Floor fans, table fans, and celing fans are the most cost effective electric cooling devices available. You could conceivably run several fans and still use less energy than you would with a single AC unit. It is important to note that using a fan during very hot and humid weather may not be a cost-effective cooling strategy if you use an air conditioner most of the time. Window fans and whole-house fans are the best ways to accomplish power ventilation. Effective attic ventilation helps keep attic temperatures below 110 F during hot weather.
Attic fans are ideal in ranch style homes where most of the living space is just below the attic.
The purpose of the attic fan is to speed up the cooling process by pulling air in through open windows up through the attic and back outside. When the fan is on, you can let air into the attic either by opening the attic door or by installing a simple louver that automatically does the same thing. These fans are usually installed in a hallway ceiling on the top floor of your house. They work by pulling the air from the entire house up into the attic, where it is vented to the outside. The resulting pressure difference causes fresh air to flow into your living areas from the outside.