Actually the way to do it is to have the upstairs fans blowing out the windows, then the downstairs window open. This is more effective at night when the outsi

Actually the way to do it is to have the upstairs fans blowing out the windows, then the downstairs window open. This is more effective at night when the outside temperature has dropped and the house is still hot. Hot air rises, so you will get cool air pulled in. This is how whole house/attic fans work.