An attic fan is a ventilation unit equipped with a fan blade, a motor that runs the unit and housing. It is usually attached to a small attic window or through the roof, then connected to a power source.
Once the attic fan circulates hot air out and cool air in, the fan pushes the air through the rest of the house through an opening between the attic and the home's living areas.
The home is further ventilated and refreshed by the flow of air from the attic opening into every area that is left opened. This evenly distributes outside air to all parts of the house without full exposure to the outdoors through a door or window.
Attic fans also function as exhaust fans, releasing unpleasant aromas and stale air from the entire house. It can be operated for a brief period during the winter to give the house a prespring refresher.
Attic fans are not too difficult to install for the handy do-it-yourselfer. With a little help, the fan can be attached through your home's roof, then wired to your home's electrical supply.
Consult a roofer and an electrician about the safety codes and special instructions for your home's location.