CalcHPWHDXCoil – EnergyPlusFortran

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public subroutine CalcHPWHDXCoil(DXCoilNum, PartLoadRatio)

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Arguments

Type	Intent	Optional	Attributes		Name
integer,	intent(in)			::	DXCoilNum
real(kind=r64),	intent(in)			::	PartLoadRatio
Source Code

SUBROUTINE CalcHPWHDXCoil(DXCoilNum,PartLoadRatio)

          ! SUBROUTINE INFORMATION:
          !       AUTHOR         Richard Raustad
          !       DATE WRITTEN   May 2005
          !       MODIFIED       na
          !       RE-ENGINEERED  na

          ! PURPOSE OF THIS SUBROUTINE:
          ! Calculates the gross cooling capacity of a heat pump water heater evaporator and
          ! heating capacity of the condenser coil given the rated heating capacity and COP.

          ! METHODOLOGY EMPLOYED:
          ! The routine requires the user to enter the total heating capacity and COP for the
          ! heat pump water heater along with logicals defining if fan and condenser pump are included.
          ! Since manufacturer's can rate their HPWH equipment with or without including condenser
          ! pump heat, this information is required to accurately determine the condenser's leaving
          ! water temperature. In addition, knowledge of the fan heat is required to back into
          ! a compressor COP.

          ! USE STATEMENTS:
  USE CurveManager,    ONLY: CurveValue
  USE General,         ONLY: TrimSigDigits
  USE DataHVACGlobals, ONLY: FanElecPower, HPWHInletDBTemp, HPWHInletWBTemp, DXCoilTotalCapacity

  IMPLICIT NONE    ! Enforce explicit typing of all variables in this routine

          ! SUBROUTINE ARGUMENT DEFINITIONS:
  INTEGER, INTENT(IN) :: DXCoilNum        ! the number of the DX coil to be simulated
  REAL(r64),    INTENT(IN) :: PartLoadRatio    ! sensible water heating load / full load sensible water heating capacity

          ! SUBROUTINE PARAMETER DEFINITIONS:
  CHARACTER(len=*), PARAMETER ::  RoutineName='CalcHPWHDXCoil'

          ! INTERFACE BLOCK SPECIFICATIONS
          ! na

          ! DERIVED TYPE DEFINITIONS
          ! na

          ! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
REAL(r64) :: RatedHeatingCapacity       ! Water heating rated capacity with or without condenser water pump heat (W)
REAL(r64) :: RatedHeatingCOP            ! Water heating rated COP with or without evap fan and cond water pump heat (W/W)
REAL(r64) :: OperatingHeatingCapacity   ! Water heating operating capacity including the impact of capacity and COP curves (W)
REAL(r64) :: OperatingHeatingCOP        ! Water heating operating COP including the impact of capacity and COP curves (W/W)
REAL(r64) :: OperatingHeatingPower      ! Water heating operating Power (W)
REAL(r64) :: CompressorPower            ! Power consumed by compressor only (W)

REAL(r64) :: TotalTankHeatingCapacity   ! Water heating capacity corrected for condenser water pump heat (W)
REAL(r64) :: TankHeatingCOP             ! Water heating COP corrected for fan and condenser water pump power (W/W)
                                      ! (these previous 2 variables also include the impact of capacity and COP curves)
REAL(r64) :: EvapCoolingCapacity        ! Air cooling capacity corrected for evap fan and cond water pump heat (W)
REAL(r64) :: InletWaterTemp             ! Condenser water inlet temperature (C)
REAL(r64) :: OutletWaterTemp            ! Condenser water outlet temperature (C)
REAL(r64) :: EvapInletMassFlowRate      ! Evaporator air inlet mass flow rate (m3/s)
REAL(r64) :: CondInletMassFlowRate      ! Condenser water inlet mass flow rate (m3/s)
REAL(r64) :: CpWater                    ! Specific heat of condenser inlet water (J/Kg/k)
REAL(r64) :: InletAirTemp               ! HPWH inlet air temperature (dry-bulb or wet-bulb) (C)
REAL(r64) :: HeatCapFTemp               ! Output of HPWH Heating Capacity as a Function of Temperature curve
REAL(r64) :: HeatCapFAirFlow            ! Output of HPWH Heating Capacity as a Function of Air Flow Rate Ratio curve
REAL(r64) :: HeatCapFWaterFlow          ! Output of HPWH Heating Capacity as a Function of Water Flow Rate Ratio curve
REAL(r64) :: HeatCOPFTemp               ! Output of HPWH COP as a Function of Temperature curve
REAL(r64) :: HeatCOPFAirFlow            ! Output of HPWH COP as a Function of Air Flow Rate Ratio curve
REAL(r64) :: HeatCOPFWAterFlow          ! Output of HPWH COP as a Function of Water Flow Rate Ratio curve
REAL(r64) :: AirFlowRateRatio           ! Ratio of evaporator inlet air mass flow rate to rated mass flow rate
REAL(r64) :: WaterFlowRateRatio         ! Ratio of evaporator inlet water mass flow rate to rated mass flow rate
REAL(r64) :: PartLoadFraction             ! Output of Part Load Fraction as a Function of Part Load Ratio curve
REAL(r64) :: PumpHeatToWater            ! Amount of pump heat attributed to heating water
REAL(r64) :: HPRTF                      ! Heat pump run time fraction
INTEGER :: EvapInletNode              ! Evaporator air inlet node number
INTEGER :: EvapOutletNode             ! Evaporator air outlet node number
INTEGER :: CondInletNode              ! Condenser water inlet node number
INTEGER :: CondOutletNode             ! Condenser water outlet node number

  CondInletNode  = DXCoil(DXCoilNum)%WaterInNode
  CondOutletNode = DXCoil(DXCoilNum)%WaterOutNode

! If heat pump water heater is OFF, set outlet to inlet and RETURN
  IF(PartLoadRatio .EQ. 0.0d0)THEN
    Node(CondOutletNode) = Node(CondInletNode)
    RETURN
  ELSE
    RatedHeatingCapacity   = DXCoil(DXCoilNum)%RatedTotCap2
    RatedHeatingCOP        = DXCoil(DXCoilNum)%RatedCOP(1)
    EvapInletNode          = DXCoil(DXCoilNum)%AirInNode
    EvapOutletNode         = DXCoil(DXCoilNum)%AirOutNode
    InletWaterTemp         = Node(CondInletNode)%Temp
    CondInletMassFlowRate  = Node(CondInletNode)%MassFlowRate / PartLoadRatio
    EvapInletMassFlowRate  = Node(EvapInletNode)%MassFlowRate / PartLoadRatio
    CpWater                = CPHW(InletWaterTemp)
    CompressorPower        = 0.0d0
    OperatingHeatingPower  = 0.0d0
    TankHeatingCOP         = 0.0d0
  END IF

! determine inlet air temperature type for curve objects
  IF(DXCoil(DXCoilNum)%InletAirTemperatureType .EQ. WetBulbIndicator) THEN
    InletAirTemp = HPWHInletWBTemp
  ELSE
    InletAirTemp = HPWHInletDBTemp
  END IF

! get output of Heating Capacity and Heating COP curves (curves default to 1 if user has not specified curve name)
  IF(DXCoil(DXCoilNum)%HCapFTemp .GT. 0)THEN
    IF(DXCoil(DXCoilNum)%HCapFTempCurveType .EQ. Cubic) THEN
      HeatCapFTemp = CurveValue(DXCoil(DXCoilNum)%HCapFTemp,InletAirTemp)
    ELSE
      HeatCapFTemp = CurveValue(DXCoil(DXCoilNum)%HCapFTemp,InletAirTemp,InletWaterTemp)
    END IF
!   Warn user if curve output goes negative
    IF(HeatCapFTemp .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCapFTempErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating Capacity Modifier curve (function of temperature) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCapFTemp,3))//').')
        IF(DXCoil(DXCoilNum)%HCapFTempCurveType .EQ. Biquadratic) THEN
          CALL ShowContinueError(' Negative value occurs using an inlet air temperature of ' &
                            //TRIM(TrimSigDigits(InletAirTemp,1))// &
                               ' and an inlet water temperature of '//TRIM(TrimSigDigits(InletWaterTemp,1))//'.')
        ELSE
          CALL ShowContinueError(' Negative value occurs using an inlet air temperature of ' &
                            //TRIM(TrimSigDigits(InletAirTemp,1))//'.')
        END IF
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating Capacity Modifier curve (function of temperature) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCapFTempErrorIndex, HeatCapFTemp, HeatCapFTemp,  &
            ReportMinUnits='[C]',ReportMaxUnits='[C]')
      HeatCapFTemp = 0.0d0
    END IF
  ELSE
    HeatCapFTemp = 1.0d0
  END IF

  IF(DXCoil(DXCoilNum)%HCOPFTemp .GT. 0)THEN
    IF(DXCoil(DXCoilNum)%HCOPFTempCurveType .EQ. Cubic) THEN
      HeatCOPFTemp = CurveValue(DXCoil(DXCoilNum)%HCOPFTemp,InletAirTemp)
    ELSE
      HeatCOPFTemp = CurveValue(DXCoil(DXCoilNum)%HCOPFTemp,InletAirTemp,InletWaterTemp)
    END IF
!   Warn user if curve output goes negative
    IF(HeatCOPFTemp .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCOPFTempErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating COP Modifier curve (function of temperature) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCOPFTemp,3))//').')
        IF(DXCoil(DXCoilNum)%HCOPFTempCurveType .EQ. Biquadratic) THEN
          CALL ShowContinueError(' Negative value occurs using an inlet air temperature of ' &
                            //TRIM(TrimSigDigits(InletAirTemp,1))// &
                               ' and an inlet water temperature of '//TRIM(TrimSigDigits(InletWaterTemp,1))//'.')
        ELSE
          CALL ShowContinueError(' Negative value occurs using an inlet air temperature of ' &
                            //TRIM(TrimSigDigits(InletAirTemp,1))//'.')
        END IF
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating COP Modifier curve (function of temperature) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCOPFTempErrorIndex, HeatCOPFTemp, HeatCOPFTemp,  &
            ReportMinUnits='[C]',ReportMaxUnits='[C]')
      HeatCOPFTemp = 0.0d0
    END IF
  ELSE
    HeatCOPFTemp = 1.0d0
  END IF

  IF(DXCoil(DXCoilNum)%HCapFAirFlow .GT. 0) THEN
    AirFlowRateRatio = EvapInletMassFlowRate / (DXCoil(DXCoilNum)%RatedAirMassFlowRate(1))
    HeatCapFAirFlow  = CurveValue(DXCoil(DXCoilNum)%HCapFAirFlow,AirFlowRateRatio)
!   Warn user if curve output goes negative
    IF(HeatCapFAirFlow .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCapFAirFlowErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating Capacity Modifier curve (function of air flow fraction) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCapFAirFlow,3))//').')
        CALL ShowContinueError(' Negative value occurs using an air flow fraction of ' &
                            //TRIM(TrimSigDigits(AirFlowRateRatio,3))//'.')
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating Capacity Modifier curve (function of air flow fraction) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCapFAirFlowErrorIndex, HeatCapFAirFlow, HeatCapFAirFlow)
      HeatCapFAirFlow = 0.0d0
    END IF
  ELSE
    HeatCapFAirFlow  = 1.0d0
  END IF

  IF(DXCoil(DXCoilNum)%HCOPFAirFlow .GT. 0) THEN
    AirFlowRateRatio = EvapInletMassFlowRate / (DXCoil(DXCoilNum)%RatedAirMassFlowRate(1))
    HeatCOPFAirFlow  = CurveValue(DXCoil(DXCoilNum)%HCOPFAirFlow,AirFlowRateRatio)
!   Warn user if curve output goes negative
    IF(HeatCOPFAirFlow .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCOPFAirFlowErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating COP Modifier curve (function of air flow fraction) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCOPFAirFlow,3))//').')
        CALL ShowContinueError(' Negative value occurs using an air flow fraction of ' &
                            //TRIM(TrimSigDigits(AirFlowRateRatio,3))//'.')
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating COP Modifier curve (function of air flow fraction) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCOPFAirFlowErrorIndex, HeatCOPFAirFlow, HeatCOPFAirFlow)
      HeatCOPFAirFlow = 0.0d0
    END IF
  ELSE
    HeatCOPFAirFlow  = 1.0d0
  END IF

  IF(DXCoil(DXCoilNum)%HCapFWaterFlow .GT. 0) THEN
    WaterFlowRateRatio = CondInletMassFlowRate / (DXCoil(DXCoilNum)%RatedHPWHCondWaterFlow*RhoH2O(InletWaterTemp))
    HeatCapFWaterFlow  = CurveValue(DXCoil(DXCoilNum)%HCapFWaterFlow,WaterFlowRateRatio)
!   Warn user if curve output goes negative
    IF(HeatCapFWaterFlow .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCapFWaterFlowErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating Capacity Modifier curve (function of water flow fraction) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCapFWaterFlow,3))//').')
        CALL ShowContinueError(' Negative value occurs using a water flow fraction of ' &
                            //TRIM(TrimSigDigits(WaterFlowRateRatio,3))//'.')
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating Capacity Modifier curve (function of water flow fraction) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCapFWaterFlowErrorIndex, HeatCapFWaterFlow, HeatCapFWaterFlow)
      HeatCapFWaterFlow = 0.0d0
    END IF
  ELSE
    HeatCapFWaterFlow  = 1.0d0
  END IF

  IF(DXCoil(DXCoilNum)%HCOPFWaterFlow .GT. 0) THEN
    WaterFlowRateRatio = CondInletMassFlowRate / (DXCoil(DXCoilNum)%RatedHPWHCondWaterFlow*RhoH2O(InletWaterTemp))
    HeatCOPFWaterFlow  = CurveValue(DXCoil(DXCoilNum)%HCOPFWaterFlow,WaterFlowRateRatio)
!   Warn user if curve output goes negative
    IF(HeatCOPFWaterFlow .LT. 0.0d0)THEN
      IF(DXCoil(DXCoilNum)%HCOPFWaterFlowErrorIndex == 0)THEN
        CALL ShowWarningMessage(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":')
        CALL ShowContinueError(' HPWH Heating COP Modifier curve (function of water flow fraction) output is negative (' &
                           //TRIM(TrimSigDigits(HeatCOPFWaterFlow,3))//').')
        CALL ShowContinueError(' Negative value occurs using a water flow fraction of ' &
                            //TRIM(TrimSigDigits(WaterFlowRateRatio,3))//'.')
        CALL ShowContinueErrorTimeStamp(' Resetting curve output to zero and continuing simulation.')
      END IF
      CALL ShowRecurringWarningErrorAtEnd(TRIM(DXCoil(DXCoilNum)%DXCoilType)//' "'//TRIM(DXCoil(DXCoilNum)%Name)//'":'//&
          ' HPWH Heating COP Modifier curve (function of water flow fraction) output is negative warning continues...' &
          , DXCoil(DXCoilNum)%HCOPFWaterFlowErrorIndex, HeatCOPFWaterFlow, HeatCOPFWaterFlow)
      HeatCOPFWaterFlow = 0.0d0
    END IF
  ELSE
    HeatCOPFWaterFlow  = 1.0d0
  END IF

! adjust Heating Capacity and COP for off-design conditions
  OperatingHeatingCapacity = RatedHeatingCapacity * HeatCapFTemp * HeatCapFAirFlow * HeatCapFWaterFlow
  OperatingHeatingCOP      = RatedHeatingCOP      * HeatCOPFTemp * HeatCOPFAirFlow * HeatCOPFWaterFlow

  IF(OperatingHeatingCOP .GT. 0.0d0) OperatingHeatingPower = OperatingHeatingCapacity / OperatingHeatingCOP

  PumpHeatToWater          = DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower * DXCoil(DXCoilNum)%HPWHCondPumpFracToWater
  TankHeatingCOP           = OperatingHeatingCOP

! account for pump heat if not included in total water heating capacity
  IF(DXCoil(DXCoilNum)%CondPumpHeatInCapacity)THEN
    TotalTankHeatingCapacity = OperatingHeatingCapacity
  ELSE
    TotalTankHeatingCapacity = OperatingHeatingCapacity + PumpHeatToWater
  END IF

! find part load fraction to calculate RTF
  IF(DXCoil(DXCoilNum)%PLFFPLR(1) .GT. 0) THEN
    PartLoadFraction = MAX(0.7d0,CurveValue(DXCoil(DXCoilNum)%PLFFPLR(1),PartLoadRatio))
  ELSE
    PartLoadFraction = 1.0d0
  END IF

  HPRTF = MIN(1.0d0,(PartLoadRatio / PartLoadFraction))

! calculate evaporator total cooling capacity
  IF(HPRTF .GT. 0.0d0)THEN
    IF(DXCoil(DXCoilNum)%FanPowerIncludedInCOP)THEN
      IF(DXCoil(DXCoilNum)%CondPumpPowerInCOP)THEN
!       make sure fan power is full load fan power
        CompressorPower = OperatingHeatingPower - FanElecPower/HPRTF - DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower
        IF(OperatingHeatingPower .GT. 0.0d0)TankHeatingCOP = TotalTankHeatingCapacity / OperatingHeatingPower
      ELSE
        CompressorPower = OperatingHeatingPower - FanElecPower/HPRTF
        IF((OperatingHeatingPower + DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower) .GT. 0.0d0) &
          TankHeatingCOP = TotalTankHeatingCapacity / (OperatingHeatingPower + DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower)
      END IF
    ELSE
      IF(DXCoil(DXCoilNum)%CondPumpPowerInCOP)THEN
!       make sure fan power is full load fan power
        CompressorPower = OperatingHeatingPower - DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower
        IF((OperatingHeatingPower + FanElecPower/HPRTF) .GT. 0.0d0) &
          TankHeatingCOP = TotalTankHeatingCapacity / (OperatingHeatingPower + FanElecPower/HPRTF)
      ELSE
        CompressorPower = OperatingHeatingPower
        IF((OperatingHeatingPower + FanElecPower/HPRTF + DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower) .GT. 0.0d0) &
          TankHeatingCOP = TotalTankHeatingCapacity / &
                          (OperatingHeatingPower + FanElecPower/HPRTF + DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower)
      END IF
    END IF
  END IF

  IF(DXCoil(DXCoilNum)%CondPumpHeatInCapacity)THEN
    EvapCoolingCapacity = TotalTankHeatingCapacity - PumpHeatToWater - CompressorPower
  ELSE
    EvapCoolingCapacity = TotalTankHeatingCapacity - CompressorPower
  END IF

! set evaporator total cooling capacity prior to CalcDOE2DXCoil subroutine
  DXCoil(DXCoilNum)%RatedTotCap(1) = EvapCoolingCapacity

! determine condenser water inlet/outlet condition at full capacity
  IF(CondInletMassFlowRate .EQ. 0.0d0)THEN
    OutletWaterTemp         = InletWaterTemp
  ELSE
    OutletWaterTemp         = InletWaterTemp + TotalTankHeatingCapacity/(CpWater * CondInletMassFlowRate)
  END IF

  Node(CondOutletNode)%Temp = OutletWaterTemp

  Node(CondOutletNode)%MassFlowRate = Node(CondInletNode)%MassFlowRate

! send heating capacity and COP to water heater module for standards rating calculation
! total heating capacity including condenser pump
  HPWHHeatingCapacity = TotalTankHeatingCapacity
! total heating COP including compressor, fan, and condenser pump
  HPWHHeatingCOP      = TankHeatingCOP

! send DX coil total cooling capacity to HPWH for reporting
  DXCoilTotalCapacity = EvapCoolingCapacity

  DXCoil(DXCoilNum)%TotalHeatingEnergyRate = TotalTankHeatingCapacity * PartLoadRatio

! calculate total compressor plus condenser pump power, fan power reported in fan module
  DXCoil(DXCoilNum)%ElecWaterHeatingPower = (CompressorPower + DXCoil(DXCoilNum)%HPWHCondPumpElecNomPower) * HPRTF

RETURN
END SUBROUTINE CalcHPWHDXCoil
CalcHPWHDXCoil Subroutine

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public subroutine CalcHPWHDXCoil(DXCoilNum, PartLoadRatio)

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