Me, I use a small window unit. We have the side by side windows, too, but DH opened one of the windows, set the unit in the window, then places plywood over the rest of the opening and used insulation to block any cracks. The unit works really well. I turn it on about thirty minutes before I start and by the time I go in, the room is comfortably cool. Give it shot. Oh, and the small unit only raised our light bill by about twenty bucks, well worth it, if you ask me.