Roof Venting Requirements
Why Having Sufficient Roof Venting Is Important!
It’s all about balance! A whole house fan brings outdoor air into your home which is measured in cubic feet per minute. As the air flows into your home, and through your attic – your roof vents allow the hot attic air to escape from your home. Making sure you have adequate roof vents, which allow the hot attic air to escape is important.
Required Venting: Determine How Much Net Free Venting Your Fan Will Require:
1. Take The Total Cubic Feet Per Minute Of Air Flow (CFM) Of The Fan – And Divide By 750,
2. This Will Give You The Amount Of Net Free Venting In Square Feet Required For The Fan You Select.
For the Quiet Cool Models - the amount of venting you need is listed.
To Calculate How Much Net Free Venting you Have in Your Home
Simply measure the width and length, in inches of all the vents in your attic. Multiply them together; then divide that number by 144, and that is your gross free vent area in square feet.
To get the net free venting simply deduct 25% off that number. That accounts for any air restrictions through the vent. Do this for every vent, add them all up, and you will know exactly how much venting you have or will need to add to equal the venting requirement stated in your local building codes.