A Whole house fan draws outside air in through your screened windows and doors and blows it out through your attic. The result is a mild cooling breeze that can lower skin temperature by 2 to 8 degrees.

 Whole house fans are practical and affordable and provide natural air-conditioning. Whole house fans
work well when outside temperature is below 82 degrees Fahrenheit. If you already have air-conditioning, a whole house fan can be used to thoroughly ventilate the house before the air-conditioning is turned on. This reduces air-conditioning operating time and costs. 

Whole house fans are centrally located usually
in a hallway. The fan itself is concealed by a ceiling grill that opens and closes automatically.