[Tobra]

Whole house fan is the droid you are looking for, especially if you live anyplace where it cools off at night, like, not Arizona or Texas. It mounts between the ceiling joists and moves a LOT of air. Like you would use if you were painting airplanes in your garage or something.

In Sacramento, there is a nice delta breeze most nights. My parents put one in when they remodeled, and it is shocking how much it reduced their A/C bill. You get up early, open some windows and start the fan. It blows air from the house into the attic. This draws cool air in from the windows you opened, and blows the hot air in the attic out the vents. If it is 60* outside, you can get it to 60* inside in about 5-10 minutes, including the air in the attic. As it warms up during the day, the air in the attic has to warm up quite a bit before it warms up in the house, especially if you have the place insulated.

I was watching their house a few years ago. Went over in the morning, ran the house fan, brought in the paper, closed up the house. Went by in the evening to bring the mail in and move the cars around a little so it looked like someone was home. Thermostat was set to 80* and it was well over a 100* every day they were gone. The air conditioner did not even come on at all most days.