Abstract: A pellet burner has inner and outer housings for defining a high pressure air plenum between. Angled perforations at strategic locations in the inner housing supplied pressurized primary and secondary combustion air so that, with pellets supplied to a burn pot of the inner housing and activation of a blower and an ignitor cartridge, the pellets auto-ignite and the air flow establishes a swirling flame in the burn pot that travels to a flame conduit of the inner housing where further swirling occurs in a venture section for shaping the flame into a clean, hot, symmetrical form.

Abstract: A heating unit and solid fuel feeder comprises a vertical furnace having a combustion chamber for burning solid fuel, a water jacket around the combustion chamber and an exhaust chamber at an upper outlet end of the combustion chamber. A plenum box is connected to the furnace and defines an interior space. Water circulation tubes extend from an upper end of the water jacket, through the plenum and into a water tank positioned on an opposite side of the plenum. Additional water tubes are connected between a lower end of the water tank and a lower end of the jacket. Water circulates as hot water rises in the jacket and falls in the water tank. A plurality of exhaust conduits which also extend in the plenum, are connected between the exhaust chamber and a smoke box. A stack is connected to the exhaust box. Air flowing or blown through the plenum picks up heat from the water pipes and exhaust conduit. Hot water from the tank may be used as an additional source of heat or to heat domestic hot water.