When you re finished write the number down somewhere you ll need it to find the right size piece of plywood for your attic fan to be installed on.
How to size an attic exhaust fan.
10 feet x 12 feet x 8 feet that computes to 960 cubic feet of air in the room.
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 a tape measure to get an accurate measurement.
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.
You now need to multiply 960 x 15.
You multiply length times width times height.
How to size attic exhaust vent fans for your home attic size.
To determine the size of your attic multiply the width by the length of the attic floor in feet.
The minimum requirements say that this air should be changed 15 times an hour.
Next multiply the square feet of attic space by 0 7 to get the minimum number of cubic feet of air per.
Measure the distance between the studs on the left and right side of your vent.
This attic ventilation calculator computes the size and number of solar powered attic fans to achieve the proper ventilation for your attic.