Whole house fan sizing

Bigger is definitely better

In general, the larger your home, the larger the fan you should install. And while you can perform complex calculations using climate zone, house construction, etc., in the end, it comes down to this: Undersizing your fan can lead to disappointing performance and results. While, in our experience, no one ever regrets over-sizing their fan.

The ECM power curve

You will need a certain amount of airflow, measured in CFM (cubic feet per minute), to cool your home. Most of the whole house fan operation will be at night, on a low, quiet, maximally efficient setting. Early in the evenings, however, you will want to use a high setting to quickly force the hot air out of your home and return it to a comfortable temperature.

Usually, you can't get one without sacrificing the other, but thanks to the high-tech ECM motors and digital controls we use in our fans, this is a dilemma AirScape owners do not need to be concerned with. All of our fans have been designed to provide maximum airflow at their highest speed. Then, as the speed setting is decreased, airflow is reduced, but energy use is reduced even faster, providing increasing efficiency.