Sizing Attic Ventilation Fans

The result is a cooler attic space with plenty of air exchange.

Sizing attic ventilation fans.

A whole house fan sucks warm house. Attic fan size chart for quick reference. Example 20 wide by 50 long attic. Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic.

This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. Master flow egv5 gable mount attic ventilators are master flow egv5 gable mount attic ventilators are a great choice for exhaust ventilation. A whole house attic fan is installed in the ceiling between the top floor and the attic as a supplement to air conditioning.

For the exhaust to work properly the attic should have enough intake air vents. They are typically easier to install and won t detract from the appearance of your roof. Minimum intake air vent size cfm 300 sq ft. Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof.

So here the cfm of the fan cfm x 1 15. If your attic requires a 1500 cfm fan then it should also have a 1500 300 5 sq ft air vent. They can quickly remove a larger volume of hot and or humid air from your attic compared to static ventilation which helps save money on your heating and cooling. Our installer friendly energy star ventilation solutions help you design beyond code without compromising interior aesthetics.

Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per minute that the fan should be rated to move. How to size a whole house attic fan. Intake air vent size. 20 x 50 1 000 sq.