How To Determine Attic Fan Size

How to size a whole house attic fan.

How to determine attic fan size.

Enter the length and width of your attic or ceiling crawl space. Then click on calculate. Total square footage ft 2 calculate recalculate. 20 x 50 1 000 sq.

In order to get the right fan you ll need to size your whole house fan to exchange the appropriate amount of cfm cubic feet of air per minute. For more complex attic spaces draw a sketch of your space and divide the space into parts before performing the calculations. Use this calculator to help determine the proper amount of attic ventilation based on u s. A whole house attic fan is installed in the ceiling between the top floor and the attic as a supplement to air conditioning.

To determine the size of your attic multiply the width by the length of the attic floor in feet. Then enter the height at the highest point. Our whole house fan sizing tool can help you determine the right size for your home without doing a lot of math. 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.

Suggestions for x area. Example 20 wide by 50 long attic. Fha 1 300 guidelines length ft please enter a valid number width ft please enter a valid number or. For a single story house this is usually the same as the square footage of the house itself plus any attached garage area.

Use the chart below as an attic vent fan cfm calculator. A whole house fan sucks warm house. For heating and air conditioning airflow or for other exhaust fan situations see our airflow calculator. For open blade fans see our ceiling fan calculator.

The formula above gives an approximate value of the cfm needed for an attic fan. Attic fan size calculation. Proceed to step 2 and use the chart to determine the size and number of solar powered attic ventilation fans required to achieve a min. Calculate the two halves of the attic separately then add the spaces together.

Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute.