I am trying to model two-pipe fan-coil units. The temperature of the loop
can be adjusted with heating coming from the buildings steam boiler (through
a converter) or from the chilled water loop served by chillers. The loop
temps are based on OA temp and can vary between the 44F and 160 F. The
chilled water loop and the HW loop serve other AHUs also beside the fan-coil
units.

Appreciate any ideas on modelling this in eQuest.

If I make two two-pipe circulation loops secondary each with a primary loop
that is CHW or HW, I have to make the primary loops also two-pipe, which is
ok but then it gives an error of zero design flow.

If I model the fan-coils as four-pipe and set the availability schedule for
cooling and heating - I end up with many unmet hours during the changeover
time.

I could make all loops regular (not 2-pipe), but how do I get the
temperature to vary between 44F and 160F?

Thanks
-Rohini