I've got a project where we have shutoff VAV boxes with electric heat
and RTUs that provide the supply air and have HW heat (mainly for
preheat of OA). The RTUs are also used to provide morning warmup heat.
During the 60 mins or so that morning warmup is occurring, the RTUs send
out 80 degree air, and the electric heat at the shutoff boxes is
disabled (they are forced open 100%).

Has anyone modeled this successfully? If I could disable zone heat for
one hour a day (5:00am-6:00am), I would think the RTU would raise its
supply air temp to compensate. But this is not possible as far as I
know. Thanks for any tips!

James Hansen, PE, LEED AP