"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. Volts 120, Speeds qty. 2, Diameter in. 30, Air Delivery CFM 5,400 or 7,800, Amps 5.0, Watts 600. For 2,000 to 3,000 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"