My fan is on an end wall and my window is on a side wall. When I use the window for ventilation, I notice most of the air movement goes straight to the other side of to the side wall instead of toward the fan. I either us another box fan to push the air toward the exhaust fan or crack the big door which is opposite of the fan. That works really well but the bugs can get in that way. I checked the air movement with smoke. You got any smoke around there? lol