AU2017217243A1

AU2017217243A1 - A solar heater system and methodology for the control thereof

Info

Publication number: AU2017217243A1
Application number: AU2017217243A
Authority: AU
Inventors: David Ashby
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-02-09
Filing date: 2017-02-09
Publication date: 2018-08-30
Also published as: WO2017136883A1

Abstract

There is provided a solar heater system comprising: a plurality of open ended parallel air heating tubes; and upper and lower manifolds operably coupling respective ends of the air heating tubes and wherein the system is useable in an air heating mode of operation wherein air flows via the lower manifold for heating within the air heating tubes and via the upper manifold into a building space for heating. The system may also comprise an excessive hot air dissipation mechanism and wherein the system is usable in a non-heating mode of operation wherein excessive hot air is dissipated from the dissipation mechanism to the atmosphere.

Description

Field of the Invention [1] The present invention relates to a solar heater system and methodology for the control thereof and in particular, but not necessarily entirely, to a passively tracking solar air heater which, in embodiments may further heat water.

Background of the Invention [2] With increasing costs of fossil fuels and a widespread focus on sustainability, individuals and organisations seek various ways to reduce heating costs expense and environmental impact.

[3] In Australia for example, government policy is directed towards a number of areas of sustainability such as, water conservation (such as water tanks for domestic and commercial use) and water heating wherein for water heating rebates and building codes encourage the inclusion of solar hot water systems on new and existing buildings.

[4] Such solar hot water systems typically rely on solar collectors on roof spaces, which in the warmer months capture and transfer heat to water storage tank/s.

[5] Environmentally friendly heating systems currently utilise flat panel air collectors, solar hot water/hydronic heating systems and building design which passively captures heat from the sun using, for example, larger windows orientated towards the sun.

[6] Flat panel air collectors draw air from inside or outside the building for pumping through the collector and back into the building.

[7] These current solar air heating systems are relatively expensive to manufacture.

[8] Furthermore, these current solar air heating systems are inefficient because flat panel only achieve optimal efficiency when the sun is perpendicular to the panels at the middle of the day.

[9] Solar hot water/hydronic heating systems pump water through thermal collector such as a flat panel collector or evacuated tube hot water collector for heating and subsequent radiating using radiators or a thermal mass such as a concrete slab for heating the interior of a building.

[10] For evacuated tubes, water either flows directly through the evacuated tubes, or past the top of heat pipes which are located inside the tubes for heating.

[11] These systems can work effectively, but require careful design and specialised installation.

[12] However, on account of this efficiency, these hydronic heating systems create excess hot water during warmer spells, requiring the dumping of excess water in a swimming pool or the like or complete temporary decommission, which is an expensive or time-consuming activity.

[13] Sustainable passive building design allows sunlight to directly enter a building during the colder months for heating a thermal mass such as a concrete slab.

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PCT/AU2017/050102 [14] Whereas these passive solar designs can work very effectively, such is difficult to retrofit on account of requiring the removing of walls, installation of windows, addition of a thermal mass to be heated by the sun.

[15] Furthermore, passive solar design relies on the orientation and layout of the building wherein, ideally, a building would be orientated east to west to maximize solar exposure.

[16] Furthermore, windows of passive solar design do not track the sun, suffering from problems of achieving maximum efficiency when the sun is perpendicular.

[17] Furthermore, windows of passive solar design may result in excessive heating during warmer spells requiring heavy shutter blind systems to be installed.

[18] The present invention seeks to provide a passively tracking solar air heater, which will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative. The present invention also incorporates an optional solar hot water heating mechanism, whereby in the warmer months when air heating is not required, the tubes can be utilised to provide hot water heating to a storage tank to meet a buildings hot water needs.

[19] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

Summary of the Disclosure [20] The present invention, according to one aspect, comprises a solar heater system comprising: a plurality of open ended parallel air heating tubes; and upper and lower manifolds operably coupling respective ends of the air heating tubes and wherein the system is useable in an air heating mode of operation wherein air flows via the lower manifold for heating within the air heating tubes and via the upper manifold into a building space for heating.

[21] Now in contradistinction to existing arrangements, the present system utilises evacuated glass tubes for air heating including for being able to provide passive solar tracking to overcome the limitations of flat panel collectors.

[22] Evacuated glass tubes have been used globally to heat water since the 1980's, wherein either water sits inside the tubes and is heated directly, or copper heat pipes are placed inside the tubes which transfer the heat up to a copper bulb on the top of the heat pipe, and water is heated as is runs past the series of copper bulbs.

[23] Using this arrangement to heat water is commonplace, but is not utilised commercially to heat air.

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PCT/AU2017/050102 [24] Furthermore, a traditional evacuated glass tube is sealed at one end to retain the heat therein for transfer to either the water inside the tube, or the heat pipes in the tubes. Whereas the present heater uses open ended evacuated glass tubes.

[25] Embodiments therefore of the present system provides advantages or alternatives to the above current solutions.

[26] For example, the evacuated tubes may be over 90% efficient, and when installed to be sun facing each tube, by virtue of being cylindrical, passively tracks the sun, allowing the system to reaching and high efficiency quickly and maintain that efficiency for a long period of the day.

[27] Furthermore, because of a well-established global market for evacuated tube technology for heating water, manufacturing costs are very low, allowing the offering of an economical solution to air heating.

[28] Furthermore, the present system alleviates excessive heating problems of prior art arrangements during warmer months wherein an excessive hot air dissipation mechanism is used to dissipate excessive heat to the atmosphere.

[29] As such, unlike other arrangements, the present system can provide sufficient heating during the winter months without causing overheating during summer months because hot air can, in contradistinction to prior art arrangements, be left still in the glass tubes (unlike prior art water heating arrangements wherein retained water might boil causing steaming) or released to atmosphere (without requiring a heat dump as per prior art arrangements).

[30] Furthermore, the present system can also be used for cooling wherein air is drawn from the building space via the lower manifolds and is dissipated to the atmosphere.

[31] As such, in warmer months, the present solar air heating system can entirely be turned off, or, alternatively, only a subset of the evacuated glass tubes used to provide partial heating as required.

[32] Furthermore, unlike the hydronic heating or passive solar design, the present system can be quickly and cheaply installed on practically any building that requires heating. The evacuated tube air heaters are light enough and versatile enough for ease of installation on any sun exposed external wall or roof space.

[33] As such, the present system can be used to heat buildings/spaces for free or to supplement current heating systems and hot water systems, using the energy available from sunlight and to do so in a way that is far more efficient than anything else currently on the market.

[34] In embodiments, the present system uses Bi-coated or Tri-coated evacuated glass tubes that are open at both ends.

[35] Insulated manifolds operably connect the top and bottom of the tubes to supply and draw air respectively.

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PCT/AU2017/050102 [36] A lightweight mounting frame holds the tubes in place. In embodiments, insulated duct work and draw fans are used for some embodiments of the invention.

[37] The use of open ended evacuated tubes allows air inside the tubes to be heated directly by the sun negating inefficient heat exchange mechanisms.

[38] Furthermore, warm air rises to the upper air manifold, drawing cold air from the lower air manifold.

[39] In embodiments, where hot water generation is also required, a copper heat pipe may suspended inside each or some of the tubes with a copper bulb at the end of the heatpipe terminating inside a socket located in the copper manifold header pipe inside the upper air manifold. As such, warm air flows freely around the heat pipe and into the upper air manifold in the months when air heating is required.

[40] This simple design allows each tube to work independently from the others, and utilizes a currently mass produced item to solve a simple problem.

[41] The air may be either pumped or thermosyphoned through the air manifolds and tubes being heated from the sun and into the building space.

[42] Once the desired temperature is reached inside the building space, excess hot air may be vented to the atmosphere.

[43] As such, with the foregoing in mind, in accordance with one aspect, there is provided a solar heater system comprising: a plurality of open ended parallel air heating tubes; and upper and lower manifolds operably coupling respective ends of the air heating tubes and wherein the system may be useable in an air heating mode of operation wherein air flows via the lower manifold for heating within the air heating tubes and via the upper manifold into a building space for heating.

[44] The air may be drawn from the building space via the lower manifold.

[45] The system may operate in a passive thermosiphon mode during the air heating mode wherein convection causes the air to flow through the manifolds.

[46] The system may further comprise an excessive hot air dissipation mechanism and wherein the system may be usable in a non-heating mode of operation wherein excessive hot air may be dissipated from the dissipation mechanism to the atmosphere.

[47] The excessive hot air dissipation mechanism may be controlled by a temperature setpoint controller.

[48] The excessive hot air dissipation mechanism may be operatively couple to the upper manifold to allow excessive hot air to dissipate from the upper manifold to the atmosphere.

[49] The excessive hot air dissipation mechanism may be configurable to selectively dissipate excessive hot air from a subset of the air heating tubes.

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PCT/AU2017/050102 [50] The number of the subset may be controlled in accordance with a temperature setpoint.

[51] The system may be further be usable in a cooling mode of operation wherein air may be drawn from the building space via the lower manifold and dissipated to the atmosphere via the excessive hot air dissipation mechanism.

[52] The system may further comprise an isolation valve configured to prevent air flow through the air heating tubes and wherein the system may be further usable in an isolation mode of operation wherein air does not flow via the air heating tubes.

[53] The air heating tubes may be glass tubes [54] The air heating tubes may be double walled evacuated glass tubes [55] The system may further comprise a laminar flow interruption structure located within each tube.

[56] The laminar flow interruption structure may be a screw-type structure.

[57] The structure may be perforated.

[58] The system may further comprise a heat conductive structure located within each tube.

[59] The system further may comprise water heating tubes within the air heating tubes and wherein the system may be further configured for heating water within the water heating tubes via heat exchange.

[60] The system may be usable in a water heating mode of operation wherein water may be heated within the air heating tubes and wherein the air does not flow into the building space.

[61] According to another aspect, there may be provided a method for controlling the solar air heating system as described herein, the method comprising monitoring temperature and:

[62] when the temperature may be below a temperature setpoint, the air flows via the upper manifold into the building space; and [63] when the temperature exceeds the temperature setpoint, controlling the excessive hot air dissipation mechanism to dissipate hot air to the atmosphere.

[64] Air may be drawn from the building space via the lower manifold such that, when the temperature exceeds the temperature setpoint, the system draws air from the building space for cooling.

[65] The system further may comprise an excessive hot air dissipation mechanism, the method comprising monitoring temperature and: when the temperature may be below a temperature setpoint, the system may be in an air heating mode of operation wherein air flows into the building space via the upper manifold; and when the temperature may be above the temperature setpoint: controlling the system in an isolation mode of operation wherein the isolation valve may be closed such that air does not flow via the air heating tubes; or controlling the system in a cooling mode of

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PCT/AU2017/050102 operation wherein air flows from the building space via the lower manifold and may be dissipated to the atmosphere.

[66] The system further may comprise an excessive hot air dissipation mechanism, the method comprising monitoring temperature and when the temperature may be below a first temperature setpoint, the system may be in an air heating mode of operation wherein air flows into the building space via the upper manifold; and when the temperature may be above the first temperature setpoint, controlling the system in an isolation mode of operation wherein the isolation valve may be closed such that air does not flow via the air heating tubes; and when the temperature may be above a second temperature setpoint, controlling the system in a cooling mode of operation wherein air flows from the building space via the lower manifold and may be dissipated to the atmosphere.

[67] According to another aspect, there may be provided a method for controlling the solar air heating system as described herein, the method comprising controlling the system in an air heating mode of operation wherein air may be heated within the air heating tubes and flows via the upper manifold into the building space; and controlling the system in a water heating mode of operation wherein water may be heated within the water heating tubes for heating a hot water system and wherein air does not flow into the building space.

[68] The system further may comprise an isolation valve configured to prevent air flow through the air heating tubes and wherein, in the water heating mode, the isolation valve may be closed such that air does not flow through the air heating tubes.

[69] Other aspects of the invention are also disclosed.

Brief Description of the Drawings [70] Notwithstanding any other forms which may fall within the scope of the present invention, embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[71] Figure 1 shows a solar heater system applied to a building in accordance with a preferred embodiment of the present disclosure;

[72] Figure 2 shows a close-up view of the heater system in accordance with the preferred embodiment of the present disclosure;

[73] Figures 3 and 4 show exemplary side elevation views of a building wherein the heater system is applied to a wall or roof mounting respectively;

[74] Figure 5 shows a cross-sectional view of the manifold of the heater system in accordance with an embodiment of the present disclosure;

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PCT/AU2017/050102 [75] Figure 6 shows a top plan view of the heater system in accordance with an embodiment of the present disclosure;

[76] Figure 7 shows a magnified views of the heater system with optional hot water heating inserts, in accordance with an embodiment of the present disclosure; and [77] Figure 8 shows an exemplary side elevation views of a building wherein the heater system is applied to a roof mounting for heating both air and water in the colder and warmer months respectively.

Description of Embodiments [78] For the purposes of promoting an understanding of the principles in accordance with the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the disclosure as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the disclosure.

[79] Before the structures, systems and associated methods relating to the passively tracking solar air heater are disclosed and described, it is to be understood that this disclosure is not limited to the particular configurations, process steps, and materials disclosed herein as such may vary somewhat. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the disclosure will be limited only by the claims and equivalents thereof.

[80] In describing and claiming the subject matter of the disclosure, the following terminology will be used in accordance with the definitions set out below.

[81] It must be noted that, as used in this specification and the appended claims, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise.

[82] As used herein, the terms comprising, including, containing, characterised by, and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps.

[83] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[84] Turning now to figure 1, there is shown an exemplary in use embodiment wherein the solar heater system 1 has been fastened to the exterior wall of a building 2. As alluded to above, the system

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PCT/AU2017/050102 advantageously allows for retro fit to existing buildings or incorporation within architectural designs during construction.

[85] In the embodiment shown in figure 1, the system 1 has been retrofitted to an existing building via mounting to the exterior wall of the building 2 and the reticulation of appropriate ductwork to convey the air in the manner described herein.

[86] As also alluded to above, the system 1 is ideally located on a sun facing surface. In this regard, the system 1 may be located on a sun facing wall of the building 2, sun facing roof (as is described in further detail below with reference to figure 4) and the like.

[87] In embodiments, the system 1 may be installed in a standalone application thereby not necessarily requiring fastening to an existing building structure. In embodiments, the system 1 may in fact be multiple heaters manifolded together in a way that will provide the required amount of heat to the building.

[88] Turning now to Figure 2, there is shown the system 1 in further detail. As can be seen, the system 1 comprises a plurality of parallel and cylindrical evacuated glass air heating tubes 5 each being open-ended at top and bottom.

[89] As mentioned above, traditional evacuated glass tubes are only open at one end so as to be suitable for retaining heat for heating water conduits for example. However, the utilisation of glass air heating tubes 5 been open ended at both the top and the bottom allows air to rise by convection within the glass air heating tubes 5 during the heating process from bottom to top.

[90] In an embodiment, the glass tubes 5 are double walled, having outer wall and inner walls and wherein the volume therebetween is evacuated. In embodiments, the glass air heating tubes 5 may be coated to enhance heat absorbing properties, such as by being blackened to reduce reflection.

[91] In embodiments, the glass air heating tubes 5 need not necessarily comprise a glass and may be manufactured from other material types also.

[92] As alluded to above, the substantially cylindrical shape of the glass air heating tubes 5 allows the glass air heating tubes 5 to passively track the sun as the sun moves across the sky. As such, the substantially cylindrical glass tubes do not suffer from disadvantages of prior art systems of peak efficiencies being only obtained when the sun is at a particular region within the sky, as, for example, as is the case with solar panels which, by virtue of been substantially rectangular, are most efficient when substantially perpendicular to the angle of the sun.

[93] As is also shown in figure 2, the system 1 further comprises upper and lower air manifolds numbered 3U and 3L respectively.

[94] Furthermore, the system 1 may comprise upper and lower air ducts numbered 8U and 8L respectively.

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PCT/AU2017/050102 [95] In embodiments where the system 1 is to be wall or roof mounted for example, the system 1 may comprise mountings 12 as are best seen in figure 6.

[96] In a preferred embodiment, the system 1 comprises an excessive hot air dissipation mechanism 7 to allow the dissipation of excess hot air to the atmosphere when heating is not required.

[97] For example, during the summer months, the excessive hot air dissipation mechanism 7 may be operable to release hot air to the atmosphere rather than further warming an already warmed building. In other embodiments, see figure 8, some or all of the excess heat may be used to provide hot water for a hot water storage tank.

[98] In the embodiment shown in figure 2, the excessive hot air dissipation mechanism 7 is operably coupled to the upper air manifold 3U so as to be able to be configured for either supplying warmed air from the upper manifold into a building or space through duct 8U or releasing warmed air to the atmosphere via excessive hot air dissipation mechanism 7.

[99] In the embodiment shown in figure 2, the excessive hot air dissipation mechanism 7 comprises a vent or the like which may be manually actuated or controlled an automated manner, such as by a temperature sensitive setpoint controller.

[100] In embodiments, the excessive hot air dissipation mechanism 7 may be configured such that, when open to the atmosphere, the upper duct 8U is isolated.

[101] In embodiments, the excessive hot air dissipation mechanism 7 may be controlled automatically in accordance with various environmental factors such as the temperature within the building 2, the temperature exterior the building, user preferences and the like.

[102] For example, the user may set a desired temperature within the building 2 wherein, if the temperature exceeds the set temperature, the excessive hot air dissipation mechanism 7 may be actuated so as to release the additional heat to the atmosphere.

[103] In alternative embodiments as alluded to above, as opposed to dissipating excessive hot air to the atmosphere, the system 1 may rather close off the manifolds 3 or the ducting 8 such that air remained still within the air heating tubes 5. As also alluded to above, the retention of still air does not suffer the boiling off/steaming problems of water heating systems wherein water is retained within the heating tubes.

[104] For example, the system 1 may further comprise an isolation valve (not shown) operably connected to the lower duct 8L or the lower manifold 3L so as to prevent air being drawn into the heater.

[105] In embodiments, the system 1 may comprise both the excessive hot air dissipation mechanism 7 and the isolation valve allowing the system 1 may be controlled in three modes of operation comprising a heating mode wherein the system 1 heats air, a cooling mode wherein the system 1

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PCT/AU2017/050102 draws and via the lower duct 8 for release to the atmosphere and a third nonoperational mode of operation wherein the system 1 is isolated.

[106] Embodiments, the system 1 may be controlled according to two temperature setpoints wherein, if below a first of the temperature setpoints, the system 1 is utilised in an air heating mode of operation and wherein, when above the first setpoint, the system 1 is operated in an isolation mode of operation wherein air does not flow through the air heating tubes 5. Furthermore, when the temperature exceeds a second of the two temperature setpoints, the system 1 is operated in a cooling mode of operation wherein air is drawn from the building space via the lower manifold 3L anticipated via the heat dissipation mechanism 7.

[107] In bottoms, the heat dissipation mechanism 7 may be able to dissipate excessive hot air only from a subset of the air heating tubes 5. For example, a heat dissipation valve may be associated with each of the air heating tubes 5 such that excessive hot air is dissipated only from a subset of the heating tubes 5 and wherein the number of the subset is determined in accordance with a temperature setpoint for graduated dissipation heating control.

[108] In a preferred embodiment, the system 1 is a passive device in that the system 1 is configured to operate in a thermosiphon mode of operation wherein convection causes cool air to be drawn in from the building 2 via the lower air duct 8L and warmed air to be expelled via the upper air duct 8U to warm the building 2.

[109] It should be noted that in this mode of operation, while the excessive hot air dissipation mechanism 7 is operable, the system 1 may yet to draw air from the building so as to cool the building during the summer months.

[110] In the thermosiphon mode of operation, the heater is preferably wall mounted as substantially shown in figure 1 such that the tubes 1 are substantially vertical so as to aid convection currents. Specifically, figure 3 shows a side elevation view of the building 2 wherein the system 1 is shown on the vertical configuration.

[111] In other embodiments, including where the system 1 is not vertically orientated, such as when fastened to a pitched or flat roof or the like an air pump may be used to force air through the system 1.

[112] Specifically, figure 4 shows an exemplary side elevation view of the building 2 wherein the system 1 is roof mounted and wherein an air pump (not shown) forces air through the system 1.

[113] Returning again to figure 2, in one embodiment of each tube 1 may comprise a laminar flow interruption structure 6 located within each tube.

[114] The structure 6 is configured for interrupting laminar flow so as to slow the airflow within the tube 5 so as to increase the temperature further. In the embodiment shown, the structure 6 takes the

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PCT/AU2017/050102 form of a spiral or screw type structure 6 such that the entrapped air spirals upwards through the tube 5 around the structure.

[115] In embodiments, the structure 6 may comprise perforations to further facilitate airflow.

[116] The shape and configuration of the structure 6, the sizing and location of the perforations and the like may be configured in accordance with the various environmental factors and the like so as to be able to have an effect on the resultant air temperature warmed by the system 1.

[117] In embodiments, the structure is heat conductive such as by being made from metal, such as aluminium or the like. In this manner, the heat conductor structure 6 may draw heat from the inner walls of the air heating tubes 5 via conduction so as to further enhance the warming of the air.

[118] Turning to Figure 7, there is shown a close up of the system 1 in accordance with a further embodiment wherein the system 1 is configured for heating water in the warmer months.

[119] As can been seen, a (preferably copper) manifold header pipe 15 is inserted inside the upper manifold 3U. A water heating pipe 17 is inserted within one or more ofthe air heater tubes 5 whereby the copper bulb at the top ofthe heating pipe slots into a copper socket 16 located inside the manifold header pipe.

[120] All or only some ofthe air heating tubes 5 may have associated water heating pipe 17 wherein, the more water heating pipes 17 employed, the greater the water heating ability.

[121] The embodiment in Figure 8 shows an exemplary side elevation view where the system 1 is located on a sun facing roof of a building (alternately the system 1 could be wall mounted as per figure 1) and configured for heating water in the warmer months of the year using the manifold header pipe 15 and heat pipes 17.

[122] As is shown in Figure 8A, in the colder months, the system 1 operates as an air heater, pumping warm air into the building.

[123] In the warmer months shown in Figure 8B, the system 1 is used to provide hot water to the building. Specifically, water is pumped from a water storage tank 18, up through the copper manifold header tank 15 and back down to the storage tank.

[124] When heating water is shown in Figure 8B, the system may be configured such that hot air does not flow into the building, either by using the heat dissipation mechanism 7 or preferably, utilisation of the isolation valve such that hot air is retained within the air heating tubes 5 for enhancing the heating of the water heating pipes 17.

[125] Figure 5 shows a cross-sectional view of the manifold 3 in accordance with one embodiment.

[126] In this embodiment, the manifold 3 is substantially rectangular in elongate cross section comprising and inner stainless steel cylindrical core 13 running along the length of the manifold 3 having cutouts 14 therealong so as to accommodate the distal ends of the air heating tubes 5 therein.

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PCT/AU2017/050102 [127] The optional copper manifold header pipe 15 is mounted within the steel cylindrical core 13 when water heating is also required. As can be seen, the copper heat pipes 17 can be plugged into the copper sockets 16 of the copper manifold header pipe 15 when needed. During assembly the air heating tubes 5 may be pushed into each respective cutout 14, and where present, the heat pipes 17 sit within the air heating tubes 5. In embodiments, seals 11 may be provided at inner surfaces of the cutouts 14 so as to reduce air leakage.

[128] The manifold 3 may comprise an insulative core 10, such as a foam filled core 10 or the like for thermal insulation purposes.

[129] Figure 6 shows a top plan view of the system 1 showing the respective locations of the cut outs 14 where the air heating tubes 5 push into and seal using seals 11.

[130] Figure 6 also shows the length and position of the copper manifold header pipe 15 when installed, and the location of the copper sockets 16 where the heat pipes 17 slide into.

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Interpretation

Embodiments:

[131] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[132] Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention.

[133] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Different Instances of Objects [134] As used herein, unless otherwise specified the use of the ordinal adjectives first, second, third, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

Specific Details [135] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

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Terminology [136] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose.

Terms such as forward, rearward, radially, peripherally, upwardly, downwardly, and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

Comprising and Including [137] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word comprise or variations such as comprises or comprising are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[138] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

Scope of Invention [139] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[140] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Industrial Applicability [141] It is apparent from the above, that the arrangements described are applicable to the solar industries.

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Claims

Claims

1. A solar heater system comprising:

a plurality of open ended parallel air heating tubes; and upper and lower manifolds operably coupling respective ends of the air heating tubes and wherein the system is useable in an air heating mode of operation wherein air flows via the lower manifold for heating within the air heating tubes and via the upper manifold into a building space for heating.
2. A system as claimed in claim 1, wherein the air is drawn from the building space via the lower manifold.
3. A system as claimed in claim 1, wherein the system operates in a passive thermosiphon mode during the air heating mode wherein convection causes the air to flow through the manifolds.
4. A system as claimed in claim 1, further comprising an excessive hot air dissipation mechanism and wherein the system is usable in a non-heating mode of operation wherein excessive hot air is dissipated from the dissipation mechanism to the atmosphere.
5. A system as claimed in claim 4, wherein the excessive hot air dissipation mechanism is controlled by a temperature setpoint controller.
6. A system as claimed in claim 4, wherein the excessive hot air dissipation mechanism is operatively couple to the upper manifold to allow excessive hot air to dissipate from the upper manifold to the atmosphere.
7. A system as claimed in claim 4, wherein the excessive hot air dissipation mechanism is configurable to selectively dissipate excessive hot air from a subset of the air heating tubes.
8. A system as claimed in claim 7, wherein the number of the subset is controlled in accordance with a temperature setpoint.
9. A system as claimed in claim 4, wherein the system is further usable in a cooling mode of operation wherein air is drawn from the building space via the lower manifold and dissipated to the atmosphere via the excessive hot air dissipation mechanism.
10. A system as claimed in claim 1, further comprising an isolation valve configured to prevent air flow through the air heating tubes and wherein the system is further usable in an isolation mode of operation wherein air does not flow via the air heating tubes.
11. A system as claimed in claim 1, wherein the air heating tubes are glass tubes
12. A system as claimed in claim 11, wherein the air heating tubes are double walled evacuated glass tubes
13. A system as claimed in claim 12, further comprising a laminar flow interruption structure located within each tube.

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14. A system as claimed in claim 13, wherein the laminar flow interruption structure is a screwtype structure.
15. A system as claimed in claim 14, wherein the structure is perforated.
16. A system as claimed in claim 12, further comprising a heat conductive structure located within each tube.
17. A system as claimed in claim 1, wherein the system further comprises water heating tubes within the air heating tubes and wherein the system is further configured for heating water within the water heating tubes via heat exchange.
18. A system as claimed in claim 18, wherein the system is usable in a water heating mode of operation wherein water is heated within the air heating tubes and wherein the air does not flow into the building space.
19. A method of controlling the solar air heating system as claimed in claim 4, the method comprising monitoring temperature and:

when the temperature is below a temperature setpoint, the air flows via the upper manifold into the building space; and when the temperature exceeds the temperature setpoint, controlling the excessive hot air dissipation mechanism to dissipate hot air to the atmosphere.
20. A method as claimed in claim 19, wherein air is drawn from the building space via the lower manifold such that, when the temperature exceeds the temperature setpoint, the system draws air from the building space for cooling.
21. A method of controlling the solar air heating system as claimed in claim 10, wherein the system further comprises an excessive hot air dissipation mechanism, the method comprising monitoring temperature and:

when the temperature is below a temperature setpoint, the system is in an air heating mode of operation wherein air flows into the building space via the upper manifold; and when the temperature is above the temperature setpoint:

controlling the system in an isolation mode of operation wherein the isolation valve is closed such that air does not flow via the air heating tubes; or controlling the system in a cooling mode of operation wherein air flows from the building space via the lower manifold and is dissipated to the atmosphere.
22. A method of controlling the solar air heating system as claimed in claim 10, wherein the system further comprises an excessive hot air dissipation mechanism, the method comprising monitoring temperature and:

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23. A method of controlling the solar air heating system as claimed in claim 17, the method comprising:

controlling the system in an air heating mode of operation wherein air is heated within the air heating tubes and flows via the upper manifold into the building space; and controlling the system in a water heating mode of operation wherein water is heated within the water heating tubes for heating a hot water system and wherein air does not flow into the building space.
24. A method as claimed in claim 23, wherein the system further comprises an isolation valve configured to prevent air flow through the air heating tubes and wherein, in the water heating mode, the isolation valve is closed such that air does not flow through the air heating tubes.

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Cooler Months Warmer Months co r-1

Figure 8A Figure 8B