Attic Fan Sizing

Understanding whole house fan cfm.

Attic fan sizing.

A whole house attic fan is installed in the ceiling between the top floor and the attic as a supplement to air conditioning. The formula above gives an approximate value of the cfm needed for an attic fan. Attic fan size calculation. Whole house fans come in a variety of sizes determined by the amount of air they circulate or whole house fan cfm.

Cubic feet per minute or cfm is the amount of cubic feet of air per minute the fan moves. Choose a fan that matches your home or attic s size for optimal performance. 20 x 50 1 000 sq. Having an understanding of this makes choosing the correct fan size for your home an easier process.

Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. How to size a whole house attic fan. 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. 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.

This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic. During the summer an attic can be 40 to 50 hotter than the outside temperature which in turn heats up the house very quickly. 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. Too low of a cfm and you.

Example 20 wide by 50 long attic. 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. Help determine optimal sizing of solar attic fans.

Too high of a cfm and you ll be spending more money running the fan than you should be.