Abstract: A method and apparatus for exhausting a mixture of air laden with droplets and vapors of greases and oils from a room such as a kitchen. A motor-driven fan is mounted within a duct to exhaust the mixture to outside the room. A heater located near the intake of the duct vaporizes any droplets of grease and oil in the air, and then superheats the resulting mixture to a temperature below the ignition point. The exhaust fan motor also drives a separate fan for cooling the motor with air drawn from the outside. The superheat temperature is regulated by the exhaust fan speed and current input to the heater.