Abstract: A gas-fired burner apparatus includes a porous combustion surface disposed in a combustion chamber substantially sealed to prevent entry of secondary air. A subatmospheric pressure is maintained in the combustion chamber by a natural or aspirated draft. The subatmospheric pressure cooperates with an aspirating flow of fuel to the burner apparatus to provide an increased flow of primary combustion air which reduces the combustion temperature and the emission of pollutants. Alternatively, the subatmospheric pressure may be used to achieve a given flow of primary combustion air with a reduced combustion surface area. Water heater and room heater applications of the burner apparatus are illustrated.

Abstract: A heater comprises a combustion tube connected to receive gaseous fuel or liquid fuel dispersed within a gaseous carrier gas from a source. The combustion tube communicates with an expansion chamber whose surface is provided with a plurality of openings. The expansion chamber is housed within a perforated container, the internal surface of which is spaced from the external surface of the expansion chamber to receive heating blocks.

Abstract: A burner unit for heating a gaseous medium includes a heat exchanger provided with tubes, a space between the tubes connected on the upstream side to a feed duct for the gaseous medium; a combustion chamber connected to the downstream side of the space between the tubes; a burner placed in the combustion chamber; and a fuel supply duct connected to the burner. The side of the combustion chamber remote from the heat exchanger is connected to a first end of the tubes; and a flue gas outlet duct is connected to the other end of the tubes. The elongation of the tubes forming part of the heat exchanger renders the use of a conventional tube plate superfluous. Thus, damage resulting from thermal stresses is avoided.

Abstract: A space heating unit is designed for use in a recreational vehicle and particularly to operate in conjunction with a cooking stove wherein the heating unit has a housing which is placed over a pair of burners and air flow ducts extend across the housing above the burners to draw air from the room upwardly through the ducts and across the housing in order to heat the air and discharge it into the room. The upper end of the housing communicates with an exhaust duct and has a baffle to regulate the rate of air flow through the housing.

Abstract: A space heater for small rooms, e.g. house trailers or ship's cabins, comprises an undulating heat exchanger centered on a vertical axis and a combustion pipe surrounded thereby. A burner enters the lower end of the combination pipe whose upper end is closed except for a number of lateral openings communicating with outwardly closed smoke channels of the undulating heat exchanger which alternate with outwardly open air channels. An outer peripheral wall, spacedly surrounding the heat exchanger, forms with its air channels an annular conduit for the conveyance of ambient air entering that conduit near its bottom and leaving it at its top.

Abstract: A gas-fired condensing convector or convector/radiant room heating appliance comprising a sealed combustion chamber 12 communicating with a baffled heat exchanger 21, a gas burner 13 within the chamber 12 fed with forced or induced air for combustion from a toroidal air blower 16, a convector fan 25 for circulating air over at least the heat exchanger, and a small bore flue pipe 24 terminating in a two-way outlet terminal means for the discharge of waste gases and liquid condensate. The thermal efficiency of the appliance is at least 90% and the temperature of the waste gases is below the dew point and at less than 50.degree. C.

Abstract: A gas-fired radiant heater such as for thawing rail cars and their contents in car barns and the like during freezing weather. The heater has an elongated housing that supports a channel box and an elongated perforated semi-cylindrical mantle supported by the housing over the channel box. The channel box receives a quantity of loosely-packed, fibrous ceramic refractory material that becomes incandescent when heated. The ceramic material has an exposed upwardly facing fibrous surface that defines with the interior of the mantle an elongated combustion chamber. The ends of the combustion chamber are closed and an ignited mixture fuel gas and air is projected into the elongated combustion chamber in the form of a flame jet. The flame jet heats the fibrous ceramic material and the mantle to incandescence so that the upwardly facing surface of the refractory material and the mantle radiate heat energy in a pattern generally normal to the surface of the mantle.