Electric-powered attic vents use a thermostat and humidistat control to monitor heat and moisture buildup inside the attic.
Featuring a low-profile dome, the power attic vent is unobtrusive when installed on the roof slanting away from the front of your home. It's an efficient option to replace wind turbines or roof pots already in place. Power vents are rated in CFM—cubic feet of air moved per minute. The higher the CFM, the more powerful the vent and the more air exchanges per hour it provides. To determine the minimum CFM required, multiply the attic square footage by 0.7.
1500 square feet x 0.7 = 1050 CFM
Thus, a fan rated at least 1050 CFM is needed