Abstract: A radiant tube heater with a burner assembly, a radiant tube assembly and a combustion air pre-heater; wherein the burner assembly comprises: a burner fuel nozzle; a plenum chamber and a pre-mixer chamber; the plenum chamber having a combustion air inlet; wherein in use: combustion air flows from said plenum chamber through an orifice to said pre-mixer where said air is mixed with burner fuel entering said pre-mixer through said nozzle prior to being combusted at a burner head; said pre-mixer being at least partly located within said radiant tube assembly; and where in use at least part of the combustion air supplied to said plenum is preheated in said air pre-heater using residual sensible heat of the hot combustion gas products of the heater.

Abstract: An indirect heater assembly (10) comprises a radiant tube heater (12) and a fan (14) for generating an air flow over the heater (12). In an preferred embodiment and in another aspect, the radiant tube heater (12) comprises a radiant tube burner, an elongate tube 16 and a spiral tube (23) connected to the elongate tube (16) by a U-shaped tube (25). The spiral tube (23) extends around the elongate tube (16) coaxially thereof.

Abstract: An indirect heater assembly (10) comprises a radiant tube heater (12) and a fan (14) for generating an air flow over the heater (12). In an preferred embodiment and in another aspect, the radiant tube heater (12) comprises a radiant tube burner, an elongate tube 16 and a spiral tube (23) connected to the elongate tube (16) by a U-shaped tube (25). The spiral tube (23) extends around the elongate tube (16) coaxially thereof.

Abstract: Radiant tube space heating appliance (FIG. 1) has radiation ducting 10 with one or more inline burners 16 in a branch or branches 12 upstream of common tailpipe 20. An exhuast fan 22 in the tailpipe draws heated gases thought the ducting. A power operated control damper 28 in the tailpipe is actuated in response to sensing of the gas temperature in the tailpipe to reduce the induced flow therein when the temperature is below a certain level to counteract the increased volume throughput of the adjacent fan at lower temperature so that performance burners, e.g. on start up, is not adversely affected.

Abstract: A space heating appliance includes a radiant duct which, when heated, emits radiant heat for heating an area adjacent the duct. An insulated cowling shrouds the side of the duct away from the area to be heated in spaced relation to the duct. The cowling has a heat-emissive surface which when heated emits radiant heat toward the space to be heated. Between the duct and cowling in closely spaced proximity to the duct is an insulated heat shield which traps and redirects heat back to the duct in order to maintain the duct at a higher temperature and concentrate the emission of heat in the direction of the area to be heated.

Abstract: Space heating appliance of the radiant tube type has sheet metal or other shield formations mounted in the tube to extend downstream of fan induced gas flow from side edges of the mouth of a fluid fueled burner head which projects into the tube to feed hot gases into the flow so as initially to separate that infeed from the general flow along the tube.

Abstract: A radiant plaque heater adapted primarily for overhead use comprises the combination of a combustion panel, an emitter panel, and a combustion product flue wherein combustion products flow across the emitter panel in the direction of the flue and heat the latter to produce radiation which supplements that emitted by the combustion panel.

Abstract: Radiant tube space heating appliance includes a burner assembly (12), air flow therethrough being induced by a fan (14) by way of a restricted air inlet orifice (34) communicating with a stabilizing chamber (32) leading to the burner head (26) for smoothing and silencing the air flow; the burner head including a flame stabilizing matrix (40), conveniently formed from windings of flat and corrugated stainless strips (42,43) which define through apertures of substantial axial length. The appliance may further include a turbulator insert (50) in the radiant tube formed as a corrugated strip (52) of stainless steel or similar material which is twisted to form a helix.