Hi All,

First I want to thank Pasha for all the help on this project I am working on. Project is a WTWHP using geothemal loops as heat sink. WTWHP produces chilled and hot water to chilled beams DOAS and air handling units. I have unmet hours exceeding the allowed value.

I realized that I had sized the water to water heat pump for cooling and added a boiler with a heat exchanger for supplemental heat for the Air handling unit loop and/or to boost the geo loop to 40 F in case the loop temp drop below the setpoint. The Equest does not allow me to add a heat exchanger in the loop. According to Ashrae 90.1- 2004, "if simulation software can not model the proposed design explicitly, we can substitute a thermodynamically similar component model that can approximate performance of the component that can not be modeled explicitly".

I tried baseboard with OA reset schedule? bsbd and boiler will only activated when outside temperature drops below 30 F, this way the chilled beam will provide heating and baseboard will kick in when OA temp drops. This approach did not yield desirable results. Is there any other approach available?

Thanks,

Adee