ok my room is about 6 by 5 its a concrete room with a panda poly inside making it a tent inside the room i have fresh air comining in from the room outside this and have a duct fan pushing air through a diy carbon scrubby. i was thinging about redoing the vent about 6 feet from the room theres a window so here is what im thinking. Building a box around the window its in the basement so it won't be obvious have both intake and exhast go to this box will this work since there will always be fresh air in the box plus the exhaust air will be warm it will warm up the fresh air coming in