Abstract: The disclosure relates to a wood-burning appliance. The wood-burning appliance comprises a firebox and an airflow apparatus configured to provide a supply of oxygen for efficient primary and secondary fuel combustion within the firebox. An oven may be positioned above the firebox to improve heat exchange from exhaust exiting the wood-burning appliance. The wood-burning appliance may further have a pulley system for operation of a door that reduces gasket wear and allows the door to be at least partially removed from the wood-burning appliance for ease of access and maintenance.

Abstract: The present invention has an inner and outer hull spaced apart, so that burner intake air may flow between the inner and outer hull. The inner hull has the burner mounted in the bottom in a known manner with an air intake port placed below the burner. A burner ring is mounted above the burner to control the air drafts around the burner. On the inner hull one or more barometric draft valves are placed above the burner. As the air pressure rises, due to increasing wind speed, gas pressure, etc., the barometric valve opens automatically, providing more air to feed the flame and reducing the draft under the burner, thereby preventing the flame from being blown out. In extreme locations, more than one barometric draft valve can be provided. The valves can be set to open at different pressures, allowing for an even greater range of operating conditions.

Abstract: An improved wood burning heating unit which possesses a trapezoidal housing including a fire box portion possessing in a combustion zone a fire brick grid for supporting fuel wood. An air duct extends beneath the fire brick grid, upwardly along a back portion of the heating unit, and terminates in fluid communication with a helical heat exchanger section. The heat exchanger section surrounds a central chimney including an open upper end and an open lower end selectively closable by a damper. An outside air T connection includes a first leg connected to an outside air inlet, a second leg communicating with the chimney, above the heat exchanger section, and a third leg connected for directing combustion air to the fire box. The outside air T connection also includes a pair of air pressure actuated flapper valves for regulating combustion air flow depending upon conditions within the fire box.