Whole House Fan Mounting Location Roof Quiet Design Yes Number of Speeds 3 Nameplate Voltage 120V AC Speed Controllable Yes Blade Diameter 22 in Drive Type Direct Drive Maximum Airflow 3 543 cfm Maximum Noise Level Not Applicable Wattage 377 W Coverage Area 1 831 sq ft Rough Opening Type Square For High-Static Pressure Applications Yes High-Efficiency Motor Yes Number of Blades 3 Blade Material Steel Housing Material Steel Grille Material Aluminum Standards UL Listed