I'm running into a sizing problem with EnergyPlus. I have a multi-zone VAV system with AirTerminal:SingleDuct:VAV:Reheat terminals. When I autosize from design days, I am getting 0 heating load for a particular interior zone, so the reheat coils are getting no power. However, there IS an operational heating load created by the 55 F air getting delivered from the central air handler and the minimum flow rate for the zone terminal. As far as I can tell, this load is NOT accounted for when the coil is sized. I'm by no means an EnergyPlus sizing expert, but it looks to me that the reheat coil gets sized according to the results of Sizing:Zone, which seems to calculate design heating and cooling loads according to the loads in the space (interior, from equipment, people, lights, etc.; exterior, through the zone envelope), WITHOUT accounting for any minimum flow rate from the central system.
First of all, can somebody verify my assumptions about how these reheat coils get sized? Second, if I'm not missing anything, how can I properly account for the impact of the potential heating load generated by terminal minimum flow rates when autosizing (particularly for the case where zone loads are small)?
