Ground source heat pump supplemented by boiler

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Hello,
I am trying to model a building with ground source heat pumps in eQuest. The project is in Maine so a boiler is required to supplement the ground loop in the winter. I have set up a water loop HP type circulation loop and attached a ground loop heat exchanger and a boiler. When I run the program an error occurs saying that it is not allowed to use a ground loop heat exchanger and boiler in the same loop. Is there some type of work around to approximate a water loop HP that uses the ground loop heat exchanger as a heat sink or source when it is above a certain outside air temperature and switches to the boiler as a heat source below a certain temperature?
Thanks,

Brandon S. Frink

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Brandon,

Try this:
Create a hot water loop and assign your boiler(s) to it.
Select "Hot Water Loop" as a supplemental heat source (System -> Heating -> Supp Heat/Defrost
Set the MIN-HP-T to the temperature below which the heat pump turns off and MAX-HP-SUPP-T to the temperature below which the boiler is used.

You will need to select PVAVS, PVVT or PSZ as your system type instead of Water Loop HP to access these options.

Regards,
Bill

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