How To Size An Attic Fan

Help determine optimal sizing of solar attic fans.

How to size an attic fan.

The warm air escapes through the attic and to the attic vents allowing the circulation of chilly air from the windows. This will help to avoid premature damage to the shingles or mold building up in moist hot. A whole house attic fan is installed in the ceiling between the top floor and the attic as a supplement to air conditioning. By sizing and implementing a whole house fan you can pull the warm stale air from your entire home into the attic where it s vented outside.

How to size a whole house attic fan. How to size solar attic exhaust vent fans so we developed our solar powered attic fan sizer calculator. Attic fan size calculation. 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. To find out if you have enough vent space divide the cubic feet of air per minute that the fan is rated for by 300 to come up with the minimum number of square feet of intake vent space needed for that size fan. It helps to cool your home temperatures and the attic by approximately 30 degrees. Attic fan size cfm 0 7 x sq ft area of the attic formula 1 the size of an attic fan is calculated in terms of cfm.

A whole house fan sucks warm house. It s also important to have plenty of soffit or gable vents for the fan to draw air into the attic. Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. Simultaneously cool fresh air will be pulled through the open windows and circulated through every room effectively replacing all of the air in your home and minimizing your dependence on air conditioning.

Whole house fans work on the principle of removing the hot and humid air out of the house. The whole house fan is installed inside the attic between the living space and ceiling.