Abstract: A sheet metal housing for containing a heater unit including an electric resistance heating element and a fan for circulating air through the heating element, and for protectively supporting such a heater unit within the interior space of a vertical building wall, the housing having a pair of legs extending below a body portion which encloses the heating element and fan unit, supporting the heating element and fan unit at least a minimum distance above the base of a wall, in which either of the legs can be bent upward to a horizontal position giving the entire housing, including the horizontally extended leg, a length equal to the usual spacing between adjacent vertical studs of a wall, so that the housing can be supported at a height greater than the minimum above the base of a wall by fastening one end of the housing to a stud and fastening the outwardly extended leg to the stud near the opposite end of the housing.