Do whole house attic fans work?

How Whole House Fans Work. The whole house fan pulls air in from open windows and exhausts it through the attic and roof. It provides good attic ventilation in addition to whole house cooling. Whole house fans should provide houses with 3 to 6 air changes per hour (varies with climate, floor plan, etc.

How many CFM do I need for a whole house fan?

ft house you will need a whole house fan with ratings between 4000 to 6000 CFM. The basis of whole house fan size calculation is the number of air changes required in a house. According to the experts at, an official wing of US Department of Energy, a whole house fan need to make 3 to 6 air changes per hour.

Is it OK to run an attic fan all night?

Getting the most from your AirScape Only use your fan when the outdoor air is cooler than your indoor air. Make sure your A/C is off when you run the fan to avoid wasting energy. We recommend running the whole house fan all night. The goal is to cool your entire house down, not just the air.

How long does it take a whole house fan to cool the attic?

How Long Will It Take To Cool My Home And How Long Should I Keep The Fan On? Part 2 On average you should run the fan for 4-5 hours to ensure the attic is cooled. The attic is what keeps the home hot. We always recommend the use of a timer.

How do I calculate attic ventilation for whole house fan?

You need a minimum of 1 square foot of attic air venting for each 750 CFM of air flow. If you need 6,000 CFM of air flow through your house, divide 6,000 by 750 to get a minimum 8 square feet of attic venting. That translates to one attic vent 3 feet by 3 feet, or two attic vents, each 1 ½ feet by 1 ½ feet.

What size attic fan would an electrician need for a 1500 square foot home?

Attic fan size chart for quick reference

Attic floor area Recommended attic fan size
1000 sq.ft 700 CFM
1500 sq.ft 1050 CFM
2000 sq.ft 1400 CFM
2500 sq.ft 1750 CFM

How many vents should a whole house fan have?

A rule of thumb is you should have one square foot of “net free venting area” for every 500 CFM of airflow. So at 3000 CFM, you’ll want six square feet of venting.