How to Use a Whole House Fan Effectively

Tired of high air conditioning bills? One of the ways our family trims cooling costs is by using a whole house fan to cool our home in the summer. Unlike an air conditioner, a whole-house fan fits in the attic of a home and exhausts the hot air out of a building by replacing it with cool exterior air using negative pressure. Because whole-house fans use one-tenth of the energy of an air conditioning unit, they are an extremely efficient way to cool down a home.

While whole-house fans are pretty straight forward to use, there’s a few tips and tricks that can help a homeowner gets the maximum benefit from running the fan. Here’s a few ways that can help you use your whole-house fan for maximum results.

Operate only when the exterior temps are 70 or below.
Since whole-house fans replace the hot interior air with cooler exterior air, it doesn’t make sense to operate the fan when the temps are warm. For best results, we run the attic fan in the early morning while it’s still cool. Once the interior temperature is as cool as the outside, the fan is shut off and the house buttoned up for the day.

Open the windows.
Since the suction from a whole-house fan is so powerful, it’s best to open as many doors and windows as possible when the fan is in operation. Opening just a few windows means that instead of drawing in clean exterior air, the fan will draw air instead from the chimney, cracks in the floorboards, and other dusty places.

Run ceiling fans and box fans.
Since our home is multi-storied, our whole-house fan can take a while to cool down our home in the summer. To boost the speed of the air exchange, I run the ceiling fans and even set a few box fans in the window.

Dust the louvers regularly.
The louvered shutters that close the fan off from the house when it’s not in use can pick up lots of dust which can slow down the exchange of air. I dust the louvered shutters of our fan about once a month using the brush attachment of our canister vacuum.

Check the exterior vents periodically for obstructions.
The air pulled in by a whole house fan exhausts into the attic and out the gable or attic vents. If your whole-house fan doesn’t seem to be exhausting properly, checking the exterior vents for leaves or other obstructions is an easy fix for a DIY homeowner.

More by this contributor:
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No electricity? 5 easy things to check first.
Five cheap ways to cool your house this summer.