Whole House Fan Mounting Location Ceiling Quiet Design Yes Number of Speeds 2 Nameplate Voltage 120V AC Speed Controllable Yes Blade Diameter 20 in Drive Type Direct Drive Maximum Airflow 5 024 cfm Maximum Noise Level 1.8 sones Wattage 786 W Coverage Area 2 512 sq ft Rough Opening Type Square For High-Static Pressure Applications Yes High-Efficiency Motor No Number of Blades 3 Blade Material Steel Housing Material Steel Grille Material Aluminum Standards UL Listed