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 fan cfm rating.
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.
If you have 1 200 cubic feet of attic the calculation is 1 200 x 0 6 720.
Divide the cubic feet measurement by the cfm rating assigned to the fan.
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.
You d need an attic fan rated at approximately 720 cfm.
I read that venting is important.