Abstract: A space heater for use with fireplaces in which a metal unit is adapted to be placed in the fireplace near the rear wall but spaced therefrom and being mounted on a leg-like support structure which positions the unit above the normal level of the fire so that the hot gases and smoke will circulate on both the front and the rear sides of the unit as they pass from the fire to the flue. The unit is relatively narrow in the forward and rearward directions and elongated laterally, and contains a chamber in which a series of baffles preferably direct the circulating air through in a circuitous path. An inlet is provided with a tubular conduit connecting the inlet with the front of the fireplace and an outlet with a tubular conduit connecting the outlet with the space to be heated. A blower normally placed on the intake side of the chamber causes the air to flow from the room through the chamber where it is heated and then discharged into the room.