Add return fan in OS
I would like to add a return fan to an AHU but not quite sure where I should put it in. I put an additional fan in the Supply Equipment side of the air loop, just before the AirLoopHVAC:OutdoorAirSystem. But when I check the idf file, the fan is still in the supply branch and in this branch, there are two fans. Is it correct? What about relief fan?