Ventilation is important everywhere in the house, especially in the attic. Attic fans offer one way to improve attic ventilation, which helps homes stay cool in steamy summers and even prevents ice dams in frigid winters.

If keeping cool is your main concern, you can follow energy expert Phil Bickel’s suggestion and use fans throughout your house. “Fans keep air moving around, rather than cooling the air,” he says. “Blow air directly on people to get a cooling effect or set up your fans to draw in cooler air from the outside (or a cooler part of the house) to the warm areas.

In the attic, the strategy is a little different. You want to keep the hot air moving through the roof or gable vents, but this only works if the attic is well sealed. Otherwise, you’ll be pulling cool air out of the house and expelling it outside.

Here’s how to decide if an attic fan is right for your home.

What Are Attic Fans?

Exactly what the name suggests. An attic fan pushes out stale indoor air and brings in fresh outside air. It might not sound like much, but the simple act of circulating attic air can greatly affect home temperature and energy consumption.

Attic fans can save you money on cooling costs. How? Heat rises into the attic on hot days, so instead of letting that heat radiate back into your house, attic fans move it outside and disperse it into the cooler outdoor air. That translates to lower cooling costs.

Attic fans aren’t just for summer — you’ll use yours year-round. A too-warm attic causes ice dams on the roof, and as snow melts and refreezes, it can damage roofing, gutters, walls and more. While other preventive measures exist, such as roof de-icing cables or roof rakes to remove snow, the importance of adequate ventilation can’t be overstated. Keeping the attic ventilated in the winter helps minimize the snow melt that causes ice dams.

Be careful, though. If an attic isn’t properly insulated and vented, attic fans can remove conditioned air from your living space and expel it through the attic, according to Energy Star. Attic fans don’t work well with inadequate insulation, blocked vents or air leaks.

Types of Attic Fans

Attic fans range in price depending on size, style and features. Some mount in the gable, some mount on the roof, some plug in, some are solar powered and some are passive, meaning they rely on natural heat convection to operate.

Solar-powered attic fans

Photovoltaic (PV) panels power these types of attic fans. The solar-powered fan is generally mounted on the outside of the roof. It is used to circulate warm air from inside the home out through vents in the eaves or roof.

Electric attic fans

These draw power from your home’s electrical system. These are recommendations for homes where there is no space underneath an eave or within a gable wall for mounting a solar-powered fan.

Some electric attic fans include thermostats. These can be connected to the home’s heating and cooling system to provide better temperature control inside the house and more even ventilation.

Passive attic fans

Passive attic fans rely on natural processes, such as wind or pressure, to circulate air. Typically, they’re the least expensive type of attic fan.

Cost of attic fans

Attic fans cost anywhere from $40 to $475, with the average price being around $200. Depending on the size of your attic, you may need more than one — possibly several — so count on spending anywhere from $100 to $1,000 to maintain adequate attic ventilation.

Attic Fans vs. Whole-House Fans

A whole-house fan increases ventilation throughout the entire house, not just the attic. It pulls in fresh air from windows, venting that air through the attic, according to the U.S. Department of Energy. You’ll need extra attic ventilation to keep up with the amount of air exchanged.

Whole-house fans keep the entire home cooler in the summer, but they also have some drawbacks. They can be noisy. And if not installed and operated properly, they can create a backdraft.

Bickel recommends augmenting the draft created by a whole-house fan by using your existing exhaust fans: “Exhaust fans in your kitchens and bathrooms capture hot air before it mingles with your house air and contributes to overheating.” He particularly recommends operating your exhaust fans during showers or whenever cooking indoors.

How To Choose Between an Attic Fan and a Whole-House Fan

Whether an attic fan or whole-house fan is best for you depends on your budget, location and goal.

If your house has problems with hot and cold spots, you might benefit from a whole-house fan. Moving a large volume of air helps to equalize temperatures and prevent hot or cold spots throughout your home.

If, on the other hand, you struggle with heat in the upper floor or ice dams in the winter, an attic fan might be better. When in doubt, talk to a professional. A HVAC expert will look at your home’s specifications and help you decide on the best course of action.

Next: learn about bathroom exhaust fans for leveling up your bathroom ventilation game!

FAQs

How do attic fans know when to turn on?

Most attic fans are controlled by a thermostat that switches on the fan when the temperature rises above a pre-set value. It’s also possible to control an attic fan with a humidistat, which monitors moisture in the air. A third possibility is a timer that switches the fan on during the hottest part of the day.

  • Pro tip: A solar fan operates whenever there is enough sun to run it.

Can attic fans cause problems?

Yes. As previously mentioned, attic fans can suck conditioned air into the attic through a poorly insulated ceiling. This can make the house warmer in summer and cooler in winter, overworking the HVAC system and wasting money.

Additionally, a poorly installed fan can cause leaks in the roof.

A third problem is that attic fans may circulate air, but they do nothing to stop heat from radiating through a poorly insulated roof. For this reason, they may not have the expected cooling effect.

About the Expert

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Mikayla Borchert
Mikayla is an assistant editor for Family Handyman, specializing in indoor and outdoor gardening, organization and décor. She has one cat and holds a B.A. in English from the University of Minnesota. Outside of work, she likes running, skiing, hiking and tending her balcony garden.
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