Hello,

I'm attempting to model a PIU system with series boxes, and I'm using
the ZONE-FANS-ONLY keyword to simulate night cycling for heating
temperature control. In winter months, the hourly reports make sense
with zone fans and coils operating to condition the space, but in summer
months, the system remains off and temperatures rise above the
unoccupied setpoint (way above over the weekend when the system is
"off"). Is there a way to use this keyword such that only zone fans
operate in the winter but all fans (and cooling) operate in the summer
to maintain unoccupied setpoints?

In reality the entire system would cycle on in the summer during
unoccupied hours since cooling is required, but in winter the zone fans
would be adequate by themselves.

Thanks in advance for your responses,

Matt Edwards, PE, LEED AP BD+C