Whole House Fan, Belt Drive, 1725 Speed, Propeller Dia. 24 In., CFM High 3700, CFM Low 1610, HP 1/3, Fan RPM 529, Voltage 115, 60 Hz, 1 Phase, Amps 6.2, Height 28 In., Width 28 In., Depth 20 In., Ceiling Mounting Location, Requires Shutter For New Installations, Includes 2 Speed Wall Switch and 12-Hour Timer Assembled Whole House FansEffectively cool and ventilate an entire home by removing hot, humid air through the attic and drawing in cooler air from outside. Gasket between the venturi and plenum box reduces noise. All models include 2-speed wall switch with 12-hr. timer.Fans are UL and C-UL Listed.Mount: horizontal Thermally protected, 2-speed motors 115V/60 Hz Preassembled wood frameBelt Drive and Direct DriveGalvanized steel housing. HVI rating at 0.1" SP. CEC Certified.