In my first house (located in Ohio) I installed a squirrel cage out of
a furnace in the finished attic vented through the gable. I plugged it
into the over head light and when we wanted to cool the house I just
opened the attic door and turned on the light switch. It was so
powerful if you didn't block the door open it would suck it shut. We
never had A/C and never missed it, the constant flow of air made it
very comfortable.