modelAirHeating

Example model with an air-based heating system that conditions a thermal zone in EnergyPlus
Diagram of AirHeatingOpen the diagram
▶ Simulate in your browser

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

Example of one building with one thermal zone in which the room air temperature is controlled with a PI controller. Heating is provided through recirculated air. The control output is used to compute the set point for the supply air temperature, which is met by the heating coil. The setpoint for the room air temperature changes between day and night. The fan is either off, or operating on stage 1 or 2, depending on the output of the room temperature controller. The zone also has a constant air infiltration flow rate.

Note that for simplicity, the model has no cooling system. Therefore, in summer, the house overheats.

Parameters

TypeNameDefaultDescription
Modelica.Units.SI.VolumeVRoo453.138Room volume
Modelica.Units.SI.AreaAFlo185.834Floor area of the whole floor of the building
Modelica.Units.SI.MassFlowRatemOut_flow_nominal0.3*VRoo*1.2/3600Outdoor air mass flow rate, assuming constant infiltration air flow rate
Modelica.Units.SI.MassFlowRatemRec_flow_nominal8*VRoo*1.2/3600Nominal mass flow rate for recirculated air

Components

TypeNameDefaultDescription
BuildingbuildingBuilding model
Buildings.ThermalZones.EnergyPlus_24_2_0.ThermalZonezonThermal zone
Buildings.Fluid.Movers.FlowControlled_m_flowfanFan
Buildings.Controls.OBC.CDL.Reals.Sources.PulseTSetSetpoint for room air
Buildings.Controls.OBC.CDL.Reals.PIDconPIDController for heater
Buildings.Fluid.HeatExchangers.Heater_TheaIdeal heater
Buildings.Fluid.Sources.Boundary_pTpAtmBoundary condition
Buildings.Fluid.FixedResistances.PressureDropducDuct resistance (to decouple room and outside pressure)
Buildings.Fluid.Sources.MassFlowSource_WeatherDatafreshAirOutside air supply
Buildings.Controls.OBC.CDL.Reals.Hysteresissta1Hysteresis to switch on stage 1
Buildings.Controls.OBC.CDL.Conversions.BooleanToRealmSetFan1_flowMass flow rate for 1st stage
Buildings.Controls.OBC.CDL.Reals.Hysteresissta2Hysteresis to switch on stage 2
Buildings.Controls.OBC.CDL.Conversions.BooleanToRealmSetFan2_flowMass flow rate added for 2nd stage
Buildings.Controls.OBC.CDL.Reals.Addm_fan_setMass flow rate for fan
Buildings.Controls.OBC.CDL.Reals.AddTAirLvgSetSet point temperature for air leaving the heater
Buildings.Controls.OBC.CDL.Reals.AddParameterTSupMinMinimum supply air temperature
Modelica.Blocks.Sources.Constant[3]qIntGaiInternal heat gains, set to zero because these are modeled in EnergyPlus
Buildings.Controls.OBC.CDL.Reals.MultiplyByParametergaiGain factor

Contents

NameDescription
MediumMedium model

Revisions

  • March 13, 2024, by Michael Wetter:
    Updated idf file to add insulation, and restricted capacity of heater.
    This is for issue 3707.
  • March 1, 2018, by Michael Wetter:
    First implementation.