Although the concept is somewhat controversial, a properly installed solar attic fan could help cool your home by cooling your attic.
The photovoltaic panel that powers a solar attic fan should be located where it will capture direct sunlight. The fan may be mounted to exhaust hot air through a roof vent or a gable-end vent.
ILLUSTRATION: KEITH WARD
If outside temperatures are in the 90- to 110-degree range, the attic temperature can climb to 150 degrees. Even 105-degree outside air, when circulated through a 140-degree attic, will lower the temperature.