Procedures

ProcedureLocationProcedure TypeDescription
CalcMinimalDXCoolingMinimalDXCoolingSubroutine

Simplified EnergyPlus subroutine for calculating the performance of a DX cooling coil. Adapted from EnergyPlus CalcDoe2DXCoil by D.Meyer and R. Raustad (2018).

Read more…
CalcMinimalDXHeatingMinimalDXHeatingSubroutine

Simplified EnergyPlus subroutine for calculating the performance of a DX heating coil. Adapted from EnergyPlus CalcDXHeatingCoil by D.Meyer and R. Raustad (2018).

Read more…
CalcPsychrometricsFromRelHumpsychrolibSubroutine

Utility function to calculate humidity ratio, wet-bulb temperature, dew-point temperature, vapour pressure, moist air enthalpy, moist air volume, and degree of saturation of air given dry-bulb temperature, relative humidity and pressure.

CalcPsychrometricsFromTDewPointpsychrolibSubroutine

Utility function to calculate humidity ratio, wet-bulb temperature, relative humidity, vapour pressure, moist air enthalpy, moist air volume, and degree of saturation of air given dry-bulb temperature, dew-point temperature, and pressure.

CalcPsychrometricsFromTWetBulbpsychrolibSubroutine

Utility function to calculate humidity ratio, dew-point temperature, relative humidity, vapour pressure, moist air enthalpy, moist air volume, and degree of saturation of air given dry-bulb temperature, wet-bulb temperature, and pressure.

dLnPws_psychrolibFunction

Helper function returning the derivative of the natural log of the saturation vapor pressure as a function of dry-bulb temperature. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 5

GetDegreeOfSaturationpsychrolibFunction

Return the degree of saturation (i.e humidity ratio of the air / humidity ratio of the air at saturation at the same temperature and pressure) given dry-bulb temperature, humidity ratio, and atmospheric pressure. Reference: ASHRAE Handbook - Fundamentals (2009) ch. 1 eqn 12 Notes: This definition is absent from the 2017 Handbook. Using 2009 version instead.

GetDryAirDensitypsychrolibFunction

Return dry-air density given dry-bulb temperature and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 Notes: Eqn 14 for the perfect gas relationship for dry air. Eqn 1 for the universal gas constant. The factor 144 in IP is for the conversion of Psi = lb in⁻² to lb ft⁻².

GetDryAirEnthalpypsychrolibFunction

Return dry-air enthalpy given dry-bulb temperature. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 28

GetDryAirVolumepsychrolibFunction

Return dry-air volume given dry-bulb temperature and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 Notes: Eqn 14 for the perfect gas relationship for dry air. Eqn 1 for the universal gas constant. The factor 144 in IP is for the conversion of Psi = lb in⁻² to lb ft⁻².

GetHumRatioFromEnthalpyAndTDryBulbpsychrolibFunction

Return humidity ratio from enthalpy and dry-bulb temperature. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 30 Notes: Based on the GetMoistAirEnthalpy function, rearranged for humidity ratio.

GetHumRatioFromRelHumpsychrolibFunction

Return humidity ratio given dry-bulb temperature, relative humidity, and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetHumRatioFromSpecificHumpsychrolibFunction

Return the humidity ratio (aka mixing ratio) from specific humidity. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 9b (solved for humidity ratio)

GetHumRatioFromTDewPointpsychrolibFunction

Return humidity ratio given dew-point temperature and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetHumRatioFromTWetBulbpsychrolibFunction

Return humidity ratio given dry-bulb temperature, wet-bulb temperature, and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 33 and 35

GetHumRatioFromVapPrespsychrolibFunction

Return humidity ratio given water vapor pressure and atmospheric pressure. Reference: ASHRAE Fundamentals (2005) ch. 6 eqn. 22; ASHRAE Fundamentals (2009) ch. 1 eqn. 22.

GetMoistAirDensitypsychrolibFunction

Return moist air density given humidity ratio, dry bulb temperature, and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 11

GetMoistAirEnthalpypsychrolibFunction

Return moist air enthalpy given dry-bulb temperature and humidity ratio. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 30

GetMoistAirVolumepsychrolibFunction

Return moist air specific volume given dry-bulb temperature, humidity ratio, and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 26 Notes: In IP units, R_DA_IP / 144 equals 0.370486 which is the coefficient appearing in eqn 26 The factor 144 is for the conversion of Psi = lb in⁻² to lb ft⁻².

GetOnOffFanMinimalDXFanFunction

Simplified version of SimOnOffFan subroutine in EnergyPlus Given the mode of operation (on or off), fan motor efficiency, power of the fan, fraction of motor heat entering air stream moist air enthaply of the air entering the fan, and mass flow rate, it returns the moist air enthaply of the air after it has passed through the fan. It assumes sensible heating process only - i.e. it does not change the moisture in the air - and the mass flow rate across the component remains the same. Original Credits: NREL Energy Plus, Shirey, R. Raustad - FSEC, Brent Griffith, Chandan Sharma, Rongpeng Zhang Reference: ASHRAE HVAC 2 Toolkit, page 2-3 (FANSIM) https://github.com/NREL/EnergyPlus/blob/d37252156cb0eef0cb9b1af5ce7dcd7423011649/src/EnergyPlus/Fans.cc#L1967-L1989 This fan does not change the moisture or Mass Flow across the component

GetRelHumFromHumRatiopsychrolibFunction

Return relative humidity given dry-bulb temperature, humidity ratio, and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetRelHumFromTDewPointpsychrolibFunction

Return relative humidity given dry-bulb temperature and dew-point temperature. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 22

GetRelHumFromTWetBulbpsychrolibFunction

Return relative humidity given dry-bulb temperature, wet bulb temperature and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetRelHumFromVapPrespsychrolibFunction

Return relative humidity given dry-bulb temperature and vapor pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 12, 22

GetSatAirEnthalpypsychrolibFunction

Return saturated air enthalpy given dry-bulb temperature and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetSatHumRatiopsychrolibFunction

Return humidity ratio of saturated air given dry-bulb temperature and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 36, solved for W

GetSatVapPrespsychrolibFunction

Return saturation vapor pressure given dry-bulb temperature. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 5

GetSeaLevelPressurepsychrolibFunction

Return sea level pressure given dry-bulb temperature, altitude above sea level and pressure. Reference: Hess SL, Introduction to theoretical meteorology, Holt Rinehart and Winston, NY 1959, ch. 6.5; Stull RB, Meteorology for scientists and engineers, 2nd edition, Brooks/Cole 2000, ch. 1. Notes: The standard procedure for the US is to use for TDryBulb the average of the current station temperature and the station temperature from 12 hours ago.

GetSpecificHumFromHumRatiopsychrolibFunction

Return the specific humidity from humidity ratio (aka mixing ratio). Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 9b

GetStandardAtmPressurepsychrolibFunction

Return standard atmosphere barometric pressure, given the elevation (altitude). Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 3

GetStandardAtmTemperaturepsychrolibFunction

Return standard atmosphere temperature, given the elevation (altitude). Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 4

GetStationPressurepsychrolibFunction

Return station pressure from sea level pressure. Reference: See 'GetSeaLevelPressure' Notes: This function is just the inverse of 'GetSeaLevelPressure'.

GetTDewPointFromHumRatiopsychrolibFunction

Return dew-point temperature given dry-bulb temperature, humidity ratio, and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetTDewPointFromRelHumpsychrolibFunction

Return dew-point temperature given dry-bulb temperature and relative humidity. References: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetTDewPointFromTWetBulbpsychrolibFunction

Return dew-point temperature given dry-bulb temperature, wet-bulb temperature, and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetTDewPointFromVapPrespsychrolibFunction

Return dew-point temperature given dry-bulb temperature and vapor pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn. 5 and 6 Notes: The dew point temperature is solved by inverting the equation giving water vapor pressure at saturation from temperature rather than using the regressions provided by ASHRAE (eqn. 37 and 38) which are much less accurate and have a narrower range of validity. The Newton-Raphson (NR) method is used on the logarithm of water vapour pressure as a function of temperature, which is a very smooth function Convergence is usually achieved in 3 to 5 iterations. TDryBulb is not really needed here, just used for convenience.

GetTDryBulbFromEnthalpyAndHumRatiopsychrolibFunction

Return dry bulb temperature from enthalpy and humidity ratio. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 30 Notes: Based on the GetMoistAirEnthalpy function, rearranged for temperature.

GetTKelvinFromTCelsiuspsychrolibFunction
GetTRankineFromTFahrenheitpsychrolibFunction
GetTWetBulbFromHumRatiopsychrolibFunction

Return wet-bulb temperature given dry-bulb temperature, humidity ratio, and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 33 and 35 solved for Tstar

GetTWetBulbFromRelHumpsychrolibFunction

Return wet-bulb temperature given dry-bulb temperature, relative humidity, and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetTWetBulbFromTDewPointpsychrolibFunction

Return wet-bulb temperature given dry-bulb temperature, dew-point temperature, and pressure. References: ASHRAE Handbook - Fundamentals (2017) ch. 1

GetUnitSystempsychrolibFunction

Return the system of units in use.

GetVaporPressureDeficitpsychrolibFunction

Return Vapor pressure deficit given dry-bulb temperature, humidity ratio, and pressure. Reference: Oke (1987) eqn 2.13a

GetVapPresFromHumRatiopsychrolibFunction

Return vapor pressure given humidity ratio and pressure. Reference: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 20 solved for pw

GetVapPresFromRelHumpsychrolibFunction

Return partial pressure of water vapor as a function of relative humidity and temperature. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 12, 22

GetVapPresFromTDewPointpsychrolibFunction

Return vapor pressure given dew point temperature. References: ASHRAE Handbook - Fundamentals (2017) ch. 1 eqn 36

InitPsychrometricsPsychroWrapperSubroutine
isIPpsychrolibFunction

Check whether the system in use is IP or SI

PsyTsatFnHPbEPlusPsychroFunction
SetUnitSystempsychrolibSubroutine

Set the system of units to use (SI or IP). Notes: this function HAS TO BE CALLED before the library can be used

SimMinimalDXCoolingMinimalDXCoolingDriverSubroutine

Simplified EnergyPlus subroutine for calculating the performance of a DX heating coil. This is the subroutine to call from your program.

SimMinimalDXHeatingMinimalDXHeatingDriverSubroutine

Simplified EnergyPlus subroutine for calculating the performance of a DX heating coil. This is the subroutine to call from your program.

call~~graph~~CallGraph proc~getrelhumfromvappres GetRelHumFromVapPres proc~getsatvappres GetSatVapPres proc~getrelhumfromvappres->proc~getsatvappres proc~gettdewpointfromhumratio GetTDewPointFromHumRatio proc~getvappresfromhumratio GetVapPresFromHumRatio proc~gettdewpointfromhumratio->proc~getvappresfromhumratio proc~gettdewpointfromvappres GetTDewPointFromVapPres proc~gettdewpointfromhumratio->proc~gettdewpointfromvappres proc~getdegreeofsaturation GetDegreeOfSaturation proc~getsathumratio GetSatHumRatio proc~getdegreeofsaturation->proc~getsathumratio proc~getdryairvolume GetDryAirVolume proc~isip isIP proc~getdryairvolume->proc~isip proc~gettkelvinfromtcelsius GetTKelvinFromTCelsius proc~getdryairvolume->proc~gettkelvinfromtcelsius proc~gettrankinefromtfahrenheit GetTRankineFromTFahrenheit proc~getdryairvolume->proc~gettrankinefromtfahrenheit proc~getdryairdensity GetDryAirDensity proc~getdryairdensity->proc~isip proc~getdryairdensity->proc~gettkelvinfromtcelsius proc~getdryairdensity->proc~gettrankinefromtfahrenheit proc~calcpsychrometricsfromrelhum CalcPsychrometricsFromRelHum proc~calcpsychrometricsfromrelhum->proc~gettdewpointfromhumratio proc~calcpsychrometricsfromrelhum->proc~getdegreeofsaturation proc~getmoistairenthalpy GetMoistAirEnthalpy proc~calcpsychrometricsfromrelhum->proc~getmoistairenthalpy proc~getmoistairvolume GetMoistAirVolume proc~calcpsychrometricsfromrelhum->proc~getmoistairvolume proc~calcpsychrometricsfromrelhum->proc~getvappresfromhumratio proc~gethumratiofromrelhum GetHumRatioFromRelHum proc~calcpsychrometricsfromrelhum->proc~gethumratiofromrelhum proc~gettwetbulbfromhumratio GetTWetBulbFromHumRatio proc~calcpsychrometricsfromrelhum->proc~gettwetbulbfromhumratio proc~getmoistairenthalpy->proc~isip proc~getrelhumfromhumratio GetRelHumFromHumRatio proc~getrelhumfromhumratio->proc~getrelhumfromvappres proc~getrelhumfromhumratio->proc~getvappresfromhumratio proc~getstandardatmtemperature GetStandardAtmTemperature proc~getstandardatmtemperature->proc~isip proc~getmoistairvolume->proc~isip proc~getmoistairvolume->proc~gettkelvinfromtcelsius proc~getmoistairvolume->proc~gettrankinefromtfahrenheit proc~getdryairenthalpy GetDryAirEnthalpy proc~getdryairenthalpy->proc~isip proc~getstandardatmpressure GetStandardAtmPressure proc~getstandardatmpressure->proc~isip proc~getrelhumfromtdewpoint GetRelHumFromTDewPoint proc~getrelhumfromtdewpoint->proc~getsatvappres proc~simminimaldxcooling SimMinimalDXCooling proc~calcminimaldxcooling CalcMinimalDXCooling proc~simminimaldxcooling->proc~calcminimaldxcooling proc~calcminimaldxheating CalcMinimalDXHeating proc~calcminimaldxheating->proc~getmoistairenthalpy proc~calcminimaldxheating->proc~getrelhumfromhumratio proc~gettdrybulbfromenthalpyandhumratio GetTDryBulbFromEnthalpyAndHumRatio proc~calcminimaldxheating->proc~gettdrybulbfromenthalpyandhumratio proc~gethumratiofromenthalpyandtdrybulb GetHumRatioFromEnthalpyAndTDryBulb proc~calcminimaldxheating->proc~gethumratiofromenthalpyandtdrybulb proc~getonofffan GetOnOffFan proc~calcminimaldxheating->proc~getonofffan proc~gethumratiofromtdewpoint GetHumRatioFromTDewPoint proc~calcminimaldxheating->proc~gethumratiofromtdewpoint proc~psytsatfnhpb PsyTsatFnHPb proc~calcminimaldxheating->proc~psytsatfnhpb proc~getmoistairdensity GetMoistAirDensity proc~calcminimaldxheating->proc~getmoistairdensity proc~initpsychrometrics InitPsychrometrics proc~calcminimaldxheating->proc~initpsychrometrics proc~calcminimaldxheating->proc~gettwetbulbfromhumratio proc~gettdrybulbfromenthalpyandhumratio->proc~isip proc~dlnpws_ dLnPws_ proc~dlnpws_->proc~isip proc~dlnpws_->proc~gettkelvinfromtcelsius proc~dlnpws_->proc~gettrankinefromtfahrenheit proc~gethumratiofromenthalpyandtdrybulb->proc~isip proc~gettdewpointfromtwetbulb GetTDewPointFromTWetBulb proc~gettdewpointfromtwetbulb->proc~gettdewpointfromhumratio proc~gethumratiofromtwetbulb GetHumRatioFromTWetBulb proc~gettdewpointfromtwetbulb->proc~gethumratiofromtwetbulb proc~calcpsychrometricsfromtwetbulb CalcPsychrometricsFromTWetBulb proc~calcpsychrometricsfromtwetbulb->proc~gettdewpointfromhumratio proc~calcpsychrometricsfromtwetbulb->proc~getdegreeofsaturation proc~calcpsychrometricsfromtwetbulb->proc~getmoistairenthalpy proc~calcpsychrometricsfromtwetbulb->proc~getrelhumfromhumratio proc~calcpsychrometricsfromtwetbulb->proc~getmoistairvolume proc~calcpsychrometricsfromtwetbulb->proc~getvappresfromhumratio proc~calcpsychrometricsfromtwetbulb->proc~gethumratiofromtwetbulb proc~gethumratiofromspecifichum GetHumRatioFromSpecificHum proc~gethumratiofromvappres GetHumRatioFromVapPres proc~setunitsystem SetUnitSystem proc~getsatairenthalpy GetSatAirEnthalpy proc~getsatairenthalpy->proc~getmoistairenthalpy proc~getsatairenthalpy->proc~getsathumratio proc~calcminimaldxcooling->proc~getmoistairenthalpy proc~calcminimaldxcooling->proc~gettdrybulbfromenthalpyandhumratio proc~calcminimaldxcooling->proc~gethumratiofromenthalpyandtdrybulb proc~calcminimaldxcooling->proc~getonofffan proc~calcminimaldxcooling->proc~psytsatfnhpb proc~calcminimaldxcooling->proc~getmoistairdensity proc~calcminimaldxcooling->proc~initpsychrometrics proc~calcminimaldxcooling->proc~gettwetbulbfromhumratio proc~getvaporpressuredeficit GetVaporPressureDeficit proc~getvaporpressuredeficit->proc~getrelhumfromhumratio proc~getvaporpressuredeficit->proc~getsatvappres proc~getvappresfromrelhum GetVapPresFromRelHum proc~getvappresfromrelhum->proc~getsatvappres proc~gettwetbulbfromtdewpoint GetTWetBulbFromTDewPoint proc~gettwetbulbfromtdewpoint->proc~gethumratiofromtdewpoint proc~gettwetbulbfromtdewpoint->proc~gettwetbulbfromhumratio proc~simminimaldxheating SimMinimalDXHeating proc~simminimaldxheating->proc~calcminimaldxheating proc~getrelhumfromtwetbulb GetRelHumFromTWetBulb proc~getrelhumfromtwetbulb->proc~getrelhumfromhumratio proc~getrelhumfromtwetbulb->proc~gethumratiofromtwetbulb proc~gethumratiofromtdewpoint->proc~gethumratiofromvappres proc~gethumratiofromtdewpoint->proc~getsatvappres proc~getspecifichumfromhumratio GetSpecificHumFromHumRatio proc~calcpsychrometricsfromtdewpoint CalcPsychrometricsFromTDewPoint proc~calcpsychrometricsfromtdewpoint->proc~getdegreeofsaturation proc~calcpsychrometricsfromtdewpoint->proc~getmoistairenthalpy proc~calcpsychrometricsfromtdewpoint->proc~getrelhumfromhumratio proc~calcpsychrometricsfromtdewpoint->proc~getmoistairvolume proc~calcpsychrometricsfromtdewpoint->proc~gethumratiofromtdewpoint proc~calcpsychrometricsfromtdewpoint->proc~getvappresfromhumratio proc~calcpsychrometricsfromtdewpoint->proc~gettwetbulbfromhumratio proc~gettwetbulbfromrelhum GetTWetBulbFromRelHum proc~gettwetbulbfromrelhum->proc~gethumratiofromrelhum proc~gettwetbulbfromrelhum->proc~gettwetbulbfromhumratio proc~getsatvappres->proc~isip proc~getsatvappres->proc~gettkelvinfromtcelsius proc~getsatvappres->proc~gettrankinefromtfahrenheit proc~getsathumratio->proc~getsatvappres proc~getvappresfromtdewpoint GetVapPresFromTDewPoint proc~getvappresfromtdewpoint->proc~getsatvappres proc~getsealevelpressure GetSeaLevelPressure proc~getsealevelpressure->proc~isip proc~getsealevelpressure->proc~gettkelvinfromtcelsius proc~getsealevelpressure->proc~gettrankinefromtfahrenheit proc~gethumratiofromtwetbulb->proc~isip proc~gethumratiofromtwetbulb->proc~getsathumratio proc~psytsatfnhpb->proc~getsatairenthalpy proc~gethumratiofromrelhum->proc~gethumratiofromvappres proc~gethumratiofromrelhum->proc~getvappresfromrelhum proc~getmoistairdensity->proc~getmoistairvolume proc~gettdewpointfromvappres->proc~isip proc~gettdewpointfromvappres->proc~dlnpws_ proc~gettdewpointfromvappres->proc~getsatvappres proc~initpsychrometrics->proc~setunitsystem proc~gettwetbulbfromhumratio->proc~gettdewpointfromhumratio proc~gettwetbulbfromhumratio->proc~gethumratiofromtwetbulb proc~gettdewpointfromrelhum GetTDewPointFromRelHum proc~gettdewpointfromrelhum->proc~getvappresfromrelhum proc~gettdewpointfromrelhum->proc~gettdewpointfromvappres proc~getstationpressure GetStationPressure proc~getstationpressure->proc~getsealevelpressure proc~getunitsystem GetUnitSystem
Help