NZ551388A - Radiant gas burner heater - Google Patents

Abstract

A gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above at least the gas burner(s), and a housing about the radiant member(s), the gas burner(s) and the heat shield, the housing allowing the radiant member(s) to radiate heat directly out of the front of the housing, wherein the heat shield is set down from the top of the housing within the housing, and wherein there are lateral outlets for combustion gases and a heat exchange airflow through the part of the housing.

Description

10054995634* ;NEW ZEALAND PATENTS ACT, 1953 ;No: 551388 ;Date: 16 November 2006 ;COMPLETE SPECIFICATION ;A HEATER ;We, RINNAI NEW ZEALAND LIMITED, a company duly incorporated under the laws of New Zealand of 691 Mt Albert Road, Royal Oak, Auckland, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: ;' 1 MNOvaffl? RECEIVED ;- 2 - ;The present invention relates to gas heaters. ;We have marketed a radiant heater under the brand RINNAI™ SUPER RAY™ Outdoor Heaters. These consist of a housed arrangement for radiant grids (usually of a ceramic, silicate or the equivalent material to act as a radiant member or radiant members) so as to direct heat downwardly at an angle and over a broadcast area notwithstanding the tendency for convection to take the heat of the combustion gases upwardly and for the housing itself to irradiate heat. ;Such heaters have typically been configured in a manner substantially as hereinafter described with reference to Figure 1. They have typically been of a stainless steel housing when for outdoor usage. This provides a rust proof enclosure with low heat radiation from the housing. ;It has been appropriate where such heaters have been mounted beneath canopies, ceilings or other covers likely to be effected by heat to interpose a heat shield between such a covering surface and the heater. Typically a distance of at least one meter above the heater is requited to accommodate such shielding and to still avoid the difficulty with the rising heat and irradiated heat from the housing. ;We believe there is a need for a gas heater of a kind able to be mounted from a support (eg, brackets from a post or wall) and angled down from the horizontal to heat an area but where it can be raised to a height closer to any such cover. We propose within the gas heater an internal heat shield above the gas burners and at least partly over the flow path for the combustion gases. ;We take the view that a gas heater having radiant components (of any kind whatsoever) whether metal, ceramic, or other, can best be used in such a close to cover positioning provided there is both internal shielding of combustion gases below the other surface of the housing (so as to better dissipate heat around the housing), and a cooling flow through of a gas to be heated by heat exchange to temperatures below those that otherwise the combustion gases would attain. ;Without in any way being restrictive as to the features of a gas heater in accordance with the present invention, we also believe there is some merit in being able to provide an inlet or multiple inlets for air from at or below the burners so as to provide a heat exchange air stream to vent in the space behind and/or above the heater via at least one outlet from the housing. ;It is an object of the present invention to provide gas heaters, or the use of gas heaters in circumstances where the advantages desired are obtained and methods of heating which use such gas heaters reliant on the cooler upper housing and/or cooler gas out flows. ;We recognise an advantage from a marketing point of view for an outdoor gas heater which has the capability of being used outdoors or in a manner deemed by regulations to be sufficiently outdoors for its operation, yet which, if desired, can be operated indoors. This is ;-3- ;particularly the case now with the prospect that alfresco dining often involves at least partially open areas which can be closed down sufficiendy to provide comfort to diners in adverse weather conditions. In such a closed down state it is not then appropriate to operate an outdoor heater owing to risk of oxygen depletion. We recognise an advantage for outdoor radiant gas heaters which include a failure to safe provision in the event of oxygen depletion. ;Accordingly we propose the non-mandated use in an outdoor radiant gas heater of an oxygen depletion system which has the effect of failing the heater to safe in the event it is operated in a confined space without an air flow through even though ostensibly it is weather proofed and otherwise suitably adapted for use as an outdoor heater. We believe the Australian Gas Association Code will be fully satisfied by the operation of such an outdoor radiant gas heater in a mixed indoor / outdoor environment including such alfresco uses. ;It is therefore an object of the present invention or an alternative object of the present invention to provide a heater having such characteristics notwithstanding the fact that it is to be marketed as an outdoor radiant gas heater. ;In an aspect the invention consists in a radiant gas heater having a housing that allows radiant heat to be irradiated via an open front thereof, ;at least one gas burner in the housing, ;at least one radiant component in the housing to be heated sufficiently by combustion of gas of the gas burner(s) to irradiate heat from the housing via the open front thereof, ;at least one inlet for drawing of air ("primary combustion air") into the housing to support combustion of gas of the burner(s), ;at least one of each of an inlet, flow path and outlet for air ("non-combustion air") that is not to, or is not to substantially, support combustion of gas of the burner(s), ;a heat shield disposed (preferably directly) above at least one of (and preferably both) the gas burner(s) and the radiant component(s) but spaced below the top of the housing; ;wherein operation of the heater supports combustion of the gas of the gas burner(s) with both said primary combustion air drawn in from below and secondary combustion air drawn in from the front of the housing (eg, via at least the bottom of the open front thereof), to support combustion; ;and wherein such operation vents combustion gases at least primarily from the housing via at least one oudet of the housing to the front and/or the top (near the front); ;and wherein heat exchange to the non-combustion air results in an outflow thereof via its outlet(s). ;Preferably the combustion gas vent from over the opening of the open front. ;-4- ;Preferably said outlet(s) for the non-combustion air is to the rear and/or at the rear of the top of the housing. ;Preferably the inlet(s) for the non-combustion air is at and/or adjacent the bottom of the housing. ;Preferably said housing is partitioned so as to prevent any substantial mingling of said non-combustion air with said primary combustion air. ;Preferably the inlet(s) for the non-combustion air are not also inlet(s) for the primary combustion air. ;Preferably said heat shield is adapted to deflect combustion gases to the outlet(s) or vent for the combustion gases. ;Preferably none of the combustion gases vent directly upwards from the top and/or from the rear of the housing. ;Preferably a control system for one or more of the gas burner, and pilot therefor, any gas feed to the burner and/or any pilot therefor, is provided in the housing. ;Preferably such a control system is disposed in the housing below and/or adjacent the gas burner(s). ;Preferably the primary combustion air and/or the non-combustion air acts to cool the control system in use. ;Preferably said heat shield is associated with an additional shielding panel within the housing, the additional shielding panel being interposed between the top panel or panels of the housing and said heat shield. ;Preferably said housing includes an adaption whereby it can be mounted so as to angle the open front thereof downwardly at least slightly from the horizontal. ;Preferably said open front includes a grid or the like open structure. ;Preferably said open front is surrounded totally or in part by heat reflectors. ;Preferably said heat reflectors arc of a stainless steel and angle into the housing of which they form part from the periphery thereof. ;Preferably said radiant component(s) are ceramic. ;Preferably the heater is sufficiently weather proof so as to protect the interior thereof from normal weathering effects. ;In another aspect the invention consists in a radiant gas heater having a housing that defines at least one or more top and bottom panels and lateral panels including an open front that allows radiant heat to be irradiated, ;at least one gas burner in the housing, ;-5- ;at least one radiant component in the housing to be heated sufficiendy by combustion of gas of the gas burner(s) to irradiate heat from the housing via the open front thereof, ;at least one inlet for drawing of air ("primary combustion air") into the housing (preferably via the bottom panel(s)) to support combustion of gas of the burner(s), ;at least one of each of an inlet (preferably the bottom panel(s)), flow path and oudet for air ("non-combustion air") (preferably in a lateral panel or lateral panels eg, the rear) that is not to, or is not to substantially, support combustion of gas of the burner(s), ;a heat shield disposed (preferably directly) above at least one of (and preferably both) the gas burner(s) and the radiant component(s) but spaced below the top panel(s) of the housing; ;wherein operation of the heater supports combustion of the gas of the gas burner(s) with both said primary combustion air drawn in from below and secondary combustion air drawn in from the front of the housing to support combustion; ;and wherein such operation vents combustion gases at least from the housing via at least one lateral oudet of the housing (preferably the front or both the front and the rear); ;and wherein heat exchange to the non-combustion air results in an outflow thereof via its oudet(s). ;In another aspect the invention is an outdoor radiant gas heater having an oxygen depletion system shut off control. Preferably there is having an oxygen depletion system shut off control. ;In another aspect the invention consists in a gas heater having within its housing above the burner or burners, and above the radiant component(s), a heat shield spaced down from the upper most panel of the housing. ;Preferably there is a front outlet from the housing above the radiant components for combustion gases. ;Preferably there is a rear oudet for gases from the housing above the burners. ;Preferably passage of combustion gases is to at least the front oudet (preferably at least in part direcdy under and/or involving of the heat shield). ;Preferably there is at least one air inlet at the bottom of the housing feeding a stream of gas upwardly which is adapted to least in part exit from said rear oudet. Preferably that flow is at least in part heat exchange heated. ;In another aspect the invention consists in a gas heater having within its housing above the burner or burners, and above the radiant component(s), a heat shield spaced down from the upper most panel(s) of the housing and provision laterally below such uppermost panel(s) for allowing the escape of (a) combustion gases and (b) a heat exchange air flow. ;In another aspect the invention consists in a gas heater having ;a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above both (i) the gas burner(s) and (ii) the radiant member(s), and a housing about the radiant member(s), the gas burnei(s) and the heat shield, the housing allowing the radiant member(s) to radiate heat directly out of the front of the housing, wherein there is at least one or more of: ;(a) at least one oudet for hot combustion gases from the top front of the housing, ;(b) at least one inlet for non-combustion air to be passed in the housing to at least one oudet from the rear of the housing from behind the heat shield, ;(c) access for at least some ingress of air ("secondary combustion air") from the front to feed the combustion of the gas of the burner(s), and ;(d) at least one inlet ("inlet(s)") for air ("primary combustion air") into the housing from below the burner(s) and/or behind the burner(s). ;Preferably the heat shield is set down from the top of said housing. ;Preferably the combustion gas vent from over the opening of the open front. ;Preferably said outlet(s) for the non-combustion air is to the rear and/or at the rear of the top of the housing. ;Preferably the inlet(s) for the non-combustion air is at and/or adjacent the bottom of the housing. ;Preferably said housing is partitioned so as to prevent any substantial mingling of said non-combustion air with said primary combustion air. ;Preferably the inlet(s) for the non-combustion air are not also inlet(s) for the primary combustion air. ;Preferably said heat shield is adapted to deflect combustion gases to the oullet(s) or vent for the combustion gases. ;Preferably none of the combustion gases vent directly upwards from the top and/or from the rear of the housing. ;Preferably a control system for one or more of the gas burner, and pilot therefor, any gas feed to the burner and/or any pilot therefor, is provided in the housing. ;Preferably such a control system is disposed in the housing below and/or adjacent the gas burner(s). ;Preferably the primary combustion air and/or the non-combustion air acts to cool the control system in use. ;-7- ;Preferably said heat shield is associated with an additional shielding panel within the housing, the additional shielding panel being interposed between the top panel or panels of the housing and said heat shield. ;Preferably said housing includes an adaption whereby it can be mounted so as to angle the open front thereof downwardly at least slightly from the horizontal. ;Preferably said open front includes a grid or the like open structure. ;Preferably said open front is surrounded totally or in part by heat reflcctors. ;Preferably said heat reflectors are of a stainless steel and angle into the housing of which they form part from the periphery thereof. ;Preferably said radiant component(s) are ceramic. ;Preferably the heater is sufficiently weather proof so as to protect the interior thereof from normal weathering effects. ;In another aspect the invention consists m a gas heater having within its housing above the burner or burners, and above the radiant component(s), a heat shield spaced down from the upper most panel(s) of the housing and provision laterally below such uppermost panel(s) for allowing the escape of (a) combustion gases and (b) a heat exchange air flow. ;In another aspect the invention consists in a gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield to deflect combustion gases above the gas burner(s), and a housing about the radiant mcmber(s), the gas burnet(s) and the heat shield, the housing allowing the radiant member(s) to radiate heat directly out of the front of the housing, wherein there is at least one or more of: ;(a) at least one outlet for hot combustion gases from laterally of the housing, ;(b) at least one inlet for non-combustion air to be passed in the housing to at least one oudet laterally from the housing, ;(c) access for at least some ingress of air ("secondary combustion air") to feed the combustion of the gas of the burner(s), and ;(d) at least one inlet ("inlet(s)") for air ("primary combustion air") into the housing. In another aspect the invention consists in a gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above both (i) the gas burner(s) and (ii) the radiant member(s), and a housing about the radiant member(s), the gas burner(s) and the heat shield, the housing allowing the radiant member(s) to radiate heat directly out of the front of the housing, ;-8- ;whetein the heat shield is set down from the top of the housing within the housing. In another aspect the invention consists in a gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above both (i) the gas burner(s) and (ii) the radiant member(s), and a housing about the radiant member(s), the gas burner(s) and the heat shield, the housing (a) allowing both an inflow of primary and secondary combustion supporting inflows to the gas or combusting gas and (b) allowing the radiant member(s) to radiate heat direcdy out of the front of the housing. ;Preferably porting and flow patli(s) allows an air up flow for heating by heat exchange within the housing prior to its discharge. ;Preferably the combustion gas vent from over the opening of the open front. ;Preferably said outlet(s) for the non-combustion air is to the rear and/or at the rear of the top of the housing. ;Preferably the inlet(s) for the non-combustion air is at and/or adjacent the bottom of the housing. ;Preferably said housing is partitioned so as to prevent any substantial mingling of said non-combustion air with said primary combustion air. ;Preferably the rnlet(s) for the non-combustion air are not also inlet(s) for the primary combustion air. ;Preferably said heat shield is adapted to deflect combustion gases to the outlet(s) or vent for the combustion gases. ;Preferably none of the combustion gases vent directly upwards from the top and/or from the rear of the housing. ;Preferably a control system for one or more of the gas burner, and pilot therefor, any gas feed to the burner and/or any pilot therefor, is provided in the housing. ;Preferably such a control system is disposed in the housing below and/or adjacent the gas burner(s). ;Preferably the primary combustion air and/or the non-combustion air acts to cool the control system in use. ;Preferably said heat shield is associated with an additional shielding panel within the housing, the additional shielding panel being interposed between the top panel or panels of the housing and said heat shield. ;Preferably said housing mcludes an adaption whereby it can be mounted so as to angle the open front thereof downwardly at least slightly from the horizontal. ;-9- ;Preferably said open front includes a grid or the like open structure. ;Preferably said open front is surrounded totally or in part by heat reflectors. ;Preferably said heat reflectors are of a stainless steel and angle into the housing of which they form part from the periphery thereof. ;Preferably said radiant components) are ceramic. ;Preferably the heater is sufficiendy weather proof so as to protect the interior thereof from normal weathering effects. ;In another aspect the invention consists in a gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above at least the gas burner(s), and a housing about the radiant member(s), the gas burner(s) and the heat shield, the housing allowing the radiant member(s) to radiate heat direcdy out of the front of the housing, wherein the heat shield is set down from the top of the housing within the housing, and wherein there are lateral oudets for combustion gases and a heat exchange airflow through the part of the housing. ;In another aspect the invention consists in a gas heater having a gas burner or burners adapted or adaptable to receive a gas feed and to combust it, at least one radiant member to be heated by the combustion of the gas of the burner(s), a heat shield above the gas burner(s), and a housing about the radiant member(s), the gas burner(s) and the heat shield, the housing (a) allowing from below and from in front respectively an inflow of primary and secondary combustion supporting inflows to the gas or combusting gas, (b) allowing the radiant member(s) to radiate heat direcdy out of the front of the housing and (c) allowing an air upflow for heating by heat exchange within the housing prior to its discharge. ;In another aspect the invention is the use or operation of a heater as aforesaid. ;This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. ;A preferred form of the present invention will now be described with reference to the accompany drawings in which ;Figure 1 is a diagram of a two ceramic plaque version SUPER RAY™ gas heater referred to earlier, ;-10- ;Figure 2 is a five ceramic plaque variant of the heater of Figure 1, ;Figure 3 is a view straight into the front face or lateral front of a preferred outdoor heater in accordance with the present invention showing a metal grid over the (in this case three) radiant components to be heated by the gas flames, the radiant components being of a suitable ceramic, ;Figure 4 is a top view of the unit of Figure 3 looking down on it along lines of sight parallel to the frontal notional planar area of the heater, the view showing two top panels (one a faceting panel), ;Figure 5 is a bottom view of the heater of Figures 3 and 4, ;Figure 6 is a left hand side view of a heater of Figures 3 through 5 showing a mounting bracket on a facet providing panel between a bottom panel and the rear panel and a top panel inclined to it (but which is to lie only slightly rising to the front when mounted in use by the bracket), ;Figure 7 is the right hand side of the heater of Figures 3 through 6, there being shown the gas inlet to the gas injectors, ;Figure 8 is an isometric view of the unit of Figures 3 through 7 from one side on the rear, ;Figure 9 is a similar view to that of Figure 8 but from the other side and at an angle that shows the vents for primary air intake and to the rear thereof the non-combustion air from the bottom panel, ;Figure 10 is a similar view of the unit (i.e. as mounted) but this time in isometric from the front from that side which has the gas inlet, ;Figure 11 is another view but similar to Figure 10 (i.e. from the other side), ;Figure 12 shows a similar view to Figure 7 but showing the heater angled for use, the frontal notional planar area of the housing and its reflectors (preferably forming part of the housing), being angled backwards from the horizontal by the angle alpha, ;Figure 13 is a view from above of the unit when mounted as in Figure 12, ;Figure 14 is a view directly from in front (i.e. horizontally) showing the outlet for the combustion gases to the fore above the downwardly inclined radiant components which otherwise are surrounded by the inwardly inclined reflectors, ;Figure 15 is a view upwardly from below of the unit when mounted as in Figure 12 thereby showing the inlets for primary air to support combustion and inlets to provide the bypass non-combustion air flow which acts to cool the housing, ;Figure 16 is a sectional view at A-A of Figure 14, the arrows showing the combustion gas discharge primarily to the front but also (at least in part) to the rear via lateral vents, the vents ;-11 - ;being louvered to the front (for weather protection and to reflect heat downwardly) and rain protected to the rear, the combustion gases deflecting off the heat shield shown preferably as a planar member set down from the top of the housing, ;Figure 16A is an enlarged view of Figure 16 showing various components of the construction, ;Figure 17 is a similar view to that of Figure 16 but this time showing air inflows, the primary air inflow being from below upwardly to the gas injector and burners, the secondary inflow to support combustion being via the open face, and the non-combustion supporting gas being an upflow from the bottom or via the facet panel at or adjacent the bottom (or both) to be heated by heat exchange and to vent laterally of the unit as or adjacent its top, and ;Figure 17A is an enlarged view of the arrangement shown in Figure 17 again showing some preferred components. ;Without restriction on shape of the housing, the number of burners and plaques, a preferred embodiment is now described. ;Features of the present invention are the provision of the features shown by reference numerals 1 through 6 in Figures 16A and 17A. In these figures there is shown: ;1. A stainless steel reflector; ;2. A radiant heat shield; ;3. A top panel of the housing; ;4. A burner; ;5. A ceramic plaque (a preferred form of the radiant component described previously); ;6. A burner injector. ;As can be seen from Figures 12 through 17B, the front face is adapted to angle back from the vertical by an angle alpha. This angle preferably is in the range from 25 to 75° (ideally about 35 to 55°) but it depends on the height at which it is mounted relative to where people might be and what proportion of combustion gases are to vent to each of the fore and aft. ;Preferably however the arrangement is such that the top panel 3 still has a slight incline from rear to front. Likewise the heat shield 1, for example of a planar sheet of a high temperature stainless steel, which is set down and spaced from the top panel 3 but which has interposed therebetween a further radiant reflector or heat shield 2. This further radiant barrier 2 assists in reducing upper frontal temperatures eg, to no more than about 400°. ;Shown by reference numeral 7 are top vent outlets (preferably louvre so as to be provided with weather resistance at the angle of which it was mounted) above the open face otherwise defined by the three preferably planar but inwardly angled reflectors 8 of the housing. ;The top panel angles down to above the louvres from the top panel 3 through a facet panel 9. Similarly the base region 10 angles upwardly via facet panel 11 to a lateral rear panel 12. It is to the facet panel 11 that the mounting bracket arrangement 13 (as shown) is mounted. ;Shown in Figure 5 are a variety of openings 14 dedicated to an inflow of primary combustion air. Also shown is an intake 15 dedicated to non-combustion air. ;Shown in Figure 9 above is a teaf lateral outlet 16. ;There is therefore a series of intakes, ports, openings or the like to provide for inflow of primary combustion air and inflow of non-combustion air. There is the provision of the louvered top front outlet or vent 7 for at least some of the combustion gases. Similarly the rear top outlet, port, vent or the like 14 can allow some of the hot combustion gases to be discharged there if appropriate i.e. depending on wind directions, depending on angle of inclination of the heat shield, etc. ;As can be seen the primary and cooling air enters upwardly (see Figure 17A). Non-combustion air passes in a heat exchange relationship through the housing to be released via the rear top oudet 16. That oudet 16 as can be seen in Figure 17A is protected by an inwardly directed rain shield. That outlet 16 can also allow some diversion thereto of the hot combustion gases. ;As can be seen the burner 4 fed via gas input 17 has the injector 6 thereof positioned still further down in the housing where it can inject gas straight into admixture with the primary ait rising to the zone shown by the arrow labelled primary combustion air in Figures 17A. ;Burning then in the burner behind the ceramic plaques 5 is further supported by the roll in or draw in of secondary combustion air from the front as shown in Figure 17A. At the same time flow through under the draft effect of cooling air as shown to the rear of the burner occurs. This is via inlet 11. ;Disposed in the bottom of the housing as shown in Figures 16A and 17A are control aspects of the device which are presented underneath the combustion and are shielded from the radiant effects of the ceramic plaque 5. Moreover such control systems are subjected to cooling under the drafting effect of at least the primary combustion air and preferably also the cooling air to bypass combustion. ;It is desirable if such a unit is to be operated outdoors but in circumstances where there can be some confinement of the area around the heater to have the control system include an ("ODS") oxygen depletion system to provide shut down. Such a system is similar to that which we hitherto have employed in indoor gas heaters. Likewise the ignition, pilot and main burner controls. The unit as shown as a remote IR receiver 18 for remote inputs of control instructions. ;- 13- ;It is found a heater as in the preferred embodiment can be operated outdoors or indoors/outdoors yet be kept close under not otherwise shielded awnings, ceilings or roofs. ;In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art. *

Claims (21)

WHAT WE CLAIM IS:

1. A radiant gas heater comprising or including a housing that allows radiant heat to be irradiated via an open front thereof, at least one gas burner in the housing, at least one radiant component in the housing to be heated sufficiendy by combustion of gas of the gas burner(s) to irradiate heat from the housing via the open front thereof, at least one inlet for drawing of air ("primary combustion air") into the housing to support combustion of gas of the burner(s), at least one of each of an inlet, flow path and outlet for air ("non-combustion air'') that is not to, or is not to substantially, support combustion of gas of the burner(s), a heat shield disposed above at least one of the gas burner(s) and the radiant component(s) but spaced below the top of the housing; wherein operation of the heater supports combustion of the gas of the gas burner(s) with both said primary combustion air drawn in from below and secondary combustion air drawn in from the front of the housing (eg, via at least the bottom of the open front thereof) to support combustion; and wherein such operation vents combustion gases at least primarily from the housing via at least one outlet of the housing to the front and/or the top near the front; and wherein heat exchange to the non-combustion air results in an outflow thereof via its outlet(s).

2. A heater of claim 1 wherein the heat shield is disposed over the one or more gas burners.

3. A heater of claim 1 or 2 wherein the combustion gas vents from over the open front.

4. A heater of any one of the preceding claims wherein said outlet(s) for the non-combustion air is to the rear and/or at the rear of the top of the housing.

5. A heater of any one of the preceding claims wherein the inlet(s) for the non-combustion air is at and/or adjacent the bottom of the housing.

6. A heater of any one of the preceding claims wherein said housing is partitioned so as to prevent any substantial mingling of said non-combustion air with said primary combustion air.

7. A heater of any one of the preceding claims wherein the inlet(s) for the non-combustion air are not also inlet(s) for the primary combustion air.

8. A heater of any one of the preceding claims wherein said heat shield is adapted to deflect combustion gases to the outlet(s) or vent for the combustion gases.

9. A heater of any one of the preceding claims wherein none of the combustion gases vent direcdy upwards from the top and/or from the rear of the housing. Intellectual Property Office of N.Z. 2 0 MAY 2008 RECEIVED -15-

10. A heater of any one of the preceding claims wherein a control system for one or more of the gas burner, and pilot therefor, any gas feed to the burner and/or any pilot therefor, is provided in the housing.

11. A heater of claim 10 wherein said control system is disposed in the housing below and/or adjacent the gas burner(s).

12. A heater of claim 10 or 11 wherein the primary combustion air and/or the non-combustion air acts to cool the control system in use.

13. A heater of any one of the preceding claims wherein said heat shield is associated with an additional shielding panel within the housing, the additional shielding panel being interposed between the top panel or panels of the housing and said heat shield.

14. A heater of any one of the preceding claims wherein said housing includes an adaption whereby it can be mounted so as to angle the open front thereof downwardly at least slightly from the horizontal.

15. A heater of any one of the preceding claims wherein said open front includes a grid or the like open structure.

16. A heater of any one of the preceding claims wherein said open front is surrounded totally or in part by heat reflectors.

17. A heater of claim 16 wherein said heat reflectors are of a stainless steel and angle into the housing of which they form part from the periphery thereof.

18. A heater of any one of the preceding claims wherein said radiant components) are ceramic.

19. A heater of any one of the preceding claims wherein the heater is sufficiendy weather proof when operationally mounted so as to protect the interior thereof from normal weathering effects.

20. A heater of any one of the preceding claims wherein there is an oxygen depletion system shut off control.

21. A gas heater of any one of claims 1 to 20 when substantially as hereinbefore described with reference to any one or more of the accompanying drawings. Intellectual Property Office of N.Z. 20 MAY 2008 RECEIVED