A combustion furnace includes an inner shell, an outer shell, a gas inlet piping and a flame inhibiting cover. The inner shell defines a receiving cavity therein. The inner shell defines a plurality of first gas holes around the periphery of a top portion thereof. The inner shell defines a gas inlet hole at a bottom thereof. The outer shell encloses the inner shell such that a gas flowing space is defined between the inner shell and the outer shell. The gas inlet piping has an opening formed at one end thereof, and the gas inlet piping communicates with the gas flowing space. The flame inhibiting cover is atop the outer shell and the inner shell, and a lower flange of the flame inhibiting cover is below the first gas holes.

A solid pellet fueled heater having a base unit with forced air blowers and a dual tube chimney structure is disclosed. The dual tube chimney structure may be used to warm incoming air for distribution around the heater. The pellet heater may also include a dual auger system and multi/high speed auger motor. The dual auger may include first and second auger blades mounted on a single auger shaft having blade pitches configured to convey solid fuel in opposite directions.

Apparatuses for burning a burnable fuel source, and methods of operating the same, are disclosed. The apparatuses may include a housing defining a chamber and a tube extending through the housing and disposed at least partially within the chamber of the housing, the tube accommodating a burnable fuel source. A tray may be disposed within the chamber and accommodating at least a portion of the burnable fuel source when received within the tube. A refractory brick may be disposed on at least a portion of the tray, and a plurality of pipes may be disposed within the housing such that, upon actuation of the apparatuses, heat from the burnable fuel source contacts the plurality of pipes. The apparatuses may also include an air outlet in the first housing configured to allow air from within the chamber to exit the chamber.

A cooking appliance has a combustion zone air flow path which includes a combustion zone. A first cooking zone is positioned in thermal communication with the combustion zone. During operation of the cooking appliance, combustion products produced in the combustion zone indirectly heat air whereby heated air is produced that is then introduced into the combustion zone and/or the first cooking zone.

A cooking appliance has a cooking zone comprising a cooking surface, a combustion zone that is in thermal communication with the cooking zone, wherein the cooking zone is isolated from combustion products produced by combustion in the combustion zone, and a drip tray that is positioned external to the cooking zone and the cooking surface directs liquid produced during cooking to the drip tray.