Can I Mount a Whole House Fan in the Attic Entrance?

Function

• Whole house fans work by pulling in air from the open windows of your home and exhausting it through the attic roof. These fans can be used to supplement your air conditioner during the summer, or they can eliminate the need for its use if you live in a moderate climate. To work effectively, your whole house fan should provide your home with 30 to 60 air changes every hour.

Placement

• The United States Department of Energy recommends that homeowners place their whole house fan in their attic ceiling. A cover should be constructed to keep air from leaking from the fan when it is not in use. If you live in an area that is very cold or very hot much of the year, place covers on both sides of the fan for maximum air sealing. Remove the covers before using your whole house fan each summer.

Installation

• Brackets constructed from 2-by-4s will support your whole house fan. The fan box sits inside a truss frame on top of this bracket. This area must be properly sealed to prevent hot attic air from being pulled across the fan. Caulk or spray foam can be used to seal the frame of your whole house fan. Installing a whole house fan is often a difficult task and best done by professional contractor.

Considerations

• Most whole house fans need increased ventilation in your home to work effectively. Homes with whole house fans need two to four times the normal number of attic vents. Increased ventilation is also important to prevent backdrafts in your furnace or hot water heater, which can cause dangerous gasses such as carbon monoxide to be pulled through your home.