Abstract: An electric heater adapted to be used as a space heater or to be mounted over the discharge end of a hot air duct to diffuse air flowing into a room from the hot air duct and to heat the air in the room. The electric heater includes a housing adapted to be positioned over the discharge end of a hot air duct, the housing including an air outlet opening, and an elongated chamber therein. An elongated heating element is housed in an elongated chamber defined by the housing. An air conduit is also located in the housing and extends parallel to the elongated heating element. Air outlet openings are provided along the length of the air conduit, and a centrifugal fan blows air into the air conduit and this air is forced through the air outlet openings toward the elongated heating element and such that air is directed toward the heating element along a substantial portion of the length of the heating element.