I Built One
It's nowhere near what you house AC will do, but it did help a lot here in the South in the month of July. It consist of (2) 4" computer fans from Radio Shack, a heat exchanger from a Chevy Caviler(sp), and a single faucet pump to circulate the water. The cooling water is a closed system, with the tube coiled inside the ice chest, that way it not flow directly on the ice. I would put 3 bags of ice in the ice chest and plug the unit in. It would drop the temperature inside the cabin 10 to 15 degrees in the evening and would continue to put out cool air for about 8 or 9 hours. Battery draw was around 2 amps for the pump and both fans.Ben AllenMontgomery, AL"Latte Dah"O'Day 26