Sizing Attic Ventilation Fans

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

Sizing attic ventilation fans.

Our installer friendly energy star ventilation solutions help you design beyond code without compromising interior aesthetics. If your attic requires a 1500 cfm fan then it should also have a 1500 300 5 sq ft air vent. Example 20 wide by 50 long attic. For the exhaust to work properly the attic should have enough intake air vents.

Well managed indoor air quality is crucial to code compliance. A whole house fan sucks warm house. 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. They are typically easier to install and won t detract from the appearance of your roof.

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. 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. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. A whole house attic fan is installed in the ceiling between the top floor and the attic as a supplement to air conditioning.

Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic. So here the cfm of the fan cfm x 1 15. 20 x 50 1 000 sq. This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic.

Intake air vent size. See the benefits of attic ventilation a new roof is more than just shingles. How to size a whole house attic fan. 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.