How Much Cfm Do I Need For Attic Fan

Divide the cubic feet measurement by the cfm rating assigned to the fan.

How much cfm do i need for attic fan.

For proper cooling and efficient operation any whole house comfort ventilator requires adequate unobstructed outlets in the attic through soffit vents grilles or louvers. 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. Use the chart below as an attic vent fan cfm calculator. 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.

Ft of attic space for example 20 x 50 to be effective. What this means is that every eleven minutes the air in the home is being exchanged by a fan of this rating along with having windows open in each room. Ventilation rate of 10 air changes per hour. To calculate the amount of attic exhaust area you will need divide the fan s capacity in cfm by 750.

The formula above gives an approximate value of the cfm needed for an attic fan. Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. According to the home ventilating institute hvi powered attic ventilators need to move a minimum of 700 cubic feet per minute cfm for 1 000 sq. If you need 6 000 cfm of air flow through your house divide 6 000 by 750 to get a minimum 8 square feet of.

17600 cubic feet 1600 11. Vent fan location locate roof mounted fans on the back of the roof below the ridge but not so high as to be visible from the front of the house in the middle of the main part of the attic.