Common Myths About Whole House Fans

One of the appliances that homeowners like to install in order to keep cool is a whole house fan, and there's no doubt that these fans are excellent to have, even if you already have an air conditioner. The fans help circulate air and, in many circumstances, seriously reduce the need to run an air conditioner in areas where the electrical grid might be under strain. However, like any home appliance or fixture, the fans have a number of myths swirling about them. Whole house fans are good to have, but you need to know the proper way to use them to make them effective.

Myth #1: You Don't Need Air Conditioning if You Have a Whole House Fan

Whole house fans work by drawing up the hot air in the house, sending it outside, and replacing it with cooler air from outside. This is a great way to get cool air into your house, but that only works if the temperature outside is cooler than it is inside. So, on hot days, especially if your house has a good passive-solar system in place and is already relatively cool compared to outside temperatures, using the whole house fan won't cool the house. If the interior of the house becomes warm and the outside air is hot, you'll need to turn on your air conditioner.

That being said, the whole house fan can help move stagnant air around a bit, such as when you come home to a stuffy house, but you'll need the fan on for only a few minutes in that case. Then you should rely on your air conditioner if the air outside is very warm or hot.

Myth #2: You Shouldn't Have Them if You Like Peace and Quiet

Ever heard a noisy whole house fan? That's a sign the fan wasn't installed properly or is missing necessary noise-dampening parts. Your whole house fan will make noise in any case, but if the installation was done well, the noise won't be intrusive or excessive. If the sound from the fan is much louder than the sound from your air conditioner (assuming that was correctly installed and is working properly), or if the sound is much louder than, say, a few table fans placed on their high settings, the fan needs an inspection. It's not necessarily broken, but it's likely missing some insulating parts.

Myth #3: You Should Run These in the Afternoon to Cool the House

Again, these fans draw in outside air. That means that if it's hot out, you'd be drawing in all that hot air, possibly at the expense of cooler (if not completely cool) inside air. The best times to run whole house fans are:

  • When it's cooler outside and you want to expel hot interior air (e.g., in the morning).
  • When you need to get some stuffy, stagnant air moving (e.g., when you come home on a hot day to a closed-up house -- run for only a few minutes).
  • When you need to exhaust some smelly air (e.g., you brought home a smelly takeout meal and ate it away from the kitchen and its exhaust fan -- again, run for only a few minutes if it's a hot day).

Even air conditioning companies will agree that saving energy is a good goal. A whole house fan can be a wonderful companion appliance for an air conditioner, as long as you use the fan correctly. For more information, contact your local air conditioning contractor.