Listing of coils allowed in air loop

asked 2022-06-24 12:06:13 -0600

kbk78
621 ●1 ●9

Is there a listing of coils allowed in a central air loop. I am trying replace the HW and CHW coil with:

Coil:Heating:WaterToAirHeatPump:EquationFit

Coil:Cooling:WaterToAirHeatPump:EquationFit

But I get this error.

  ** Severe  ** GetAirPathData: AirLoopHVAC = "SYS1".
  **   ~~~   ** ..Invalid Air Loop Component Type = "COIL:HEATING:WATERTOAIRHEATPUMP:EQUATIONFIT".
  **   ~~~   ** ..Air Loop Component Name = "SYS1 WHPH HEATING COIL".

What alternatives do I have if I want to model WaterSource HP coils in a DOAS system.

There appears to be a similar unresolved question echoed here question.

answered 2022-10-10 16:12:02 -0600

Aaron Boranian

14250 ●86 ●24 http://bigladdersoftware.com/

You are experiencing a limitation for what EnergyPlus objects can be used to contain various coils and fans on the supply branch of a central air system. This limitation is shown in the first table of the Unitary Equipment Group documentation of the Input Output Reference.

If you are seeing this severe error, it is likely because you are assigning the water-to-air heat pump cooling/heating coils that you want to use directly to the Branch object. Seeing the vertical columns for these coils in the table, that is not allowed (no "X" for the first row labeled AirLoop HVAC Main Branch). Instead, you would look for a unitary option that DOES have an "X" in it's row:

AirLoopHVAC:UnitaryHeatPump:WaterToAir object (meant specifically to model a water-to-air heat pump)
AirLoopHVAC:UnitarySystem object (the most flexible unitary system that can contain virtually every coil and fan object available in EnergyPlus)