In the descriptions below, the fields for each input object
will be described but the Energy+.idd descriptions will not be
shown. Refer to the actual Energy+.idd file for complete
specifications. Energy+.idd is a text file that can be viewed
with many text editors or word processors. The Site:Location
object will serve as an example.
Site:Location,
\unique-object
\min-fields 5
A1 , \field Name
\required-field
\type alpha
N1 , \field Latitude
\units deg
\minimum -90.0
\maximum +90.0
\default 0.0
\note + is North, - is South, degree minutes represented in decimal (i.e. 30 minutes is .5)
\type real
N2 , \field Longitude
\units deg
\minimum -180.0
\maximum +180.0
\default 0.0
\note - is West, + is East, degree minutes represented in decimal (i.e. 30 minutes is .5)
\type real
N3 , \field Time Zone
\note basic these limits on the WorldTimeZone Map (2003)
\units hr
\minimum -12.0
\maximum +14.0
\default 0.0
\note Time relative to GMT. Decimal hours.
\type real
N4 ; \field Elevation
\units m
\minimum -300.0
\maximum< 8900.0
\default 0.0
\type real
The IDD excerpt above is the complete definition as seen in
the IDD file.
First, the object name is given. (Site:Location) This is
followed by a comma in both the definition (IDD) and in an
input file (IDF). In fact, all fields except the terminating
field of an IDD class object and IDF object are followed by
commas. The final field in an IDD class object or in an IDF
object is terminated by a semi-colon.
Next is an alpha field, the location name. As noted above,
for input, spaces are significant in this field. The main
inputs for Site:Location
are numeric fields. These are numbered (as is the alpha field)
for convenience. The \ designations will show various
information about the objects as described above in the IDD
conventions discussion. Of importance for reading this
document are the units and possible minimum and maximum values
for a field.
There is automatic processing of the \minimum, \maximum and
\default data for numeric fields. Any infractions of the
\minimum, \maximum fields are automatically detected and
messages will appear in the standard error file. After all the
input is checked, infractions will cause program termination
(before the bulk of the simulation is completed). Defaults are
also enforced if you leave the numeric field blank.
Some objects need all the parameters listed by the
definition; some do not. In the descriptions that follow, we
will try to indicate which parts are optional. Usually, these
will be the last fields in the object input or definition.
Even if items are not used for a particular object
(e.g. Multiplier in the FenestrationSurface:Detailed
and type = Door), the field must be included unless it is the
last field in the object. So, for this instance, one
must include a multiplier field (must be numeric and would
need to obey any \minimum, \maximum rules) for doors.
Two spreadsheet files are included with the
installation:
ExampleFiles.xls – shows many details about the
included example files including highlights of
features.
ExampleFiles-ObjectsLink.xls – shows, for each object,
the first three occurrences of that object in an example
file.
Output Descriptions[LINK]
In the descriptions below, we will endeavor to have each
object’s output displayed as well as each of the outputs
described. The output variables for a run are selected by
choosing the Output:VariableDictionary
object. This object displays the available output variables
for a run on the eplusout.rdd (regular
variables) and eplusout.mdd (meter variables)
files. Two significant styles are available for these displays
and the descriptions below may have one for some objects and
another for other objects. The variables are the same but will
look a bit different. For clarity, the two displays are shown
below:
Note that the IDF-Editor can interpret both sets of files
and assist you in getting output variables into your input
files. But you will have to successfully run your input file
first.
The Simple (or regular) display looks like the following
figure and is interpreted:
Zone/HVAC – when the output is produced at
the “Zone”
timestep (ref: number of timesteps in each hour) or at the
“HVAC” aka System timestep (which can vary for each hour).
Average/Sum – whether this is a averaged
value over the reporting period (such as a temperature or
rate) or whether this is a summed value over the reporting
period. Reporting periods are specified in the Output:Variable
or Output:Meter
objects.
<Variable Name> – The variable name
one uses for reporting is displayed (e.g., Site Outdoor
Drybulb Temperature) along with the units (e.g., [C]).
Example from the eplusout.rdd file:
Zone,Average,Site Outdoor Air Drybulb Temperature
[C]
Zone,Average,Site Outdoor Air Dewpoint Temperature
[C]
Zone,Average,Site Outdoor Air Wetbulb Temperature
[C]
Zone,Average,Site Outdoor Air Humidity Ratio
[kgWater/kgAir]
Zone,Average,Site Outdoor Air Relative Humidity
[%]
Zone,Average,Site Outdoor Air Barometric Pressure
[Pa]
Zone,Average,Wind Speed [m/s]
Zone,Average,Site Wind Direction [deg]
Zone,Average,Site Sky Temperature [C]
HVAC,Sum,Zone Air System Sensible Heating Energy
[J]
HVAC,Sum,Zone Air System Sensible Cooling Energy
[J]
HVAC,Average,Zone Air System Sensible Heating Rate
[W]
HVAC,Average,Zone Air System Sensible Cooling Rate
[W]
HVAC,Average,Zone Air Temperature [C]
HVAC,Average,Zone Thermostat Air Temperature
[C]
Note that the eplusout.mdd file is
similar, but meters are only available at the Zone
timestep.
Zone,Meter,Electricity:Facility [J]
Zone,Meter,ExteriorLights:Electricity [J]
Zone,Meter,Grounds Lights:ExteriorLights:Electricity
[J]
Zone,Meter,EnergyTransfer:Facility [J]
Zone,Meter,EnergyTransfer:Building [J]
Zone,Meter,EnergyTransfer:Zone:R13WALL WALLS
[J]
The IDF display has all the same information in an
IDF-ready form (i.e., you could copy and paste it into your
input file using a text editor).
Example from the eplusout.rdd file:
Output:Variable,*,Site Outdoor Air Drybulb
Temperature,hourly; !- Zone
Average [C]
Output:Variable,*,Site Outdoor Air Dewpoint
Temperature,hourly; !- Zone
Average [C]
Output:Variable,*,Site Outdoor Air Wetbulb
Temperature,hourly; !- Zone
Average [C]
Output:Variable,*,Site Outdoor Air Humidity
Ratio,hourly; !- Zone
Average [kgWater/kgAir]
Output:Variable,*,Site Outdoor Air Relative
Humidity,hourly; !- Zone
Average [%]
Output:Variable,*,Site Outdoor Air Barometric
Pressure,hourly; !- Zone
Average [Pa]
Output:Variable,*,Zone Air System Sensible Heating
Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Zone Air System Sensible Cooling
Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Zone Air System Sensible Heating
Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Zone Air System Sensible Cooling
Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Zone Air Temperature,hourly; !- HVAC
Average [C]
Output:Variable,*,Zone Thermostat Air
Temperature,hourly; !- HVAC Average [C]
All of the same information appears in a slightly different
form and defaults to “hourly” reporting frequency (which, of
course, can be changed when you put it into your input file).
The “*” is preselected so that you would be reporting for all
those items.
Input – Output Descriptions (Document)[LINK]
Input Descriptions[LINK]
In the descriptions below, the fields for each input object will be described but the Energy+.idd descriptions will not be shown. Refer to the actual Energy+.idd file for complete specifications. Energy+.idd is a text file that can be viewed with many text editors or word processors. The Site:Location object will serve as an example.
The IDD excerpt above is the complete definition as seen in the IDD file.
First, the object name is given. (Site:Location) This is followed by a comma in both the definition (IDD) and in an input file (IDF). In fact, all fields except the terminating field of an IDD class object and IDF object are followed by commas. The final field in an IDD class object or in an IDF object is terminated by a semi-colon.
Next is an alpha field, the location name. As noted above, for input, spaces are significant in this field. The main inputs for Site:Location are numeric fields. These are numbered (as is the alpha field) for convenience. The \ designations will show various information about the objects as described above in the IDD conventions discussion. Of importance for reading this document are the units and possible minimum and maximum values for a field.
There is automatic processing of the \minimum, \maximum and \default data for numeric fields. Any infractions of the \minimum, \maximum fields are automatically detected and messages will appear in the standard error file. After all the input is checked, infractions will cause program termination (before the bulk of the simulation is completed). Defaults are also enforced if you leave the numeric field blank.
Some objects need all the parameters listed by the definition; some do not. In the descriptions that follow, we will try to indicate which parts are optional. Usually, these will be the last fields in the object input or definition. Even if items are not used for a particular object (e.g. Multiplier in the FenestrationSurface:Detailed and type = Door), the field must be included unless it is the last field in the object. So, for this instance, one must include a multiplier field (must be numeric and would need to obey any \minimum, \maximum rules) for doors.
Two spreadsheet files are included with the installation:
ExampleFiles.xls – shows many details about the included example files including highlights of features.
ExampleFiles-ObjectsLink.xls – shows, for each object, the first three occurrences of that object in an example file.
Output Descriptions[LINK]
In the descriptions below, we will endeavor to have each object’s output displayed as well as each of the outputs described. The output variables for a run are selected by choosing the Output:VariableDictionary object. This object displays the available output variables for a run on the eplusout.rdd (regular variables) and eplusout.mdd (meter variables) files. Two significant styles are available for these displays and the descriptions below may have one for some objects and another for other objects. The variables are the same but will look a bit different. For clarity, the two displays are shown below:
Note that the IDF-Editor can interpret both sets of files and assist you in getting output variables into your input files. But you will have to successfully run your input file first.
The Simple (or regular) display looks like the following figure and is interpreted:
Zone/HVAC – when the output is produced at the “Zone” timestep (ref: number of timesteps in each hour) or at the “HVAC” aka System timestep (which can vary for each hour).
Average/Sum – whether this is a averaged value over the reporting period (such as a temperature or rate) or whether this is a summed value over the reporting period. Reporting periods are specified in the Output:Variable or Output:Meter objects.
<Variable Name> – The variable name one uses for reporting is displayed (e.g., Site Outdoor Drybulb Temperature) along with the units (e.g., [C]).
Example from the eplusout.rdd file:
Zone,Average,Site Outdoor Air Drybulb Temperature [C]
Zone,Average,Site Outdoor Air Dewpoint Temperature [C]
Zone,Average,Site Outdoor Air Wetbulb Temperature [C]
Zone,Average,Site Outdoor Air Humidity Ratio [kgWater/kgAir]
Zone,Average,Site Outdoor Air Relative Humidity [%]
Zone,Average,Site Outdoor Air Barometric Pressure [Pa]
Zone,Average,Wind Speed [m/s]
Zone,Average,Site Wind Direction [deg]
Zone,Average,Site Sky Temperature [C]
HVAC,Sum,Zone Air System Sensible Heating Energy [J]
HVAC,Sum,Zone Air System Sensible Cooling Energy [J]
HVAC,Average,Zone Air System Sensible Heating Rate [W]
HVAC,Average,Zone Air System Sensible Cooling Rate [W]
HVAC,Average,Zone Air Temperature [C]
HVAC,Average,Zone Thermostat Air Temperature [C]
Note that the eplusout.mdd file is similar, but meters are only available at the Zone timestep.
Zone,Meter,Electricity:Facility [J]
Zone,Meter,ExteriorLights:Electricity [J]
Zone,Meter,Grounds Lights:ExteriorLights:Electricity [J]
Zone,Meter,EnergyTransfer:Facility [J]
Zone,Meter,EnergyTransfer:Building [J]
Zone,Meter,EnergyTransfer:Zone:R13WALL WALLS [J]
The IDF display has all the same information in an IDF-ready form (i.e., you could copy and paste it into your input file using a text editor).
Example from the eplusout.rdd file:
Output:Variable,*,Site Outdoor Air Drybulb Temperature,hourly; !- Zone Average [C]
Output:Variable,*,Site Outdoor Air Dewpoint Temperature,hourly; !- Zone Average [C]
Output:Variable,*,Site Outdoor Air Wetbulb Temperature,hourly; !- Zone Average [C]
Output:Variable,*,Site Outdoor Air Humidity Ratio,hourly; !- Zone Average [kgWater/kgAir]
Output:Variable,*,Site Outdoor Air Relative Humidity,hourly; !- Zone Average [%]
Output:Variable,*,Site Outdoor Air Barometric Pressure,hourly; !- Zone Average [Pa]
Output:Variable,*,Zone Air System Sensible Heating Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Zone Air System Sensible Cooling Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Zone Air System Sensible Heating Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Zone Air System Sensible Cooling Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Zone Air Temperature,hourly; !- HVAC Average [C]
Output:Variable,*,Zone Thermostat Air Temperature,hourly; !- HVAC Average [C]
All of the same information appears in a slightly different form and defaults to “hourly” reporting frequency (which, of course, can be changed when you put it into your input file). The “*” is preselected so that you would be reporting for all those items.
Documentation content copyright © 1996-2026 The Board of Trustees of the University of Illinois and the Regents of the University of California through the Ernest Orlando Lawrence Berkeley National Laboratory. All rights reserved. EnergyPlus is a trademark of the US Department of Energy.
This documentation is made available under the EnergyPlus Open Source License v1.0.