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Are Whole House Fans Energy Efficient?

By May 9, 2020May 16th, 2020Energy Efficiency
Lady sweating by fan

Whole house fans have been around since the 1950s.  Mounted in the ceiling or the attic, they pull in warm air from the living spaces in the home.  This then allows the fan to bring in cooler air from the outside through doors and open windows.  The turn over in temperature change can cool down a house in an hour or less.  However, once the sun comes up, the fan will shut off and the doors and windows close to keep the cooler air inside.  Whole house fans are known for cooling down the house faster than an attic fan can, but are whole house fans energy-efficient?  Let’s take a look.

Recommendations in Washington State

Washington State University recommends that houses built in 2012 and after, and have a whole house fan, should run it for 24 hours a day.  With the changes in season, it is important to keep the outside air outside, and the conditioned air inside.  According to the university, their chart shows the size of a house, combined with the number of bedrooms for the required continuous operation ventilation rate in CFMs.  Using the exhaust fan along with the whole house fan will keep the house cooler and cleaner. It will also keep out air pollutants.  The fan has an easy wall switch to turn it on and off.  If your house was built before 2012, it is a good idea to check with the company that installed the fan to see what they recommend.

How Much Do You Save With A Whole House Fan? 

If you have central air conditioning in the home, the whole house fan can run on the days the outside air is cooler.  This will allow you to use the air conditioning unit on the warmer days so the warmer air is not brought back into the home.

If your home does not have a whole house fan they range from $900-$1500. It is energy efficient to use a whole house fan before the central air conditioning unit.  A whole house fan uses 200-700 watts while an air conditioner uses 2,000-5,000 watts.  It will cost 90% less to run a whole house fan than the central air. For example, if your bill is $150 for a month, using a whole house fan will allow you to save up to $135 a month! You can see that you will make up the cost of the system in no time.

Benefits of Installing a Whole House Fan

Still not convinced that a whole house fan sounds like a great idea if you live in a less humid area? Here are some additional benefits:

  • Reduces energy costs- The bill drops by as much as 95%!
  • Elevates home comfort- The fans will keep your home cool and comfortable year-round!
  • Improves indoor air quality –The outdoor air pulls in, and the indoor air goes out; thus making the air in your home cleaner and easier to breathe.
Whole house fan - Department of Energy photo
Vent for a whole house fan (credit: US Department of Energy)

Is Your Home Right For a Whole House Fan?

If you like having your windows open, and not running the air conditioner often, this can be a great investment!  This type of fan, unlike the attic fan, also helps increase homes’ resale value.  In addition, if you want to use a ceiling-mounted whole house fan, you will need adequate ventilation in the home.  The downside is if you live in an area that is heavy with dust or pollen, this will not work for those who suffer from allergies. Unfortunately, it brings the air in from the outside which causes a problem for allergy sufferers.  In hot and humid climates you will want to avoid a whole house fan and stick with the central air. It is too hot for several months of the year to switch over.


Buying a home with a whole house fan will require an inspection. This is so you have a piece of mind that the air is coming in and leaving properly.  A trained professional in this area is essential. A novice will not like to tackle attic measurements, dedicated circuit wiring, and vents.

If you have questions about whole-house fans, please contact us at Boggs today!