Caframo; EcoFan For Wood Stoves Black Body Nickel Blades 150 CFM; 123903 No unsightly electric cords and no batteries to change. Just sit the fan on the top of the stove. Heat produces an electrical current. This electricity is then used to drive a DC motor and fan-blade that circulates the warm air throughout the room. As the stove gets warmer, more electricity is generated and the fan goes faster, boosting stove efficiency by up to 30%.