Dual-burner firepit

Abstract

Heating apparatus including: a housing defining an internal volume configured to contain a fuel source, a heat emitter connected to the fuel source and configured to emit radiant heat, and a burner connected to the fuel source and configured to emit visible flames. The heat emitter and the burner can be horizontally aligned and arranged concentrically with respect to each other such that one of the heat emitter and the burner is disposed radially inward of the other.

Description

DUAL-BURNER FIREPITCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 650,891, entitled “Propane Firepit with Dual Ambient and Radiant Burners,” filed May 22, 2024, which is hereby incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure is directed to gas firepits, more specifically to gas firepits with dual burners.BACKGROUND

[0003] Gas-fueled firepits (e.g., propane-fueled firepits) are increasing in popularity as an alternative to traditional, wood-burning firepits due to their relative ease-of-use, safety, and ability to operate in environments where burning wood is not permitted (e.g., on rooftop terraces of apartment buildings). However, gas firepits generally struggle to create environments that are as comfortable and warm as their wood-burning counterparts. Typically, most of the heat emitted by a gas firepit is released into a narrow volume that extends directly upward from the top of the firepit. As a result, users who wish to feel the firepit’s warmth must crowd extremely close to the firepit, which significantly limits the number of people who can make use of the firepit at any given time. Moreover, since such a large proportion of heat generated by a gas firepit is emitted in a vertical direction, even those users standing nearest to the firepit may only feel its warmth on parts of their bodies (e.g., their hands) that can be extended over the top the firepit. Therefore, a substantial amount of heat generated by a gas firepit may never be felt by its users. This inefficiency results in high fuel costs that are disproportionate to the benefits provided by the firepit.SUMMARY

[0004] Various firepits are provided herein. In one embodiment, an apparatus is provided having a housing defining an internal volume configured to contain a fuel source, a heat emitter coupled to the fuel source and configured to emit radiant heat, and a first burner coupled to the fuel source and configured to emit visible flames. The first burner and the heat emitter can be horizontally aligned and arranged concentrically with respect to each other such that one of the first burner and the heat emitter is disposed radially inward of the other. In some embodiments,the first burner and the heat emitter can both be positioned proximate to an upper portion of the housing.

[0005] In some aspects, the apparatus can further include a first fuel tube and a second fuel tube, each configured to connect to the fuel source. The heat emitter can be connected to the first fuel tube, and the first burner can be connected to the second fuel tube. Various fuel sources can be used, such as a propane fuel source.

[0006] In some embodiments, the heat emitter can include a second burner and an emitter plate surrounding the second burner. The second burner can be configured to couple to the fuel source and to emit heat toward the emitter plate, and the emitter plate can be configured to direct radiant heat in a direction normal to an outer surface of the emitter plate. In some aspects, the second burner can be configured to emit visible flames through outlet holes formed in the second burner. The second burner can be, for example, an annular burner, and the outlet holes formed in the second burner can include outlet holes disposed along an upper surface of the burner. In some embodiments, the outlet holes formed in the second burner include elongate slot-shaped holes arranged in a staggered pattern.

[0007] In other aspects, the first burner can be configured to emit the visible flames through outlet holes formed in the first burner. The first burner can be, for example, an annular burner, and the outlet holes formed in the first burner can include outlet holes disposed along an upper surface of the second burner. In some embodiments, the outlet holes formed in the first burner can include a combination of circular holes and elongate slot-shaped holes. Each elongate slotshaped hole can be positioned between a pair of circular holes.

[0008] In another embodiment, an apparatus is provided having a housing defining an internal volume configured to contain a fuel source, a heat emitter configured to emit radiant heat and including a first portion coupled to the fuel source and a second portion coupled to the fuel source, and a second burner configured to emit visible flames and coupled to the fuel source. The first portion of the heat emitter, the second portion of the heat emitter, and the first burner can be configured to be controlled independently from each other. The apparatus can further include a control assembly configured to independently adjustably control a provision of fuel from the fuel source to each of the first portion of the heat emitter, the second portion of the heat emitter, and the second burner.

[0009] In some aspects, the apparatus can include a first fuel tube, a second fuel tube, and athird fuel tube each configured to connect to the fuel source. The first portion of the heat emitter can be connected to the first fuel tube, the second portion of the heat emitter can be connected to the second fuel tube, and the first burner can be connected to the third fuel tube.

[0010] In other embodiments, the heat emitter and the first burner can both be positioned proximate to an upper portion of the housing and can be arranged concentrically with respect to each other such that one of the first burner and the heat emitter is disposed inside of the other. In some embodiments, the heat emitter and the first burner are concentrically arranged and in other embodiments they are offset. In some embodiments, the first burner can be horizontally aligned with the heat emitter and in other embodiments, the first burner can be horizontally offset from the heat emitter.

[0011] In some aspects, the heat emitter can include a second burner that includes a first portion configured to couple to the fuel source and a second portion configured to couple to the fuel source. The apparatus can further include a first thermopile configured to ignite the first portion of the second burner, a second thermopile configured to ignite the second portion of the second burner, and a third thermopile configured to ignite the first burner. The heat emitter can further include an emitter plate that surrounds the second burner such that the first and second portions of the second burner are substantially enclosed by the heat emitter. The emitter plate can be configured to direct heat emitted by the second burner in a direction normal to an outer surface of the emitter plate. The emitter plate can include a first portion that surrounds the first portion of the second burner and a second portion that surrounds the second portion of the second burner. The second burner can be configured to emit the visible flames through outlet holes formed in the second burner.

[0012] In another embodiment, an apparatus is provided having a housing defining an internal volume configured to contain a fuel source, a heat emitter coupled to the fuel source and configured to emit radiant heat, a first burner coupled to the fuel source and configured to emit visible flames, and a heat reflector disposed radially inward of at least a portion of the heat emitter and including a vertical surface and an angled surface disposed along a top edge of the vertical surface that flares outward from the vertical surface.

[0013] In some aspects, the fuel source can be a propane fuel source. In other aspects, the apparatus can include a first fuel tube and a second fuel tube each configured to connect to the fuel source. The first burner can be connected to the first fuel tube, and the heat emitter can be connected to the second fuel tube. In other aspects, the first burner can be configured to emit thevisible flames through outlet holes formed in the first burner.

[0014] In other aspects, the vertical surface of the heat reflector can be aligned with a longitudinal axis of the housing. The angled surface of the heat reflector can be joined to the vertical surface of the heat reflector at an angle between 90° and 150°. The angled surface of the heat reflector may extend at least partially above a portion of the heat emitter, such as a second burner. The first burner can be at least partially surrounded by the heat reflector.

[0015] In other embodiments, the heat emitter can include a second burner and an emitter plate that surrounds the second burner and the heat reflector. The emitter plate can be configured to direct heat emitted by the second burner in a direction normal to an outer surface of the emitter plate. The heat reflector can be configured to reflect heat emitted by the second burner toward the emitter plate.

[0016] In other aspects, an apparatus is provided having a housing defining an internal volume configured to contain a fuel source, a heat emitter coupled to the fuel source and configured to emit radiant heat, and a first burner coupled to the fuel source and configured to emit visible flame. The heat emitter can be configured to generate a heated region that extends outward from the heat emitter and encircles the housing such that, at a radial distance of approximately 1 meter from an outer surface of the housing, between approximately 40 cm above a bottom surface of the housing and approximately 120 cm above the bottom surface of the housing, the radiant flux is at least 400 W / m2.

[0017] In some embodiments, the apparatus can include a first fuel tube and a second fuel tube each configured to connect to the fuel source. The heat emitter can be connected to the first fuel tube, and the first burner can be connected to the second fuel tube. The heat emitter can be configured to emit the radiant heat through outlet holes formed in the heat emitter. In some embodiments, the heat emitter can include a second burner, and the first and second burners can be configured to emit the visible flames through outlet holes formed therein. In some aspects, the fuel source can be a propane fuel source.

[0018] In some aspects, the heated region can be such that, at the radial distance of approximately 1 meter from the outer surface of the housing, between the bottom surface of the housing and approximately 20 cm above the bottom surface of the housing, the radiant flux is less than 250 W / m2. In other aspects, the heated region can be such that, at the radial distance of approximately 1 meter from the outer surface of the housing, above approximately 140 cm abovethe bottom surface of the housing, the radiant flux is less than 250 W / m2. In yet other aspects, the heated region can be such that, at the radial distance of approximately 1 meter from the outer surface of the housing, above approximately 150 cm above the bottom surface of the housing, the radiant flux is negligible.

[0019] In other embodiments, the heated region can have a maximum radiant flux between approximately 70 cm above the bottom surface of the housing and approximately 90 cm above the bottom surface of the housing. The maximum radiant flux is at least 600 W / m2.BRIEF DESCRIPTION OF THE FIGURES

[0020] These and other features will be more readily understood from the following detailed description taken in conjunction with the accompanying drawings.

[0021] FIG. 1 shows a block diagram of an exemplary heating system, according to some embodiments;

[0022] FIG. 2A shows a front view of an embodiment of a heating apparatus;

[0023] FIG. 2B shows a rear view of the apparatus of FIG. 2A;

[0024] FIG. 2C shows a rear view of the apparatus of FIG. 2A with the housing door and the lid removed;

[0025] FIG. 3 A shows a top-down view of the dual heat emitter and ambient flame burner of the apparatus of FIG. 2A;

[0026] FIG. 3B shows a perspective view of a first embodiment of the radiant heat burner of the apparatus of FIG. 2A;

[0027] FIG. 3C shows a perspective view of a second embodiment of the radiant heat burner of the apparatus of FIG. 2A;

[0028] FIG. 3D shows a perspective view of a third embodiment of the radiant heat burner of the apparatus of FIG. 2A;

[0029] FIG. 3E shows a magnified view of the outlet holes in the radiant heat burner of the apparatus of FIG. 2A;

[0030] FIG. 3F shows a perspective view of the ambient flame burner of the apparatus ofFIG. 2A;

[0031] FIG. 3G shows a magnified view of the outlet holes in the ambient flame burner of the apparatus of FIG. 2A;

[0032] FIG. 4 shows a perspective view of the fuel control system of the apparatus of FIG. 2A;

[0033] FIG. 5 A shows a cross-sectional view of the upper portion of the apparatus of FIG. 2 A with the lid removed;

[0034] FIG. 5B shows a magnified cross-sectional view of the angled heat reflector and the heat emitter of the apparatus of FIG. 2A;

[0035] FIG. 5C shows a perspective view of the angled heat reflector of the apparatus of FIG. 2A;

[0036] FIG. 5D shows a perspective view of the emitter plate of the heat emitter of the apparatus of FIG. 2A;

[0037] FIG. 6A shows a diagram of a heated region generated by an exemplary heating apparatus, according to some embodiments;

[0038] FIG. 6B shows a map of the radiant heat flux (measured in kW / m2) produced by an exemplary heating apparatus when the heat emitter and the ambient flame burner of the heating apparatus are ignited;

[0039] FIG. 7A shows a perspective view of another embodiment of a heating apparatus;

[0040] FIG. 7B shows a cross-sectional perspective view of the apparatus of FIG. 7 A;

[0041] FIG. 7C shows a cross-sectional view of the upper portion of the apparatus of FIG.7A;

[0042] FIG. 7D shows a perspective view of the radiant heat burner of the apparatus of FIG. 7A;

[0043] FIG. 7E shows a diagram of heat radiated by the radiant heat burner of the apparatus of FIG. 7A;

[0044] FIG. 7F shows a perspective view of the ambient flame burner of the apparatus of FIG. 7A;

[0045] FIG. 8 A shows a side view of another embodiment of a heating apparatus;

[0046] FIG. 8B shows a cross-sectional view of the upper portion of the apparatus of FIG.8A;

[0047] FIG. 8C shows a perspective view of the radiant heat burner of the apparatus of FIG. 8A;

[0048] FIG. 8D shows a perspective view of the heat emitter of the apparatus of FIG. 8 A.

[0049] FIG. 8E shows a diagram of heat radiated by the radiant heat burner of the apparatus of FIG. 8 A;

[0050] FIG. 8F shows a cross-sectional view of ceramic plates for receiving and directing flames emitted by the ambient flame burner of the apparatus of FIG. 8 A; and

[0051] FIG. 9 shows a schematic of an example segmented burner gas control system, according to some embodiments.DETAILED DESCRIPTION

[0052] Gas-fueled heaters have been suggested as potential alternatives to wood firepits due to their ability to generate heat without the negative side-effects (e.g., smoke production, uncontrolled flare-ups, etc.) of burning wood. However, existing gas heaters may use fuel and distribute heat inefficiently. In particular, existing gas heaters are frequently unable to heat sufficiently extensive regions of their surrounding environments, limiting their utility and desirability. For example, many outdoor heaters are designed to focus emitted heat only on narrow regions of space. Tower heaters, for instance, are designed to emit heat downward from the top of a vertical pole. As a result, people standing beneath a tower heater generally feel warmth on their heads and faces, but not on their cores or limbs.

[0053] In addition to their inability to distribute heat widely and efficiently, existing heaters and home firepits lack maneuverability and adaptability. Most outdoor heaters and home firepits (e.g., tower heaters and heaters that are built into dining tables) are both bulky and heavy and, therefore, cumbersome to move. The low portability of such heaters typically makes using theheaters in a variety of different locations difficult.

[0054] Gas heating apparatuses are provided herein that incorporate innovative features to enhance efficiency, safety, versatility, convenience, and aesthetic appeal. The disclosed apparatuses seamlessly integrate powerful heating capabilities that are fuel efficient into a compact design without compromising safety or appearance. The apparatuses can be easily assembled and disassembled, and their sleek, sturdy, and compact design facilitates their portability, making them suitable for a wide range of outdoor settings and activities.

[0055] In some aspects, an apparatus is provided having both a radiant heat emitter and an ambient flame burner, enabling the apparatus to efficiently produce and distribute heat while simultaneously supplying an aesthetically pleasing flame. The ambient flame burner creates a gentle, flickering flame that adds charm and warmth to the surrounding area. Meanwhile, the heat emitter emits a consistent, steady heat that provides warmth to those seated or standing nearby, extending the usability of outdoor spaces when temperatures are low. A strategically positioned heat reflector in combination with the innovative heat emitter may maximize radiant heat output and ensure even heat distribution, reducing fuel consumption and ensuring that the apparatus operates at optimal efficiency.

[0056] The heat emitter may be charged by a radiant heat burner that is distinct from the ambient flame burner. Although the burners are referred to herein as a radiant heat burner and an ambient flame burner, the burners may have the same configuration and both burners may emit flames. The nomenclature is provided to distinguish the burner used to charge the heat emitter from the burner used to emit visible flames. The radiant heat burner and the ambient flame burner may be independently controllable, allowing users to, for example, increase the height of the flames without overheating the surrounding area.

[0057] To further minimize unnecessary fuel consumption, a radiant heat burner of a provided apparatus can be divided into multiple independent sections. For example, a provided apparatus can include an annular radiant heat burner that is divided into two distinct sections, each spanning 180 degrees, each being separately connected to the fuel source, and each being equipped with its own independent control mechanism. This may allow users to independently control the flow of fuel to each section of the burner, and as a result, independently increase or decrease the intensity of the heat emitted by each corresponding section of the heat emitter.

[0058] Certain illustrative embodiments will now be described to provide an overallunderstanding of the structure, function, manufacture, and use of the heating apparatuses disclosed herein. Examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the apparatuses specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present disclosure is defined solely by the claims.

[0059] FIG. 1 shows a block diagram of an exemplary heating system 100. System 100 includes a fuel source 102, an ambient flame burner 104, a heat emitter 104 having a radiant burner 135 and an emitter plate 136, a first thermopile valve 108, a second thermopile valve 110, an igniter 112, and a controller 114. Those skilled in the art will appreciate that, in other embodiments, a heating apparatus can include additional components or features that are not present in system 100 or can exclude components or features that are present in system 100.

[0060] In some embodiments, the fuel source 102 can be a gas fuel source. For example, the fuel source 102 can be a propane fuel source (e.g., a propane tank such as a five-gallon propane tank containing propane) or a butane fuel source. In other embodiments, the fuel source 102 can be another combustible material, for example wood pellets or wood chips. It should be understood, however, that the heating system can utilize any type of fuel source suitable for generating heat via the emitter 104 and flames via the burner 106.

[0061] The system 100 can include a housing (not shown in FIG. 1) that defines an internal volume configured to house the fuel source 102. Alternatively, the fuel source 102 can be located outside of the housing of the system 100, and can be connected to the system 100 by, e.g., a fuel hose or another suitable connector. The housing can be configured to stabilize the system 100 on a support surface (not shown in FIG. 1). For example, the housing can include feet, wheels, or a combination thereof configured to enable the system 100 to be positioned on the ground in an outdoor environment (e.g., on a patio or in a yard). In other embodiments, the housing can be configured to enable the system 100 to be positioned and operated on a tabletop.

[0062] The ambient flame burner 106 can be fluidically coupled to the fuel source 102 via the thermopile valve 108. The thermopile valve 108 can include an electric valve and a thermopile configured to generate a voltage to operate the valve. Similarly, the heat emitter 104 can be fluidically coupled to the fuel source 102 via the thermopile valve 110 which, like the thermopile valve 108, can include an electric valve and a thermopile configured to generate a voltage to operate the valve.

[0063] The igniter 112 is positioned along a fluidic flow path between the fuel source 102 and the thermopile valves 108, 110. The igniter 112 is configured to ignite fuel from the fuel source 102 in the ambient flame burner 106 and the heat emitter 104. The igniter 112 can be any suitable device or combination of devices capable of generating sparks to ignite the fuel, for example a battery-powered igniter or a piezoelectric igniter.

[0064] While a single igniter 112 is depicted in FIG. 1, it will be apparent to those skilled in the art that any suitable number of igniters can be used. In some embodiments, the heating system 100 includes a first igniter positioned along a fluid flow path between the fuel source 102 and the thermopile valve 108 and a second igniter positioned along a fluid flow path between the fuel source 102 and the thermopile valve 110. The first igniter can be configured to ignite fuel from the fuel source 102 in the ambient flame burner 106 and the second igniter can be configured to ignite fuel in the heat emitter 104.

[0065] The controller 114 can include one or more user controls configured to operate the igniter 112 and the thermopile valves 108, 110 to control the ambient flame burner 106 and the heat emitter 104. In some embodiments, the controller 114 enables the burner 106 and the heat emitter 104 to be controlled independently of one another. In other embodiments, the controller 114 controls the burners 104 simultaneously.

[0066] The ambient flame burner 106, when ignited, can be configured to produce visible flames. To light the ambient flame burner 106, the controller 114 can be used to cause the igniter 112 to ignite fuel from the fuel source 102. The thermopile valve 108 can be arranged such that heat from the fuel ignited by the igniter 112 increases the temperature of the thermopile of the thermopile valve 108, causing the thermopile to generate a voltage. This voltage, in turn, causes the electric valve of the thermopile valve 108 to open, allowing the burning fuel to flow into the ambient flame burner. After the ambient flame burner 106 is lit, the controller 114 can be used to increase, decrease, or cut off the flow of fuel from the fuel source 102 into the ambient flame burner 106 to increase the size of the flames, decrease the size of the flames, or turn off the burner.

[0067] As indicated above, the heat emitter 104 can include a radiant heat burner 135 and an emitter plate 136. The emitter plate 136 can at least partially surround the radiant heat burner 135. When the radiant heat burner 135 is ignited, the heat emitter 104 can be configured to radiate heat in a direction normal to the outer surface of the emitter plate 136. To light the radiant heat burner 135, the controller 114 can be used to cause the igniter 112 to ignite fuel from thefuel source 102. The thermopile valve 110 can be arranged such that heat from the fuel ignited by the igniter 112 increases the temperature of the thermopile of the thermopile valve 110, causing the thermopile to generate a voltage. This voltage, in turn, causes the electric valve of the thermopile valve 110 to open, allowing the burning fuel to flow into the burner 135. After the radiant heat burner 135 is lit, the controller 114 can be used to increase, decrease, or cut off the flow of fuel from the fuel source 102 into the radiant heat burner 135 to increase the amount of radiated heat, decrease the amount of radiated heat, or turn off the burner.

[0068] FIGS. 2A-2C show an exemplary propane heating apparatus 200. FIGS. 3A-3E, 4, and 5A-5D show various portions and components of the apparatus 200. As described in further detail below, the apparatus 200 has a compact, minimalistic design, which enhances portability and aesthetic appeal, and leverages an innovative dual-burner arrangement, which enables the apparatus 200 to provide both fuel-efficient heating and atmospheric flames.

[0069] As shown in FIGS. 2A-2C, the main body of the apparatus 200 is defined by a housing 216. The housing 216 is cylindrical in shape and can be formed from any suitable material or combination of materials, for example stainless steel, cast iron, carbon steel, or plastic. In the illustrated embodiment, the housing 216 is cylindrical in shape, though it will be apparent to those skilled in the art that the housings of the disclosed heating apparatuses can have any suitable shape, such as square, rectangular, etc.

[0070] An upper portion of the apparatus 200 can be capped with a lid 218, as illustrated in FIGS. 2A-2B. The lid 218 is removable and includes a handle 220 that extends from its top surface. The lid 218 may be placed on the apparatus 200 when the apparatus 200 is not in use to (for example) shield the internal components of the apparatus 200 from moisture, dirt, or other undesirable elements. The lid 218 can be formed from the same material(s) as the housing 216, or from a different material or combination of materials. As shown in FIGS. 2A-2B, the lid 218 is shaped such that, when placed atop the housing 216, its side surface aligns with the side surface of the housing 216. In the illustrated embodiment, the lid 218, like the housing 216, is cylindrical in shape.

[0071] As shown in FIG. 2 A, a controller 214 is arranged on the outer surface of the housing216 on one side (referred to hereinafter as the “front” side) of the apparatus 200. The controller 214 can include a pair of vertically stacked control knobs 214a, 214b. The controller 214 can perform functions similar to those performed by the controller 114 described above with respect to FIG. 1. Additional details about the functions of the controller 214 can be found below in thediscussion of FIGS. 3B-3E.

[0072] A pair of wheels 222 (FIG. 2 A) can be connected to an outer bottom surface of the housing 216 near the front side of the apparatus 200. The wheels 222 enable the apparatus 200 to be easily maneuvered around on a support surface (e.g., the ground). The outer surfaces of the wheels 222 can be sufficiently rugged so as to allow the apparatus 200 to be easily moved over varied and uneven surfaces. In some embodiments, the wheels 222 are configured to be interchanged with other wheels of a different ruggedness. To facilitate movement of the apparatus 200, the apparatus 200 can include a collapsing, hinged, or flip-up handle 238 (FIG. 2C) that enables the apparatus 200 to tilted onto the wheels 222 and pushed or pulled along a surface.

[0073] A pair of feet 226 (FIGS. 2B-2C) can be connected to the outer bottom surface of the housing 216 near the side of the apparatus 200 that is opposite the front side (referred to hereinafter as the “back” side). The feet 226 stabilize the apparatus 200 on the support surface (e.g., the ground) when the apparatus 200 is not being moved. The feet 226 also prevent the apparatus 200 from rolling freely on the wheels 222 if, for example, the apparatus 200 is positioned on an inclined surface or the apparatus 200 is exposed to a strong wind.

[0074] While the size of the apparatus can vary significantly, in one embodiment the height of the apparatus 200, measured from the wheels 222 and the feet 226 to the top surface of the lid 218, can be between 50 cm and 300 cm, for example about 80 cm, about 90 cm, about 100 cm, about 110 cm, about 120 cm, about 130 cm, about 140 cm, or about 150 cm. In some embodiments, the height of the apparatus 200 is between 70 cm and 100 cm, for example about 72 cm, about 72.2 cm, about 72.4, about 72.6 cm, about 72.8 cm, or about 73 cm. The diameter of the apparatus 200 can be between 20 cm and 100 cm, for example about 25 cm, about 35 cm, about 45 cm, about 55 cm, about 65 cm, about 75 cm, about 85 cm, or about 95 cm. In some embodiments, the diameter of the apparatus 200 is between 45 cm and 55 cm, for example about 50 cm, about 50.2 cm, about 50.4 cm, about 50.6 cm, about 50.8 cm, or about 51 cm.

[0075] An opening to an internal volume 228 that is covered by a door 224 (FIG. 2B) can be formed in the housing 216 on the back side of the apparatus 200. The internal volume 228 is configured to contain a fuel source (e.g., a propane fuel source such as a five-gallon propane tank). As shown in FIG. 2C, the bottom surface 230 of the housing 216 includes a central hole 231 into which a bottom portion of a fuel tank can be inserted. Also contained within the internal volume 228 is a fuel control system 240 configured to facilitate the flow of fuel from a fuel source contained in the internal volume 228 to various components of the apparatus 200.

[0076] In addition to the fuel source and the fuel control system 240, the internal volume 228 can be configured to contain the handle 238 when the apparatus 200 is not being transported or repositioned. When a user wishes to move the apparatus 200, the user can rotate or flip the handle 238 out of the internal volume 228 into an upright position (not shown) and then use the handle 238 to push, pull, lift, or otherwise maneuver the apparatus 200.

[0077] An emitter guard 232 (FIG. 2C) can be disposed beneath the lid 218 and it can be connected to an upper edge of the housing 216. A heat emitter 204 can be disposed radially inward of the emitter guard 232. The emitter guard 232 can be in the form of a grate or otherwise cage-like structure that surrounds the heat emitter 204, thereby forming a barrier between users of the apparatus 200 and the heat emitter 204. The emitter guard 232 can also be used to grip, lift, and carry the apparatus 200 when the apparatus 200 is not in operation (that is, when the flow of fuel from the fuel source is turned off, no flames are present, and the emitter guard 232 is cool to the touch and safe to handle). The emitter guard 232 may therefore enable the apparatus 200 to, e.g., be easily moved over terrain that is too uneven to allow the apparatus to be rolled on the wheels 222, or to be loaded into a vehicle for transport.

[0078] In the illustrated embodiment, a metal screen 234 is positioned above the heat emitter 204. The metal screen 234 can form a barrier between users of the apparatus 200 and an ambient flame burner (not shown in FIGS. 2A-2C) of the apparatus 200. In some embodiments, the metal screen 234 is removable, for example to allow a region surrounding the ambient flame burner (not shown in FIGS. 2A-2C) to be filled with aesthetically pleasing fire media (e.g., rocks). Additional details about such fire media are provided below with reference to, e.g., FIG. 8F. In other embodiments, a heating apparatus may not include a metal screen.

[0079] FIGS. 3A-3G show various views of the heat emitter 204 and an ambient flame burner 306 of the propane heating apparatus 200. The heat emitter 204 is configured to emit radiant heat and can include one or more features of the heat emitter 104 of system 100 described above with respect to FIG. 1. The ambient flame burner 306 is configured to produce visible flames and can include one or more features of the ambient flame burner 106 of system 100 described above with respect to FIG. 1.

[0080] In the disclosed heating apparatuses, the heat emitter and the ambient flame burner can be positioned proximate to an upper portion of the apparatus housing and can be arranged concentrically with respect to one another such that one of the heat emitter and the ambient flame burner is disposed radially inward of the other. FIG. 3 A depicts the ambient flame burner 306positioned (from a top-down perspective) radially inward of the heat emitter 204, with the ambient flame burner 306 arranged concentrically with respect to the heat emitter 204 such that the ambient flame burner 306 is disposed radially inward of the heat emitter 204. It will be apparent to those skilled in the art that, in other embodiments, the heat emitter 204 can be disposed radially inward of the ambient flame burner 306.

[0081] While the ambient flame burner and the heat emitter can be arranged concentrically with respect to one another when viewed from a top-down perspective (e.g., as are the emitter 204 and the burner 306 in FIG. 3 A), the ambient flame burner and the heat emitter can be positioned in the same horizontal plane or in different horizontal planes when viewed from a side perspective. In some heating apparatus embodiments, the heat emitter and the ambient flame burner can be positioned in distinct horizontal planes. That is, in some embodiments, the heat emitter can be positioned in a first horizontal plane or region and the ambient flame burner is positioned in a second horizontal plane or region that is higher in vertical space than the first horizontal plane (or vice versa). In other embodiments, the ambient flame burner can be positioned within the same horizontal plane or space as the heat emitter (e.g., the ambient flame burner and the heat emitter can be horizontally aligned). For example, in some embodiments, the ambient flame burner can be positioned at a vertical height that is below a vertical height of an upper edge of the heat emitter and above a vertical height of a lower edge of the heat emitter. For example, in the apparatus 200, as shown in detail in FIG. 5A, the ambient flame burner 306 is positioned in a first horizontal plane (indicated by the dashed line P±) that is below a second horizontal plane (indicated by the dashed line P2) that is parallel to an upper edge of the heat emitter 204 and above a third horizontal plane (indicated by the dashed line P3) that is parallel to a lower edge of the heat emitter 204. Positioning the ambient flame burner 306 both radially inward from and in vertical space within the heat emitter 204 provides the apparatus 200 with a compact design that enables the apparatus 200 to produce both radiant heat and visible flames while also being easily portable and allows users to gather around the visible flames without the flames being so high that they block views across the apparatus, enhancing the social benefits of the apparatus.

[0082] As indicated in FIG. 3 A, the heat emitter 204 can include a radiant heat burner 335 and a emitter plate 336. The radiant heat burner 335 can be configured to couple to a fuel source housed in the housing 216. The emitter plate 336 can surround the radiant heat burner 335 and, when the burner 335 is ignited, can be configured to direct radiant heat emitted by the burner 335 in a direction normal to an outer surface of the emitter plate 336. In this way, the burner 335 cancharge the emitter plate 336 with energy that is then radiated by the emitter plate 336 as warming heat to users of the apparatus 200.

[0083] The radiant heat burner 335, as illustrated in FIGS. 3B-3E, is an annular burner. In other embodiments of the disclosed heating apparatuses, the radiant heat burner can be a plateshaped burner or another suitable burner. The radiant heat burner 335 has a radius R . The radius 7?! can be between 5 cm and 50 cm, for example about 10 cm, about 15 cm, about 20 cm, about 25 cm, about 30 cm, about 35 cm, about 40 cm, or about 45 cm.

[0084] A plurality of outlet holes 344 are formed in an upper surface (that is, the surface that faces upward when the apparatus 200 is positioned with the wheels 222 and the feet 226 on the ground - see FIGS. 2A-2C) of the burner 335. When the radiant heat burner 335 is lit, visible flames are emitted via the outlet holes 344. The number of outlet holes in a radiant heat burner can vary based on, e.g., the radius of the radiant heat burner. In various embodiments, the radiant heat burner of a heating apparatus can include at least 50, at least 75, at least 100, at least 125, or at least 150 outlet holes.

[0085] The total number of outlet holes 344 in the burner 335 can be such that the port loading of the burner 335 is optimized. The port loading of the burner 335 is the ratio of the total amount of heat generated by the burner 335 (measured in, e.g., BTUs) to the cumulative port area (that is, the product of the open area of a single outlet hole and the total number of outlet holes 344). Optimizing the port loading of the burner 335 ensures that the amount of oxygen available to the burner 335 when the burner 335 is ignited is sufficient for complete combustion to occur, thereby optimizing the fuel efficiency of the burner 335.

[0086] In the illustrated embodiment, the outlet holes 344 have an elongate, rectangular slot shape and are arranged in a staggered pattern, as shown in FIG. 3E. Each outlet hole has a width w and a length I. The width w can be between 0.1 cm and 1 cm, for example about 0.05 cm, about 0.1 cm, about 0.11 cm, about 0.12 cm, about 0.13 cm, about 0.14 cm, 0.15 cm, about 0.2 cm, about 0.25 cm, about 0.3 cm, about 0.35 cm, about 0.4 cm, about 0.45 cm, or about 0.5 cm. Importantly, the range of outlet hole widths specified herein can be essential for significantly reducing the likelihood of a flame traveling backwards through the port, whereas a width outside the specified range may fail to protect against such occurrence. The length I can be greater than or equal to the width w. In some embodiments, the length I is between 0.5 cm and 5 cm, for example about 0.6 cm, about 0.7 cm, about 0.8 cm, about 0.9 cm, about 1 cm, about 1.5 cm, about 2 cm, about 2.5 cm, about 3 cm, about 3.5 cm, or about 4 cm.

[0087] In some heating apparatus embodiments, the geometry of the outlet holes in the radiant heat burner can differ from the geometry of the outlet holes 344 in the illustrated radiant heat burner 335. For example, in some embodiments, the outlet holes can have an elongate oval shape. Moreover, while the outlet holes 344 of the illustrated radiant heat burner 335 are identical in shape and size, in other embodiments, the radiant heat burner can have outlet holes that vary in shape and / or size.

[0088] Adjacent outlet holes of the plurality of outlet holes 344 are separated by a distance x. The separation distance x can be between 0.25 cm and 10 cm, for example about 0.5 cm, about 0.75 cm, about 1 cm, about 2 cm, about 3 cm, about 4 cm, or about 5 cm. In some embodiments, the separation distance x is between about .4 cm and about .45 cm, for example about .41 cm, about .42 cm, about .43 cm, or about .44 cm. In the radiant heat burner 335, the separation distance x between each adjacent pair of outlet holes is the same. In other heating apparatus embodiments, the separation distance between adjacent outlet holes in the radiant heat burner can vary. For example, in some heating apparatus embodiments, an outlet hole may be separated from a first adjacent outlet hole by a first separation distance and separated from a second adjacent outlet hole by a second separation distance that is different from the first separation distance.

[0089] The radiant heat burner 335 has numerous possible implementations. A first embodiment of the radiant heat burner 335 is illustrated in FIG. 3B. In this embodiment, the radiant heat burner 335 comprises a continuous circular (i.e., 360-degree) portion 335a. A fuel tube 342 is fluidically coupled to the circular portion 335a (e.g., via an inlet into the circular portion 335a). The fuel tube 342 can be any member, element, structure, or device comprising a lumen, passageway, bore, or other suitable throughway through which fuel can flow into the burner 335. For example, the fuel tube 342 can be a rigid pipe, a flexible tube, or a combination thereof. In FIG. 3B, the fuel tube 342 extends from an inner side of the burner 335 toward the center of the region encircled by the burner 335, though one skilled in the art would understand that the fuel tube can be arranged in any suitable manner. The fuel tube 342 can be configured to connect to a fuel source contained in the housing 216 of the apparatus 200 (see, e.g., FIG. 2B). Fuel from the fuel source can be provided to the circular portion 335a of the burner 335 via the fuel tube 342.

[0090] A second embodiment of the radiant heat burner 335 is illustrated in FIG. 3C. In this embodiment, the radiant heat burner 335 comprises a continuous circular (i.e., 360-degree)portion 335a that is similar to the continuous circular portion of the embodiment illustrated in FIG. 3B. Apair of fuel tubes 342a, 342b are fluidically coupled to the circular portion 335a (e.g., via inlets into the circular portion 335a). The fuel tubes 342a, 342b can be any member, element, structure, or device comprising a lumen, passageway, bore, or other suitable throughway through which fuel can flow into the burner 335. For example, the fuel tubes 342a, 342b can be a rigid pipe, a flexible tube, or a combination thereof. In FIG. 3C, the fuel tubes 342a, 342b extend from opposed inner sides of the burner 335 toward the center of the region encircled by the burner 335, though one skilled in the art would understand that the fuel tubes can be arranged in any suitable manner. The fuel tubes 342a, 342b can each be configured to connect to a fuel source contained in the housing 216 of the apparatus 200 (see, e.g., FIG. 2B). Fuel from the fuel source can be provided to the circular portion 335a of the burner 335 via one of the two fuel tubes 342a, 342b individually or via both fuel tubes 342a, 342b simultaneously. The two fuel tubes 342a, 342b can enable greater amounts of fuel to be provided to the burner 335, thereby increasing the maximum heat output of the burner 335. It should be understood that the radiant heat burner shown in FIG. 3C can include additional fuel tubes as well, thus increasing the amount of fuel provided to the burner even further.

[0091] A third embodiment of the radiant heat burner 335 is illustrated in FIG. 3D. In this embodiment, the radiant heat burner 335 comprises two semi-circular (i.e., 180-degree) portions 335a, 335b. A first fuel tube 342a is fluidically coupled to the first portion 335a and a second fuel tube 342b is fluidically coupled to the second portion.). The fuel tubes 342a, 342b can be any member, element, structure, or device comprising a lumen, passageway, bore, or other suitable throughway through which fuel can flow into the burner 335. For example, the fuel tubes 342a, 342b can be a rigid pipe, a flexible tube, or a combination thereof. In FIG. 3D, the fuel tubes 342a, 342b extend from opposed inner side surfaces of the radiant heat burner 335 toward the center of the region encircled by the radiant heat burner 335, though one skilled in the art would understand that fuel tubes can be arranged in any suitable manner. The first fuel tube 342a and the second fuel tube 342b are configured to independently connect to a fuel source contained in the housing 216 of the apparatus 200 (see, e.g., FIG. 2B). Fuel from the fuel source can be provided to the first portion 335a of the radiant burner 335 via the first fuel tube 342a. Similarly, fuel from the fuel source can be provided to the second portion 335b of the radiant burner 335 via the second fuel tube 342b. The first portion 335a and the second portion 335b are fluidically isolated from one another such that fuel received by the first portion 335a remains contained in the first portion 335a (i.e., does not flow into the second portion 335b) and fuel received by the second portion 335b remains contained in the second portion 335b (i.e., does not flow into thefirst portion 335a). This enables the heat output of the first portion 335a to be controlled independently of the heat output of the second portion 335b such that corresponding portions of the emitter plate 336 can be independently charged with varying levels of energy to emit different amounts of heat. In some embodiments, the radiant heat burner 104 shown in FIG. 3D can include additional fuel tubes coupled to either one or both of the semi-circular portions of the burner, thus increasing the amount of fuel supplied thereto.

[0092] Like the radiant heat burner 335, the ambient flame burner 306 is an annular burner, as shown in FIG. 3F. In other embodiments of the disclosed heating apparatuses, the ambient flame burner can be a plate-shaped burner or another suitable burner. The ambient flame burner 306 has a radius R2that is less than the radius of the radian heat burner 335. The radius R2can be between 2 cm and 30 cm, for example about 5 cm, about 8 cm, about 10 cm, about 12 cm, about 14 cm, about 16 cm, about 18 cm, or about 20 cm.

[0093] A plurality of outlet holes 348 are formed in the burner 306. In the illustrated implementation, the outlet holes 348 are formed in an upper surface (that is, the surface that faces upward when the apparatus 200 is positioned with the wheels 222 and the feet 226 on the ground - see FIGS. 2A-2C) of the burner 306. In other implementations, the positioning of the outlet holes 348 can differ from the positioning of the outlet holes 348 shown in FIG. 3F. Adjusting the positioning of the outlet holes 348 around an outer radius of the burner 306 can optimize flame size and wind resistance. For example, in some embodiments, the outlet holes 348, rather than being formed in an upper surface of the burner 306 as shown in FIG. 3F, can be formed on along an inner diameter of the burner 306 such that the outlet holes 348 face inwards toward the center of the burner 306 (and, thus, the center of the apparatus 200).

[0094] When the ambient flame burner 306 is lit, visible flames are emitted via the outlet holes 348. The number of outlet holes in an ambient flame burner can vary based on, e.g., the radius of the ambient heat burner. In various embodiments, the ambient flame burner of a heating apparatus can include at least 50, at least 75, at least 100, at least 125, or at least 150 outlet holes.

[0095] The total number of outlet holes 348 in the burner 306 can produce a port loading of the burner 348 that is such that yellow- or orange-colored flames are emitted by the burner 306. The port loading of the burner 306 is the ratio of the total amount of heat generated by the burner 306 (measured in, e.g., BTUs) to the cumulative port area (that is, the product of the open area of a single outlet hole and the total number of outlet holes 348). Configuring the port loading of the burner 306 ensures that the amount of oxygen available to the burner 306 when the burner 306 isignited is less than what is sufficient for complete combustion to occur, thereby enabling the burner 306 to produce aesthetically pleasing flames.

[0096] As shown in FIG. 3G, the outlet holes 348 include a combination of circular outlet holes 348a and elongate, rounded-rectangular slot shaped holes 348b. This configuration of outlet holes enables the creation of natural, uniformly distributed flames by the ambient flame burner 306. Each circular outlet hole 348a has a diameter dj. The diameter di can be between 0.1 cm and 1 cm, for example about 0.15 cm, about 0.2 cm, about 0.25 cm, about 0.3 cm, about 0.35 cm, about 0.4 cm, about 0.45 cm, or about 0.5 cm. Each elongate hole 348b has a length d2that is greater than the diameter dj of the circular holes 348a. In some embodiments, the length d2is between 0.5 cm and 5 cm, for example about 0.6 cm, about 0.7 cm, about 0.8 cm, about 0.9 cm, about 1 cm, about 1.5 cm, about 2 cm, about 2.5 cm, about 3 cm, about 3.5 cm, or about 4 cm.

[0097] Each elongate hole 348b is positioned between a pair of circular holes 348a. Each elongate hole 348b is separated from the adjacent circular holes 348b by a separation distance y . The separation distance yxcan be between 0.25 cm and 10 cm, for example about 0.5 cm, about 0.75 cm, about 1 cm, about 2 cm, about 3 cm, about 4 cm, or about 5 cm. Adjacent circular holes 348a are separated from one another by a separation distance y2that is greater than or equal to the separation distance y between each elongate hole 348b and its adjacent circular holes 348b. In some embodiments, the separation distance y2is between 1 cm and 25 cm, for example about 2 cm, about 4 cm, about 6 cm, about 8 cm, or about 10 cm. It will be apparent to those skilled in the art that, in other heating apparatus embodiments, the separation distance between elongate outlet holes and adjacent circular outlet holes in the ambient flame burner and / or the separation distance between adjacent circular outlet holes can vary. For example, in some heating apparatus embodiments, an outlet hole may be separated from a first adjacent outlet hole by a first separation distance and separated from a second adjacent outlet hole by a second separation distance that is different from the first separation distance.

[0098] As shown in FIG. 3E, a fuel tube 346 is fluidically coupled to the ambient flame burner 306. The fuel tube 346 can be any member, element, structure, or device comprising a lumen, passageway, bore, or other suitable throughway through which fuel can flow into the burner 306. For example, the fuel tube 346 can be a rigid pipe, a flexible tube, or a combination thereof. In the illustrated embodiment, the fuel tube 346 extends perpendicularly from a lower surface (that is, the surface that faces downward when the apparatus 200 is positioned with the wheels 222 and the feet 226 on the ground - see FIGS. 2A-2C) of the burner 306, though oneskilled in the art would understand that the fuel tube 346 can be arranged in any suitable manner. The fuel tube 346 is configured to connect to a fuel source contained in the housing 216 of the apparatus 200 (see, e.g., FIG. 2B). Fuel from the fuel source can be provided to the ambient flame burner 306 via the fuel tube 346.

[0099] The controller 214 of the apparatus 200 (shown in FIG. 2A) can include one or more controls (e.g., one or more of control knobs 214a, 214b) configured to adjustably control a provision of fuel from the fuel source to the radiant heat burner 335 and the ambient flame burner 306 independently from one another. If the radiant heat burner 335 includes a single, continuous circular portion and a single fuel tube (e.g., as illustrated in FIG. 3B), the controller 214 can include one control for controlling a provision of fuel to the fuel tube of the radiant heat burner 335 and one control for controlling a provision of fuel to the fuel tube the ambient flame burner 306. If the radiant heat burner 335 includes a single, continuous circular portion and two fuel tubes (e.g., as illustrated in FIG. 3C) or two, semi-circular portions and two fuel tubes (e.g., as illustrated in FIG. 3D), the controller 214 can include a first control for controlling a provision of fuel to the first fuel tube of the radiant heat burner, a second control for controlling a provision of fuel to the second fuel tube of the radiant heat burner, and a third control for controlling a provision of fuel to the fuel tube of the ambient flame burner 306. The controller 214 can be configured to independently operate valves (e.g., valves similar to the thermopile valve 108 of the system 100 shown in FIG. 1) that are fluidically coupled to (or included within) the fuel tubes of the radiant heat burner 335 and the ambient flame burner 306 to increase or decrease a provision of fuel from the fuel source to the burner 335 and the burner 306.

[0100] FIG. 4 shows a perspective view of an example fuel control system 240 for the apparatus 200. The depicted fuel control system 240 is configured to transport fuel from a fuel source contained in the housing 216 of the apparatus (see FIGS. 2A-2C) to a radiant heat burner with a continuous circular portion and two fuel tubes 342a, 342b (see FIGS. 3C) and an ambient flame burner with a single fuel tube 346 (see FIG. 3F). A gas inlet 456 is configured to connect to the fuel source. A manifold 450 connects the gas inlet 456 to gas outlets 451a, 451b, and 451c. The outlet 451a is connected by a manifold 452a to an outlet 458a that is configured to connect to the fuel tube 342a of the radiant heat burner 335 (FIG. 3C), the outlet 451b is connected by a manifold 452b to an outlet 458b that is configured to connect to the fuel tube 342b of the radiant heat burner 335 (FIG. 3C), and is the outlet 451c connected by a manifold 454 to an outlet 460 that is configured to connect to the fuel tube 346 of the ambient flame burner 306 (FIG. 3F). The manifolds 450, 452a-b, and 454 can be element comprising a suitable passageway through whichfuel can travel, for example a rigid pipe or a flexible hose.

[0101] The flow of fuel through the fuel control system 240 is controlled using the controller 214, which includes a control knob 214a and a control knob 214b. The control knob 214a is operatively coupled to a valve arranged in or upstream of the outlet 451c and to an ignition switch. Rotating the control knob 214a in a first direction (e.g., clockwise) may open the valve and allow fuel to flow from the manifold 450, through the manifold 454, and into the ambient flame burner 306 via the fuel tube 346 (see FIG. 3F). Pressing the knob inward (e.g., toward the housing (not shown in FIG. 4) of the apparatus) while the valve in the outlet 451c is open may activate the ignition switch, causing the switch to generate a spark that ignites the fuel flowing through the outlet 451c. Rotating the control knob 214a in a second direction (e.g., counterclockwise) may close the valve, stemming the flow of fuel into the manifold 454. Similarly, the control knob 214b is operatively coupled to a valve arranged upstream of the outlets 451a, 451b and to an ignition switch. Rotating the control knob 214b in a first direction (e.g., clockwise) may open the valve and allow fuel to flow from the manifold 450, through the manifolds 452a, 452b, and into the radiant heat burner 335 via the fuel tubes 342a, 342b (see FIG. 3C). Pressing the knob inward (e.g., toward the housing (not shown in FIG. 4) of the apparatus) while the valve is open may activate the ignition switch, causing the switch to generate a spark that ignites the fuel flowing through the outlets 451a, 451b. Rotating the control knob 214b in a second direction (e.g., counterclockwise) may close the valve, stemming the flow of fuel into manifolds 452a, 452b.

[0102] The top surface of the housing 216 includes a circumferential rim portion 570 and a central frustoconical portion 571. Connected to the outer edge of the rim portion 570, encircling the upper portion of the apparatus 200, is the emitter guard 232.

[0103] The emitter plate 336 of the heat emitter 204 is disposed radially inward of the emitter guard 232 adjacent to the inner edge of the rim portion 570. Disposed radially inward of the emitter plate 336 is the radiant heat burner 335. As shown, the fuel tubes 342a, 342b extend inward toward the center of the apparatus 200, where they respectively connect to the fuel tube connectors 458a, 458b of the fuel tubes 452a, 452b (see FIG. 4). The heat reflector 566 is disposed radially inward of the radiant heat burner 335, and the ambient heat burner 306 is disposed radially inward of the heat reflector 566. A magnified cross-sectional view showing the arrangement of the emitter plate 336, the radiant heat burner 335, and the heat reflector 566 is provided in FIG. 5B.

[0104] The frustoconical portion 571 of the top surface of the housing 216 extends vertically upward through the region encircled by the heat reflector 566. Connected to the upper surface of the frustoconical portion 571 is a bowl-shaped cover plate 568. Arranged within the bowl-shaped cover plate 568 is the ambient flame burner 306. The fuel tube 346 of the ambient flame burner 306 extends vertically downward through the bowl-shaped cover plate 568 and the upper surface of the frustoconical portion 571 to connect to the fuel tube connector 460 of the fuel tube 454 (not shown in FIG. 5A; see FIG. 4). The screen 534 can be (removably) connected to the upper rim of the bowl-shaped cover plate 568 and can cover the opening of the bowl-shaped cover plate 568.

[0105] A perspective view of the heat reflector 566 is provided in FIG. 5C. As shown, the heat reflector 566 includes a vertical surface 566a and an angled surface 566b. The vertical surface 566a aligns with the longitudinal axis of the apparatus 200. The angled surface 566b is joined to the upper edge of the vertical surface 566a and flares outward from the vertical surface 566a at an angle 0. The angle 0 between the vertical surface 566a and the angled surface 566b can be greater than or equal to 90° and less than 180°, for example about 100°, about 110°, about 120°, about 130°, about 140°, about 150°, about 160°, or about 170°. In some embodiments, the angle 0 between the vertical surface 566a and the angled surface 566b is between about 145° and about 150°, for example about 146°, about 147°, about 148°, or about 149°. As a result of the angled surface 566a, the heat reflector 566 extends at least partially above the radiant heat burner 335, as shown in FIGS. 5A-5B.

[0106] The heat reflector 566 is configured to reflect heat emitted by the radiant heat burner 335 toward the emitter plate 336, ensuring the heat is distributed efficiently into the environment surrounding the apparatus 200. As shown in FIG. 5D, the emitter plate 336 can include an upper portion 336a and a lower portion 336b that bulges outward relative to the upper portion 336a. The upper portion 336a and part of the lower portion 336a are perforated with a plurality of outlet holes 572. The holes 572 are configured to direct heat that is reflected toward the emitter plate 336 by the heat reflector out of the apparatus in a direction normal to the outer surface of the emitter plate 336.

[0107] In some embodiments, one or more of the outlet holes 572 shown in FIG. 5D can be covered or not formed at all in the upper portion 336a of the emitter plate 336. For example, one or more horizontal rows of the outlet holes 572, one or more vertical columns of the outlet holes 572, or selected individual outlet holes 572 shown in FIG. 5D can be covered or not formed at allin the upper portion 336a of the emitter plate 336. Selectively covering or not forming subset(s) of the outlet holes 572 in the emitter plate 336 can prevent wind or debris from passing into the upper portion 572 from the environment outside the apparatus 200. For instance, covering or not forming the lower-most three horizontal rows of the outlet holes 572 (that is, the horizontal rows containing the outlet holes 572a, 572b, and 572c, respectively) shown in the emitter plate 336 illustrated in FIG. 5D can shield flames generated by the radiant heat burner 335 and a thermopile corresponding to the radiant heat burner 335 (e.g., the thermopile valve 110 depicted in FIG. 1) from wind in the outside environment, preventing the flames from being undesirably extinguished. In the disclosed apparatuses, the radiant heat burner, in combination with the heat reflector and the heat emitter, can produce a heated region that surrounds the apparatus housing. A diagram of an exemplary heated region that can be generated by a heat emitter 604 of an example heating apparatus 600 is provided in FIG. 6A. As shown, the heated region can be such that:

[0018] at a radial distance from the outer surface of the apparatus housing, between the height h0of the bottom surface of the apparatus 600 and a height ht above the bottom surface of the housing, the radiant flux produced by the heat emitter 604 is less than a first threshold flux value

[0109] between a radial distance r2and a radial distance r3from the outer surface of the apparatus housing, between a height h2above the bottom surface of the housing and a height h3above the bottom surface of the housing, the radiant flux $ produced by the radiant heat burner 604 is greater than or equal to a second threshold flux value <b2that is greater than the first threshold flux value

[0110] at a radial distance r4from the outer surface of the apparatus housing, above a height h4above the bottom surface of the housing, the radiant flux produced by the radiant heat burner 604 is less than a third threshold flux value <b3that is less than the second threshold flux value[01 1 1] at a radial distance r5from the outer surface of the apparatus housing, above a height h5above the bottom surface of the housing, the radiant flux $ produced by the heat emitter 604 is negligible.

[0112] In some embodiments, the heated region is such that rx= r2= r3= r4= r5= r. For example, the heated region can be such that, at a radial distance T = r2= r3= r4= r5= r «1 m from the outer surface of the apparatus housing:

[0113] between the height h0of the bottom surface of the apparatus 600 and a height h « 20 cm above the bottom surface of the housing, the radiant flux produced by the heat emitter 604 is less than250 W / m2;

[0114] between a height h2« 40 cm above the bottom surface of the housing and a height h3« 120 cm above the bottom surface of the housing, the radiant flux produced by the heat emitter 604 is greater than or equal to <P2® 400 W / m2;

[0115] above a height h4« 140 cm above the bottom surface of the housing, the radiant flux produced by the heat emitter 604 is less than <b3« 250 W / m2; and

[0116] above a height h5« 150 cm above the bottom surface of the housing, the radiant flux produced by the heat emitter 604 is negligible.

[0117] In some embodiments, the heated region produced by the radiant heat burner 604 can have a maximum radiant flux between the height h2above the bottom surface of the housing and the height h3above the bottom surface of the housing. For example, if h2« 40 cm and h3« 120 cm, the region in which the radiant flux is maximized may be between approximately 70 cm above the bottom surface of the housing and approximately 90 cm above the bottom surface of the housing.[Oi l 8] In FIG. 6A, an exemplary user 10 is depicted standing beside the apparatus 600. As shown, the region between the height h2above the bottom surface of the housing and the height h3above the bottom surface of the housing wherein the radiant flux produced by the heat emitter 604 is greater than or equal to the second threshold flux value <P2maY extend between the shins 5 of the user 10 and the chin 15 of the user 10. In other embodiments, the region between the height h2above the bottom surface of the housing and the height h3above the bottom surface of the housing wherein the radiant flux produced by the heat emitter 604 is greater than or equal to the second threshold flux value <J2may extend between the shins and the chin of a user who is seated (e.g., in a chair) beside the apparatus 600.

[0119] In some embodiments, the heat emitter 604 produces a heated region having a toroidal or toroid-like shape that surrounds the apparatus housing. A cross-sectional shape of the heated region can be, for example, approximately triangular or approximately circular-sector shaped. As a result of the disclosed ambient heat burner and radiant heat burner arrangement, an optimalheated region for providing warmth to users seated or standing around the apparatus 600 is achieved. Unlike devices that only produce an ambient flame, where significant heat is lost in the region above the flame, or devices having only a radiant heat source, such as a tower stand heater, where heat is substantially focused only downward towards the heads of users, apparatus 600 provides both a visual ambient flame and heated region surrounding the apparatus 600 that warm the entire body of the user, from at least the shins to chin region.

[0120] Importantly, the heated region extending outwardly from the heat emitter 604, as specified above (e.g., approximately 40 cm above a bottom surface of the housing and approximately 120 cm above the bottom surface of the housing), within which the radiant flux is at least 400 W / m2, provides an optimal heating range from approximately the user’s chin to approximately the user’s shins. Testing conducted by the inventors has revealed that a heat output having the specified radiant flux of at least 400 W / m2applied to the user’s body approximately between the chin and shins results in optimized heating experience while positioned approximately 1 meter from an outer surface of the housing.

[0121] FIG. 6B shows a map of the radiant heat flux (measured in kW / m2) produced by an example heating apparatus 600 when the radiant heat burner and the ambient flame burner of the heating apparatus 600 are ignited. Overlaid on the heat flux map are diagrams of a seated user 10A and a standing user 10B. As shown, within a radial distance of approximately 1.15 m from the longitudinal (central) axis of the apparatus 600, between a height of approximately 0.4 m above the bottom surface of the apparatus housing and a height of approximately 1.20 m above the bottom surface of the apparatus housing, the radiant heat flux is at least 0.4 kW / m2. This region wherein the radiant heat flux is greater than or equal to 0.4 kW / m2extends from the shins of the seated user 10A to the top of the head of the seated user 10 A. Meanwhile, the standing user 10B, who is positioned radially further than the seated user 10A from the apparatus 600, is exposed to a heated region that extends from their shins (at a height of approximately 0.2 m above the bottom surface of the apparatus housing) to about their chest (at a height of approximately 1.25 m above the bottom surface of the apparatus housing) and has a radiant heat flux of at least 0.2 kW / m2.

[0122] FIGS. 7A-7E show various views and components of another example propane heating apparatus 700. Like the apparatus 200 described above, and as described in further detail below, the apparatus 700 includes a housing 716 configured to contain a fuel source 772 (FIGS. 7A-7B), a heat emitter 704 configured to emit radiant heat (FIGS. 7B-7E), and an ambient flame burner 706 configured to emit visible flames (FIGS. 7A-7C and 7F).

[0123] As illustrated in FIG. 7A, the housing 716 that includes a wall 713 that extends upwardly from the base and provides support and stability during use and maneuvering of the propane heating system. An upper opening of the wall is substantially covered by a cover 768. The housing 716 thus forms an enclosed internal volume 728 for a propane fuel source 772, as shown in FIG. 7B. The fuel control system 740 that connects the propane fuel source 772 to the heat emitter 704 and the burner 706 is also contained in the internal volume 728 (FIG. 7B). Generally, the housing 716 and the propane heating apparatus in turn can take on a variety of forms, but as depicted, the housing base has a generally cylindrical shape.

[0124] Further shown in FIG. 7A is the control assembly 714 of the apparatus 700. The control assembly 714 can comprise a first radiant burner fuel controller 714a, a second radiant burner fuel controller 714b, and an ambient burner fuel controller 714d disposed on the outer surface of the wall 713. The radiant burner fuel controllers 714a, 714b and ambient burner fuel controller 714d can be rotatable knobs configured to control the flow of fuel from the propane fuel source 772 to the heat emitter 704 and the ambient flame burner 706 of the apparatus 700, respectively. The control assembly can also include an ignitor button 714c that is configured to activate each of the radiant and ambient burners.

[0125] The ambient flame burner 706 of the apparatus 700 can be placed atop the cover 768 of the housing 716, as illustrated in FIGS. 7A-7C. The ambient burner 706 can be connected to the propane fuel source 772 through an ambient burner fuel tube 746. As shown in FIG. 7F, the ambient flame burner 706 can include a plurality of outlet holes 748 configured to emit visible flames. The plurality of holes 748 can be positioned on an upper surface of the ambient burner 706 and can comprise a sequence of holes including a first circular hole 748a, followed by a longitudinal opening 748b and then a second circular hole 748c. This configuration of outlet holes can provide for a more natural, uniform distribution of flames from the ambient burner of the propane heating system.

[0126] The heat emitter 704 can include a radiant heat burner 735 and an emitter plate 736. The radiant heat burner 735, visible in the apparatus 700 in FIGS. 7B-7C, can be in the form of a ring-shaped tube divided into two 180-degree portions. The ring-shaped radiant heat burner 735can be disposed concentrically within the apparatus 700, radially outward of the ambient flame burner 706 and radially inward of the emitter plate 736. As shown in FIG. 7D, the ringshaped radiant heat burner 735 can include a plurality of holes 744 disposed along an upper surface of the burner. The ring-shaped radiant heat burner 735 can receive fuel from the propane fuel source 772 via a first fuel tube 742a to a first section 735a of the ring-shaped radiant heatburner 735. The first fuel tube 742a can be connected to the first radiant burner fuel controller 714a. Similarly, the ring-shaped radiant heat burner 735can receive fuel from the propane fuel source 772 via a second burner tube (not shown) to a second section 735b of the ring-shaped radiant heat burner 735. The second burner tube can be connected to the second radiant burner fuel controller 714b and configured to control the flow of fuel to section 735b of the burner 735. The two portions 735a, 735b of the radiant heat burner 735 can be adjusted individually to have separate control zones between the two regions. For instance, one burner can be on and the other off, or one burner can be set to high, and the other burner set to low. The split burner design described herein uses less fuel when only one section of radiant heat is needed.

[0127] The emitter plate 736, positioned radially outward of the radiant heat burner 735, can form a rounded surface and can include a plurality of holes configured to emit radiant heat to the surrounding environment. The rounded surface of the emitter plate 736 can receive heat from the radiant heat burner 735 and distribute the radiant heat uniformly in a direction normal to the rounded surface.

[0128] To distribute heat to the surrounding environment efficiently, the apparatus can include a heat reflector 766. As shown in FIGS. 7B-7C, the heat reflector 766 can be disposed radially inward of the emitter plate 736 and partially inward and partially above the radiant heat burner 735 and can include an angled surface configured to receive the heat from the radiant heat burner 735 and deflect it outward into the surrounding environment. In addition, as shown in FIG. 7B, the heat reflector 766 can form a concentric shape around the ambient flame burner 706. FIG. 7E illustrates an example of radiant heat reflecting off the heat reflector 766. As shown, the heat reflector 766 comprises a lower end 766b and an upper end 766a. The lower end 766b can be positioned inward of the upper end 766a and can form an angled surface relative to a rising radiant heat 776. The heat 776 is received inside the emitter plate 736 and can travel vertically towards the heat reflector 766. The angled surface of the heat reflector 766 can reduce the amount of volume inside the emitter plate 736, and above the radiant heat burner 735, thereby allowing the heat produced by the heat emitter 704 to rise upward within the heat emitter chamber and deflect outward towards the surrounding environment. As shown, the radiant heat 776 can rise at a first position (indicated by line wxin FIG. 7E), then change to a second position (indicated by line w2in FIG. 7E) once it reaches the heat reflector 766.

[0129] FIGS. 8A-8E show various views and components of another example propane heating apparatus 800. Like the apparatuses 200 and 700 described above, and as described infurther detail below, the apparatus 800 includes a housing 816 configured to contain a fuel source (FIG. 8A), a heat emitter 804 configured to emit radiant heat (FIGS. 8B-8C), and an ambient flame burner 806 configured to emit visible flames (FIGS. 8B).

[0130] As shown in FIG. 8 A, the housing 816 provides a wall 813 extending upwardly from the base having an upper opening therein. The upper opening of the wall can provide for a cover 868 to substantially cover the upper opening, thus forming the enclosed internal volume for the propane fuel source (not shown). Further shown in FIG. 8A is the control assembly 814 of the apparatus 800, which can comprise a first radiant burner fuel controller 814a, a second radiant burner fuel controller (not shown), and an ambient burner fuel controller 814c disposed on the outer surface of the wall 610. The radiant burner fuel controller 814a and ambient burner fuel controller 814c can be rotatable knobs configured to control the movement of the flow of fuel from the propane fuel source to the heat emitter 804 and the ambient flame burner 806. The control assembly can also include an ignitor button 814d configured to activate the heat emitter 804 and the ambient flame burner 806.

[0011] Similar to the propane heating system 700, as described above, the ambient flame burner 706 can be placed atop the cover 868 of the housing 816 and can include a plurality of outlet holes configured to emit visible flames, as shown in FIG. 8B. The ambient flame burner 706 can have an annular shape and can further include a plurality of holes 848 positioned on an upper surface of the burner and configured to emit visible flames.

[0132] The heat emitter 804 can include a radiant heat burner 835 and an emitter plate 836.The emitter plate 836 can be disposed atop the cover 868. The emitter plate 836 includes a hood 874 for deflecting heat to the surrounding environment. As shown in FIG. 8B, the emitter plate 836 can provide an internal volume for holding the radiant heat burner 835. As shown in FIG. 8C, the radiant heat burner 835 can take the form of a plate comprising a first section 835a and a second section 835b. The radiant heat burner 835 can include a plurality of outlet holes 844 provided on the periphery of the first burner section 835a and the second burner section 835b, thereby forming two 180-degree heating zones. Similar to the sections of the split ring-shaped burners 335 and 735 described above, the two sections 835a, 835b can be adjusted individually to provide separate control of heat between the two regions. One burner can be on and the other off or one burner can be set to high, and the other burner set to low.

[0133] FIG. 8C further shows that the radiant heat burner 835 can comprise of a first burner tube 842a and a second burner tube 842b. The first burner tube 842a can be connected to a firstradiant burner fuel controller 814a (FIG. 8 A) and the second burner tube 842b can be connected to a second radiant burner fuel controller (not shown). Each section of the plate-shaped radiant burner can receive fuel from the propane fuel source in an independently controlled manner to allow for maximum fuel efficiency. For instance, if only one side of the propane heating system is necessary, one portion can be turned off, while the other can be turned on.

[0134] As shown in FIG. 8B, in addition to being positioned radially inward of the emitter plate 836, the radiant heat burner 835 can be positioned below an inner heat reflector 866. The inner reflector 866 can form the shape of an inverted pyramid and can be positioned concentrically above the radiant heat burner 835. The inner heat reflector 866 can reduce the amount of volume above the radiant heat burner 835 so that hot combustion gases are encouraged to exhaust outward through the plurality of holes on the emitter 836. If the inner heat reflector 866 was not above the burner 835, the hot combustion gases might pool above the burner 835, causing heat to be lost to the top surface of the hood 874. The inner reflector 866 can also absorb some of the heat produced by the burner 835 and reradiate the heat through the outer emitter plate 836. This effect can allow for more uniform absorption of high temperatures on the emitter face, therefore radiating more heat out from the emitter.

[0135] As illustrated in FIG. 8D, the emitter plate 836 can include a first portion 837a and a second portion 837b. The first portion 837a can surround the first portion 835a of the plateshaped radiant burner 835 (FIG. 8C). Similarly, the second portion 837b can surround the second portion 835bof the plate-shaped radiant burner 835(FIG. 8C). The heat emitter portions 837a, 837b can be coupled such that the plate-shaped radiant heat burner 835 is fully enclosed within the emitter plate 836. Once fully enclosed, the emitter plate 836 can form a concentric shape comprising an inwardly angled flat surface 836a and an outwardly angled flat surface 836b positioned adjacent to one another. The inwardly angled flat surface 836a and the outwardly angled flat surface 836b can include a plurality of holes configured to receive heat from the plateshaped radiant burner 835 and emit the radiant heat outwardly towards the surrounding environment. The length of the inwardly angled surface 836a of the emitter plate 836 can be greater than the length of the outwardly angled surface emitter plate 836b. This arrangement can provide for optimal radiant heat output to the surrounding environment.

[0136] FIG. 8E illustrates an example radiant heat flow resulting from the angled surfaces 836a, 836b of the emitter plate 836 shown in FIG. 8D. Radiant heat 876 can rise and exit at the first outwardly angled flat surface 836b and away from the base of the propane heating system.The radiant heat 876 can emit at a first direction z normal to the outwardly angled surface 836b and away from the base of the propane heating system. As heat rises within the heat emitter 836, radiant heat 876 can deflect from the inverted pyramidal shaped heat reflector 866 and can exit from the inwardly angled flat surface 836a. The radiant heat 876 at this stage can emit at a second direction z2normal to the inwardly angled surface 836a of the emitter plate and towards the base of the apparatus 800.

[0137] The apparatus 800 can provide fire media atop the ambient heating sources to enhance to overall appearance of the firepit. FIG. 8F illustrates an embodiment of the propane system 800 in which fire media is provided atop the ambient flame burner 806. The fire media can comprise a first ceramic plate 878 and a second ceramic plate 880, each having a plurality of openings along the plate formed through laser-cutting techniques. The plurality of openings of the first ceramic plate 878 can be different from the outlets provided atop the ambient burner 806. The plurality of openings of the first ceramic plate 878 can be configured immediately above the outlet holes of the ambient burner 806. In addition, the plurality of openings of the first ceramic plate 878 can be of irregular shape such that each opening can be different from the other in terms of its size, shape, and orientation. The second ceramic plate 880 can be positioned atop the first ceramic plate 878. The second ceramic plate 880 can be positioned immediately above the openings of first ceramic plate 878 and can be configured to receive the irregular flame output from the first ceramic plate 878. The flames emitted into the surrounding environment can be formed through the irregular openings 882 of the second ceramic plate 880. The irregular openings 882 can be different than the outlets of the ambient burner and can be formed through laser-cutting techniques such each opening can be different from the other in terms of its size, shape, and orientation. The fire media can be formed in shape as a concentric ring to provide enhanced effects to the propane heating apparatus 800.

[0138] The propane heating apparatuses provided herein can include a segmented burner gas control system, which provides numerous advantages not found with traditional propane heating systems. FIG. 9 depicts a schematic of an example segmented burner gas control system 20 configured to control a heat emitter with two independent sections (e.g., the emitter 704 of the apparatus 700 or the emitter 804 of the apparatus 800) as well as an ambient flame burner (e.g., the burner 706 of the apparatus 700 or the burner 806 of the apparatus 800). The environment surrounding a propane heating apparatus can include a group of upright individuals, seated individuals or a group of individuals located on one side of the propane heating system, leaving the other side vacant. Each of these scenarios can require differing levels of radiant heat outputemitted from portioned points of the propane heating system. The segmented burner gas control system 90 can provide means for independently controlling the first and second portions of the radiant burners, respectively.

[0139] As illustrated in FIG. 9, the segmented burner gas control system 90 can include a first radiant burner fuel controller 22, a second radiant burner fuel controller 23 and an ambient burner fuel controller 21. Each of the radiant burner fuel controllers and ambient burner fuel controllers can further include rotatable knobs. Each one of the rotatable knobs can be coupled to a propane fuel source through a series of gas lines and can be configured to adjustably control the provision of fuel to the burners. For instance, the rotatable knob of the ambient fuel burner controller 21 can be coupled to a first gas line 24 connecting to the propane fuel source. Similarly, rotatable knobs of radiant fuel burner controller 22, 23 can be coupled to a second and third gas line 25 and 27, respectively, each connecting to the propane fuel source. Furthermore, the ambient burner fuel controller 21 can be connected to the ambient burner through a fourth gas line 27 to allow for fuel to reach the ambient burner 32, independently from the radiant burners, and provide visible flames. The first radiant burner gas controller 22 can be connected to the first portion of the radiant burner 33 and can provide fuel independently from the second portions of the radiant burner. The second radiant burner gas controller 23 can be connected to the second portion of the radiant burner 33 and can provide fuel independently from the first portions of the ring-shaped, or plate shaped radiant burner. The propane fuel source can also include a rotatable knob 30 configured to provide a pilot flame to the propane heating system.

[0140] An example of the segmented gas burner control system operation is described in greater detail. Once the propane fuel source is activated through turning the knob 30, a pilot flame is provided to the control system 90. As shown in FIG. 9, each fuel controller can be rotatable between four positions as follows: OFF, IGNITE, MIN and MAX. With the pilot flame burning, a user of the propane heating system can initiate operation of the three burners simultaneously or independently of one another. For instance, the control assembly can include an ignitor button 31 configured to generate a small electric spark. When pressed, the ignitor button 31 can activate a piezoelectric igniter mechanism inside the control assembly, for example. A user of the propane heating system may choose to activate the ambient burner first, therefore moving the position of the ambient burner fuel controller to “IGNITE”. Consequently, fuel can flow from the gas line 27 to the ambient burner 32. In this case, to ensure that all the heat from the propane fuel source is captured and ignited, a thermopile can be positioned proximate to the ambient burner. The thermopile can be adjusted based on the position of therotatable knob of the ambient burner fuel controller 21. For instance, if a higher ambient flame is desired, the ambient burner fuel controller can be rotated to the “MAX” position, therefore allowing more heat to be released. In order operate the rotatable knob of the ambient burner fuel controller 21, the thermopile can generate electrical energy from the heat produced buy ambient burner. The rotatable knob can then use the electrical energy generated by the thermopile to control the flow valves coupled to the propane fuel source.

[0141] Alongside operation of the ambient burner, as described above, a user may choose to activate one or both portions of the radiant burner. For instance, a user can position the rotatable knob 22 to “IGNITE”. Then, fuel can flow from the gas line 28 to the first portion of the radiant burner. Similar to the ambient burner, a thermopile can be positioned proximate to the radiant burner so that when ignitor 31 is pressed, all the heat generated from the first portion of the radiant burner can be captured and controlled. As such, the thermopile of the first portion of the radiant burner can be adjusted based on the position of the rotatable knob 22. This process can be activated simultaneously for the second portion of the radiant burner as well. For instance, if a higher ambient flame is desired on the second portion of the radiant burner, the second radiant burner fuel controller 23 can be rotated to the “MAX” position, meanwhile the first radiant burner fuel controller 22 can be rotated to the “MIN” position. Nevertheless, the rotatable knob of the first radiant burner fuel controller 22 and the rotatable knob of the second radiant burner fuel controller 23 can operate simultaneously due to the electrical energy generated by the thermopiles located proximate to each respective portion of the radiant burner.

[0142] Certain illustrative implementations have been described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the systems, devices, and methods disclosed herein. One or more examples of these implementations have been illustrated in the accompanying drawings. Those skilled in the art will understand that the systems, devices, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting illustrative implementations and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one illustrative implementation may be combined with the features of other implementations. Such modifications and variations are intended to be included within the scope of the present invention. Further, in the present disclosure, like-named components of the implementations generally have similar features, and thus within a particular implementation each feature of each like-named component is not necessarily fully elaborated upon.

[0143] Approximating language, as used herein throughout the specification and claims, maybe applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and / or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

[0144] One skilled in the art will appreciate further features and advantages of the invention based on the above-described implementations. Accordingly, the present application is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated by reference in their entirety.

[0145] What is claimed is:

Claims

CLAIMS1. An apparatus comprising: a housing defining an internal volume configured to contain a fuel source; a heat emitter coupled to the fuel source and configured to emit radiant heat; a first burner coupled to the fuel source and configured to emit visible flames; wherein the first burner and the heat emitter are horizontally aligned and arranged concentrically with respect to each other such that one of the first burner and the heat emitter is disposed radially inward of the other one of the first burner and the heat emitter.

2. The apparatus of claim 1 , further comprising a first fuel tube and a second fuel tube each configured to connect to the fuel source, wherein the heat emitter is connected to the first fuel tube, and the first burner is connected to the second fuel tube.

3. The apparatus of claim 1 , wherein the first burner and the heat emitter are both positioned proximate to an upper portion of the housing.

4. The apparatus of claim 1 , wherein the heat emitter comprises a second burner and an emitter plate surrounding the second burner, wherein the second burner is configured to couple to the fuel source and to emit heat toward the emitter plate, and the emitter plate is configured to direct radiant heat in a direction normal to an outer surface of the emitter plate.

5. The apparatus of claim 4, wherein the second burner is configured to emit visible flames through outlet holes formed in the second burner.

6. The apparatus of claim 5, wherein the second burner is an annular burner, and wherein the outlet holes formed in the second burner comprise outlet holes disposed along an upper surface of the first burner.

7. The apparatus of claim 6, wherein the outlet holes formed in the second burner comprise elongate slot-shaped holes arranged in a staggered pattern.

8. The apparatus of claim 1 , wherein the first burner is configured to emit the visible flames through outlet holes formed in the first burner.

9. The apparatus of claim 8, wherein the first burner is an annular burner, and wherein the outlet holes formed in the first burner comprise outlet holes disposed along an upper surface of the first burner.

10. The apparatus of claim 8, wherein the outlet holes formed in the first burner comprise a combination of circular holes and elongate slot-shaped holes.

11. The apparatus of claim 10, wherein each elongate slot-shaped hole is positioned between a pair of circular holes.

12. The apparatus of claim 1 , wherein the fuel source is a propane fuel source.

13. An apparatus comprising : a housing defining an internal volume configured to contain a fuel source; a heat emitter configured to emit radiant heat and comprising a first portion coupled to the fuel source and a second portion coupled to the fuel source; and a first burner configured to emit visible flames and configured to couple to the fuel source; wherein the first portion of the heat emitter, the second portion of the heat emitter, and the first burner are configured to be controlled independently from each other.

14. The apparatus of claim 13, further comprising a control assembly configured to independently adjustably control a provision of fuel from the fuel source to each of the first portion of the heat emitter, the second portion of the heat emitter, and the first burner.

15. The apparatus of claim 13, further comprising a first fuel tube, a second fuel tube, and a third fuel tube each configured to connect to the fuel source, wherein the first portion of the heat emitter is connected to the first fuel tube, the second portion of the heat emitter is connected to the second fuel tube, and the first burner is connected to the third fuel tube.

16. The apparatus of claim 13, wherein the first burner and the heat emitter are positioned proximate to an upper portion of the housing and are arranged concentrically with respect to each other such that one of the first burner and the heat emitter is disposed radially inward of the other.

17. The apparatus of claim 13, wherein the first burner and the heat emitter are horizontally aligned.

18. The apparatus of claim 13, wherein the heat emitter comprises a second burner, the second burner comprising a first portion configured to couple to the fuel source and a second portion configured to couple to the fuel source.

19. The apparatus of claim 18, further comprising:a first thermopile configured to ignite the first portion of the second burner; a second thermopile configured to ignite the second portion of the second burner; and a third thermopile configured to ignite the first burner.

20. The apparatus of claim 18, wherein the heat emitter further comprises an emitter plate that surrounds the second burner such that the first and second portions of the second burner are substantially enclosed by the emitter plate, wherein the emitter plate is configured to direct heat emitted by the second burner in a direction normal to an outer surface of the emitter plate.

21. The apparatus of claim 20, wherein the emitter plate comprises a first portion that surrounds the first portion of the second burner and a second portion that surrounds the second portion of the first second.

22. The apparatus of claim 13, wherein the heat emitter is configured to emit the radiant heat through outlet holes formed in the heat emitter.

23. The apparatus of claim 13, wherein the first burner is configured to emit the visible flames through outlet holes formed in the first burner.

24. The apparatus of claim 13, wherein the fuel source is a propane fuel source.

25. An apparatus comprising: a housing defining an internal volume configured to contain a fuel source; a heat emitter configured to couple to the fuel source and to emit radiant heat; a first burner configured to couple to the fuel source and to emit visible flames; and a heat reflector having at least a portion disposed radially inward of the heat emitter and comprising a vertical surface and an angled surface disposed along a top edge of the vertical surface that flares outward from the vertical surface.

26. The apparatus of claim 25, further comprising a first fuel tube and a second fuel tube each configured to connect to the fuel source, wherein the heat emitter is connected to the first fuel tube, and the first burner is connected to the second fuel tube.

27. The apparatus of claim 25, wherein the vertical surface is aligned with a longitudinal axis of the housing.

28. The apparatus of claim 25, wherein the angled surface of the heat reflector is joined to the vertical surface of the heat reflector at an angle between 90° and 150°.

29. The apparatus of claim 25, wherein the angled surface of the heat reflector extends at least partially above the first burner.

30. The apparatus of claim 25, wherein the second burner is at least partially surrounded by the heat reflector.

31. The apparatus of claim 25, wherein the heat emitter comprises a second burner and an emitter plate that surrounds the second burner and the heat reflector, wherein the second burner is configured to couple to the fuel source and to emit the radiant heat, and wherein the emitter plate is configured to direct the heat emitted by the second burner in a direction normal to an outer surface of the emitter plate.

32. The apparatus of claim 31 , wherein the heat reflector is configured to reflect heat emitted by the second burner toward the emitter plate.

33. The apparatus of claim 31, wherein the heat emitter is configured to emit the radiant heat through outlet holes formed in the emitter plate.

34. The apparatus of claim 25, wherein the first burner is configured to emit the visible flames through outlet holes formed in the first burner.

35. The apparatus of claim 25, wherein the fuel source is a propane fuel source.

36. An apparatus comprising: a housing defining an internal volume configured to contain a fuel source; a heat emitter configured to couple to the fuel source and configured to emit radiant heat; and a first burner configured to couple to the fuel source and configured to emit visible flames; wherein the heat emitter is configured to generate a heated region that extends outward from the heat emitter and encircles the housing such that, at a radial distance of approximately 1 meter from an outer surface of the housing, between approximately 40 cm above a bottom surface of the housing and approximately 120 cm above the bottom surface of the housing, the radiant flux is at least 400 W / m2.

37. The apparatus of claim 36, further comprising a first fuel tube and a second fuel tube each configured to connect to the fuel source, wherein the heat emitter is connected to the first fuel tube, and the first burner is connected to the second fuel tube.

38. The apparatus of claim 36, wherein the heated region is such that, at the radial distance of approximately 1 meter from the outer surface of the housing, between the bottom surface of the housing and approximately 20 cm above the bottom surface of the housing, the radiant flux is less than 250 W / m2.

39. The apparatus of claim 36, wherein the heated region is such that, at the radial distance of approximately 1 meter from the outer surface of the housing, above approximately 140 cm above the bottom surface of the housing, the radiant flux is less than 250 W / m2.

40. The apparatus of claim 36, wherein the heated region is such that, at the radial distance of approximately 1 meter from the outer surface of the housing, above approximately 150 cm above the bottom surface of the housing, the radiant flux is negligible.

41. The apparatus of claim 36, wherein the heated region has a maximum radiant flux between approximately 70 cm above the bottom surface of the housing and approximately 90 cm above the bottom surface of the housing.

42. The apparatus of claim 41, wherein the maximum radiant flux is at least 600 W / m2.

43. The apparatus of claim 36, wherein the heat emitter is configured to emit the radiant heat through outlet holes formed in the heat emitter.

44. The apparatus of claim 36, wherein the first burner is configured to emit the visible flames through outlet holes formed in the first burner.

45. The apparatus of claim 36, wherein the fuel source is a propane fuel source.

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