Whole house fans vs. attic fans

What's the difference? And which is right for your home?

Definitions of whole house fan vs. attic fan vary by region, causing some confusion. In a nutshell, whole house fans are designed to run after sundown, using cool night air to ventilate and cool your entire living space. Attic fans are designed to run on hot sunny days to clear super-heated air from your attic. Both can be worthwhile, but they do different jobs. Let's look closer.

Whole house fans

A whole house fan is a primary natural cooling device that can significantly reduce or even eliminate the need for ‘manufactured’ cool air. Consuming far less energy than air conditioning, a whole house fan is run when outdoor temperatures drop, taking advantage of the natural cool outdoor air to ventilate and cool the building from the heat of the day.

A whole house fan:

  • mounts between living space and attic
  • runs only during cooler evening, night, and morning hours
  • pulls stale indoor air into the attic and forces hot attic air out through the roof vents
  • draws fresh cool air into your living space through open windows
  • cools the living space and draws heat buildup out of entire building structure

Attic fans

Attic fans operate during the heat of the day to reduce attic heat buildup—they ventilate the attic space only.

An attic fan:

  • mounts between attic space and outside
  • runs only during the heat of the day
  • removes super-heated air from your attic actively (typically, this is achieved passively using roof vent convection)
  • creates negative pressure in the attic that draws outside air in through roof venting
  • helps mitigate heat buildup in the attic structure, keeping the temperature as close to ambient as possible and minimizing heat radiating into your living space from the attic

Which is right for your home?

AirScape whole house fans deliver energy efficient natural cooling whenever evenings cool off. We recommend them for all regions across the US to reduce your home energy consumption while improving indoor air quality and livability.

If you live in a hot climate, we recommend adding a solar-powered attic fan in addition to a whole house fan. They are not a replacement for a whole house fan, but they are a smart move in hot regions. This device is self-powered, easy to install, turns on automatically as appropriate, and will have a significant impact in reducing building heat load.