Whole House vs Attic Fans

In some parts of the country, whole house fans are commonly referred to as attic fans. This can cause some confusion because, technically speaking, an attic fan is quite a different piece of equipment.

The confusion is understandable. In both cases we’re talking about a fan that you mount in your attic to help cool your house. But these two distinct devices have very different functionality and application.

In a nutshell, the difference is this: Attic fans are run during the heat of the day, in order to reduce attic heat buildup — they ventilate attic space only. Whole house fans are run in the cool of the evening, night and morning, to draw fresh cool air into the whole house while forcing hot air out through the attic.

A whole house fan is a primary cooling device that can significantly reduce or even eliminate the need for A/C. An attic fan, while it can be helpful to reduce A/C load in very hot climates, has no direct impact on your living environment.

Whole House fans vs. Attic fans

An attic fan: mounts between attic space and outside runs during the heat of the day ejects 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 building	A whole house fan: mounts between living space and attic runs only during cooler evening, night and morning periods draws fresh cool air in through your living space through open windows pulls indoor air into the attic and forces hot attic air out through the roof vents cools the living space and draws heat buildup out of entire building structure

The bottom line

An AirScape whole house fan provides natural cooling efficiency, energy savings, added home comfort and enjoyable evening breezes. While they are most effective in dry climates with warm days and cool nights, we recommend them for nearly any climate. To learn more, read our Whole House Fan Overview .

As for attic fans, if you live in a hot, dry, sunny climate, consider adding a solar-powered attic fan in addition to a whole house fan. This device is self-powered, easy to install, turns on automatically as appropriate, and will have a significant impact in reducing building heat load. They don’t replace whole house fans, but can be a smart addition to your home cooling strategy in sunny hot climates. Here’s a link to a solar-powered attic fan on our general ventilation site HVACquick.com