Whole House Fan And Attic Fan: What Do You Need?

Both whole-house fans and attic fans are designed to minimize the amount you need to spend on conditioned air. When installed and maintained correctly, these forms of ventilation improve your home’s indoor comfort during the warm season, increase energy efficiency, and also improve indoor air quality by keeping interior spaces supplied with fresh air.

Whole House Fan And Attic Fan: Not the Same Thing!

Sometimes, the terms whole house fan and attic fans are used interchangeably, even though they’re not the same thing. And, in most cases, Bay Area homeowners benefit from having both in place to minimize air conditioning needs during the warm months, which can significantly minimize utility spending during the summer season.

Whole House Fans Bring Fresh Cool Air Into Your Home

A whole house fan is installed between the living spaces and the attic. It is designed to run when the temperatures outside are cooler than those indoors, making it an energy-saving cooling device. 

Our Bay Area summer temperatures mean most homeowners benefit from installing a whole-house fan because it minimizes the amount of time the AC has to run. And, if you time the fan’s operation wisely, syncing it with the coolest parts of the night/morning, a well-insulated home may not even use AC on the average warm day.

A whole house fan cools the home and improves indoor air quality by:

• Running only during the cooler hours of the day (evenings, nights, and early mornings).
• Drawing cool air in through open windows.
• Pushing warm, stale, recirculated air up into the attic, where it is then exhausted outside via attic fans/vents.

As long as your attic is properly ventilated, your whole-house fan can do a surprisingly effective job at keeping your home cool no matter how hot it gets outside. That said, we recommend optimizing your whole-house fan’s effects by pairing it with an attic fan.

Whole-house fans are more complex systems than attic fans, which makes them more expensive than a simple attic fan. However, the two-fold benefits of cooling and improving indoor air quality make them worth it.

Benefits Of An Attic Fan

As we touched on in the intro, whole-home energy efficiency requires a combination of core features, which include a sound roof, sufficient attic and wall insulation, and adequate attic ventilation. The attic fan is a key player in that latter category. 

There are a variety of attic ventilation options, but attic fans are one of the most effective. While your whole-house fan operates during the coolest parts of the day, attic fans are the opposite. They work during the warmest parts of the day, pulling stale hot air up and out of the attic.

Attic fans:

• Are installed between the attic and the roof.
• Kick on independently when the temperatures rise in the attic (so there’s no need to worry about whether the fan is on or off).
• Only remove air from the attic. Venting hot air out of the attic is very effective at keeping the rest of the home cooler.
• Are an active form of ventilation, as opposed to the passive ventilation offered by roof vents.
• Minimize radiant heat transference from the attic to the living spaces below.
• Usually less expensive than whole-house fans.
• Can also help to maintain healthy moisture levels during the winter months.

Not All Bay Area Homes Need Attic Fans

While it’s true that the most effective whole-home ventilation usually leverages the benefits of both whole-house fans and attic fans, attic fans aren’t always necessary.

For example, you may not need an attic fan at all if:

• You live in one of the Bay’s notoriously cool areas (typically, the western and southern regions of San Francisco tend to have the coolest temperatures.
• Your house is well-shaded by trees or other buildings in the summer (which minimizes solar heat gain).
• You hardly ever use your air conditioner in the summer months.

Schedule An Attic Inspection With The Attic Solution Pros

Do you suspect a whole-house or attic fan would improve your home’s comfort this summer? Schedule an attic inspection with Attic Solutions. Our knowledgeable professionals will listen to your questions and ask some of our own to determine which type of fan would help you save money on cooling costs and improve interior comfort.

During the inspection, we’ll also let you know about any other attic red flags we notice, like inadequate attic ventilation, evidence of roof leaks, moisture control issues, or pests. We can also make recommendations about how to clean up and sanitize your attic, or upgrade damaged or outdated insulation.

Maintaining a clean, well-insulated, and well-ventilated attic space makes a big difference in energy efficiency and healthy indoor air quality. Your whole house and attic fans can be important parts of that equation.