Abstract: An apparatus and method for burning organic farm bedding waste includes a firebox having an air injector disposed within the firebox. A heat exchanger is also disposed within the firebox above the air injector. The fuel to be burned, a mixture of organic farm bedding waste, is piled in the firebox surrounding the air injector and heat exchanger. By injecting air into the pile of fuel, the fuel is burned from the inside out, surrounding the heat exchanger with the burning fuel. The unburned fuel acts to insulate the burning fuel from the walls of the firebox. The apparatus can be used as an incinerator or as a furnace to heat a building.