FIELD OF THE INVENTION

The present invention relates to an apparatus and a method for controlling temperature. In more specific embodiments, the present invention relates to a system for affecting the temperature of a room and to a structure suitable for accommodation. The structure may be used for remote area accommodation.

BACKGROUND TO THE INVENTION

Providing comfortable accommodation in remote areas frequently presents challenges. For example, many mining sites in Australia are located in regions of climatic extremes. Daytime temperatures in summer in many such regions can frequently exceed

40 ⁰ C. Further, due to the remoteness of many such sites, it is difficult, and often prohibitively expensive, to connect such sites to the national electricity grid. Therefore, supply of electricity becomes dependant upon the use of local generators which are typically operated on diesel or petrol fuel. In order to minimise consumption of fuel, it is desirable to minimise electricity consumption in such areas.

Remote sites in Australia frequently experience an arid climate having hot day time summer temperatures with low humidity but much cooler winter time temperatures, ha order to provide cost effective cooling to workers' accommodation in summer, the workers' accommodation structures are frequently provided with evaporative air conditioning units. In such units, water is pumped through a porous filter or similar medium. Exterior air is blown through the water in the medium. This causes some of the water in the medium to evaporate, thereby cooling the air. The cool air is then blown into the accommodation structure. Whilst such evaporative cooling is effective in arid zones to cool the air, it also greatly increases the humidity of the air entering the accommodation structure, sometimes to undesirable levels. Water consumption in such evaporative air conditioning units can also be excessive. The increase in the level of humidity inside the house or room also makes evaporative air conditioning unsuitable for use in tropical regions. hi the colder months of the year (or in regions located in colder climates), it can be difficult to provide effective heating to such structures to ward off the cold.

It is an object of the present invention to overcome or at least ameliorate one

or more of the above disadvantages.

BRIEF DESCRIPTION OF THE INVENTION

In a first aspect, the present invention provides a system for affecting the temperature of a room, the system including a tank containing a liquid, at least one surface of the tank being in contact with air from an interior of the room, an air inlet for admitting air to an interior of the tank and an air outlet through which air leaves the tank, wherein air leaving the tank through the air outlet is vented to a region located outside the room.

Preferably, the air inlet is positioned above the level of the liquid in the tank. Preferably, the air outlet is positioned above the level of the liquid in the tank.

In one embodiment, at least one fan is provided to cause air to flow from the air inlet to the air outlet. More preferably, an inlet fan is provided to cause air to flow through the inlet and an outlet fan is provided to cause air to flow out of the air outlet.

The system of the first aspect of the present invention is arranged such that at least one surface of the tank is in contact with air from the interior of the room. Suitably, one wall of the tank forms part of an interior wall of the room. Alternatively, interior air from the room may pass into a duct and be caused to flow past the at least one surface of the tank, with the air then being returned to the interior of the room.

In a more preferred embodiment, the room includes exterior walls and the tank is positioned adjacent to an exterior wall, with a wall of the tank forming part of an interior wall of the room. Preferably, this interior wall of the room is spaced from the exterior wall. Suitably, the exterior walls of the room are insulated with insulating material.

In other embodiments, the tank may comprise a free standing wall that can affect the temperature of one or more rooms. The tank may also be retrofitted into an existing structures as a separate element.

The liquid in the tank may be any liquid that can evaporate or otherwise affect the temperature of the room or space. Suitably, the liquid is water or an aqueous solution.

In one preferred embodiment, the room forms part of a remote area accommodation structure, the tank contains water and the water in the tank forms part of the water supply to the accommodation structure.

As mentioned above, preferred embodiments of the first aspect of the present

invention include one or more fans to cause the air to flow through the tank. The one or more fans are preferably powered by electricity generated from solar energy. More suitably, the electricity is generated from solar panels which produce electricity on the basis of the photovoltaic principle. The system of the first aspect of the present invention has a tank. It will be appreciated that the system may be provided with one or more tanks. The one or more tanks may be made from any material known to be suitable for manufacturing tanks. Such materials include metal such as galvanised iron or sheet steel, plastics such as polypropylene, or fibreglass. The particular design of the tank is not especially critical, provided that it has at least one surface that can be exposed to the air from the interior of the room. It is preferred that the surface of the tank that is exposed to air from the interior of the room forms at least part of a wall of the interior of the room. Therefore, a preferred tank for use in the first aspect of the present invention incorporates at least one generally planar wall.

The system of the present invention may further include at least one fan to cause the room's interior air to move across the surface of the tank. In this fashion, more efficient heat transfer between the surface of the tank and the interior air is achieved.

In the system of the present invention, air enters the air inlet of the tank. It is especially preferred that the air that enters the air inlet of the tank is air that is taken from a region located exterior to the room. Most suitably, the air that enters the tank is external air or air from outside the structure that has the room. The air passes through the headspace in the tank (which is located between the upper level of liquid in the tank and the top of the tank). This causes some evaporation of the liquid to take place, thereby cooling the liquid in the tank. The air containing evaporated liquid then passes out of the air outlet from the tank. As the air containing the evaporated liquid passes to a region that is located exterior to the room, the air in the interior of the room does not suffer from an unwanted increase in the amount of evaporated liquid in the room. Where water is the liquid in the tank, this results in the humidity inside the room not increasing. This is in sharp contrast to the effects caused by using conventional evaporative air conditioning systems.

It will be appreciated that operation of the system in accordance with the present invention will cause evaporation of the liquid within the tank. In a preferred embodiment, the tank includes automatic filling means for filling the tank to a maximum level when the liquid in the tank reaches a predetermined minimum level. A simple float

valve is a preferred automatic filling means in this regard. Other automatic filling means may also be utilised.

The system may further include a heating means for heating the liquid in the tank. The heating means may comprise solar heating means. The solar heating means preferably comprises a solar heating system in which one or more tubes are positioned such that the one or more tubes are heated by the sun whereby water can flow from the tank through the one or more tubes and back to the tank in order to heat the liquid, m this regard, the solar heating means may be very similar to solar heating used on domestic swimming pools. A further advantage of incorporating such solar heating systems in the system of the present invention arises where the system is located in a region that experiences high day time temperatures but relatively cooler night time temperatures. In these regions, as night falls and the temperature drops, if the exterior temperature becomes lower than the temperature of the liquid in the tank, the liquid in the tank can be circulated through the solar heating system. This causes the water circulating through the solar heating system to radiate heat outwardly and thereby further cool the liquid in the tank.

It will also be appreciated that the liquid in the tank could be heated by any other heating means, desirably an energy efficient heating means. For example, solar energy may be used to generate electricity, which electricity can be used to drive electric heating means to heat the water in the tank. In a second aspect, the present invention provides a structure comprising a building having exterior walls and at least one interior room, a tank containing a liquid, at least one surface of the tank being in contact with air from at least one interior room, an air inlet for admitting air to an interior of the tank and an air outlet through which air leaves the tank, wherein air leaving the tank through the air outlet is vented to a region located outside the room.

Preferred embodiments of the second aspect of the present invention may include the features described with reference to the first aspect of the present invention.

This structure can be used as a structure for remote area accommodation. The structure suitably has insulated walls. The tank may form part of an interior wall of the structure. Alternatively, the tank may be positioned adjacent to an inside of an exterior wall, with the respective interior wall being spaced from the exterior wall, wherein the tank is positioned in the space between the exterior wall and its respective interior wall.

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In embodiments where the tank is positioned inside the exterior walls, the exterior walls are suitably provided with openings that allow air to flow from outside the structure to the air inlet and from the air outlet to a region located outside the structure.

Suitably, an exterior wall located adjacent to the tank is provided with openings that are in register with the air inlet and the air outlet.

In all aspects of the present invention, it is preferred that the air inlet is spaced from the air outlet. This will assist in avoiding air from the air outlet being taken back into the tank via the air inlet. To facilitate this, the air inlet may be located at one end of the tank and the air outlet may be located at another end of the tank. Alternatively, the air inlet may be located at an end face of the tank and the air outlet located at an opposed end face of the tank. As a further alternative, the air inlet may be located in an end face of the tank and the air outlet may be located at a far end of a side of the tank, or vice versa.

In a third aspect, the present invention provides a method for affecting the temperature of a room comprising the steps of providing a tank containing a liquid, causing air to flow through the tank such that air is vented outside the room, and placing air from the room in contact with a surface of the tank.

In all aspects of the present invention, the fan or fans may operate intermittently to minimise water consumption. For example, it may not be necessary to operate the fans at night time in order to maintain a comfortable temperature inside the room.

In a fourth aspect, the present invention provides a system for affecting the temperature of a room, the system including a tank containing a liquid, at least one passage extending at least partly into the tank, the passage having an inlet for admitting air and at least one outlet from which air passes into the room, said passage being arranged such that direct contact between the air flowing through the passage and the liquid in the tank is avoided.

Suitably, the inlet of the at least one passage opens into the room such that air entering the inlet of the at least one passage is taken from the room.

Preferably, at least one fan causes air to flow from the inlet to the outlet of the at least one passage. The at least one fan may be arranged adjacent the inlet, or adjacent the outlet or adjacent both the inlet and the outlet, of the at least one passage.

The at least one passage may comprise a conduit in the tank. The conduit may

have an inlet at a side of the tank and an outlet at a side of the tank, with the conduit extending between the inlet and the outlet. The side of the tank may include any side wall of the tank, the top of the tank or the bottom of the tank. More suitably, a plurality of such conduits are provided. Alternatively, the at least one passage may comprise a honeycomb structure in the tank.

In the fourth aspect of the present invention, air flows through the passage(s) and either heats up or cools down, depending on the temperature of the liquid in the tank. The air then moves into the room to thereby affect the temperature in the room. The tank may be similar to the tank used in accordance with the first to third aspects of the present invention. For example, the tank may have an air inlet for admitting air to an interior of the tank and an air outlet through which air leaves the tank, wherein air leaving the tank through the air outlet is vented to a region located outside the room. These air inlets and outlets are additional to the inlets and outlets of the passages through which air flows and is moved into the room.

Other features of the tank may be as described with reference to the first to third aspects of the present invention.

In a fifth aspect, the present invention provides a structure comprising a building having exterior walls and at least one interior room, a tank containing a liquid, at least one passage extending at least partly into the tank, the passage having an inlet for admitting air and at least one outlet from which air passes into the room, said passage being arranged such that direct contact between the air flowing through the passage and the liquid in the tank is avoided.

In a sixth aspect, the present invention provides a method for effecting the temperature of a room comprising providing at least one passage extending at least partly into the tank, the passage having an inlet for admitting air and at least one outlet from which air passes into the room, said passage being arranged such that direct contact between the air flowing through the passage and the liquid in the tank is avoided.

In the fourth to sixth aspects of the present invention, it is preferred that the tank is provided with a plurality of passages that pass through an interior volume of the tank. The tank may be located in the room, it may have an external surface in the room or it may be located remotely from the room. If the tank is located remotely from the room, the outlet

of the at least one passages either opens into the room or is in fluid communication with another passage that opens into the room.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will now be described with reference to the following drawings in which:

Figure 1 shows a cross-sectional side view of a structure in accordance with an embodiment of the present invention;

Figure 2 shows a front perspective view of the structure shown in Figure 1; Figure 3 shows a rear perspective view of the structure shown in Figure 1 ;

Figure 4 is a rear view of the structure shown in Figure 1; Figure 5 is a top cross-sectional view of the structure shown in Figure 1; Figure 6 is a perspective view of a tank for use in the present invention; Figure 7 shows a side view, partly in cross section, of a structure in accordance with another aspect of the present invention; and

Figure 8 shows a schematic arrangement of the inlets and outlets of the passages in the tank shown in Figure 7.

The structure shown in Figures 1 to 6 in the accompanying drawings incorporates a system in accordance with an embodiment of the first aspect of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

It is to be understood that the drawings attached to the specification have been provided for the purposes for illustrating certain preferred embodiment of the invention and that the invention should not be considered to be limited to the features as shown in the drawings.

The structure 10 shown in the accompanying drawings includes an internal room 12 that is bounded by front wall 14, rear wall 16 and opposed side walls 18, 20. The internal room 12 has a floor 22 and a roof 24. Stairs 26 provide access to front door 28. The structure 10 further includes an external structure 30 having a roof 32, a sloping front wall 34, a sloping rear wall 36 and side walls 38, 40. External structure 30 is provided for the following reasons:

a) Roof 32 of external structure 30 has a larger surface area than roof 24. Therefore, extra space is provided for solar panels, recirculating water tubes, etc; b) The external structure 30 provides additional shade to the internal room and, in effect, acts as a radiation heat shield to assist in lowering the temperature inside the internal room 12; and c) The external structure 30 improves the aesthetics of the overall structure.

The structure 10 is supported on posts 41 that are held in the ground in conventional manner. Front wall 14 is provided with louvers 42, 44 to assist in ventilation of the internal room 12. Similarly, rear wall 16 is provided with louvers 46, 48.

The internal room 12 may also be provided with kitchen facilities, toilet and bathroom facilities, sleeping facilities, dinning facilities and entertainment facilities. For the sake of clarity, these facilities are not shown in the drawings. hi order to assist in moderating temperature changes in the internal room 12, a water tank 50 is mounted in the internal room 12. Water tank 50 is designed to be filled with water to the level shown by reference numeral 52 in Figure 1. Thus, it can be seen that a headspace 54 is formed in the water tank 50 above the level of the water 52. hi order to ensure that the water in tank 50 does not go above level 52, the tank may be provided with an overflow weir or an overflow outlet such that any excess water added once the level reaches level 52 simply flows out of the tank. Alternatively, the tank may be filled by an automatic filling mechanism which includes a float valve (or similar), which float valve turns off the supply of water to the tank 50 when the water level reaches level 52. Water tank 50, as shown in Figures 1-6, is suitably of generally rectangular prism shape. The front surface or wall 56 is exposed to the internal room 12. The rear surface wall 58 of tank 50 abuts the inner face of rear wall 16.

As best shown in Figure 6, the rear wall 58 of tank 50 is provided with an air inlet 60 and an air outlet 62. An ingress fan 64 is mounted in a hole 66 formed in rear wall 16, which hole 66 is in register with air inlet 60 of water tank 50. Similarly, an exit fan 68 is mounted in a hole 70 in rear wall 16, which hole 70 is in register with air outlet 62. In this fashion, air from outside the structure is introduced through air inlet 60 and caused to flow

through the headspace 54 of tank 50. This causes evaporation of water in the tank 50, which cools the water. The humidified air then leaves the tank via air outlet 62 and hole 70 in rear wall. Thus, the humidified air is exhausted to an exterior space outside of the internal room 12. It will be appreciated that the air flowing through the headspace 54 acts to cool the water inside tank 50. The cool water in tank 50 will then act to cool the internal room 12, by virtue of the tank 50 being in indirect heat exchange with air inside the internal room 12 (mainly by virtue of the large front wall 56 of tank 50). Moreover, although evaporative cooling is used to cool the water inside tank 50, the humidified air is not vented into the internal room 12, but rather vented to an exterior space. Thus, the air inside internal room 12 does not become humidified.

In order to provide at least supplementary electric power to the structure 10 shown in the figures, the roof 32 may be provided with solar panels 72. Solar panels 72 are suitably photovoltaic cells that generate electricity when solar energy is instant upon them. The solar energy generated by solar panels 72 may be stored in batteries (not shown) to provide for electricity supply during cloudy periods and night time.

The roof 32 may also be provided with recirculating water tubes 74. Recirculating water tubes 74 are in fluid communication with water inside tank 50. Water is recirculated through recirculating water tubes 74 by use of appropriate pumps (not shown), as will be readily understood by persons skilled in the art. The recirculating water tubes 74 are used in the following manner: a) during summer time, if the night time temperature drops below the temperature of the water in tank 50, water is circulated through recirculating water tube 74 to cool the water in the tank 50; or b) in winter time, if the temperature of the water drops below a predetermined minimum temperature during the daytime, water from tank 50 is circulated through the recirculating water tube 74 to heat the water.

In both modes of operation, the recirculating water tubes act similarly to known solar heating systems for swimming pools. The person skilled in the art will readily understand how such solar heating systems work and further description need not be provided.

It will be appreciated that, in colder climates, a similar water tank system may be provided to provide thermal mass to the interior room 12. For use in colder climates, it may not be necessary to include the provision of air inlets and air outlets to the tank in order to enable air to circulate through the headspace of the tank. Furthermore, the rear wall of the tank may be positioned such that it is exposed to sunlight during the daytime in order to further heat the water inside the tank. The water inside the tank may also be heated by the use of recirculating water tubes on the roof of the structure. The particular construction suitable for use in cold climates forms a separate aspect of the present invention.

The present invention provides a system and a structure that can result in comfortable living temperatures being obtained inside the structure. The structure is energy efficient and may incorporate solar panels to generate at least some of its electricity requirements. The presence of the water tank provides a thermal mass that tends to dampen fluctuations in temperature inside the room, thereby minimising the extremes of temperature inside the room. The water tank and the associated fan or fans also forms a separate aspect of the present invention.

Although the drawings shown in Figures 1-5 show an external structure 30 being used, it will be appreciated that the external structure 30 comprises an optional feature of the present invention and is not necessarily required in all embodiments of the present invention. The structure shown in Figures 7 and 8 shows an embodiment of the invention that incorporates elements from both the first to third aspects of the present invention and the fourth to sixth aspects of the present invention.

The structure shown in Figures 7 and 8 has a number of features in common with the structure shown in Figures 1 to 6 and, for convenience, like features will be denoted by like reference numerals. It will be understood that the embodiment shown in Figures 7 and 8 incorporates blowing of air across the surface of the liquid in the tank followed by venting of the air from the headspace to a position external to the room. This feature is an optional feature of the fourth to sixth aspects of the invention.

The tank 50 shown in Figure 7 includes a plurality of conduits 90 that extend through the interior volume of the tank. Each conduit 90 has an inlet 92 and an outlet 94. In the tank shown in Figure 7, the inlets 92 and outlets 94 are positioned in a side wall of the tank that faces into the room. The inlets and outlets are provided with fans 96 to assist in

moving air through the passages. In operation, air from the room enters inlet 92 and travels along passage 90 and back into the room via outlet 94. As the air travels along passage 90, it cools down (when the system is being operated in a cooling mode) by indirect heat exchange from the water in the tank and thus cooled air is returned to the room. It has been found that this is more effective at cooling or heating the room than the arrangement shown in Figures l to 6.

Although the tank shown in Figure 7 has part of its side wall in contact with the room, it will be appreciated that the tank may be located remotely from the room as well. In this case, further passages will be required to move air from the outlets of the passages 90 to the room.

Further, the air that passes through the passages 90 may be taken from the room or taken from a position external to the room.

Figure 8 shows one possible arrangement of inlets 92 and outlets 94 that may be used. It will also be understood that the fans 96 may be bi-directional such that the inlets and outlets may be swapped, if desired. This could be advantageous when swapping from a cooling mode (in which the outlets may be desirably located at a higher level) to a heating mode (in which the outlets maybe desirably located at a lower level).

The embodiments shown in Figures 7 and 8 may also include a number of other features of the embodiments shown in Figures 1 to 6, although these have not been described for the sake of brevity.

Finally, the embodiments shown in Figures 7 and 8 may not necessarily require the headspace airflow feature, although this is a preferred feature when operating in a cooling mode.

Those skilled in the art will appreciate that the present invention is susceptible to variations and modifications other than those described herein. It is to be understood that the present invention extends to all such variations and modifications that fall within its spirit and scope.