Abstract: An inner shell is incorporated within an outer shell and is of smaller dimensions to provide side spaces for the upward flow of heat, a top space communicating with an outlet, and a rear space having a V-shaped baffle therein causing upward flow of heat in the rearward area to be circulated and slowed for increased heating efficiency. An extension is attachable to the baffle for extending it upwardly and forwardly to control the flow of heat at the baffle. The inner shell has an imperforate tray extending from side to side and arranged to be moved forwardly through an opening in the inner shell and providing a natural forced flow of heat around it from the bottom for heating room areas.