Has anyone been successful or tried to use the Coil:Cooling:WaterToAirHeatPump:VariableSpeedEquationFit component on an AirLoopHVAC:UnitarySystem as a way of modeling a self-contained VAV with a variable speed compressor? I have used the OpenStudio API to set up a self-contained VAV with the unitary system and a Coil:Cooling:WaterToAirHeatPump:EquationFit component, which works fine, and I also used the setString method to set the control type to SetPoint rather than load based (sorry!). No problems here. However, when I changed the heat pump out with the variable speed component then no load was seen on the unitary system and the compressor didn't turn on. The EnergyPlus example file that has the variable speed heat pump on a unitary system uses a load control type on a zone so I tried adjusting my IDF and got the error below. It is wanting me to use a Fan:OnOff object, but this defeats the purpose of the VAV if I have to do this.
* Severe * AirLoopHVAC:UnitarySystem = AIR LOOP HVAC UNITARY SYSTEM 1 * ~~~ * Supply Fan Object Type = * ~~~ * Fan type must be Fan:OnOff when Supply Air Fan Operating Mode Schedule Name = Blank. * Fatal * GetUnitarySystemInput: Errors found in input. Program terminates.
If anyone has encountered this before, or if they have any advice, it'd be much appreciated.
