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The Best Way to Use a Whole House Fan

A whole house fan is a large fan that mounts in the ceiling, usually in a hallway common to multiple rooms. The fan can reduce cooling costs and bring fresh air into your house quickly using little energy. By leaving a few windows or doors open, the fan draws in fresh air from outside into the attic, creating a cooling breeze throughout the house, and then pushes the air out through attic vents, venting off hot attic air.

Step 1

Calculate the square footage of your home, and select a house fan with the correct footage capability according to the fan's manufacturer. Most fans also include a CFM (cubic feet per minute) rating, and the greater the CFM number, the more air the fan can move.

Step 2

Find the best location for your fan, generally a hallway common to several rooms, near windows or doors with screens. Screened windows or doors are necessary for drawing in fresh air without also bringing in dirt, debris and bugs. Don't place your fan behind a door.

Step 3

Open just the windows and doors of the rooms you're in. Fewer open windows results in a stronger breeze from your house fan, which makes the room feel cooler. Moving air in unoccupied rooms doesn't make the rest of the house feel cooler.

Step 4

Do not use the fan on humid days. Since the effectiveness of the fan is directly related to relative humidity, the fan works best on days with lower humidity.

Step 5

Regularly clean the fan blades, motor and screens. Dust build-up can lead to overheating of the fan's moving parts, and can add to indoor air pollution, aggravating allergies. Be sure to turn off the power supply to the fan before cleaning.