Dear Friends,

I have met a problem when using 2-pipe loop for air conditioning. The model is an office tower with chillers and water source heat pumps in the plant.
The cooling load will be taken by chillers and heat pumps (cooling mode) and heating load will be taken only by heat pump. All the airside systems are 4pipe. CHW loop and 2-pipe loop are created for cooling and heating separately. For the VAV system(PIU in equest) it is OK, while for CAV system(single zone reheat in equest) when I using 2-pipe for zone hot water loop and chw loop in system cooling, there is only heating but no cooling output.
I am confused about the results and guessing maybe the cooling coil could not be attached to another chw loop when heating coils is in a 2-pipe loop.
Anyone has some ideas about this odd thing? And is there another approach to model my system?

Thanks!

Jie Zhang