"This Ventamatic Whole House Belt-Drive Fan offers an efficient way to trim cooling costs while keeping your entire home more comfortable. A 1/3 HP motor pulls hot air from your home and expels it through your attic exhaust vents. U.S.A. Air Delivery CFM 5,400 or 7,800, Speeds qty. 2, Diameter in. 30, Volts 120, Amps 5.0, Watts 600. For 2000 to 3000 square foot attics 2-speed thermally protected 1/3 HP PSC motor White powder-coat finish Ceiling mount only Joist-in or joist-out installation Requires minimum 12 square feet of net free air exhaust vent area"