I live in the wonderful desert of Southwestern Arizona. The winters are awesome but the summers a miserably HOT!! I've heard people talk about installing attic fans in their houses before to ventilate the attic with the intention of keeping the attic cooler thus keeping the house cooler and saving on energy costs...I'm wondering if anyone can tell me if these work and are worth the effort and expence?
If so...How are they installed?
I also live in southern AZ. I just got through investigating this myself.
The first thing you need to do is to see if you actually have a problem or not. That is, compare the temperature of your attic to the outside temp. My home was built in 1999, and quite frankly the attic stays reasonably cool without any fan at all. The attic only runs about 10 degrees hotter than the outside temp, which I think is about as good as you can expect. This can mean that your attic is 110 degrees, but if it is 100 outside you can't expect much improvement. (I suppose if you have an a/c unit in the attic that could have some 'waste' cooling effect as well. I looked at the attic temp when the a/c hadn't run for quite a few hours.)
I have a tile roof, with soffet vents along the entire side of the house, plus a gable vent on one end only. This seems to be plenty.
Some people report that their attics are 30 or more degrees hotter than the outside temp, which probably does indicate a problem.
From what I have read, using sufficient passive vents is a better idea than smaller forced air venting.