Attic Exhaust Fan Sizing

During the summer an attic can be 40 to 50 hotter than the outside temperature which in turn heats up the house very quickly.

Attic exhaust fan sizing.

That translates to one attic vent 3 feet by 3 feet or two attic vents each 1 feet by 1 feet. With an attic fan you can cool the attic to the same temperature as it is outside greatly reducing the house from heating as quickly. 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. Those vents would give you 9 square feet of vent area which meets the venting need.

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. Powered exhaust vents feature an electric or solar powered fan to create an effect similar to that of a turbine view example on amazon. This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic. The formula above gives an approximate value of the cfm needed for an attic fan.

Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic. Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. The result is a cooler attic space with plenty of air exchange. To determine what size power vent fan s you need for your attic you first need to know the size of your attic in square feet.

A standard powered. Well managed indoor air quality is crucial to code compliance. Attic vent fans are designed either to fit over a hole cut in your roof or to mount to the inside of a gable vent. Our installer friendly energy star ventilation solutions help you design beyond code without compromising interior aesthetics.