This WhisperGreen model features built-in intelligence called SmartFlow Optimum CFM Technology. This unique electronic-brain lets the fan do what was once thought to be impossible: perform at a constant CFM regardless of elbows and other factors that might hinder performance. Basically, when a WhisperGreen fan faces static pressure, its speed is automatically increased to ensure that the desired CFM is actually achieved. This allows the fan to perform as rated and makes for easier sizing because the specifiers no longer has to worry as much about compromising the fan's performance.Quiet motor means quiet operation Bright ideas Energy star-qualified for energy savings User-friendly installation Tired of cold air coming through your ventilation fanBlower Wheel Type: Sirocco CustomVent Variable Speed Control: No Depth: 16-3 4 Duct Diameter (inches): 4 or 6 Energy Star Qualified: Yes Grille Size (inches sq.): 13 Height: 11-1 4 High Low Delay Timer: No Motor Type: DC Mounting Opening (inches sq.): 10-1 2 SmartAction Motion Sensor: No SmartFlow Optimum CFM Technology: Yes Thermal Fuse Protection: Yes Type of Motor: Bearing Ball UL Listed for Tub Shower Enclosure: Yes Weight: 13.4 Width: 14-1 4
