How Much Cfm Do I Need For Attic Fan

Use the chart below as an attic vent fan cfm calculator.

How much cfm do i need for attic fan.

Cfm cubic feet per minute is a measure of the amount of air the fan moves in a minute. 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. Divide the cubic feet measurement by the cfm rating assigned to the fan. 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.

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. Ventilation rate of 10 air changes per hour. You need a minimum of 1 square foot of attic air venting for each 750 cfm of air flow. 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.

Ft of attic space for example 20 x 50 to be effective. 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. For proper cooling and efficient operation any whole house comfort ventilator requires adequate unobstructed outlets in the attic through soffit vents grilles or louvers. 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.

Attic vent fans are commonly rated from 800 to 1 600 cfm making one fans suitable for attics of up to around 2 200 square feet. 17600 cubic feet 1600 11.