walkins, that are cooled by this refrigeration secondary system. The name will be validated against the case, walkin, and CaseAndWalkInList names (ref. Refrigeration:Case, Refrigeration:WalkIn and Refrigeration:CaseAndWalkInList) in the input file.
Field: Circulating Fluid Type[LINK]
Specifies whether the fluid is always liquid (e.g., glycol solution), or undergoes a partial phase change (e.g., CO\(_{2}\) liquid overfeed system). The options are “FluidAlwaysLiquid” and “FluidPhaseChange”.
Field: Circulating Fluid Name[LINK]
The name of the secondary circulating fluid.
For “FluidAlwaysLiquid”, this name must correspond to either an ethylene or propylene glycol (ref: FluidProperties:GlycolConcentration) or to a user-defined glycol (ref: FluidProperties:Name and FluidProperties: GlycolConcentration) in the input file. Note that the corresponding property data, including FluidProperties:Concentration, FluidProperties:Temperatures, and FluidProperties:GlycolConcentration must also be included in the input file and are provided in GlycolPropertiesRefData.idf for typical ethylene and propylene glycols.
For “FluidPhaseChange”, the refrigerant used by the secondary system must be listed in the FluidProperties:Name object. The corresponding property data must also be supplied in the input file. Property data for many refrigererants, including R11, R123, R134A, R12, R22, R404A, R507A, R410A, and R744, are available in FluidPropertiesRefData.idf.
Field: Evaporator Capacity[LINK]
For “FluidAlwaysLiquid”, this numeric field should be the rated heat evaporator capacity (W). Be sure the rating corresponds to the correct refrigerant and secondary circulating fluid. If this variable is specified and the rated evaporator flow rate for secondary fluid is not, then the flow rate will be calculated. At least one of these two input variables is required.
For “FluidPhaseChange”, this numeric field should be the evaporator capacity (W) at full-load design conditions. If this input is left blank, the capacity will be set to the sum of the capacities of the cases and walk-ins served by the secondary loop plus the pump motor load at full-load design conditions.
Field: Evaporator Flow Rate for Secondary Fluid[LINK]
For “FluidAlwaysLiquid” systems, this is the rated evaporator secondary fluid flow rate in m\(^{3}\)/s. If this variable is specified and the rated evaporator capacity in watts is not, then the rated capacity will be calculated. At least one of these two input variables is required.
For “FluidPhaseChange”, this field is not used (see “Phase Cange Circulating Rate”).
Field:Evaporator Evaporating Temperature[LINK]
This numeric field provides the evaporating temperature (C) corresponding to the evaporator capacity. This is the evaporating temperature on the primary side of the heat exchanger used to chill or condense the secondary loop circulating fluid. It is NOT the temperature in any cases or walkins served by the secondary loop.
Field: Evaporator Approach Temperature Difference[LINK]
For “FluidAlwaysLiquid”, this numeric field is the rated temperature difference (DeltaC) between the circulating secondary fluid leaving the heat exchanger and the heat exchanger’s evaporating temperature.
For “FluidPhaseChange”, this is the temperature difference (DeltaC) between the primary refrigerant evaporating and secondary refrigerant condensing temperatures at full-load design conditions.
Field: Evaporator Range Temperature Difference[LINK]
For “FluidAlwaysLiquid”, this numeric field is the rated temperature difference (DeltaC) between the circulating secondary fluid entering and leaving the heat exchanger. This value is not used for “FluidPhaseChange”.
Field: Number of Pumps in Loop[LINK]
This numeric field provides the integer number of pumps used to circulate the secondary heat transfer fluid. The default value is 1. Unless a variable speed pump is specified, pump energy will be calculated in linear steps to achieve the necessary flow rate.
Field: Total Pump Flow Rate[LINK]
This is the secondary fluid circulating flow rate in m\(^{3}\)/s at full-load design conditions. For “FluidAlwaysLiquid”, if no value is input, the Evaporator Flow Rate for Secondary Fluid will be used. For “FluidPhaseChange”, if no value is input, the flow rate will be calculated using the Evaporator Capacity and the PhaseChange Circulating Rate.
Field: Total Pump Power[LINK]
This numeric field should be the pump power (W) at full-load design conditions. Be sure the rating corresponds to the correct secondary circulating fluid at the design fluid temperature. EITHER the Total Pump Power OR the Total Pump Head is required.
Field: Total Pump Head[LINK]
This numeric field should be the design pressure drop, or head, across the secondary loop (Pa) at full load design conditions. Be sure the rating corresponds to the correct secondary circulating fluid at the design fluid temperature. EITHER the Total Pump Power OR the Total Head is required.
Field: PhaseChange Circulating Rate[LINK]
This field is not used for “FluidAlwaysLiquid”.
For “FluidPhaseChange”, the Circulating Rate is defined as the total mass flow at the pump divided by the mass flow rate of vapor returning to the separator. Values between 2.1 and 3 are common for CO\(_{2}\) systems and the default is 2.5. If Total Pump Flow Rate is also defined, the PhaseChange Circulating Rate will only be used to check whether the two values are consistent.
Field: Pump Drive Type[LINK]
Specifies whether the pump(s) is constant speed or variable speed. The options are “Constant” and “Variable”. The default is “Constant”.
Field: Variable Speed Pump Cubic Curve Name[LINK]
The name of a cubic performance curve (ref: Performance Curves) that parameterizes the variation of the variable speed pump power (and the associated load on the secondary refrigeration load) at off-rated conditions. The curve should be normalized to have the value of 1.0 at full-load design conditions. The variable speed pump cubic curve name is used only for the a pump drive type of “Variable”.
Field: Pump Motor Heat to Fluid[LINK]
This choice field determines how much of the pump motor heat will be added to the circulating secondary fluid. This represents the motor efficiency for a non-hermetic motor. The default is 0.85. For a semi-hermetic motor, enter 1.0. The value entered must be between 0.5 and 1.0.
Field: Sum UA Distribution Piping[LINK]
This optional field is typically used when trying to compare the impact of pipe heat gains on system performance, particularly in comparing a DX system to a secondary system. Enter the value for secondary loop distribution piping heat gain (in W/C). That is, sum up the product of the pipe insulation conductance times the outer piping insulation surface area. Please see the Engineering Reference for guidance in calculating this value.
Field: Distribution Piping Zone Name[LINK]
This optional field is used when trying to determine the impact of pipe heat gains on system performance, particularly in comparing a DX system to a secondary system. (If the previous field, Sum UA Distribution Piping, is blank, this field will not be used.) Enter the name of the zone where the Distribution piping is located. The distribution piping heat gains will be calculated based upon the air temperature within this zone and will count as a cooling credit for this zone.
Field: Sum UA Receiver/Separator Shell[LINK]
This optional field is typically used when trying to compare the impact of refrigeration component heat gains on system performance, particularly in comparing a conventional primary DX system to a secondary system. Enter the value for receiver/separator heat gain (in W/C). That is, sum up the product of the tank insulaton conductance times the outer tank insulation surface area. Please see the Engineering Reference for guidance in calculating this value.
Field: Receiver/Separator Zone Name[LINK]
This optional field is used when trying to determine the impact of refrigeration component heat gains on system performance, particularly in comparing a conventional primary DX system to a secondary system. (If the previous field, Sum UA Receiver/Separator, is blank, this field will not be used.) Enter the name of the zone where the receiver/separator is located. The heat gains will be calculated based upon the air temperature within this zone and will count as a cooling credit for this zone.
Field: Evaporator Refrigerant Inventory[LINK]
The secondary loop is chilled by a primary system via a heat exchanger. This field is the refrigerant inventory on the cold (primary) side of that heat exchanger, in kg. The default value is zero.
Field: End-Use Subcategory[LINK]
This field allows the specification of a user-defined end-use subcategory (e.g., “Low Temperature Rack”). A new meter for reporting is created for each unique subcategory (Ref: Output:Meter objects). Any text may be used here to further subcategorize the end-uses in the ABUPS End Uses by Subcategory table and in the LEED Summary EAp2-4/5 Performance Rating Method Compliance table. If this field is left blank, the equipment will be assigned to the “General” end-use subcategory.
The following is an example input for a brine-type (“FluidAlwaysLiquid”)refrigeration secondary system.
The following is an example input for a liquid-overfeed-type (“FluidPhaseChange”) refrigeration secondary system.
Outputs[LINK]
FOR SECONDARY SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average,Refrigeration Secondary Loop Pump Electric Power [W]
Zone,Sum,Refrigeration Secondary Loop Pump Electric Energy [J]
Zone,Average,Refrigeration Secondary Loop Load Heat Transfer Rate [W]
Zone,Sum,Refrigeration Secondary Loop Load Heat Transfer Energy [J]
Zone,Average,Refrigeration Secondary Loop Total Heat Transfer Rate [W]
Zone,Sum,Refrigeration Secondary Loop Total Heat Transfer Energy [J]
Zone,Average,Refrigeration Secondary Loop Estimated Refrigerant Inventory Mass[kg] Zone,Average,Refrigeration Secondary Loop Volume Flow Rate [m3/s]
Zone,Average,Refrigeration Secondary Loop Pipe Heat Gain Rate [W]
Zone,Average,Refrigeration Secondary Loop Pipe Heat Gain Energy [J]
Zone,Average,Refrigeration Secondary Loop Receiver Heat Gain Rate [W]
Zone,Average,Refrigeration Secondary Loop Receiver Heat Gain Energy [J]
FOR SECONDARY SYSTEMS SERVING AIR CHILLERS:
HVAC,Average,Refrigeration Air Chiller Secondary Loop Pump Electric Power [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Pump Electric Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Load Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Load Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Total Heat Transfer Rate [W]
HVAC,Sum,Refrigeration Air Chiller Secondary Loop Total Heat Transfer Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Estimated Refrigerant Inventory Mass[kg]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Volume Flow Rate [m3/s]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Pipe Heat Gain Rate [W]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Pipe Heat Gain Energy [J]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Receiver Heat Gain Rate [W]
HVAC,Average,Refrigeration Air Chiller Secondary Loop Receiver Heat Gain Energy [J]
FOR SECONDARY SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration Secondary Loop Pump Electric Power [W][LINK]
This output is the total electric power input to the pump(s) in Watts.
Refrigeration Secondary Loop Pump Electric Energy [J][LINK]
This is the electricity consumption of the system’s pump(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Secondary Loop Load Heat Transfer Rate [W][LINK]
This is the amount of refrigeration provided to the cases and walkins served by the secondary loop in W.
Refrigeration Secondary Loop Load Heat Transfer Energy [J][LINK]
This is the amount of refrigeration provided to the cases and walkins served by the secondary loop in Joules for the timestep being reported.
Refrigeration Secondary Loop Total Heat Transfer Rate [W][LINK]
This is the total amount of refrigeration load placed upon the primary refrigeration system (including loads due to the cases and walkins plus the loads from the secondary loop pumps and any energy absorbed by the loop via pipe heat gains) in W.
Refrigeration Secondary Loop Total Heat Transfer Energy [J][LINK]
This is the total amount of energy placed upon the primary refrigeration system by the secondary loop in Joules for the timestep being reported.
Refrigeration Secondary Loop Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for the cases and walkins and the refrigerant circulating through the loop.
Refrigeration Secondary Loop Volume Flow Rate [m3/]s[LINK]
This output is the calculated volume flow through the pumps for this secondary loop.
Refrigeration Secondary Loop Pipe Heat Gain Rate [W][LINK]
This output is the total heat transferred to the pipes in Watts.
Refrigeration Secondary Loop Pipe Heat Gain Energy [J][LINK]
This is the total heat transferred to the pipes in Joules for the timestep being reported.
Refrigeration Secondary Loop Receiver Heat Gain Rate [W][LINK]
This output is the total heat transferred to the receiver in Watts.
Refrigeration Secondary Loop Receiver Heat Gain Energy [J][LINK]
This is the total heat transferred to the receiver in Joules for the timestep being reported.
FOR SECONDARY SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Air Chiller Secondary Loop Pump Electric Power [W][LINK]
This output is the total electric power input to the pump(s) in Watts.
Refrigeration Air Chiller Secondary Loop Pump Electric Energy [J][LINK]
This is the electricity consumption of the system’s pump(s) in Joules for the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Plant (Ref. Output:Meter objects).
Refrigeration Air Chiller Secondary Loop Load Heat Transfer Rate [W][LINK]
This is the amount of refrigeration provided to the air chillers served by the secondary loop in W.
Refrigeration Air Chiller Secondary Loop Load Heat Transfer Energy [J][LINK]
This is the amount of refrigeration provided to the air chillers served by the secondary loop in Joules for the timestep being reported.
Refrigeration Air Chiller Secondary Loop Total Heat Transfer Rate [W][LINK]
This is the total amount of refrigeration load placed upon the primary refrigeration system (including loads due to the air chillers plus the loads from the secondary loop pumps and any energy absorbed by the loop via pipe heat gains) in W.
Refrigeration Air Chiller Secondary Loop Total Heat Transfer Energy [J][LINK]
This is the total amount of energy placed upon the primary refrigeration system by the secondary loop in Joules for the timestep being reported.
Refrigeration Air Chiller Secondary Loop Estimated Refrigerant Inventory Mass [kg][LINK]
This output is the sum of the input inventory values for the air chillers and the refrigerant circulating through the loop.
Refrigeration Air Chiller Secondary Loop Volume Flow Rate [m3/]s[LINK]
This output is the calculated volume flow of coolant through the pumps for this secondary loop.
Refrigeration Air Chiller Secondary Loop Pipe Heat Gain Rate [W][LINK]
This output is the total heat transferred to the pipes in Watts.
Refrigeration Air Chiller Secondary Loop Pipe Heat Gain Energy [J][LINK]
This is the total heat transferred to the pipes in Joules for the timestep being reported.
Refrigeration Air Chiller Secondary Loop Receiver Heat Gain Rate [W][LINK]
This output is the total heat transferred to the receiver in Watts.
Refrigeration Air Chiller Secondary Loop Receiver Heat Gain Energy [J][LINK]
This is the total heat transferred to the receiver in Joules for the timestep being reported.
Additional Refrigeration Outputs Available for Each Zone[LINK]
Multiple refrigeration cases and walkins may be located within a single zone. Each zone may also exchange heat with refrigeration system suction piping, secondary loop distribution piping, and secondary loop receivers. Output variables have been prepared to sum up the total heat exchange due to all refrigeration objects within a single zone. The output variables that start with “Zone Refrigeration” do not account for refrigeration provided by refrigeration chiller sets or any piping from systems serving air chillers. The output variables that start with “Zone Chillers” account for all the refrigeration system elements serving air chillers.
Additional Refrigeration Outputs for Each Zone[LINK]
FOR THE SUM OF ALL COOLING SYSTEMS SERVING CASES AND/OR WALKINS:
Zone,Average, Refrigeration Zone Case and Walk In Sensible Cooling Rate [W]
Zone,Sum, Refrigeration Zone Case and Walk In Sensible Cooling Energy [J]
Zone,Average, Refrigeration Zone Case and Walk In Heating Rate [W]
Zone,Sum, Refrigeration Zone Case and Walk In Heating Energy [J]
Zone,Average, Refrigeration Zone Case and Walk In Total Sensible Cooling Rate [W]
Zone,Sum, Refrigeration Zone Case and Walk In Total Sensible Cooling Energy [J]
Zone,Average, Refrigeration Zone Case and Walk In Total Latent Cooling Rate [W]
Zone,Sum, Refrigeration Zone Case and Walk In Total Latent Cooling Energy [J]
Zone,Sum, Refrigeration Zone Case and Walk In Total Cooling Energy [J]
Zone,Average,Refrigeration Zone Case and Walk In Total Cooling Rate [W]
Zone,Average, Refrigeration Zone Case and Walk In Total Heat Transfer Rate [W]
Zone,Sum, Refrigeration Zone Case and Walk In Total Heat Transfer Energy [J]
FOR THE SUM OF ALL COOLING SYSTEMS SERVING CHILLERS:
HVAC,Average, Refrigeration Zone Air Chiller Sensible Heat Transfer Rate [W]
HVAC,Sum, Refrigeration Zone Air Chiller Sensible Heat Transfer Energy [J]
HVAC,Average, Refrigeration Zone Air Chiller Latent Cooling Rate [W]
HVAC,Sum, Refrigeration Zone Air Chiller Latent Cooling Energy [J]
HVAC,Average, Refrigeration Zone Air Chiller Total Cooling Rate [W]
HVAC,Sum, Refrigeration Zone Air Chiller Total Cooling Energy [J]
FOR THE SUM OF ALL COOLING SYSTEMS SERVING CASES AND/OR WALKINS:[LINK]
Refrigeration Zone Case and Walk In Total Sensible Cooling Rate [W][LINK]
This output is the total sensible heat transfer between all refrigeration objects located in the zone in Watts. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Case and Walk In Total Sensible Cooling Energy [J]
This is the total sensible heat transfer between all refrigeration objects located in the zone in Joules for for the timestep being reported. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Case and Walk In Total Latent Cooling Rate [W][LINK]
This output is the total latent heat transfer between all refrigeration objects located in the zone in Watts. A negative value will be reported when the refrigeration equipment provides dehumidification (thereby reducing the zone latent load).
Refrigeration Zone Case and Walk In Total Latent Cooling Energy [J]
This is the total latent heat transfer between all refrigeration objects located in the zone in Joules for for the timestep being reported. A negative value will be reported when the refrigeration equipment provides dehumidification (thereby reducing the zone latent load).
Refrigeration Zone Case and Walk In Total Heat Transfer Rate [W][LINK]
This output is the total heat transfer (sensible plus latent) between all refrigeration objects located in the zone in Watts. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Case and Walk In Total Heat Transfer Energy [J]
This is the total heat transfer (sensible plus latent) between all refrigeration objects located in the zone in Joules for for the timestep being reported. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Case and Walk In Sensible Cooling Rate [W][LINK]
This output is the total sensible cooling from all refrigeration objects located in the zone in Watts.
Refrigeration Zone Case and Walk In Sensible Cooling Energy [J]
This is the total sensible cooling from all refrigeration objects located in the zone in Joules for for the timestep being reported.
Refrigeration Zone Case and Walk In Heating Rate [W][LINK]
This output is the total heating from all refrigeration objects located in the zone in Watts.
Refrigeration Zone Case and Walk In Heating Energy [J]
This is the total heating from all refrigeration objects located in the zone in Joules for for the timestep being reported.
Refrigeration Zone Case and Walk In Total Cooling Rate [W][LINK]
This output is the total cooling (sensible plus latent) from all refrigeration objects located in the zone in Watts.
Refrigeration Zone Case and Walk In Total Cooling Energy [J]
This is the total cooling (sensible plus latent) from all refrigeration objects located in the zone in Joules for for the timestep being reported.
FOR THE SUM OF ALL COOLING SYSTEMS SERVING AIR CHILLERS:[LINK]
Refrigeration Zone Air Chiller Heating Rate [W][LINK]
This output is the total heating from all air chillers located in the zone in Watts.
Refrigeration Zone Air Chiller Heating Energy [J]
This is the total heating from all air chillers located in the zone in Joules for for the timestep being reported.
Refrigeration Zone Air Chiller Sensible Cooling Rate [W][LINK]
This output is the total sensible cooling from all air chillers located in the zone in Watts.
Refrigeration Zone Air Chiller Sensible Cooling Energy [J]
This is the total sensible cooling from all air chillers located in the zone in Joules for for the timestep being reported.
Refrigeration Zone Air Chiller Sensible Heat Transfer Rate [W][LINK]
This output is the total sensible heat transfer from all air chillers located in the zone in Watts. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Air Chiller Sensible Heat Transfer Energy [J][LINK]
This is the total sensible heat transfer from all air chillers located in the zone in Joules for for the timestep being reported. A negative value will be reported when the refrigeration objects cool (that is, remove heat from) the zone.
Refrigeration Zone Air Chiller Latent Cooling Rate [W][LINK]
This output is the total latent cooling from all air chillers located in the zone in Watts.
Refrigeration Zone Air Chiller Latent Cooling Energy [J]
This is the total latent cooling from all air chillers located in the zone in Joules for for the timestep being reported.
Refrigeration Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This is the total amount of water removed by all air chillers located in the zone in kg/s for for the timestep being reported.
Refrigeration Zone Air Chiller Total Cooling Rate [W][LINK]
This output is the total cooling (sensible plus latent) from all air chillers located in the zone in Watts.
Refrigeration Zone Air Chiller Total Cooling Energy [J]
This is the total cooling (sensible plus latent) from all air chillers located in the zone in Joules for for the timestep being reported.
Refrigeration:AirChiller[LINK]
The Refrigeration:AirChiller object works in conjunction with a refrigeration chiller set, compressor rack, a refrigeration system, or a refrigeration secondary system object (Ref. ZoneHvac:RefrigerationChillerSet, and a Refrigeration:CompressorRack, Refrigeration:System, or Refrigeration:SecondarySystem) to simulate the performance of an air chiller, similar to one found in a refrigerated warehouse. The air chiller model uses information at rated conditions along with the zone conditions to determine performance. Energy use for fans and heaters is modeled based on inputs for nominal power, schedules, and control type. The refrigeration chiller model accounts for the sensible and latent heat exchange with the surrounding environment.
The refrigeration chiller cooler object inputs include a name, an availability schedule name, the rated cooling capacity, the rated operating temperature, the rated cooling source temperature, the rated total heating power and heating power schedule, the rated fan power and schedules, defrost type, defrost control type, defrost schedule name, drip-down schedule name, defrost power, the portion of the defrost energy used to melt ice (only for temperature termination control type), and refrigerant inventory.
Chiller coils are rated under multiple conventions. Each rating is typically based upon a selected fin material and refrigerant cycle, with correction factors for other materials or refrigerants. Fields are provided here for those correction factors. The performance of all chiller coils depends upon the inlet air temperature, relative humidity, and flow rate. Multiple methods of expressing this relationship are provided here to accommodate the way information is provided by different manufacturers.
Inputs[LINK]
Field: Name[LINK]
A unique user-assigned name for an instance of a refrigeration chiller. Any reference to this refrigeration chiller by another object will use this name.
Field: Availability Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigeration chiller can operate during a given time period. A schedule value greater than 0 (maximum schedule value of 1.0 is typically used) indicates that the refrigeration chiller will operate during a given time period. A value equal to 0 denotes that the case does not operate (everything is OFF: refrigeration, fans, lights, anti-sweat, etc.). Typically the refrigeration chiller will operate throughout the day (i.e., the schedule will contain 1 for all time periods); however, refrigeration chillers require maintenance and/or cleaning and this can be modeled accordingly using this schedule if desired. If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Capacity Rating Type[LINK]
The type of capacity rating used for this refrigeration chiller. Valid choices are UnitLoadFactorSensibleOnly, CapacityTotalSpecificConditions, EuropeanSC1Standard, EuropeanSC1NominalWet, EuropeanSC2Standard, EuropeanSC2NominalWet, EuropeanSC3Standard, EuropeanSC3NominalWet, EuropeanSC4Standard, EuropeanSC4NominalWet, EuropeanSC5Standard, and EuropeanSC5NominalWet. In each case, select the rating option that corresponds to the expected service conditions. For example, U.S. manufacturers quote a separate Unit Load Factor for wet or frosted coils. If the evaporating temperature is less than 0C, input the frosted coil value. Within the European convention, select SC1, 2, 3, 4, or 5 depending upon the expected evaporating temperature. This field is required and there is no default value. Refer to the Engineering Reference for further information on these rating types. NOTE: If the CapacityTotalSpecificConditions rating type is specified, the input file must include the manufacturer’s coil capacity correction curve in tabular form using the Table:MultiVariableLookup object. An example of this may be found in the RefrigeratedWarehouse.idf example file.
NOTE – ONLY ONE OF THE FOLLOWING TWO FIELDS IS USED[LINK]
Field: Rated Unit Load Factor[LINK]
The sensible cooling capacity in watts (W/C) at rated conditions. The value entered for this field must be greater than zero, with no default value. This value is only used if the Capacity Rating Type is UnitLoadFactorSensibleOnly. The value given must be based upon the difference between the chiller inlet and outlet air temperatures, not on the difference between the zone mean temperature and the outlet air temperature.
Field: Rated Capacity[LINK]
The cooling capacity in watts (W) at rated conditions. The value entered for this field must be greater than zero, with no default value. This field is only used if the Capacity Rating Type is CapacityTotalSpecificConditions, EuropeanSC1Standard, EuropeanSC1NominalWet, EuropeanSC2Standard, EuropeanSC2NominalWet, EuropeanSC3Standard, EuropeanSC3NominalWet, EuropeanSC4Standard, EuropeanSC4NominalWet, EuropeanSC5Standard, or EuropeanSC5NominalWet. For CapacityTotalSpecificConditions, this capacity includes both sensible and latent at the conditions given in the next two fields. Note that the European Standard ratings are sensible only and the European Nominal ratings include latent capacity as well. The value given here must correspond to the capacity rating type given previously.
Field: Rated Relative Humidity[LINK]
This field is ONLY used if the Capacity Rating Type is CapacityTotalSpecificConditions and represents the relative humidity at rated conditions, expressed as a percent. The default is 85.
Field: Rated Cooling Source Temperature[LINK]
For a DX evaporator coil, enter the saturated evaporating temperature in ˚C. For a fluid coil, enter the fluid coil entrance temperature in ˚C. There is no default value. This number is used, with temperatures for other refrigeration loads on any one system, to set that system’s minimum suction pressure or minimum circulating fluid temperature.
Field: Rated Temperature Difference DT1[LINK]
The rated difference between the air entering the refrigeration chiller and the cooling source temperature in ˚C. The entered value for this field must be less than 20˚C. There is no default value.
Field: Maximum Difference Between Inlet Air and Evaporating Temperature[LINK]
The maximum difference between the air entering the refrigeration chiller and the cooling source temperature in °C used to limit capacity during pull-down. The default is 1.3 times the Rated Temperature Difference DT1.
Field: Coil Material Correction Factor[LINK]
This field is used to enter the manufacturer’s correction factor for coil material corresponding to the rating previously input. The default is 1.0 (dimensionless).
Field: Refrigerant Correction Factor[LINK]
This field is used to enter the manufacturer’s correction factor for refrigerant corresponding to the rating previously input. The default is 1.0 (dimensionless). (Note, the refrigerant itself is specified for the detailed system or secondary loop providing the refrigerant to this coil.)
Field: Capacity Correction Curve Type[LINK]
The type of capacity correction curve used to account for the impact of the room air conditions on the chiller capacity. Valid choices are LinearSHR60, QuadraticSHR, European, and TabularRHxDT1xTRoom. This field will default to LinearSHR60, unless the CapacityTotalSpecificConditions rating type is specified, in which case, the TabularRHxDT1xTRoom correction curve type must be used. Refer to the Engineering Reference for further information on these curve types. The resulting correction factor for LinearSHR60, QuadraticSHR, and European types will be applied to the sensible capacity and must have output values between 1 and 2. The resulting correction factor for TabularRHxDT1xTRoom will be applied to the CapacityTotalSpecificConditions capacity and can have values between 0.2 and 2. If TabularRHxDT1xTRoom is used, the curve type within the table must be specified as “Quadratic”.
Field: Capacity Correction Curve Name[LINK]
The name of the curve object defining the total refrigerating capacity. For correction curve types LinearSHR60 and QuadraticSHR, the independent variable is the Sensible Heat Ratio and the output values are between 1.0 and 2.0. For correction curve type European, EnergyPlus contains built-in capacity correction curves and specification of a capacity correction curve name is not required. For correction curve type TabularRHxDT1xTRoom, enter the name of a Table:MultiVariableLookup object that gives the total capacity (in W) as a function of RH, DT1, and Room Temperature; IN THAT ORDER. An example of a TabularRHxDT1xTRoom correction curve using the Table:MultiVariableLoopkup object may be found in the RefrigeratedWarehouse.idf example file.
Field: SHR60 Correction Factor[LINK]
This field is only used when the capacity correction curve type is LinearSHR60. It should correspond to the capacity factor, that is, the total capacity divided by the sensible capacity corresponding to a Sensible Heat Ratio of 0.6. The default is 1.48 (dimensionless).
Field: Rated Total Heating Power[LINK]
The total heating power in watts including drip-pan and any other heaters (W). This value is required and has no default value.
Field: Heating Power Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes the fraction of heater power that operates during a given time period. A schedule value of zero denotes that all heaters are off. A schedule value greater than 0 indicates that some portion of the total heater power will operate during that time period (maximum schedule value of 1.0 means all heaters are fully on). If this field is left blank, the default schedule has a value of 1 for all time periods.
Field: Fan Speed Control Type[LINK]
The type of fan speed control used by the cooling coil’s fan(s). Valid choices are Fixed, FixedLinear, VariableSpeed, and TwoSpeed. If the field is blank, Fixed will be used. See the Engineering Reference for a discussion of this option’s effect on fan energy consumption.
Field: Rated Fan Power[LINK]
The cooling coil fan power in watts (W). This value has a default value of 375W. This fan is assumed to run continuously except during electric, hot brine, or hot gas defrost periods.
Field: Rated Air Flow[LINK]
The cooling coil fan rated air flow in cubic meters per second (m\(^{3}\)/s). This value has no default value and must be input.
Field: Minimum Fan Air Flow Ratio[LINK]
The minimum fraction of the rated air flow for part-load fan operation, must be between 0. and 1.0. The default value is 0.2.
Field: Defrost Type[LINK]
The type of defrost used for this refrigeration chiller. Valid choices are None, Off-Cycle, HotFluid, and Electric. The default defrost type is Electric if the field is blank. HotFluid includes both hot gas and hot brine defrost systems. Refer to the Engineering Reference for further information on how the different defrost types are modeled.
Field: Defrost Control Type[LINK]
The type of defrost control used for this refrigeration chiller. Valid choices are TimeSchedule and TemperatureTermination. The default is TimeSchedule if the field is blank. Refer to the Engineering Reference for further information on how the different defrost controls are modeled.
Field: Defrost Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes when the refrigeration chiller requires defrosting. A schedule value of 1.0 indicates that defrost can be on during a given time period. A value equal to 0 denotes that the defrost is off. Defrost schedules normally repeat the duration and number of defrost cycles for each day of the year. The refrigeration chiller manufacturer typically provides this information with the product literature. If TemperatureTermination control type is used, the defrost schedule is used for the defrost cycle start time and the defrost cycle end time is not allowed to extend beyond the scheduled off time. The use of Compact Schedules (ref. Schedules) are ideal for this purpose.
Field: Defrost Drip-Down Schedule Name[LINK]
The name of the schedule (ref: Schedule) that denotes whether the refrigeration chiller requires additional time for draining condensate after the defrost period. A schedule value of 1.0 indicates that the defrost drip-down period is on during a given time period. A value equal to 0 denotes that the defrost drip-down period is over. The refrigeration chiller manufacturer typically provides this information with the product literature.
Each defrost drip-down period specified in this schedule should start at the same time as the corresponding defrost period specified in the schedule for Defrost Schedule, and the drip-down schedule defrost period should always be longer than or equal to the length of the defrost schedule time period. For example, if the defrost schedule contains a defrost period from 7:00 to 7:15, you would specify a case defrost drip-down period from 7:00 to 7:20 if you wanted to model a 5 minute condensate drip-down period after the regular defrost period. If no drip-down schedule is entered, then the defrost schedule (specified for the previous input field) will be used. The use of Compact Schedules (ref. Schedules) are ideal for this purpose.
Field: Defrost Power[LINK]
The defrost power in watts. This input is required for hot-fluid (hot gas or hot brine), or electric defrost types. Refrigeration chiller manufacturers do not typically provide information on the heat input for hot gas and hot brine defrost. Information provided for electric defrost power can be substituted here for refrigeration chillers using hot-gas or hot-brine defrost if other information is not available. Only electric Defrost Types consume electricity during the defrost period. The entered value for this field must be greater than or equal to zero.
Field: Temperature Termination Defrost Fraction to Ice[LINK]
When cooling coils go through a defrost cycle, only a portion of the defrost energy is actually used to melt the ice. The rest of the defrost energy goes to increasing the temperature of the coils themselves and to the refrigeration chiller environment. The Temperature Termination defrost control type calculates the end of the defrost cycle that corresponds to melting all the ice. Therefore, the user must input this fractional value. The default value is 0.7 for electric defrost and 0.3 for hot fluid defrost. Refer to the Engineering Reference for further information on how the defrost energy control types are modeled.
Field: Vertical Location[LINK]
The vertical location for this refrigeration chiller. Valid choices are Floor, Middle, and Ceiling. The default is Middle if the field is blank. The vertical location is used to transform the mixed zone air temperature to the coil inlet air temperature. Refer to the Engineering Reference for further information on how the different vertical locations are modeled.
Field: Average Refrigerant Charge Inventory[LINK]
The value of this optional field is the refrigerant inventory present in the refrigeration chiller during ordinary operation. The value is used to produce an estimate of the total refrigerant present in the refrigeration system. The value is entered in kg.
The following is an example input for a refrigeration air chiller.
The following is an example input for a refrigeration air chiller.
Outputs[LINK]
HVAC,Average,Refrigeration Zone Air Chiller Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Sensible Cooling Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Latent Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Latent Cooling Energy [J]
HVAC,Average, Refrigeration Zone Air Chiller Water Removed Mass Flow Rate [kg/s]
HVAC,Average,Refrigeration Zone Air Chiller Total Electric Power [W]
HVAC,Sum,Refrigeration Zone Air Chiller Total Electric Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Fan Electric Power [W]
HVAC,Sum,Refrigeration Zone Air Chiller Fan Electric Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Heater Electric Power [W]
HVAC,Sum,Refrigeration Zone Air Chiller Heater Electric Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Sensible Heat Ratio []
HVAC,Average,Refrigeration Zone Air Chiller Frost Accumulation Mass [kg]
HVAC,Average,Refrigeration Zone Air Chiller Zone Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Zone Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Zone Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Zone Sensible Cooling Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Zone Heating Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Zone Heating Energy [J]
Report only for Air Chillers using electric defrost
HVAC,Average,Refrigeration Zone Air Chiller Defrost Electric Power [W]
HVAC,Sum,Refrigeration Zone Air Chiller Defrost Electric Energy [J]
Report for each Zone exchanging energy with the Air Chiller
HVAC,Average,Refrigeration Zone Air Chiller Sensible Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Sensible Cooling Energy [J]
HVAC,Average, Refrigeration Zone Air Chiller Heating Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Heating Energy [J]
HVAC,Average, Refrigeration Zone Air Chiller Latent Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Latent Cooling Energy [J
HVAC,Average,Refrigeration Zone Air Chiller Total Cooling Rate [W]
HVAC,Sum,Refrigeration Zone Air Chiller Total Cooling Energy [J]
HVAC,Average,Refrigeration Zone Air Chiller Water Removed Mass Flow Rate [kg/s]
Refrigeration Zone Air Chiller Total Cooling Rate [W][LINK]
This field is the total (sensible plus latent) cooling rate of the Air Chiller evaporator coil in Watts.
Refrigeration Zone Air Chiller Total Cooling Energy [J][LINK]
This field is the total (sensible plus latent) cooling of the Air Chiller evaporator coil in Joules over the timestep being reported. This output is also added to a meter with Resource Type = EnergyTransfer, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Zone Air Chiller Sensible Cooling Rate [W][LINK]
Refrigeration Zone Air Chiller Sensible Heat Transfer Rate [W][LINK]
This field is the sensible cooling rate of the Air Chiller evaporator coil in Watts.
Refrigeration Zone Air Chiller Sensible Cooling Energy [J][LINK]
Refrigeration Zone Air Chiller Sensible Heat Transfer Energy [J][LINK]
This field is the sensible cooling of the Air Chiller evaporator coil in Joules over the timestep being reported.
Refrigeration Zone Air Chiller Latent Cooling Rate [W][LINK]
This field is the latent cooling (dehumidification) rate of the Air Chiller evaporator coil in Watts.
Refrigeration Zone Air Chiller Latent Cooling Energy [J][LINK]
This field is the latent cooling (dehumidification) of the Air Chiller evaporator coil in Joules over the timestep being reported.
Refrigeration Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This field is the latent cooling (dehumidification) of the Air Chiller evaporator coil in kilograms per second over the timestep being reported.
Refrigeration Zone Air Chiller Total Electric Power [W][LINK]
This field is the total electricity (fan, heaters, lights, and electric defrost) used by the Air Chiller in Watts.
Refrigeration Zone Air Chiller Total Electric Energy [J][LINK]
This field is the electricity (fan, heaters, lights, and electric defrost)used by the Refrigeration chiller in Joules over the timestep being reported.
Refrigeration Zone Air Chiller Fan Electric Power [W][LINK]
This field is the electric power input to the Air Chiller fan(s) in Watts.
Refrigeration Zone Air Chiller Fan Electric Energy [J][LINK]
This field is the electricity consumption of the Air Chiller fan(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Zone Air Chiller Heater Electric Power [W][LINK]
This field is the electric power input to the Air Chiller heaters in Watts.
Refrigeration Zone Air Chiller Heater Electric Energy [J][LINK]
This field is the total electricity consumption of the Air Chiller heaters in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects).
Refrigeration Zone Air Chiller Defrost Electric Power [W][LINK]
This field is the electric power input to the Air Chiller electric defrost heater(s) in Watts. This output is available if case defrost type is Electric.
Refrigeration Zone Air Chiller Defrost Electric Energy [J][LINK]
This field is the total electricity consumption of the Air Chiller electric defrost heater(s) in Joules over the timestep being reported. This output is also added to a meter with Resource Type = Electricity, End Use Key = Refrigeration, Group Key = Building (Ref. Output:Meter objects). This output is available if case defrost type is Electric.
Refrigeration Zone Air Chiller Sensible Heat Ratio[LINK]
This field is the Sensible Cooling Energy Rate divided by the Total Cooling Energy Rate.
Refrigeration Zone Air Chiller Frost Accumulation Mass [kg][LINK]
This field is the total amount of frost present on the coil during the timestep being reported.
Refrigeration Zone Air Chiller Zone Total Cooling Rate [W][LINK]
This field is the rate of total cooling delivered to the zone in Watts. A positive value is reported when the zone is cooled by the air chiller, otherwise a zero is reported.
Refrigeration Zone Air Chiller Zone Total Cooling Energy [J][LINK]
This field is the amount of total cooling energy delivered to the zone in Joules. A positive value is reported when the zone is cooled by the air chiller, otherwise a zero is reported.
Refrigeration Zone Air Chiller Zone Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling delivered to the zone in Watts. A positive value is reported when the zone is cooled by the air chiller, otherwise a zero is reported.
Refrigeration Zone Air Chiller Zone Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling energy delivered to the zone in Joules. A positive value is reported when the zone is cooled by the air chiller, otherwise a zero is reported.
Refrigeration Zone Air Chiller Zone Heating Rate [W][LINK]
This field is the rate of sensible heating delivered to the zone in Watts. A positive value is reported when the zone is heated by the air chiller (typically only occurs during defrost), otherwise a zero is reported.
Refrigeration Zone Air Chiller Zone Heating Energy [J][LINK]
This field is the amount of sensible heating energy delivered to the zone in Joules. A positive value is reported when the zone is heated by the air chiller (typically only occurs during defrost), otherwise a zero is reported.
The following output variables are available for each zone served by any Air Chiller. An output variable identification is created for each zone exchanging energy with the Air Chiller. For example if the Air Chiller, “DairyRefrigeration chiller”, were exchanging energy with the zone, “SalesArea”, the output variable identification would be “DairyRefrigeration chillerInZoneSalesArea”.
Refrigeration Zone Air Chiller Sensible Cooling Rate [W][LINK]
This field is the rate of sensible cooling delivered to the zone, net of any auxiliary heat input, in Watts..
Refrigeration Zone Air Chiller Sensible Cooling Energy [J][LINK]
This field is the amount of sensible cooling energy, net of any auxiliary heat input, delivered to the zone in Joules.
Refrigeration Zone Air Chiller Latent Cooling Rate [W][LINK]
This field is the rate of latent cooling (dehumidification) delivered to the zone in Watts. A negative value will be reported when the Air Chiller provides dehumidification (thereby reducing the zone latent load).
Refrigeration Zone Air Chiller Water Removed Mass Flow Rate [kg/s][LINK]
This field is the rate of latent cooling (dehumidification) delivered to the zone in kg/s. A negative value (or zero) will be reported when the Air Chiller provides dehumidification (thereby reducing the zone latent load).
Refrigeration Zone Air Chiller Latent Cooling Energy [J][LINK]
This field is the amount of latent cooling (dehumidification) energy delivered to the zone in Joules. A negative value (or zero) will be reported when the Air Chiller provides dehumidification (thereby reducing the zone latent load).
Refrigeration Zone Air Chiller Total Cooling Rate [W][LINK]
This field is the total rate of cooling, sensible plus latent, delivered to the zone in Watts.
Refrigeration Zone Air Chiller Total Cooling Energy [J][LINK]
This field is the total amount of cooling, sensible plus latent, energy delivered to the zone in Joules.
Refrigeration Zone Air Chiller Heating Rate [W][LINK]
This field is the rate of net heating due to any auxiliary or defrost heat input delivered to the zone, in Watts.
Refrigeration Zone Air Chiller Heating Energy [J][LINK]
This field is the amount of net heating energy due to any auxiliary heat input, delivered to the zone in Joules.
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This documentation is made available under the EnergyPlus Open Source License v1.0.