I built a 13x16' theater room in my basement. I spent time to sound isolate the room and most sound is transfered via a single HVAC inflow register in the ceiling via flex duct. I live in central NC and weather is normally moderate. The basement is a walk-in type and the basement HVAC unit [a Heat Pump] is separate and does less than the other units. The theater room has all electronics out of it and remoted to an exterior closet except the projector. The problem is heat from 3-6 bodies and the projector causes the room to get too hot. The room as a side effect of soundproofing [including a solid exterior door] is pretty well air sealed. I realize I have to provide a return register in the room but I am not sure that just hooking it into the same HVAC unit would do very much good. The HVAC in the basement rarely runs so the heat just sits there in the room, in winter I even shut off the air vent to limit heating. The work to add a return air duct would be small but may not do much since I do the same thing by cracking the door and that doesn't work too well either. The other option I thought about is to tie into the main level HVAC intake since it works more often and the HVAC unit is located just behind the rear wall of the room. I almost would like to be able to get cold fresh air from outside to the room but that will only help in the winter. This would be possible if I installed a fanned duct through a utility closet next to an exterior wall. But except during the winter, that option has little use. Any ideas what I should do other than a separate unit just for that room? My DIY project was great except this final detail is really stumping me for a proper solution.