Abstract: A furnace is provided which is capable of heating a circulating current of air by heat produced from the combustion of either solid or fluid fuel. The furnace is constructed with two separate combustion compartments and a surrounding chamber for circulation of the air to be heated. By means of temperature sensor and control means, the fluid fuel supply is stopped when adequate heat is being produced from the solid fuel. The furnace is adapted to heat remotely located rooms by means of conduits which transport air heated within said chamber. The room in which the furnace is located is heated by the front of said furnace by radiation and convectively heated contiguous air. The compartment which combusts solid fuel is provided with a door on the rear of said furnace, thereby permitting wood to be entered into said compartment from outside the room or building in which said furnace is situated.

Abstract: A furnace is provided which is capable of heating a circulating current of air by heat produced from the combustion of either solid or fluid fuel. The furnace is constructed with two separate combustion compartments and an intervening chamber for circulation of the air to be heated. By means of temperature sensor and control means, the fluid fuel supply is stopped when adequate heat is being produced from the solid fuel. The furnace is adapted to heat remotely located rooms by means of conduits which transport said heated air. The room in which the furnace is located is heated by radiation and convectively heated contiguous air.