I have a water to water heat pump loop challenge.

The project design the calls for the following 3 systems which are tied to a geothermal closed ground loop.

1) Water to air heat pumps to serving all zones.

2) A water to water heat pump serving the coil in an enthalpy energy recovery unit that provides 100% of the OA ventilation. The ERU supplies tempered air into the return air plenums

3) A water to water heat pump serving hydronic radiant floor zones in part of the project.

My first cut was to just model the project as water to water heat pumps with the energy recovery modeled as part of each water to air heat pump. The ERU fan kW/cfm was distributed to each heat pump under Heat Recovery 2 tab. I used a lake/well heat exchanger on the geothermal loop.

This disregards the efficiency differences for the design radiant floor hot water heating and the design pumping energy of the water to water heat pump loops.

Should I somehow use the water to water heat pumps modeled with a loop-to-loop chiller? Can anyone provide a better approach?

I'm using eQuest v3.63b.

Thanks in advance.

Brett Fero, P.E., LEED AP