Hi all,
The project is an New construction office building with a 30 tons ground
source heat pump with a back-up boiler and Hybrid Hydronic Heat Pumps at
zone level (total cooling capacity is 110 tons).

In EE4, when you model the plant as Combination Ground Source Heat
Pump/Boiler, you can't choose a hydronic heat pump as system. So I
modeled HHHPs as 4-pipe fan-coils. In heating mode, this will fairly
represent the operation of the HHHPs (no condenser/compressor work) but
in cooling mode it doesn't.

DOE 2.1 converts the GSHP to an equivalent centrifugal chiller and
electric boiler (with a modified COP). The problem here is that heat
rejected by the chiller in cooling mode is not shared with the loop and
cannot be used for space heating. The other issue is the loop
temperatures. HHHP operate at a lower temperature than standard HPs.

How can you account for heat sharing in this case?

Anyone has a workaround for this situation?
Thanks

Hayssam Barhoun, LEED AP, Ing.