Panasonic. Available for spot or continuous ventilation, the WhisperGreen-Lite FV-08VKML2 vent fan offers variable-speed control from 0 to 80 cfm, a delay timer, and a SmartAction Motion Sensor, which activates when a person enters the room and returns to a pre-set lower speed when they depart. Designed for 4-inch ducts, the fan operates at less than 0.3 sones and includes two 18-watt CFL bulbs and a 4-watt nightlight bulb. The unit is Energy Star–rated and HVI-certified. 866.292.7292.