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.
Attic fans 1200 square feet.
Moving plenty of air through an average sized attic roughly 1 200 square feet.
An attic fan used for venting pushes the hot air out the roof space so if it isn t replaced from outdoors you get depressurization.
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.
Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.
In order to find the right calculator divide the attic floor space by 300 sq feet.
I read that venting is important.
Types of attic fans.
Add an additional 20 cfm x 1 20 if you have a steep roof and 15 cfm x 1 15 for a dark roof.
If you have 1 200 cubic feet of attic the calculation is 1 200 x 0 6 720.
Quietcool attic fans work almost everywhere almost anytime.
Net free area in square inches.
If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.
With an attic fan you can cool the attic to the same temperature as it is outside greatly reducing the house from heating as quickly.
You d need an attic fan rated at approximately 720 cfm.
And a 3 1 amp motor that provides ventilation for up to 1 600 square feet of attic.
Attic area in square feet.
Ventilation area in square feet.
1 cubic foot is 12 x 12 144 cubic inches.
The fan is able to accommodate anywhere from 1 200 to 1 800 square feet of attic space.
Step 5 add together the square footage values of the square rectangular and triangular floor areas to find the total square footage of your attic.
It s perfect for reducing cooling costs as it pulls fresh air from outside and expels warm attic air out through the exhaust vents.
During the summer an attic can be 40 to 50 hotter than the outside temperature which in turn heats up the house very quickly.