How To Size An Attic Fan

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.

How to size an attic fan.

Measure the length and width of each floor of your home with the tape measure. Find the overall air volume of your home. By dispelling hot air from your attic an attic fan can reduce the temperatures of your upper level rooms by 10 degrees extend the life of your roof shingles and cut air conditioning expenses by up to 30 percent. Calculate the required cfm air flow.

Enter the length and width of your attic or ceiling crawl space. 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. To determine the size of your attic multiply the width by the length of the attic floor in feet. The warm air escapes through the attic and to the attic vents allowing the circulation of chilly air from the windows.

How to size a whole house attic fan. Some professionals multiply the square feet value with 0 6 instead of 0 7. How to size attic exhaust vent fans for your home attic size. Always have a balanced ventilation system.

The formula above gives an approximate value of the cfm needed for an attic fan. Multiply the total air volume in cubic feet by 30 which represents a complete air change every 2 minutes. I know the dimensions of my attic space. Then click on calculate.

The whole house fan is installed inside the attic between the living space and ceiling. It helps to cool your home temperatures and the attic by approximately 30 degrees. Attic fan size calculator step 1. 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.

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. Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per. Select if your roof is more flat of peaked. Whole house fans work on the principle of removing the hot and humid air out of the house.

This is a quick rundown of the different types of attic fans their most common features and. Then enter the height at the highest point.