5/20    Has anyone installed an attic fan? Does it REALLY cool down your
        house while saving 3X the AC electricity fee?
        \_ I don't know about attic fans, house fans are pretty good.
           Pull all the cool air into the house over night, and you
           usually don't need AC during the day.
        \_ In general, you want to make sure your attic has enough
           ventilations, and you have enough insulations in the attic
           to keep the house cool. The insulation will make the
           biggest difference. Here in the bay area, you need about
           12-inches of fiberglass or cellulose to have an R-value
           about 30+ for the attic. Some utilities company will do a
           free energy audit, have them come out and take a look.