Standard EnergyPlus Units[LINK]
EnergyPlus expects information in a single unit system (SI). This requires interface developers to convert user inputs from those preferred by architects and engineers into the standard metric units of EnergyPlus. EnergyPlus will not perform any units conversions and will not have any unit conversion routines.
ASCII with no spaces is used for abbreviations. Note that exponents appear without any indication of exponentiation: i.e., kg/m3 not kg/m^3 or kg/m**3. Also note the use of dashes. We have W/m2K not W/m2*K or W/(m2*K).
At the end we note the “problem” variables – the inputs that have nonstandard units. Inputs using these units will have to be changed and the code checked to see how the quantities are used internally.
Standard EnergyPlus Units
angular degrees 
degree 
deg 
Length 
meter 
m 
Area 
square meter 
m2 
Volume 
cubic meter 
m3 
Time 
seconds 
s 
Frequency 
Hertz 
Hz 
Temperature 
Celsius 
C 
absolute temperature 
Kelvin 
K 
temperature difference 
Kelvin 
delK 
speed 
meters per second 
m/s 
energy (or work) 
Joules 
J 
power 
Watts 
W 
mass 
kilograms 
kg 
force 
Newton 
N 
mass flow 
kilograms per second 
kg/s 
volume flow 
cubic meters per second 
m3/s 
pressure 
Pascals 
Pa 
pressure difference 
Pascals 
delPa 
specific enthalpy 
Joules per kilogram 
J/kg 
density 
kilograms per cubic meter 
kg/m3 
heat flux 
watts per square meter 
W/m2 
specific heat 
———————————————————————— 
J/kgK 
conductivity 
———————————————————————— 
W/mK 
diffusivity 
———————————————————————— 
m2/s 
heat transfer coefficient 
———————————————————————— 
W/m2K 
Rvalue 
———————————————————————— 
m2K/W 
heating or cooling capacity 
Watts 
W 
electric potential 
volts 
V 
electric current 
Amperes 
A 
illuminace 
lux 
lx 
luminous flux 
lumen 
lm 
luminous intensity 
candelas 
cd 
luminance 
candelas per square meter 
cd/m2 
vapor diffusivity 
m2/s 

viscosity 
———————————————————————— 
kg/ms 
porosity 
———————————————————————— 
m3/m3 
thermal gradient coeff for moisture capacity 
———————————————————————— 
kg/kgK 
isothermal moisture capacity 
———————————————————————— 
m3/kg 
Standard EnergyPlus Units[LINK]
EnergyPlus expects information in a single unit system (SI). This requires interface developers to convert user inputs from those preferred by architects and engineers into the standard metric units of EnergyPlus. EnergyPlus will not perform any units conversions and will not have any unit conversion routines.
ASCII with no spaces is used for abbreviations. Note that exponents appear without any indication of exponentiation: i.e., kg/m3 not kg/m^3 or kg/m**3. Also note the use of dashes. We have W/m2K not W/m2*K or W/(m2*K).
At the end we note the “problem” variables – the inputs that have nonstandard units. Inputs using these units will have to be changed and the code checked to see how the quantities are used internally.
Documentation content copyright © 19962020 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.