I need a new roof on my house, so I had a roofer come by and give an estimate. I asked him about installing a couple of those turbine fans on the roof. Those are the ones that turn with a breeze. He said he didn't think they really help in cooling the house. They cool the attic, but don't help much with the rooms, according to him.
He also said there are roof mounted electrical fans that are thermostatically controlled. Even one that uses a solar cell for fan motor power. Those cost another $250.
Sounds interesting...what do you think?