For optimal effectiveness, use your whole house fan in the late afternoons, evenings, and/or early mornings when the outside temperatures are cooler than inside temperatures.

Here are a few basic tips for using a whole-house fan:

1) Turn off the central air conditioning when using a whole-house fan. Otherwise, you will expel all of that expensively-cooled air in your home!

2) Open the windows and doors. If you do not, the fan may cause your gas-burning appliances, furnace, or water heater to back-draft exhaust fumes and carbon monoxide into your home.

3) Do not have a fire going in the fireplace. A fire will not vent properly because of the change of air pressure that a whole-house fan causes.

Why we like it: • 2 Speed wall switch included • Relatively quiet • Automatic shutters open and close

There are some drawbacks to whole house fans:

1) They can only cool the inside of the house to the outside temperature, so if it is hot outside, it will be just as hot inside, except for the coolness offered by air movement.

2) Unlike an air conditioner, a whole-house fan cannot dehumidify the air.

3) A whole-house fan can draw dust and pollen into the house.

4) In winter months, whole house fans could present energy loss as heated room air leaks into the attic. A shutter or cover can minimize this problem. See How to Build a Box Cover.