modelAirToWater

Air-to-water heat pump plant

Extends from Buildings.Templates.Plants.HeatPumps.Interfaces.PartialHeatPumpPlant (Interface class for heat pump plant).

Information

Description

This template represents an air-to-water heat pump plant with closed-loop controls. While the heat pump plant configuration can be changed through parameters, the image below shows a typical configuration with two reversible air-to-water heat pumps, a primary-secondary distribution system and a sidestream heat recovery chiller. For a detailed schematic of the actual plant configuration, refer to the diagram view of the plant component. In Dymola, for example, you can access this by right-clicking the component pla in the model Buildings.Templates.Plants.HeatPumps.Validation.AirToWaterReversibleHeatRecovery and selecting "Show Component" from the context menu.

Image of heat pump plant

Currently, only identical heat pumps are supported. Although the template can accommodate any number of identical units, the graphical feedback for system configuration via the diagram layer is only accurate for up to 6 units.

The supported plant configurations are enumerated in the table below. The first option displayed in bold characters corresponds to the default configuration.

Configuration parameter	Options	Notes
Function and equipment type	Heating and cooling with reversible heat pumps Heating-only with non-reversible heat pumps Heating and cooling with reversible heat pumps and heat recovery chiller Heating and cooling with reversible (2-pipe) heat pumps and polyvalent (4-pipe) heat pumps Heating and cooling with polyvalent (4-pipe) heat pumps	The plant always provides heating hot water. For configurations without polyvalent heat pumps, the heat pumps may be unequally sized, with only a subset of the units participating in lead/lag alternation. For configurations with polyvalent heat pumps, the reversible heat pumps must be equally sized among themselves, and the polyvalent heat pumps must be equally sized among themselves. All units are lead/lag alternated within their own pool. For the configuration with a heat recovery chiller, the template includes a chiller and its associated dedicated primary CHW and CW pumps. The chiller is considered connected in a sidestream configuration to both the CHW return and the HW return.
Type of distribution	Constant primary-variable secondary centralized Variable primary-only	It is assumed that the HW and the CHW loops have the same type of distribution, as specified by this parameter. Most AWHPs on the market use a reverse cycle for defrosting. This requires maximum primary flow during defrost cycles. Consequently, variable primary plants commonly adopt a high minimum flow setpoint, typically close to the design flow rate, effectively operating akin to constant primary plants but with variable speed pumps controlling the loop differential pressure. While the flow rate directed towards the loads varies, the bypass valve control loop ensures a constant primary flow for a given number of staged units. "Centralized secondary pumps" refers to configurations with a single group of secondary pumps that is typically integrated into the plant. Distributed secondary pumps with multiple secondary loops served by dedicated secondary pumps are currently not supported.
Type of primary pump arrangement	Dedicated Headered	It is assumed that the HW and the CHW loops have the same type of primary pump arrangement, as specified by this parameter. Primary-secondary plants with both reversible and polyvalent heat pumps must have primary dedicated pumps: primary headered pumps are not supported for this configuration.
Separate dedicated primary pumps for the CHW and HW circuits	False True	This option is only available for reversible heat pumps with dedicated primary pumps. If this option is not selected (default setting), each AWHP uses a common dedicated primary pump for CHW and HW – this pump is then denoted as the primary HW pump. Otherwise, each AWHP relies on a separate dedicated HW pump and a separate dedicated CHW pump.
Type of primary pumps	Variable speed Constant speed	For constant primary-variable secondary distributions, the variable speed primary pumps are commanded at fixed speeds, determined during the Testing, Adjusting and Balancing phase to provide design AWHP flow in heating and cooling modes. The same intent is achieved with constant speed primary pumps through the use of balancing valves. It is assumed that the HW and the CHW loops have the same type of primary pumps, as specified by this parameter.
HW buffer tank	HW buffer tank in the primary supply HW buffer tank in the primary return No HW buffer tank	By default, the HW buffer tank is considered integrated into the primary supply to mitigate the impact of defrost cycles on the temperature of the HW supplied to the loads. This assumes that the buffer tank is well-mixed. The default sizing of the tank corresponds to 4 min of the design primary flow rate. This is based on manufacturer recommendations, which account for the fact that defrost cycles can take 3 to 5 min to complete.
CHW buffer tank	CHW buffer tank in the primary return CHW buffer tank in the primary supply No CHW buffer tank	By default, the CHW buffer tank is considered integrated into the primary return to mitigate the impact of rapid load variations on the plant controls. This assumes that the buffer tank is well-mixed. The default sizing of the tank corresponds to 2 min of the design primary flow rate, based on manufacturer recommendations.
Controller	Closed-loop controls with supply temperature and differential pressure reset	Most parts of the sequence of operation are similar to that described in ASHRAE, 2024 for chiller plants. See the documentation of Buildings.Templates.Plants.Controls.HeatPumps.AirToWater for more details. An open loop controller is also available for validation purposes.

Control points

The control sequence implemented in this template requires the external input points specified in the documentation of the controller Buildings.Templates.Plants.HeatPumps.Components.Controls.AirToWater.

Implementation details

The pressure drops of the heat pump CHW and HW heat exchangers are calculated within the isolation valve component valIso based on lumped flow coefficients for the sake of computational efficiency.

The template uses a heat pump model that interpolates capacity and power from manufacturer data along the CHW/HW temperature, the outdoor air temperature and the part load ratio. The heat pump performance data are provided via the subrecords dat.hp.perHeaHp and dat.hp.perCooHp for the heating mode and the cooling mode, respectively. The polyvalent heat pump performance data are provided via the subrecord dat.hp.perPhp. For the required format of the performance data files, please refer to the documentation of the blocks Buildings.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.BaseClasses.TableData2DLoadDep and Buildings.Fluid.HeatPumps.ModularReversible.RefrigerantCycle.BaseClasses.TableData2DLoadDepSHC.

References

ASHRAE, 2024. Guideline 36-2024, High-Performance Sequences of Operation for HVAC Systems. Atlanta, GA.

Parameters

Type	Name	Default	Description
Boolean	have_hp (from PartialHeatPumpPlant)	typ <> Buildings.Templates.Plants.Controls.Types.PlantHeatPump.Polyvalent	Set to true for plants with non-reversible or reversible heat pumps
Boolean	have_hrc (from PartialHeatPumpPlant)	typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.ReversibleHeatRecovery	Set to true for plants with sidestream heat recovery chiller
Boolean	have_php (from PartialHeatPumpPlant)	typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.ReversiblePolyvalent or typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.Polyvalent	Set to true for plants with polyvalent heat pumps
Buildings.Templates.Plants.Controls.Types.PlantHeatPump	typ (from PartialHeatPumpPlant)	Buildings.Templates.Plants.Controls.Types.PlantHeatPump.Reversible	Type of plant
Buildings.Templates.Plants.HeatPumps.Configuration.HeatPumpPlant	cfg (from PartialHeatPumpPlant)		Configuration parameters
Buildings.Templates.Plants.HeatPumps.Data.HeatPumpPlant	dat (from PartialHeatPumpPlant)		Design and operating parameters
Integer	nHp (from PartialHeatPumpPlant)	if have_hp then nHp_select else 0	Number of heat pumps (excluding polyvalent HPs)
Integer	nPhp (from PartialHeatPumpPlant)	if have_php then nPhp_select else 0	Number of polyvalent heat pumps
Boolean	is_rev (from PartialHeatPumpPlant)	typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.Reversible or typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.ReversibleHeatRecovery or typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.ReversiblePolyvalent	Set to true for reversible heat pumps, false for heating only
Buildings.Templates.Plants.HeatPumps.Types.Distribution	typDis (from PartialHeatPumpPlant)	if typHp == Buildings.Templates.Components.Types.HeatPump.AirToWater then typDis_select1 else typDis_select2	Type of distribution system
Boolean	have_valHpInlIso (from PartialHeatPumpPlant)	if not have_hp then false elseif not have_chiWat and typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then false else true	Set to true for isolation valves at HP inlet
Boolean	have_valHpOutIso (from PartialHeatPumpPlant)	if not have_hp then false elseif not have_chiWat and typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then false elseif nHp == 1 then false elseif have_chiWat and typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated and not have_pumPriDedComHp then false else true	Set to true for isolation valves at HP outlet
Boolean	have_valPhpInlIso (from PartialHeatPumpPlant)	if not have_php then false elseif typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then false else true	Set to true for isolation valves at polyvalent HP inlet
Boolean	have_valPhpOutIso (from PartialHeatPumpPlant)	false	Set to true for isolation valves at polyvalent HP outlet
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumPri (from PartialHeatPumpPlant)	if typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 then typPumPri_select else Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.Variable	Type of primary CHW/HW pumps
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumHeaWatPri (from PartialHeatPumpPlant)	if have_heaWat then typPumPri else Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None	Type of primary HW pumps
Buildings.Templates.Components.Types.IntegrationPoint	typTanHeaWat (from PartialHeatPumpPlant)	if have_heaWat then typTanHeaWat_select else Buildings.Templates.Components.Types.IntegrationPoint.None	Specify if there is a HW buffer tank and where it is integrated into the system
Boolean	have_pumChiWatPriDedHp (from PartialHeatPumpPlant)	have_hp and have_chiWat and typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated and not have_pumPriDedComHp	Set to true for HP with separate dedicated primary pumps for CHW and HW circuits
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumChiWatPri (from PartialHeatPumpPlant)	if have_chiWat and (typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Headered or have_hp and have_pumChiWatPriDedHp or have_php) then typPumPri else Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None	Type of primary CHW pumps
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumChiWatPriHp (from PartialHeatPumpPlant)	if have_hp and have_chiWat and (not have_pumPriDedComHp or typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Headered) then typPumPri else Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None	Type of HP primary CHW pumps
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumChiWatPriPhp (from PartialHeatPumpPlant)	if have_php then typPumPri else Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None	Type of polyvalent HP primary CHW pumps
Buildings.Templates.Components.Types.IntegrationPoint	typTanChiWat (from PartialHeatPumpPlant)	if have_chiWat then typTanChiWat_select else Buildings.Templates.Components.Types.IntegrationPoint.None	Specify if there is a CHW buffer tank and where it is integrated into the system
Modelica.Units.SI.MassFlowRate	mHeaWatPri_flow_nominal (from PartialHeatPumpPlant)	if have_heaWat then dat.hp.mHeaWatHp_flow_nominalnHp + dat.hp.mHeaWatPhp_flow_nominalnPhp else 0	Primary HW mass flow rate
Modelica.Units.SI.MassFlowRate	mHeaWat_flow_nominal (from PartialHeatPumpPlant)	if have_heaWat then (if typPumHeaWatSec == Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.None then mHeaWatPri_flow_nominal else sum(dat.pumHeaWatSec.m_flow_nominal)) else 0	HW mass flow rate (total, distributed to consumers)
Modelica.Units.SI.HeatFlowRate	capHea_nominal (from PartialHeatPumpPlant)	if have_heaWat then abs(dat.hp.capHeaHp_nominal)nHp + abs(dat.hp.capHeaPhp_nominal)nPhp else 0	Heating capacity - All units
Modelica.Units.SI.HeatFlowRate	QHea_flow_nominal (from PartialHeatPumpPlant)	capHea_nominal	Heating heat flow rate - All units
Modelica.Units.SI.Temperature	THeaWatSup_nominal (from PartialHeatPumpPlant)	dat.ctl.THeaWatSup_nominal	Maximum HW supply temperature
Modelica.Units.SI.Temperature	THeaWatRet_nominal (from PartialHeatPumpPlant)	THeaWatSup_nominal - QHea_flow_nominal/cpHeaWat_default/mHeaWat_flow_nominal	HW return temperature
Modelica.Units.SI.MassFlowRate	mChiWatPri_flow_nominal (from PartialHeatPumpPlant)	if have_chiWat then dat.hp.mChiWatHp_flow_nominalnHp + dat.hp.mChiWatPhp_flow_nominalnPhp else 0	Primary CHW mass flow rate
Modelica.Units.SI.MassFlowRate	mChiWat_flow_nominal (from PartialHeatPumpPlant)	if have_chiWat then (if typPumChiWatSec == Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.None then mChiWatPri_flow_nominal else sum(dat.pumChiWatSec.m_flow_nominal)) else 0	CHW mass flow rate - Total, distributed to consumers
Modelica.Units.SI.HeatFlowRate	capCoo_nominal (from PartialHeatPumpPlant)	if have_chiWat then abs(dat.hp.capCooHp_nominal)nHp + abs(dat.hp.capCooPhp_nominal)nPhp else 0	Cooling capacity - All units
Modelica.Units.SI.HeatFlowRate	QCoo_flow_nominal (from PartialHeatPumpPlant)	-capCoo_nominal	Cooling heat flow rate - All units
Modelica.Units.SI.Temperature	TChiWatSup_nominal (from PartialHeatPumpPlant)	dat.ctl.TChiWatSup_nominal	Minimum CHW supply temperature
Modelica.Units.SI.Temperature	TSouHea_nominal (from PartialHeatPumpPlant)	if have_hp then dat.hp.TSouHeaHp_nominal else dat.hp.TSouHeaPhp_nominal	OAT or source fluid supply temperature (evaporator entering) in heating mode - Each unit
Modelica.Units.SI.Temperature	TSouCoo_nominal (from PartialHeatPumpPlant)	if have_hp then dat.hp.TSouCooHp_nominal else dat.hp.TSouCooPhp_nominal	OAT or source fluid supply temperature (evaporator entering) in cooling mode - Each unit
MediumHeaWat.Density	rhoHeaWat_default (from PartialHeatPumpPlant)	MediumHeaWat.density(staHeaWat_default)	HW default density
MediumHeaWat.SpecificHeatCapacity	cpHeaWat_default (from PartialHeatPumpPlant)	MediumHeaWat.specificHeatCapacityCp(staHeaWat_default)	HW default specific heat capacity
MediumHeaWat.ThermodynamicState	staHeaWat_default (from PartialHeatPumpPlant)	MediumHeaWat.setState_pTX(T = THeaWatSup_nominal, p = MediumHeaWat.p_default, X = MediumHeaWat.X_default)	HW default state
MediumChiWat.Density	rhoChiWat_default (from PartialHeatPumpPlant)	MediumChiWat.density(staChiWat_default)	CHW default density
MediumChiWat.SpecificHeatCapacity	cpChiWat_default (from PartialHeatPumpPlant)	MediumChiWat.specificHeatCapacityCp(staChiWat_default)	CHW default specific heat capacity
MediumChiWat.ThermodynamicState	staChiWat_default (from PartialHeatPumpPlant)	MediumChiWat.setState_pTX(T = TChiWatSup_nominal, p = MediumChiWat.p_default, X = MediumChiWat.X_default)	CHW default state
MediumSou.Density	rhoSou_default (from PartialHeatPumpPlant)	MediumSou.density(staSou_default)	Source fluid default density
MediumSou.SpecificHeatCapacity	cpSou_default (from PartialHeatPumpPlant)	MediumSou.specificHeatCapacityCp(staSou_default)	Source fluid default specific heat capacity
MediumSou.ThermodynamicState	staSou_default (from PartialHeatPumpPlant)	MediumSou.setState_pTX(T = TSouHea_nominal, p = MediumSou.p_default, X = MediumSou.X_default)	Source fluid default state
Boolean	is_dpBalCal	is_dpBalYPumSetCal and (typPumPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.Constant or have_hp and have_php and typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only)	Set to true to automatically size balancing valves
Boolean	is_yPumSetCal	is_dpBalYPumSetCal and typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 and typPumPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.Variable	Set to true to automatically evaluate pump speed providing design flow
Modelica.Units.SI.PressureDifference	dpValCheHeaWatBalHp_nominal	if have_heaWat and have_hp then (if have_pumPriDedComHp then dat.dpValCheHeaWat_nominal[1]*(hp.mHeaWatHp_flow_nominal/dat.pumHeaWatPri.m_flow_nominal[1])^2 elseif typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.dpValCheHeaWat_nominal[1] else dpValCheHeaWatBalHdr_nominal) else 0	HP primary (HW or common HW and CHW) pump check valve pressure drop at design HW flow rate
Modelica.Units.SI.PressureDifference	dpValCheChiWatBalHp_nominal	if have_chiWat and have_hp then (if have_pumPriDedComHp then dat.dpValCheHeaWat_nominal[1]*(hp.mChiWatHp_flow_nominal/dat.pumHeaWatPri.m_flow_nominal[1])^2 elseif typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.dpValCheChiWat_nominal[1] else dpValCheChiWatBalHdr_nominal) else 0	HP primary (CHW or common HW and CHW) pump check valve pressure drop at design CHW flow rate
Modelica.Units.SI.PressureDifference	dpValCheHeaWatBalPhp_nominal	if have_php then (if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.dpValCheHeaWat_nominal[nPumHeaWatPri] else dpValCheHeaWatBalHdr_nominal) else 0	Polyvalent HP primary HW pump check valve pressure drop at design HW flow rate
Modelica.Units.SI.PressureDifference	dpValCheChiWatBalPhp_nominal	if have_php then (if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.dpValCheChiWat_nominal[nPumChiWatPri] else dpValCheChiWatBalHdr_nominal) else 0	Polyvalent HP primary CHW pump check valve pressure drop at design CHW flow rate
Modelica.Units.SI.VolumeFlowRate	VHeaWatBalHdr_nominal	(nHpdat.hp.mHeaWatHp_flow_nominal + nPhpdat.hp.mHeaWatPhp_flow_nominal)/rhoHeaWat_default	Total design HW flow rate for balancing valve and pump speed calculation – Headered pumps
Modelica.Units.SI.VolumeFlowRate	VChiWatBalHdr_nominal	(nHpdat.hp.mChiWatHp_flow_nominal + nPhpdat.hp.mChiWatPhp_flow_nominal)/rhoChiWat_default	Total design CHW flow rate for balancing valve and pump speed calculation – Headered pumps
Modelica.Units.SI.VolumeFlowRate	VHeaWatBalHp_nominal	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.hp.mHeaWatHp_flow_nominal/rhoHeaWat_default else VHeaWatBalHdr_nominal	Target HW flow rate for HP balancing valve and pump speed calculation
Modelica.Units.SI.VolumeFlowRate	VChiWatBalHp_nominal	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.hp.mChiWatHp_flow_nominal/rhoChiWat_default else VChiWatBalHdr_nominal	Target CHW flow rate for HP balancing valve and pump speed calculation
Modelica.Units.SI.VolumeFlowRate	VHeaWatBalPhp_nominal	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.hp.mHeaWatPhp_flow_nominal/rhoHeaWat_default else VHeaWatBalHdr_nominal	Target HW flow rate for polyvalent HP balancing valve and pump speed calculation
Modelica.Units.SI.VolumeFlowRate	VChiWatBalPhp_nominal	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then dat.hp.mChiWatPhp_flow_nominal/rhoChiWat_default else VChiWatBalHdr_nominal	Target CHW flow rate for polyvalent HP balancing valve and pump speed calculation
Modelica.Units.SI.PressureDifference	dpValCheHeaWatBalHdr_nominal	if typPumHeaWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then 0 else max(dat.dpValCheHeaWat_nominal)(VHeaWatBalHdr_nominalrhoHeaWat_default/sum(dat.pumHeaWatPri.m_flow_nominal))^2	Primary HW pump check valve pressure drop at design HW flow rate – Headered pumps
Modelica.Units.SI.PressureDifference	dpValCheChiWatBalHdr_nominal	if typPumChiWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then 0 else max(dat.dpValCheChiWat_nominal)(VChiWatBalHdr_nominalrhoChiWat_default/sum(dat.pumChiWatPri.m_flow_nominal))^2	Primary CHW pump check valve pressure drop at design CHW flow rate – Headered pumps
Integer	nPoiPrePumHeaWat	size(dat.pumHeaWatPri.per.pressure.V_flow, 2)	Number of points in primary HW pump pressure curve
Integer	nPoiPrePumChiWat	size(dat.pumChiWatPri.per.pressure.V_flow, 2)	Number of points in primary CHW pump pressure curve
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumHeaWatBalHdr		Equivalent pressure curve of parallel primary HW pumps – Headered pumps
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumChiWatBalHdr		Equivalent pressure curve of parallel primary CHW pumps – Headered pumps
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumHeaWatBalHp	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters(V_flow = if typPumHeaWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumHeaWatPri.per[1].pressure.V_flow, dp = if typPumHeaWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumHeaWatPri.per[1].pressure.dp) else prePumHeaWatBalHdr	Pump pressure curve for HP HW balancing valve and pump speed calculation
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumChiWatBalHp	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then (if have_pumPriDedComHp then prePumHeaWatBalHp else Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters(V_flow = if typPumChiWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumChiWatPri.per[1].pressure.V_flow, dp = if typPumChiWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumChiWatPri.per[1].pressure.dp)) else prePumChiWatBalHdr	Pump pressure curve for HP CHW balancing valve and pump speed calculation
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumHeaWatBalPhp	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters(V_flow = if typPumHeaWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumHeaWatPri.per[nPumHeaWatPri].pressure.V_flow, dp = if typPumHeaWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumHeaWatPri.per[nPumHeaWatPri].pressure.dp) else prePumHeaWatBalHdr	Pump pressure curve for polyvalent HP HW balancing valve and pump speed calculation
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters	prePumChiWatBalPhp	if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters(V_flow = if typPumChiWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumChiWatPri.per[nPumChiWatPri].pressure.V_flow, dp = if typPumChiWatPri == Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.None then {0, 0, 0} else dat.pumChiWatPri.per[nPumChiWatPri].pressure.dp) else prePumChiWatBalHdr	Pump pressure curve for polyvalent HP CHW balancing valve and pump speed calculation
Modelica.Units.SI.PressureDifference	dpHeaWatLooBal_nominal	if typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only then (if cfg.typCtl == Buildings.Templates.Plants.HeatPumps.Types.Controller.AirToWater and not cfg.have_senDpHeaWatRemWir then dat.ctl.dpHeaWatLocSet_max else dpHeaWatLoo_nominal) else 0	HW loop differential pressure at design flow rate used for balancing valve and pump speed calculation
Modelica.Units.SI.PressureDifference	dpChiWatLooBal_nominal	if typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only then (if cfg.typCtl == Buildings.Templates.Plants.HeatPumps.Types.Controller.AirToWater and not cfg.have_senDpChiWatRemWir then dat.ctl.dpChiWatLocSet_max else dpChiWatLoo_nominal) else 0	CHW loop differential pressure at design flow rate used for balancing valve and pump speed calculation
Modelica.Units.SI.PressureDifference	dpBalHeaWatHp_nominal	if have_hp then (if is_dpBalCal then Buildings.Templates.Utilities.computeBalancingPressureDrop(V_flow_nominal = VHeaWatBalHp_nominal, dp_nominal = hp.dpHeaWatHp_nominal + max(valIso.dpValveHeaWat_nominal[1:nHp])*((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)) + dpValCheHeaWatBalHp_nominal + dpHeaWatLooBal_nominal, prePum = prePumHeaWatBalHp) else dat.dpBalHeaWatHp_nominal) else 0	HP HW balancing valve pressure drop at design HW flow
Modelica.Units.SI.PressureDifference	dpBalChiWatHp_nominal	if have_hp and have_chiWat then (if is_dpBalCal then Buildings.Templates.Utilities.computeBalancingPressureDrop(V_flow_nominal = VChiWatBalHp_nominal, dp_nominal = hp.dpChiWatHp_nominal + max(valIso.dpValveChiWat_nominal[1:nHp])*((if have_valHpInlIso then 1 else 0) + (if have_valHpOutIso then 1 else 0)) + dpValCheChiWatBalHp_nominal + dpChiWatLooBal_nominal, prePum = prePumChiWatBalHp) else dat.dpBalChiWatHp_nominal) else 0	HP CHW balancing valve pressure drop at design CHW flow
Modelica.Units.SI.PressureDifference	dpBalHeaWatPhp_nominal	if have_php then (if is_dpBalCal then Buildings.Templates.Utilities.computeBalancingPressureDrop(V_flow_nominal = VHeaWatBalPhp_nominal, dp_nominal = dat.hp.dpHeaWatPhp_nominal + max(valIso.dpValveHeaWat_nominal[nHp + 1:nHp + nPhp])*((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0)) + dpValCheHeaWatBalPhp_nominal + dpHeaWatLooBal_nominal, prePum = prePumHeaWatBalPhp) else dat.dpBalHeaWatPhp_nominal) else 0	Polyvalent unit HW balancing valve pressure drop at design HW flow
Modelica.Units.SI.PressureDifference	dpBalChiWatPhp_nominal	if have_php then (if is_dpBalCal then Buildings.Templates.Utilities.computeBalancingPressureDrop(V_flow_nominal = VChiWatBalPhp_nominal, dp_nominal = dat.hp.dpChiWatPhp_nominal + max(valIso.dpValveChiWat_nominal[nHp + 1:nHp + nPhp])*((if have_valPhpInlIso then 1 else 0) + (if have_valPhpOutIso then 1 else 0)) + dpValCheChiWatBalPhp_nominal + dpChiWatLooBal_nominal, prePum = prePumChiWatBalPhp) else dat.dpBalChiWatPhp_nominal) else 0	Polyvalent unit CHW balancing valve pressure drop at design CHW flow
Real	yPumHeaWatPriHdrSet		Primary HW pump speed providing design flow – Headered pumps
Real	yPumChiWatPriHdrSet		Primary CHW pump speed providing design flow – Headered pumps
Real	yPumHeaWatPriDedHpSet		Primary pump speed providing design flow in heating mode – HP dedicated pumps
Real	yPumChiWatPriDedHpSet		Primary pump speed providing design flow in cooling mode – HP dedicated pumps
Real	yPumHeaWatPriDedPhpSet		Primary HW pump speed providing design flow – Polyvalent HP dedicated pumps
Real	yPumChiWatPriDedPhpSet		Primary CHW pump speed providing design flow – HP dedicated pumps
Configuration
Boolean	have_heaWat (from PartialHeatPumpPlant)	true	Set to true if the plant provides HW
Boolean	have_chiWat (from PartialHeatPumpPlant)	typ <> Buildings.Templates.Plants.Controls.Types.PlantHeatPump.HeatingOnly	Set to true if the plant provides CHW
Boolean	have_hotWat (from PartialHeatPumpPlant)	false	Set to true if the plant provides DHW
Buildings.Templates.Plants.HeatPumps.Types.Distribution	typDis_select1 (from PartialHeatPumpPlant)	Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2	Type of distribution system
Buildings.Templates.Plants.HeatPumps.Types.Distribution	typDis_select2 (from PartialHeatPumpPlant)		Type of distribution system
Heat pumps
Buildings.Templates.Components.Types.HeatPump	typHp (from PartialHeatPumpPlant)		Type of heat pump
Integer	nHp_select (from PartialHeatPumpPlant)		Number of heat pumps (excluding polyvalent HPs)
polyvalent heat pumps
Integer	nPhp_select (from PartialHeatPumpPlant)		Number of polyvalent heat pumps
Primary loop
Buildings.Templates.Components.Types.PumpArrangement	typArrPumPri_select (from PartialHeatPumpPlant)	Buildings.Templates.Components.Types.PumpArrangement.Dedicated	Type of primary pump arrangement
Buildings.Templates.Components.Types.PumpArrangement	typArrPumPri (from PartialHeatPumpPlant)	if typ == Buildings.Templates.Plants.Controls.Types.PlantHeatPump.ReversiblePolyvalent and typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 then Buildings.Templates.Components.Types.PumpArrangement.Dedicated else typArrPumPri_select	Type of primary pump arrangement
Boolean	have_bypHeaWatFix (from PartialHeatPumpPlant)	have_heaWat and (typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1And2)	Set to true if the HW loop has a fixed bypass
Boolean	have_valHeaWatMinByp (from PartialHeatPumpPlant)	have_heaWat and typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only	Set to true if the HW loop has a minimum flow bypass valve
Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary	typPumPri_select (from PartialHeatPumpPlant)	Buildings.Templates.Plants.HeatPumps.Types.PumpsPrimary.Variable	Type of CHW/HW primary pumps
Integer	nPumHeaWatPri_select (from PartialHeatPumpPlant)	nHp + nPhp	Number of primary HW pumps
Integer	nPumHeaWatPri (from PartialHeatPumpPlant)	if have_heaWat then (if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Headered then nPumHeaWatPri_select else nHp + nPhp) else 0	Number of primary HW pumps
Buildings.Templates.Components.Types.IntegrationPoint	typTanHeaWat_select (from PartialHeatPumpPlant)	Buildings.Templates.Components.Types.IntegrationPoint.Supply	Specify if there is a HW buffer tank and where it is integrated into the system
Boolean	have_pumPriDedComHp_select (from PartialHeatPumpPlant)	true	Set to true for HP with single dedicated primary pump serving both CHW and HW circuits
Boolean	have_pumPriDedComHp (from PartialHeatPumpPlant)	if have_hp and have_chiWat and typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Dedicated then have_pumPriDedComHp_select else false	Set to true for HP with single dedicated primary pump serving both CHW and HW circuits
Boolean	have_bypChiWatFix (from PartialHeatPumpPlant)	have_chiWat and (typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1And2)	Set to true if the CHW loop has a fixed bypass
Boolean	have_valChiWatMinByp (from PartialHeatPumpPlant)	have_chiWat and typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only	Set to true if the CHW loop has a minimum flow bypass valve
Integer	nPumChiWatPri_select (from PartialHeatPumpPlant)	nHp + nPhp	Number of primary CHW pumps
Integer	nPumChiWatPri (from PartialHeatPumpPlant)	if have_chiWat then (if typArrPumPri == Buildings.Templates.Components.Types.PumpArrangement.Headered then nPumChiWatPri_select elseif not have_pumPriDedComHp then nHp + nPhp else nPhp) else 0	Number of primary CHW pumps
Buildings.Templates.Components.Types.IntegrationPoint	typTanChiWat_select (from PartialHeatPumpPlant)	Buildings.Templates.Components.Types.IntegrationPoint.Return	Specify if there is a CHW buffer tank and where it is integrated into the system
Secondary HW loop
Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary	typPumHeaWatSec (from PartialHeatPumpPlant)	if have_heaWat and (typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1And2) then Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.Centralized else Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.None	Type of secondary HW pumps
Integer	nPumHeaWatSec_select (from PartialHeatPumpPlant)		Number of secondary HW pumps
Integer	nPumHeaWatSec (from PartialHeatPumpPlant)	if not have_heaWat or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only then 0 else nPumHeaWatSec_select	Number of secondary HW pumps
Secondary CHW loop
Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary	typPumChiWatSec (from PartialHeatPumpPlant)	if have_chiWat and (typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Constant1Variable2 or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1And2) then Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.Centralized else Buildings.Templates.Plants.HeatPumps.Types.PumpsSecondary.None	Type of secondary CHW pumps
Integer	nPumChiWatSec_select (from PartialHeatPumpPlant)		Number of secondary CHW pumps
Integer	nPumChiWatSec (from PartialHeatPumpPlant)	if not have_chiWat or typDis == Buildings.Templates.Plants.HeatPumps.Types.Distribution.Variable1Only then 0 else nPumChiWatSec_select	Number of secondary CHW pumps
Nominal condition
Modelica.Units.SI.Temperature	TChiWatRet_nominal (from PartialHeatPumpPlant)	if is_rev or have_php then TChiWatSup_nominal - QCoo_flow_nominal/cpChiWat_default/mChiWat_flow_nominal else Buildings.Templates.Data.Defaults.TChiWatRet	CHW return temperature - Each heat pump
Dynamics › Conservation equations
Modelica.Fluid.Types.Dynamics	energyDynamics (from PartialHeatPumpPlant)	Modelica.Fluid.Types.Dynamics.FixedInitial	Type of energy balance: dynamic (3 initialization options) or steady state
Assumptions
Boolean	allowFlowReversal (from PartialHeatPumpPlant)	true	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
Boolean	linearized (from PartialHeatPumpPlant)	false	= true, use linear relation between m_flow and dp for all valves
Boolean	is_dpBalYPumSetCal	false	Set to true to automatically size balancing valves or evaluate pump speed providing design flow
Modelica.Units.SI.PressureDifference	dpHeaWatLoo_nominal		HW loop differential pressure at design flow rate
Modelica.Units.SI.PressureDifference	dpChiWatLoo_nominal		CHW loop differential pressure at design flow rate
Advanced › Diagnostics
Boolean	show_T (from PartialHeatPumpPlant)	false	= true, if actual temperature at port is computed

Connectors

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_a	port_aHeaWat (from PartialHeatPumpPlant)	HW return
Modelica.Fluid.Interfaces.FluidPort_b	port_bHeaWat (from PartialHeatPumpPlant)	HW supply
Modelica.Fluid.Interfaces.FluidPort_a	port_aChiWat (from PartialHeatPumpPlant)	CHW return
Modelica.Fluid.Interfaces.FluidPort_b	port_bChiWat (from PartialHeatPumpPlant)	CHW supply
Buildings.Templates.Plants.HeatPumps.Interfaces.Bus	bus (from PartialHeatPumpPlant)	Plant control bus
Buildings.Templates.AirHandlersFans.Interfaces.Bus[cfg.nAirHan]	busAirHan (from PartialHeatPumpPlant)	Air handling unit control bus
Buildings.Templates.ZoneEquipment.Interfaces.Bus[cfg.nEquZon]	busEquZon (from PartialHeatPumpPlant)	Terminal unit control bus
BoundaryConditions.WeatherData.Bus	busWea (from PartialHeatPumpPlant)	Weather bus

Components

Type	Name	Description
Buildings.Templates.Plants.HeatPumps.Components.Interfaces.PartialController	ctl (from PartialHeatPumpPlant)
Buildings.Fluid.Sources.Outside	out (from PartialHeatPumpPlant)	Outdoor air conditions
Buildings.Fluid.Sensors.Temperature	TOut (from PartialHeatPumpPlant)	OA temperature
Buildings.Templates.Plants.HeatPumps.Components.HeatPumpGroups.AirToWater	hp	Heat pump group
Components.PumpsPrimaryDedicated	pumPri	Dedicated primary pumps
Components.ValvesIsolation	valIso	Heat pump isolation valves
Buildings.Templates.Components.Pumps.Multiple	pumChiWatPri	Headered primary CHW pumps
Buildings.Templates.Components.Routing.SingleToMultiple	inlPumChiWatPri	Primary CHW pumps inlet manifold
Buildings.Templates.Components.Routing.MultipleToSingle	outPumChiWatPri	Primary CHW pumps outlet manifold
Buildings.Templates.Components.Routing.PassThroughFluid	supChiWatPri	Primary CHW supply pipe - Plant with dedicated primary CHW pumps
Buildings.Templates.Components.Sensors.VolumeFlowRate	VChiWatPri_flow	Primary CHW volume flow rate
Buildings.Templates.Components.Routing.Junction	junChiWatBypSup	Fluid junction
Buildings.Templates.Components.Sensors.Temperature	TChiWatPriSup	Primary CHW supply temperature
Buildings.Templates.Components.Routing.Junction	junChiWatBypRet	Fluid junction
Buildings.Templates.Components.Sensors.Temperature	TChiWatPriRet	Primary CHW return temperature
Buildings.Templates.Components.Actuators.Valve	valChiWatMinByp	CHW minimum flow bypass valve or fixed bypass depending on type of distribution
Buildings.Templates.Components.Tanks.Buffer	tanChiWatSup	CHW buffer tank
Buildings.Templates.Components.Tanks.Buffer	tanChiWatRet	CHW buffer tank
Buildings.Templates.Components.Pumps.Multiple	pumChiWatSec	Secondary CHW pumps
Buildings.Templates.Components.Routing.SingleToMultiple	inlPumChiWatSec	Secondary CHW pumps inlet manifold
Buildings.Templates.Components.Routing.MultipleToSingle	outPumChiWatSec	Secondary CHW pumps outlet manifold
Buildings.Templates.Components.Routing.PassThroughFluid	supChiWatSec	Secondary CHW supply pipe - Plant without secondary CHW pumps
Buildings.Templates.Components.Sensors.VolumeFlowRate	VChiWatLooOrSec_flow	CHW loop (primary-only) or secondary (primary-secondary) volume flow rate
Buildings.Templates.Components.Sensors.Temperature	TChiWatSecSup	Secondary CHW supply temperature
Buildings.Templates.Components.Sensors.Temperature	TChiWatLooOrSecRet	CHW loop (primary-only) or secondary (primary-secondary) return temperature
Buildings.Templates.Components.Sensors.DifferentialPressure	dpChiWatLoc	Local CHW ∆p sensor
Buildings.Templates.Components.Routing.SingleToMultiple	inlPumHeaWatPri	Primary HW pumps inlet manifold
Buildings.Templates.Components.Pumps.Multiple	pumHeaWatPri	Headered primary HW pumps
Buildings.Templates.Components.Routing.MultipleToSingle	outPumHeaWatPri	Primary HW pumps outlet manifold
Buildings.Templates.Components.Routing.PassThroughFluid	supHeaWatPri	Primary HW supply pipe - Plant with dedicated primary HW pumps
Buildings.Templates.Components.Sensors.VolumeFlowRate	VHeaWatPri_flow	Primary HW volume flow rate
Buildings.Templates.Components.Routing.Junction	junHeaWatBypSup	Fluid junction
Buildings.Templates.Components.Sensors.Temperature	THeaWatPriSup	Primary HW supply temperature
Buildings.Templates.Components.Sensors.Temperature	THeaWatPriRet	Primary HW return temperature
Buildings.Templates.Components.Routing.Junction	junHeaWatBypRet	Fluid junction
Buildings.Templates.Components.Actuators.Valve	valHeaWatMinByp	HW minimum flow bypass valve or fixed bypass depending on type of distribution
Buildings.Templates.Components.Tanks.Buffer	tanHeaWatSup	HW buffer tank
Buildings.Templates.Components.Tanks.Buffer	tanHeaWatRet	HW buffer tank
Buildings.Templates.Components.Pumps.Multiple	pumHeaWatSec	Secondary HW pumps
Buildings.Templates.Components.Routing.SingleToMultiple	inlPumHeaWatSec	Secondary HW pumps inlet manifold
Buildings.Templates.Components.Routing.MultipleToSingle	outPumHeaWatSec	Secondary HW pumps outlet manifold
Buildings.Templates.Components.Routing.PassThroughFluid	supHeaWatSec	Secondary HW supply pipe - Plant without secondary HW pumps
Buildings.Templates.Components.Sensors.VolumeFlowRate	VHeaWatLooOrSec_flow	HW loop (primary-only) or secondary (primary-secondary) volume flow rate
Buildings.Templates.Components.Sensors.Temperature	THeaWatSecSup	Secondary HW supply temperature
Buildings.Templates.Components.Sensors.Temperature	THeaWatLooOrSecRet	HW loop (primary-only) or secondary (primary-secondary) return temperature
Buildings.Templates.Components.Sensors.DifferentialPressure	dpHeaWatLoc	Local HW ∆p sensor
Components.HeatRecoveryChiller	hrc	Sidestream heat recovery chiller
Buildings.Templates.Components.Routing.Junction	junHeaWatHrcEnt	Fluid junction
Buildings.Templates.Components.Routing.Junction	junHeaWatHrcLvg	Fluid junction
Buildings.Templates.Components.Routing.Junction	junChiWatHrcEnt	Fluid junction
Buildings.Templates.Components.Routing.Junction	junChiWatHrcLvg	Fluid junction
Buildings.Templates.Components.Sensors.Temperature	TChiWatRetUpsHrc	CHW return temperature upstream of HRC
Buildings.Templates.Components.Sensors.Temperature	THeaWatRetUpsHrc	HW return temperature upstream of HRC
Fluid.Sources.Boundary_pT	bouHeaWat	Pressure boundary condition mimicking expansion tank
Fluid.Sources.Boundary_pT	bouChiWat	Pressure boundary condition mimicking expansion tank

Revisions

July 10, 2026, by Antoine Gautier:
Refactored for plants with polyvalent heat pumps.
This is for #4512.
March 23, 2026, by Antoine Gautier:
Refactored HP and HRC components with two separate connectors for HW and CHW supply temperature setpoints.
This is for #4507.
August 21, 2025, by Antoine Gautier:
Refactored with load-dependent 2D table data heat pump model.
This is for #4152.
May 31, 2024, by Antoine Gautier:
Added sidestream heat recovery chiller, primary-only pumping, buffer tanks, failsafe staging conditions and internal computation of pump speed or balancing valve ∆p to meet design flow.
This is for #3808.
March 29, 2024, by Antoine Gautier:
First implementation.