Attic Fan Cfm Rating

I read that venting is important.

Attic fan cfm rating. As the attic cools the smart fan will automatically cycle down to lower speeds the lowest being 1 000 cfm which only uses 15 watts of energy resulting in a cheaper air conditioning bill and cooler home temperature temperatures can drop as much as 50 degrees these two factors make it an excellent energy and cost saver. Divide the cubic feet measurement by the cfm rating assigned to the fan. 17600 cubic feet 1600 11 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. 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.

To facilitate faster air exchange would necessitate choosing a fan with a higher cfm. If you have 1 200 cubic feet of attic the calculation is 1 200 x 0 6 720.