TECHNICAL FIELD

This invention relates to an air handling system. The invention is also directed to a thermal chamber comprising an air handling system.

BACKGROUND

Air handling systems are used to control the internal temperature and air quality within buildings. There are a wide range of applications of air handling systems, including residential dwellings, commercial complexes such as offices, shops and hotels, as well as a plethora of industrial applications.

Such systems may incorporate a selection of equipment ranging from low-capacity (less than 10kW) self-contained systems, to larger systems serving entire buildings with high-capacity. Broadly speaking, air handling systems can be classified into two categories: 1) centralised systems and 2) decentralised systems.

Centralised systems serve multiple zones from a single central chiller. These typically use chilled water as a cooling medium and use extensive ductwork to distribute chilled air to the multiple zones. Drawbacks of these systems include expensive installation costs, and due to their complexity, the high costs to service and maintain. Additionally, in the case of a breakdown or failure, multiple zones will be affected, potentially causing inconvenience. The footprint of the central chiller can also take-up valuable real estate.

In contrast, a decentralised system typically serves a single zone from a dedicated chiller unit located within or adjacent to the zone being chilled. One such example is a heat pump, or “reverse-cycle” system. Typically, a reverse-cycle system is a split system, comprising of two parts: an outdoor unit and an indoor unit. The outdoor unit, fitted outside the treatment zone to be chilled, generally houses a compressor, external heat exchanger and an expansion valve.

The indoor unit generally comprises an air handler, an internal heat exchanger and a cooling fan. The indoor and outdoor units are interconnected by at least two refrigerant pipes that circulate the refrigerant with the system. When operating in cooling mode, heat from ambient air inside the treatment zone is absorbed by the indoor heat exchanger (acting as an evaporator) and expelled to an external air source via the external heat-exchanger (acting as a condenser). When operating in a heating mode the above described operation is reversed. A problem associated with reverse-cycle systems is the size of the external heat exchanger required to discharge heat. This can lead to large equipment footprints heavily encroaching upon balcony or roof space of residential dwellings. The same issue is encountered by hotels. Where space is a premium, it may not be desirable or possible to install a conventional reverse-cycle system. In such situations, centralised systems may be the only available option, with a central chiller unit serving several rooms or dwellings. In the same way, an alternative to a central system may see entire floors of apartment buildings or hotels taken-up by individual external heat-exchanger units.

Another problem associated with reverse-cycle systems is that the air supplied can be unpleasantly musty, or in some cases unclean. This is due in part to the fact that a reverse-cycle system cannot generate enough heat to sterilise the air supply, which can result in bacterial and biofilm growth within the handling system. In addition to the health and hygiene issues, the overall reliability of the system can be reduced resulting in shortened equipment life.

Reverse-cycle systems also have a limited operational temperature window. Their efficiency and ability to provide heat is reduced in low temperature ambient conditions. As the ambient temperature outside reduces, the unit must work harder to remove heat from the air, lowering its efficiency. In near or sub-zero conditions reverse-cycle systems may stop functioning all together.

The present invention was conceived with these shortcomings in mind.

SUMMARY

In a first aspect, the invention provides an air handing system comprising an internal unit for handling air within a treatment zone and an external unit located outside of the treatment zone: the internal unit comprising a housing defining a first air chamber and a second air chamber therein, the first air chamber in fluid communication with an air inlet drawing in an air source and including an infrared emitter and a filtering device, the second air chamber in fluid communication with an air outlet expelling treated air into the treatment zone, a first heat exchanger disposed across the housing forming a barrier between the first air chamber and the second air chamber such that the air source from the inlet passes over the first heat exchanger when moving from the first air chamber to the second air chamber towards the outlet, a compressor and an expansion device in fluid communication with the first heat exchanger to impose a change of state on a working fluid therein; the external unit comprising a second heat exchanger in fluid communication with the first heat exchanger, wherein the air handling system is configured to operate in a first cooling mode to reduce an initial temperature of the air source to the treatment zone, and a second heating mode to increase the initial temperature of the air source to the treatment zone.

In some embodiments, the first heat exchanger may provide heat transfer between the working fluid and an air source within the treatment zone, and the second heat exchanger may provide heat transfer between the working fluid and an external air source to the treatment zone. The working fluid may be a refrigerant.

When operating in the first cooling mode, the air handling system may operate on a vapour compression cycle. When operating in the second heating mode, the air handling system may operate on a vapour compression cycle. When operating in the second heating mode, the infrared emitter may be used to increase the initial temperature of the air within the treatment zone and the compressor is disengaged.

In some embodiments, the air handling system may further comprise an accumulator configured to provide a sub-cooling circuit, the accumulator comprising: a first conduit providing fluid communication of the working fluid between the first heat exchanger and the compressor; and a second conduit providing fluid communication of the working fluid between the second heat exchanger and the expansion device, wherein heat is transferred between the first conduit and the second conduit. The expansion device may be an electronic expansion valve.

The air handling system may further include a hot water system, comprising a third heat exchanger located in close proximity to a discharge line between the compressor and the second heat exchanger, wherein the third heat exchanger draws heat from the discharge line and transfers the heat to a discrete hot water circuit to heat water therein.

The air handling system may further comprise a geothermal heat exchanger. At least one of the first, second and third heat exchangers may be a geothermal heat exchanger.

The second heat exchanger may be a static condenser. The second heat exchanger may be a tube and fin configuration. The second heat exchanger may be driven by natural convection. The second heat exchanger may be mountable within existing ducting of a building to utilise existing air flows. The second heat exchanger may be configured to minimise vertical height and maximise horizontal width and breath, to facilitate installation in restricted spaces. The second heat exchanger may be an adiabatic condenser.

In some embodiments, the second heat exchanger may comprise at least one fan to draw air across the second heat exchanger and promote heat exchange with the air external to the treatment zone. The second heat exchanger may comprise a micro-channel circuit, such that an inlet of the micro-channel circuit receives the working fluid from the internal unit, and an outlet of the micro-channel circuit expels the working fluid back to the internal unit after heat exchange across the second heat exchanger has occurred. The second heat exchanger may comprise a pair of micro-channel circuits running in series, such that a first of the micro-channel circuits receives the working fluid from the internal unit, and a second of the micro-channel circuits expels the working fluid back to the internal unit after heat exchange across the second heat exchanger has occurred. The pair of micro-channel circuits may be mounted to a base plate of the second heat exchanger and may each be inclined towards the base plate by 15-25 degrees. The second heat exchanger may be configured to mount vertically to a wall. The second heat exchanger may be configured to mount horizontally within a roof space.

In some embodiments, the second heat exchanger may be a multi-circuit condenser, comprising a plurality of micro-circuit condensers, each respectively fluidly connected to a dedicated internal unit. At least one fan may be arranged to drive external air across the plurality of micro-circuit condensers, simultaneously. The at least one fan may be a blower.

In some embodiments, the housing of the internal unit may comprise of a compressor module, an air handler module and a connection module, horizontally stacked one above the other to form an elongate cabinet. The dimensions of the cabinet may be maximised in a vertical direction to allow the horizontal and lateral dimensions to be minimised. The air inlet and the air outlet may be disposed at two opposing sides of the cabinet, and an access panel may be provided therebetween defining a front of the cabinet. The access panel at the front of the cabinet may be formed in three discrete portions to provide selective to the compressor module, the air handler module and the connection module. The access panel of the air handler module may further comprise an electronic controller with an external user interface.

The air handler module may further house an electronic control system. The electronic control system may be mounted in an insulated enclosure. In some embodiments, an ultraviolet light source may be located within the second air chamber downstream of the first heat exchanger. The first heat exchanger, the infrared emitter and the filtering device may be housed within the air handler module of the cabinet. The air handler module may further house at least one fan to drive air flow across the first heat exchanger. The air handler module may comprise a plurality of fans arranged in series along a longitudinal axis of the first heat exchanger within the first air chamber. In some embodiments, the connection module may provide a first aperture to the air inlet of the cabinet and a second aperture to the air outlet of the cabinet and cooperating apertures and/or flanges for connecting with a ducting system of the treatment zone. At least one of the compressor and the expansion device may be housed within the compressor module of the cabinet.

In some embodiments, at least one of the first heat exchanger, the infrared emitter and the filtering device may be mounted to a slidable member to form a cassette that can be ejected and inserted into the cabinet. The first heat exchanger and the filtering device may be oriented on the slidable member to extend across the cabinet from front to back, such that ejecting the cassette provides full visual access to the first heat exchanger and the filtering device, from the access panel. The or each of the fans may be mounted to the slidable cassette. The slidable cassette may be mounted to a pair of guide rails within the air handler module of the cabinet. The slidable cassette may be mounted below the electronic control system in the cabinet. The slidable cassette may be removable from within the cabinet for cleaning, inspection and replacement.

In another aspect, the invention provides a thermal chamber comprising: a cell defining a treatment zone; and an air handling system, the air handling system comprising: a housing divided by a barrier to define a first air chamber and a second air chamber, the first air chamber in fluid communication with an air inlet and including an infrared emitter and a filtering device, and the second air chamber having an air outlet, wherein both the first air chamber and the second air chamber are in fluid communication with the chamber, a first heat exchanger is disposed within the first air chamber such that an air source from the inlet passes over the first heat exchanger when moving from the first air chamber towards the cell, a second heat exchanger located within the second air chamber such that air from the cell is drawn over the second heat exchanger when discharged from the air handling system, and a compressor and an expansion device in fluid communication with the first heat exchanger and the second heat exchanger to impose a change of state on a working fluid therein, wherein the air handling system is configured to operate in a first cooling mode to reduce an initial temperature of the air source within the treatment zone, and a second heating mode to increase the initial temperature of the air source within the treatment zone.

In some embodiments, the air handling system may further comprise at least one of a portable power source and a connection to mains power. The air handling system may further comprise at least one fan or blower to move air across the first and second heat exchangers. The housing may be mounted to a trolley. The housing may provide a user control interface for controlling the air handling unit.

The cell may be a tent or similar enclosed chamber. The tent may be an inflatable tent, comprising a flexible membrane supported by internal stiffeners that pressurise when filled with air to support the flexible membrane of the tent. The tent may further comprise at least one closable opening for ingress and egress of a treatment subject. The tent may further comprise at least one of a seat, a light, a power socket and a de-humidifier. The treatment zone of the tent may be in fluid communication with the outlet of the air handling system via a conduit.

In a third aspect, the invention provides a thermal chamber comprising: a cell defining a treatment zone; and an air handling system, the air handling system comprising: a housing divided by a barrier to define a first air chamber and a second air chamber, the first air chamber in fluid communication with an air inlet drawing in air from an air source and including an infrared emitter and a filtering device, and the first air chamber having an air outlet, wherein the first air chamber is in fluid communication with the cell; a first heat exchanger disposed within the first air chamber such that the air source from the inlet passes over the first heat exchanger when moving from the first air chamber towards the cell; a second heat exchanger located within the second air chamber, and a compressor and an expansion device in fluid communication with the first heat exchanger and the second heat exchanger to impose a change of state on a working fluid therein, wherein the air handling system is configured to operate in a first cooling mode to reduce an initial temperature of the air source to the treatment zone, and a second heating mode to increase the initial temperature of the air source to the treatment zone.

The illustrative embodiments described herein, depicted in the drawings and defined in the claims, are not intended to be limiting. Persons skilled in the art are capable of appreciation of other embodiments and features from the following detailed description in conjunction with the drawings.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention are illustrated by way of example, and not by way of limitation, with reference to the accompanying drawings, of which:

Figure 1 is a circuit diagram of an air handling system according to one embodiment of the invention; Figure 2 is an exploded perspective view of an internal unit of the air handling system of Figure 1, comprising a compressor, an air handler, and an air duct connecting assembly;

Figure 3A is a perspective view of internal components of the air handler of Figure 2 in an assembled state;

Figure 3B is an exploded view of internal components of the air handler of Figure 2;

Figure 3C is a top view of the air handler, illustrating an inlet and an outlet in a lid of the handler;

Figure 3D is a top view of the air handler with the lid removed showing the components of the electric control system positioned below the lid;

Figure 3E is a top view of the air handler with the lid and an electrical control system removed, showing a layout of the components within the air handler;

Figure 3F is a top view of the handler schematically illustrating a pair of internal air chambers within an internal cavity of the air handler;

Figure 4A is a perspective view of an evaporator of the air handler, according to one embodiment where the evaporator is a cross channel heat exchanger;

Figure 4B is an exploded view of the components of the air handler, a circle highlighting the evaporator of Figure 4A within the exploded representation of the internal components of the air handler.

Figure 5A is a perspective view of an infrared light assembly of the air handler;

Figure 5B is an exploded view of the components of the air handler, a circle highlighting the Infrared light assembly of Figure 5A within the exploded representation of the internal components of the air handler.

Figure 6A is a perspective view of the air handler, illustrating a sliding assembly in a partially removed position;

Figure 6B is an enlarged view of the encircled region of Figure 6a, illustrating a sliding interface between the sliding assembly and guide rails;

Figure 7 A is a perspective view of an electronic control system of the air handling system, with front and side panels of an enclosure removed to show the internal components;

Figure 7B is a side view of the electronic control system of Figure 7A, illustrating components of the enclosure (with a side panel removed);

Figure 7C is an exploded view of the components of the air handler, highlighting the electronic control system of Figure 7 A within the exploded representation of the internal components of the air handler; Figure 8 is a perspective view of the compressor motor within the compressor;

Figure 9 is a perspective view of an air duct connecting assembly of the air handling system;

Figure 10 is a perspective view of a condenser of the air handling system, according to one embodiment of the invention where the condenser is a static condenser;

Figure 11A is an exploded perspective view of a condenser of the air handling system, according to one embodiment of the invention where the condenser is a micro- channel condenser;

Figure 11B is a perspective view of the micro channel condenser of Figure 11A, in an assembled state;

Figure 11C is a perspective view of the micro channel condenser of Figure 11A, showing an embodiment mountable in a vertical orientation;

Figure 12 is a perspective view of a condenser of the air handling system, according to one embodiment of the invention where the condenser is a multi-circuited condenser;

Figure 13 is a schematic layout of one embodiment of the air handling system, illustrating a sub-cooling circuit and hot water generation circuit;

Figure 14 is a perspective view of a geothermal heat exchanger for use in the hot water generation circuit of Figure 13;

Figure 15 is a perspective view of an electronic expansion valve;

Figure 16A is a perspective view of an embodiment of an air handling system, in the form of a portable thermal chamber comprising an inflatable tent and a portable air treatment unit;

Figure 16B is a top view of the portable thermal chamber of Figure 17A, showing fluid connections between the portable air treatment unit and the inflatable tent;

Figure 16C is a perspective view of the portable air treatment unit of Figure 17A with transparent side walls, illustrating the arrangement of internal components within the unit; and

Figure 16D is a rear view of the portable air treatment unit of Figure 17C, showing an interface for connecting the air treatment unit with the inflatable tent.

DETAILED DESCRIPTION

In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings may be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

The invention is described herein in reference to Figures 1-15, and provides an air handing system 1 comprising an internal unit 3 for handling air within a treatment zone and an external unit 4 located outside of the treatment zone: the internal unit 3 comprising a housing 8 defining a first air chamber 61 and a second air chamber 62 therein, the first air chamber 61 in fluid communication with an air inlet 57 drawing in an air source and including an infrared emitter 66A and a filtering device 67, the second air chamber 62 in fluid communication with an air outlet 58 expelling treated air into the treatment zone, a first heat exchanger 20 disposed across the housing 8 forming a barrier between the first air chamber and the second air chamber such that the air source passes over the first heat exchanger 20 when moving from the first air chamber 61 to the second air chamber 62 towards the outlet, a compressor 30 and an expansion device 10 in fluid communication with the first heat exchanger 20 to impose a change of state on a working fluid 2 therein; the external unit 4 comprising a second heat exchanger 40 in fluid communication with the first heat exchanger 20, wherein the air handling system 1 is configured to operate in a first cooling mode to reduce an initial temperature of the air source to the treatment zone, and a second heating mode to increase the initial temperature of the air source to the treatment zone.

Figure 1 illustrates an air handling system 1 in accordance with one embodiment of the invention, comprising an internal unit 3 and an external unit 4. Within internal unit 3 there is an expansion device 10, an indoor heat exchanger 20, and a compressor 30. Wthin the external unit 4 there is provided an external heat exchanger 40 which can operate in combination with a fan or blower (not shown). The internal unit 3 and the external unit 4 are fluidly connected by a discharge line 5 (channelling compressed refrigerant to the condenser 40) and a return line 6 (that channels liquified refrigerant 2 back towards the expansion device 10 of the interior unit 3).

The air handling system 1 will be described herein in relation to its operation in a first, cooling mode. In this cooling mode, the indoor heat exchanger 20 operates as an evaporator, and the external heat exchanger 40 operates as a condenser. This arrangement is shown in Figure 1. It is understood that the air handling system 1 can also operate in a second, heating mode. In heating mode, the function of the indoor heat exchanger 20 and the external heat exchanger 40 are reversed.

The air handling system 1 operates on a thermal vapour compression cycle in which a transfer fluid is heated or cooled to provide a desired temperature output from the system 1 into a treatment zone or controlled volume. The transfer fluid is a refrigerant 2. Refrigerant

2 can be R134A or similar.

The term ambient air as recited herein is understood to mean air within the treatment zone or controlled volume that is to be treated by the air handling system; for example, the air within a room or treatment zone which is to be cooled. This is distinct from the exterior air, which is understood herein to refer to air from outside the controlled volume; for example, air from outside the home to which the exterior unit rejects heat.

Refrigerant 2 is metered by an expansion device 10 into the indoor heat exchanger 20 operating as an evaporator where the refrigerant 2 absorbs heat from an ambient air source having a higher temperature than the refrigerant 2. A fan 63 (shown in Figure 3B) forces air from the ambient air source across the indoor heat exchanger 20, increasing the heat transfer. An increase in the temperature of the refrigerant 2 causes it to boil. In boiling, the refrigerant 2 undergoes a first phase change, evaporating from a liquid to a vaporous gas. The vaporous refrigerant 2 is then pumped to the compressor 30 via suction line 7.

The vaporous refrigerant 2 gains more heat energy as it passes through the compressor 30, through an adiabatic compression process. This in turn cools the compressor 30. The now superheated vaporous refrigerant 2 is pumped via discharge line 5 to the external heat exchanger 40. The vaporous refrigerant 2 is now a higher temperature than an exterior air temperature, so heat energy is transferred from the vaporous refrigerant 2 to the exterior air as it passes through the external heat exchanger 40, which operates as a condenser. Exterior air is forced across the external heat exchanger 40 by a condenser fan (not shown) to increase the heat transfer. As the heat energy is released, the vaporous refrigerant 2 loses heat energy and undergoes a second phase change, condensing to a high-pressure liquid refrigerant on its return to the expansion device 10, via return line 6. The expansion device 10 expands the high-pressure liquid refrigerant 2, resulting in a drop in the pressure and temperature of the liquid refrigerant 2.

The indoor heat exchanger 20, compressor 30 and expansion device 10 are located at the same physical location forming the single internal unit 3: with the condenser 40 located within the external unit 4 remotely located from the internal unit 3.

Figure 2 shows an embodiment of internal unit 3 comprising a compressor unit 35, an air handler 50 and an air duct connecting assembly 100. The compressor 30 is contained within a compressor housing 31. The air handler unit 50 is contained within an air handler casing 51. Each casing 31, 51 includes an openable access panel 32, 55 respectively. The compressor casing 31 is located beneath the air handler casing 51. This is to be contrasted to decentralised or reverse-cycle systems where the compressor 30 is located remotely of the indoor heat exchanger 20. Compressors and condensers of air-conditioning units are typically placed together, externally of the controlled volume or treatment zone to be cooled. An advantage of having the compressor 30 and associated electrical sensors located within the internal unit 3 is their reduced exposure to an external environment, providing a stable operating temperature and reducing the change of electronics failure due to water ingress and other environmental factors. As shown in Figure 2, the air duct connecting assembly 100 has two apertures, an inlet duct 101 taking air into the air handler 50 and an outlet duct 102 expelling air from the air handler 50.

The compressor unit 35, air handler 50, and air duct connecting assembly 100 are configured in Figure 2 to have a similar cross-section to enable the three components to form a slimline, upright cabinet 8 encompassing all interior components of the internal unit 3 therein. This cabinet 8 can be easily installed in a hallway, cupboard, wardrobe or apartment with minimal encroachment on living space.

The air handler 50 will be described in further detail in reference to Figures 3A-3F. Figure 3A illustrates internal components of the air handler 50, oriented in a vertical or upward manner. The air handler 50, has a height, a width and a depth. To minimise cross- sectional area of the air handler 50, the internal components of the air handler 50 are arranged such that the width and depth are minimised, and the height is maximised.

The casing 51 is substantially rectangular and comprises a rear panel 52, two opposing side panels 53, a base 54, an openable access panel 55 (not shown in Figure 3A) and a lid 56. As illustrated in Figure 3B, access panel 55 takes the form of a door. In some embodiments, the door is hinged on one side and secured with a locking mechanism that can be opened without the use of specialised tools.

Also packaged within the air handler casing 51 are circulation fans 63. The circulations fans 63 are mounted within a fan casing 64. The circulation fans 62 create an air flow across the indoor heat exchanger 20. A filter assembly 67 and lamp assembly 66 treat the air as it flows within the air handler 50. An electronics control system 70 is located within the air handler casing 51, providing a simple and easy to access location for carrying out inspection and diagnostic works.

The door 55 provides a visible surface to which operating instructions and safety operations of the air treatment system 1 , and air handler 50 are affixed. In other embodiments, the access panel 55 can take the form of a sliding panel or viewing window. The base 54 provides a connection between the casing 51 of the air handler 50 and the casing 31 of the compressor unit 35. The lid 56 is located on an uppermost surface of the casing 51 and provides inlet and outlet apertures 57, 58 which provide a fluid connection to the air duct connecting assembly 100.

Figures 3D and 3E illustrate a compact packaging of the components within the casing 51 which enables the air handler 50 to take a small footprint and generally slim form. When the air handler 50 is mounted in a vertical orientation, the electronics control system 70 is positioned uppermost within casing 51. This provides simple access to the electronics control system 70, by removing lid piece 56. The indoor heat exchanger 20, fan casing 64 and filter assembly 67, are positioned below the electronics system. The casing 51 tightly wraps around an exterior of these components. This is advantageous, as it enables the air handler 50 to be located out of view in the home, such as within a cupboard or wardrobe.

The casing 51 and lid 56 define a cavity 60 within the air handler 50. This is illustrated in Figure 3F. The cavity 60 provides a first chamber 61 located upstream of the indoor heat exchanger 20. The first chamber 61 is located on the inlet side of the indoor heat exchanger 20. As such, untreated air from the treatment zone is exposed to the components within the first chamber 61 , for example, the filter assembly 67 within the first chamber 61. Untreated air from the treatment zone thus flows through the filter assembly 67, prior to flowing over the indoor heat exchanger 20. This is advantageous, as it provides a clean air supply flowing over the indoor heat exchanger 20. This reduces the likelihood of air contaminants coming into contact with the indoor heat exchanger 20, which can negatively affect its operation.

The cavity 60 provides a second chamber 62 located downstream of the indoor heat exchanger 20. The second chamber 62 is located on the outlet side of the indoor heat exchanger 20. Treated air is thus exposed to the components within the second chamber 62, for example, a UV lamp can be fitted within the second chamber 62 to further treat air that is to be pumped into the treatment zone. This exposure to UV provides an air treatment by the UV lamp which can kill or minimise bacterial contaminants that may be air-born, or contaminants that may have been transferred to the air as it flowed across the indoor heat exchanger 20.

Referring once again to Figure 3A, the air handler 50 forms part of a cabinet 8 containing the components that make-up the internal unit 3. The air handler 50 is combined with a compressor module 35 and a duct or connection module 100 to form the cabinet 8.

Ambient air from the treatment zone is filtered by a filter assembly 67, which is located adjacent and parallel to a first side panel 53. Filter assembly 67 is attached to the rear panel 52 via a mounting bracket 69. Air is forced through the filter assembly 67 by at least one air circulating device, illustrated as a pair of fans 63. The plurality of fans 63 draw air through the inlet 57 into the upstream chamber 61. From the upstream chamber 61 air is propelled across the indoor heat exchanger 20 and into the second chamber 62 and then expelled through the outlet 58 back into the treatment zone.

The plurality of circulation fans 63 is mounted within a fan casing 64. The fan casing 64 is situated within the upstream chamber 61. The plurality of circulation fans 63 is arranged parallel to the indoor heat exchanger 20 to provide an even air flow across the indoor heat exchanger 20. The plurality of circulation fans 63 is equidistantly spaced with respect to the first coiled face 22 of the indoor heat exchanger 20, to provide a consistent air flow across the indoor heat exchanger 20.

Each of the plurality of circulation fans 63 has a PID loop to control their rotational speed. Each PID loop includes an air temperature sensor (not shown) located on the first coiled face 22 of the indoor heat exchanger 20 within the downstream chamber 62. The rotational speed of each fan 63 is calculated by the PID loop in response to temperature data from the sensor, to thereby control the fan to provide: (i) an even air flow across the indoor heat exchanger 20, maximising efficiency of heat exchanger 20; and (ii) a uniform air flow rate across the indoor heat exchanger 20.

An electronic control system 70 is mounted to an underside of the lid 56, providing easy access for inspection and servicing. The electronic control system 70 is positioned in the cavity 60 above the filter assembly 67 and the indoor heat exchanger indoor heat exchanger 20. A lamp assembly 66 is situated adjacent to the indoor heat exchanger 20, within the upstream chamber 61.

In some embodiments, the indoor heat exchanger 20 is a cross-flow heat exchanger 120. This is shown in Figures 4A and 4B. The cross-flow heat exchanger 120 comprises a series of coils 121 formed from a continuous length of constant section tube 121. The cross- flow heat exchanger 120 measures approximately 900mm along a longest dimension. The cross-flow heat exchanger 120 is mounted within the cavity 60 of the air handler 50. The cross-flow heat exchanger 120 divides the internal chamber 60 of the air handler into the upstream chamber 61 and downstream chamber 62. Refrigerant 2 enters the cross-flow heat exchanger 120 via an inlet 124 and flows through a length of the coil tube 121. The coil tube 121 runs backwards and forwards across a width of the heat exchanger 120, looping back on itself, before exiting the heat exchanger 120 via an outlet 125. The coil tube 121 is contained between a first face 122 and a second face 123 oriented parallel to one another. The first face 122 of the cross-flow heat exchanger 120 is located within the upstream chamber 61 of the cavity 60. The second, opposing face 123, of the cross-flow heat exchanger 120 is in the downstream chamber 62 of the cavity 60.

The second face 123 of the cross-flow heat exchanger 120 is oriented adjacent and parallel to one of the side panels 53 of the air handler casing 51. As the cross-flow heat exchanger 120 is oriented to traverse the cavity 60, from front to back, both the first upstream face 122 and the second downstream face 123 are accessible to an operator from the access panel 55. This arrangement allows for easy access for servicing and visual inspection of each of the faces (122, 123) of the cross-flow heat exchanger 120.

The cross-flow heat exchanger 120 is mounted vertically within the air handler 50. The narrow vertical design results in air passing through the heat exchanger 120 from the first chamber 61 to the second chamber 62 in a semi vertical flow, at an inclined angle of between 50-70 degrees and more preferably 60 degrees. This results in the air being exposed to and passing over the coil tube 121 for a longer time than in conventional heat exchangers, optimising heat exchange between the refrigerant 2 in the coil tube121 and the air being drawn through the handler 50.

Figures 5A and 5B illustrate a lamp assembly 66 located within the upstream chamber 61. As shown, the lamp assembly 66 comprises two Infrared lamps 66A mounted to a mounting bracket 66C. Additional lamps 66A can be added to the assembly 66 as desired. Similarly, in many applications a single lamp 66A will be sufficient.

The infrared lamps 66A emit infrared rays onto the first face 122 of the cross-channel cross-flow heat exchanger 120. The infrared rays heat the coil tube121 of the cross-flow heat exchanger 120 to enhance the operation of the system 1 when operating in heating mode. In some embodiments, when operating in the second heating mode the air handling system 1 can utilise the infrared rays to assist the thermal vapour compression cycle by providing additional heat to the coil tube 121 and hence further heat the ambient air passing through the heat exchanger 120. This can provide an advantage over traditional reverse- cycle systems which have difficulty operating in low external air temperature conditions.

In an alternative embodiment, when the system 1 is operating in the second heating mode, only the infrared lamps 66A within the air handler 50 can be activated. In this embodiment, the external heat exchanger 40 and the compressor motor are idle, and the second heating mode does not rely on the vapour compression cycle. This provides energy savings and thereby reduce operating costs, whilst still providing heating to the treatment zone. In some embodiments this can significantly reduce the operating noise of the system 1. In some cases, a near silent running operation mode may be achieved.

In some embodiments, when the system 1 is operating in the first, cooling mode, the infrared lamp assembly 66 is configured to reduce humidity of the chilled air flow being circulated into the treatment zone. Infrared lamps 66A can remove moisture from the air flowing through the first chamber 63. As such, the system can provide both chilled and dehumidified air. This can overcome a known disadvantage of typical reverse cycle systems, which can struggle to provide relief in humid conditions.

The infrared lamps 66A generate sufficient heat to provide a cleaning and/or sterilising effect on the air as it passes over the heated coil tube 121. In the compact packaging arrangement within the handler 50, mounting bracket 66C is received and supported within an aperture of the fan casing 64. Air is circulated by fans 63 across the infrared lamps 66A. The upstream location of the infrared lamps 66A can improve the efficiency of the emittance of a thermal output from the infrared lamp assembly 66 onto the heat exchanger 120.

In some embodiments one or more ultraviolet lamps may be fitted in the downstream chamber 62. The ultraviolet lamps 66b are ideally positioned to avoid exposure to the heat generated by the infrared lamps 66A.

Exposure to ultraviolet rays can be used to purify air by inactivating microbial organisms such as bacteria and viruses (by altering the structure of their DNA), thus destroying the ability of the microbial organisms to reproduce. Particularly, UVC which is an ultraviolet light with wavelengths between 200 - 280 nanometres (nm). Light in the UVC wavelength can be used for disinfecting water, sterilising surfaces, and destroying harmful microorganisms in food and in air.

This can reduce the build-up or growth of microbial organisms on the heat exchanger 120, reducing maintenance costs and improving energy efficiency over the life of the system 1. A further advantage is that the air being pumped into the treatment zone has been purified, which can provide health benefits to allergy and asthma sufferers. The ultraviolet lamps are located downstream of the heat exchanger 120 in the downstream chamber 62, whilst the IR lamps are located in the upstream chamber 61. This separation of the IR and UV lamps can reduce the likelihood of a shadowing effect in which the infrared rays can shadow the ultraviolet rays on the heat exchanger 120, reducing the purifying effect of the ultraviolet rays. The downstream chamber 62 is lined with a reflective material, such as aluminium or mill finish aluminium, to reflect and thereby maximise the sanitising effect of the UV light on the air passing therethrough.

The air handler 50 also comprises the filter assembly 67, located within the upstream chamber 61, and oriented to be substantially parallel with the cross-channel heat exchanger 120. As illustrated in Figures 6A and 6B, the filter assembly 67 is mounted to a sliding member to form a cassette 68.

The cassette 68 is configured to be slidably mounted within the air handler 50. To facilitate this arrangement a pair of profiled rails 68a are disposed on at least one of the top or bottom face of the cassette 68. The profiled rails 68a are shaped to cooperate with a pair of guides 69 mounted within the handler 50, such that the profiled rails 68a are received and held in a sliding arrangement with the pair of guides 69. The sliding cassette 68 is disposed within the air handler 50 and as shown in Figure 6A, is located beneath the electronics control system enclosure 71. The enclosure 71 is dimensioned to house the electronics control system 70. In some embodiments, insulation blocks 69a can be inserted between the guides 69 and the electronics system enclosure 71, thermally insulating the electronics system 70 from the components mounted to the cassette 68.

The cassette 68 can be inserted and removed from the air handler 50 by pushing or pulling the cassette 68 into and out of the housing 51 , as indicated by the dashed arrow in Figure 6A. The sliding cassette 68 allows the filter assembly 67 to be easily accessed and removed from the air handler 50. This provides a simple method for inspecting the filter and when required, for cleaning and/or replacing of the filter. In some embodiments, the cross- flow heat exchanger 120, lamp assembly 66, and fan casing 64 are also mounted to the sliding cassette 68, and thus can also be easily accessed, inspected and replaced.

The electronic control system 70 is located within the air handler 50. Figures 7 A and 7B show an embodiment of the electrical control system 70. The control system 70 is housed within enclosure 71, and comprises an interface board 72, a control board 73 and an inverter driver 74. Interface board 72 communicates with each of the temperature sensors 65. Control board 73 can be a C++ based controller and can provide the PID loops. Each of the PID loops operates independently of one another, enabling precise control of each of the plurality of circulation fans 63, maximising the efficiency of heat exchange. Control board 73 also provides switching control of lamp assembly 66, turning the infrared lamps 66A on and off, depending on the operating mode of the system 1. The C++ code-based control board 73 communicates with the PID controllers to allow fine control over the major components of the system 1 : (expansion device 10, evaporator 20, compressor 30 and condenser 40) via interface board 72. Control board 73 is configured with built-in blue tooth, Wi-Fi, remote diagnostics, fault diagnostics, energy monitoring, fault over ride, and micro grid sequencing. The control board 73 is compatible with building management systems (BMS), to provide ease of installation and servicing. Invertor driver 74 operates the compressor motor (add number).

Enclosure 71 provides a thermally insulated housing for the electronics control system 70, the enclosure 71 comprising a front panel 76, a rear panel 77 and a pair of side panels 78. The side panels 78 are vented to ensure sufficiency of air flow for cooling of the electronic components within the enclosure 71. Enclosure 71 is securely mounted below the lid 56 of the air handler 50.

A z-shaped mounting plate 79 is removably attached via conventional means such as screws within the enclosure 71, the mounting plate 79 providing a surface to which the internal components are secured. This plate 79 enables all the electronic components to easily be removed from the enclosure 71, to provide access for technicians.

A further advantage of the electronics control system 70 is that all sensors and control components are in one location, within the stable internal environment of the air handler unit 50. This reduces the likelihood of electrical failure due to water ingress. As the electronics control system 70 is located within the air handler unit 50, it is not exposed to the large temperature variations that componentry within an outside reverse cycle system would experience. This reduces the likelihood of component failure due to overheating in excessive sunlight, or failure of components experiencing near freezing conditions.

Figure 8 shows the compressor unit 35 according to one embodiment. The compressor 30 is located internally of the compressor casing 31 (side panels, and an access panel 32 of which have been removed from Figure 8 for clarity). The compressor 30 is driven by a compressor motor 33, which is a brushless direct current (BLDC) frequency drive inverter. The frequency drive inverter has an optimal operating speed of approximately 90 revolutions per second. Internal components of the compressor unit 35 are mounted to a removable mounting plate 34, enabling the components to be removed easily from the casing 31 for inspection and servicing. An accumulator 81, acting as a pressure vessel for liquid sub-cooling is also housed within the compressor casing 31, and is described in more detail in reference to Figure 12. Figure 9 show the air duct connecting assembly 100 and a duct 105, disconnected but aligned to each other. Inlet duct 101 and outlet duct 102 are apertures disposed on a top surface 103a of a casing 103 and are fluidly connected to the inlet 57 and outlet 58 of the air handler 50, respectively.

Inlet duct 101 provides a passageway for drawing ambient air from the controlled treatment zone into the air handler 50 to be treated. The outlet duct 102 provides a passage for expelling treated air back into the controlled treatment zone.

In some embodiments, casing 103 can include bores 104, which are shaped to receive a correspondingly shaped duct 105 connected to an existing external ventilation system (not shown). The external ventilation system provides a system for circulating treated air through the air handler 50. Additionally, the external ventilation system 105 can provide air circulation within the air handling system 1. In circumstances where the air handler circulation fans 63 are idle, the external ventilation system can provide sufficient air circulation for the air treatment system 1 to operate.

Figure 10 shows the external heat exchanger 40 as a static condenser 140. The static condenser 140 is located remote to the indoor unit 3. The static condenser 140 is a low-profile design. The low-profile design minimises the height of the static condenser 140, whilst maximising its width and breadth. The low-profile design enables the static condenser 140 to be mounted internally in a roof space or similar and thus does not require the external footprint typical of other condenser units in traditional reverse-cycle systems. The static condenser 140 is contained within a generally rectangular housing 141. The rectangular housing is formed from four elongate C-sections 141a and four interconnecting corner members 141b that together form the perimeter housing 141 about the static condenser 140.

The static condenser 141 has a first coil face 142 and a second coil face 143 for exchanging heat with the external air. When mounted in a horizontal configuration, the first coil face 142 forms a bottom row of coils, and the second coil face 143 forms a top row of coils. This arrangement promotes natural convection.

Refrigerant 2 enters the second coil face 143 through inlet 144 and circulates downwardly to the first coil face 142 where outlet 145 feeds the phase changed liquified refrigerant 2 to be re-expanded. The inlet 144 and outlet 145 are contemplated to be formed as copper headers. The inlet 144 and outlet 145 are located on a common feed-in side of the static remote condenser 40.

Specifically, having the hotter superheated gas refrigerant 2 entering the second coil face 143 of the static condenser 140 increases the temperature of air within the second coil face 143 to a higher temperature than air within first coil face 142. Due to the temperature difference between air in the first and second coil faces 142,143, the air expands. The arrangement of the fins promotes the air to rise due to convection. As the hotter air rises, cooler air takes its place via natural convection. This cools the first coil face 142 of the static condenser 140 which in turn allows for the liquefaction of the refrigerant 2 to be re expanded.

As illustrated in Figure 10, the static condenser 140 is based on a “tube and fin” design with a multi circuited configuration. The density of fins per inch promotes natural convection, presently 3-8 fins per inch (typical condensers would have about 14-20 fins per inch). The inlet 144 and outlet 145 are contemplated to be formed as copper headers. The inlet 144 and outlet 145 are located on a common feed-in side of the static remote condenser 40.

The static condenser 140 can be installed in a roof space such that an existing external ventilation system promotes air flow through the static condenser 140. This enables heat from the static condenser 140 to be exhausted through the existing ventilation system. The existing ventilation system can be an existing sub-system within the building. The cooler air drawn into the static condenser 140 can be supplemented by drawing air from the existing mechanical ventilation means. Typically, existing mechanical ventilation systems are configured to provide a central ventilation shaft to which each wet area (such as a bathroom) ventilates. In one arrangement, the static condenser 140 can be positioned within the roof space above the wet area of a hotel room or apartment dwelling. Such a location is desirable, as it draws air out of the wet area and up through the remote static condenser that then ventilates the air through the existing ventilation system.

The static condenser 140 is fully contained within the air treatment zone i.e. there are no break outs from the treatment zone which would require concrete core holes and/or fire collars. These additional costs/features are eliminated when using the static condenser 140 described herein. Installation is quick and simple, requiring only metres of pipe installation as compared to the hundreds of metres of extensive ductwork present in centralised alternatives. Initial capital expense costs are reduced. Due to the accessibility of the system, ease of maintenance is increased. In some arrangements, the system can be retrofittable to existing buildings. This allows valuable real estate to be reclaimed from central chiller installations, and air handling service shafts and the like.

Figures 11A, 11 B and 11C show another embodiment of the external heat exchanger 40, where the condenser is a micro-channel condenser 240. The micro-channel condenser 240 acts as an adiabatic condenser. The micro-channel condenser 240 comprises a housing

241, at least one micro-channel heat exchanger 242 and one or more fans 243 to draw air across the micro-channel heat exchanger 240. In an assembled form, the housing 241 is rectangular, comprising opposing inlet and outlet plates 244a and 244b, a lid 246, a base 247, and two side plates 248. The one or more condenser fans 243 can be electronically commutated (EC) fans. The fans 243 are oversized, such that during use, they operate at a targeted 50% of the maximum rated rotational speed. The fans 243 are received within corresponding apertures (number needed) in the base 247 and secured with mounting plates 249.

The micro-channel condenser 240 of Figures 11 A-11 B features two heat exchangers

242, however it is contemplated that one or more heat exchangers 242 can be integrated into the micro-channel condenser 240. The heat exchangers 242 are mounted at an inclination angle ø to the base plate 247. This angle provides optimal heat transfer, whilst also enabling the low-profile design.

The micro channel condenser 240 has a hot inlet pipe 245a and a cold outlet pipe 245b through which refrigerant 2 flows through the heat exchangers 242, 242’. These heat exchangers 242, 242’ can be arranged in series or in parallel to one another. An advantage of the micro channel condenser 240 is that it only has 2 pipes: (i) the hotter inlet pipe 245a; and (ii) the cooler outlet pipe 245b. In a typical system there is a hot and a cold pipe. As such, in proximity to one another condensation is formed that requires the pipes to be insulated from one another. In the above arrangement, one pipe is hot, and one pipe is super-heated and as such, neither of these pipes need insulation. The longer the distance of the pipes between the static condenser 240 and the indoor unit 3 the more efficient the remote condenser becomes as the hotter pipe will dissipate heat.

The housing 241 is of a low-profile design that minimises height whilst maximising width and depth. This low-profile design enables the microchannel condenser 240 to be located indoors or within a ceiling space or outdoors. This is advantageous when compared to typical condenser units, which due to the incorporation of a compressor can be noisy and unsightly, and thus are required to be located outdoors.

In Figures 11A and 11 B, the microchannel condenser 240 is horizontally mounted. This enables the condenser 240 to be mounted in the following ways: surface mounted, built into a bulk head, in roof mounted and/or mounted within a sub roof.

In Figure 11 C, the microchannel condenser 240 is vertically mounted. This arrangement enables the microchannel condenser 240 to be mounted within a house, for example, directly fixed to a wall, under a window, fixed to a side wall or built into a side bulkhead. Similarly, the microchannel condenser 240 can also be mounted in a basement car park around the perimeter walls without interfering with or encroaching on car park spaces.

Figure 12 shows another embodiment of an external heat exchanger 40, where the condenser is a multi-circuited condenser 340. The multi-circuited condenser 340 is suitable for large residential dwellings that would otherwise require several individual condensers to service multiple air handlers 50. The multi-circuited condenser 340 comprises a housing 341, and at least on EC fan (or blower unit) 343 and can be pre-fitted with electrical and pipe fittings for ease of installation.

The housing 341 is illustrated in Figure 12 as a three-dimensional frame, however, this frame can be fully or partially closed in by panels or walls (not shown). The housing 341 has a ducted connection indicated at a front of the housing by arrow 345 to enable installation in a remote location or locations within a sub-roof.

The term “remote” is understood to mean that the external heat exchanger is located spaced apart from the internal unit of the air handler system 1, and thus the indoor heat exchanger. As such the term “remote” can relate to a variable distance i.e. a separate room of a house, or a separate floor of a building, or multiple floors to the roof of a tower block.

As shown in Figure 12, the multi-circuited condenser 340 has four circuits 342, 342’, 342”, 342’” which can service four air handlers 50. It is contemplated that one, two, three, four, five or more air handlers 50 can be configured to be serviced by this one condenser 340, for example between two and six. Each of the circuits 342 includes a heat exchanger 344, 344’, 344”, 344”’. As illustrated, the heat exchangers 344 are a tube and fin type. In some embodiments the heat exchangers 344 can also be micro channel condenser 240 (as described herein).

The multi-circuited condenser 340 (with external dimensions of approximately 600mm x 700mm x 600mm) is compact compared to typical arrangements and provides an energy efficient solution. The small footprint of the multi-circuited condenser 340 enables installation into the roof-space of dwellings where due to the geometry and layout, fitting several conventional condensers would not be feasible. Most gable, pitched roof spaces can house the multi-circuited condenser 340.

The air handling system 1 can also operate on a modified refrigeration cycle. Figure 13 shows a schematic layout of a modified refrigeration cycle. A sub-cooling circuit 80 reduces the temperature of the liquid refrigerant 2 entering the expansion device 10. The sub-cooling circuit 80 is comprised of approximately 8 linear meters of 3/8” (approximately 10mm) copper pipe 82, the copper piping 82 being located within a pressure vessel 81. The pressure vessel 81 is an accumulator having a round tank-like shape. The copper piping 82 is wrapped in a spiral manner to assume a U-shaped pipe path 83. The U- shaped pipe path 83 forms the suction pipe 7 exiting the evaporator 20, which transfers the vaporous refrigerant 2 from the evaporator 20 to the compressor 30. Instead of the cold vaporous refrigerant 2 returning directly to the compressor 30, the vaporous refrigerant 2 passes through pressure vessel 81.

The pressure vessel 81 provides many benefits. Firstly, in the event of failure of the expansion device 10, the pressure vessel 81 can act as an accumulator vessel. Any liquid refrigerant 2 caused by over feed will then accumulate within the pressure vessel 81 , as opposed to a conventional case of liquid flush where the over feed refrigerant 2 is directly transferred to the compressor 30 in liquid form displacing oil therein. Oil being flushed into the compressor 30 can cause terminal damage and failure of the compressor 30. The arrangement of the sub-cooling circuit 80 described above can avoid these known issues and thereby increase the working life of the compressor 30.

A further benefit provided by the sub-cooling circuit 80 is that within the pressure vessel 81, a counter-current heat exchanger provides a sub-cooling effect, and results in a further temperature drop of the liquid refrigerant 2 within the copper piping 82 by up to 20 degrees Celsius. Because of the reduced temperature of the liquid refrigerant 2 entering the expansion device 10, less volume of refrigerant 2 is required to boil off at the condenser 40. The compressor 30; therefore, has a lower volume of refrigerant 2 to super heat and can operate at a reduced capacity.

A gas-water plate heat exchanger 90 is located near the compressor 30, illustrated schematically in Figure 13. The discharge pipe 5 is directly connected to the gas-water plate heat exchanger 90. This arrangement is advantageous as it allows for the creation of a hot water generation circuit 92 passing through the heat exchanger 90, enabling near-instant hot water generation within an adjacent hot water system 91. The hot water generation circuit 92 is a closed water loop.

The hot water generation system 91 is a biproduct of the operation of the air handling system 1, in both the first cooling mode and the second heating mode. The gas to water heat exchanger 90 has a counter flow design, with a first (hot) side pipe 94 carrying vaporous refrigerant 2 and a second (cold) side pipe 95 carrying water from hot water system 91 being located adjacently to each other to facilitate heat exchange. A small water circulation pump 93 is used in the water generation circuit 92 to pump vaporous refrigerant 2 from the compressor 30 through the first side pipe 94. A temperature difference between the first side pipe 94 to the second side pipe 95 facilitates heat exchange, leading to a phase change in the vaporous refrigerant 2 to a liquified refrigerant 2 for re-expansion.

In some instances, the air handling system 1 incorporates a geothermal in-ground heat exchanger 440. Figure 14 shows an embodiment of the geothermal heat exchanger 440. The geothermal heat exchanger 440 operates as a ground heat dissipation device. The geothermal heat exchanger 440 is comprised of a closed loop of copper tubing 441. The tubing 441 comprises a series of straight sections coupled with U-bends 444 to maximise the surface area of the tubing 441 exposed to the ground temperature and is supported by several rigid support structures 445. When the system 1 is operating in cooling mode, an inlet 442 receives a hot transfer fluid such as water, from the gas-water heat exchanger 90. The hot water is then pumped via the network of tubing 441 , discharging heat to the ground, thereby cooling the water. The cooled water then returns to the gas-water heat exchanger 90 via an outlet 443.

When the geothermal heat exchanger 440 is used in combination with the gas-water heat exchanger 90, the combination provides opportunity for improved cooling efficiency.

This is because the temperature of the ground typically ranges from 22 degrees C to 34 degrees C, therefore even in extreme exterior heat conditions (i.e. air temperatures of 50 degrees C and above), the geothermal heat exchanger 440 is operating at a comparatively reduced temperature, hence a lower condensing pressure is required, resulting in a more energy-efficient air handling system.

In some embodiments, the expansion device 10 is an electronic expansion valve (EEV) 110, and embodiment of which is illustrated in Figure 15. The expansion valve 110 is located within the compressor casing 31 or within the air handler 50. The expansion valve 110 is a metering device comprising a stepper motor 114 and a valve body 115. The valve body 115 includes an internal needle 111 and a seat 116. The stepper motor 114 drives the needle 111 and seat 116 in either of a clock wise or anti clockwise direction, reducing a diameter of an aperture 113, to thereby throttle the delivery of refrigerant 2. Liquid refrigerant 2 enters the expansion valve 110 via an inlet 117 and is expanded as it passes through the aperture 113, before being fed through to an outlet 118 towards evaporator 20, thus creating a cooling effect. The aperture 113 of the expansion valve 110 is controlled by a PI D loop.

The PID loop is connected to both a pressure sensor and a temperature sensor. The temperature sensor is located within suction line 7. The set-up of the expansion valve 110 as described herein provides an advantage in that it can reduce excess refrigerant 2 that would otherwise flow through to the evaporator 20. Excess refrigerant flowing to the evaporator 20 can reduce the volume of refrigerant 2 that the compressor 30 is required to pump, and thereby reduces the volume of refrigerant 2 flowing through the external heat exchanger 40. Consequently, the compressor motor 33 and condenser fan 42 can operate at reduced loads. Accordingly, each of the compressor 30 and the external heat exchanger 40 use less energy, resulting in the potential for cost savings.

Figures 16A-16D illustrate a further embodiment of the air handling system 1 , configured to provide a thermal chamber 500 comprising: a cell configured as a tent 501 defining a treatment zone; and an air handling system 502,, the air handling system 502 comprising: a housing 503 divided by a barrier 561 to define a first air chamber 562 and a second air chamber 563, the first air chamber 562 in fluid communication with an air inlet and including an infrared emitter 566 and a filtering device, and the second air chamber 563 having an air outlet, wherein both the first air chamber 561 and the second air chambers 562 are in fluid communication with the tent 501, a first heat exchanger 520 is disposed within the first air chamber 562 such that an air source from the inlet is drawn over the first heat exchanger 520 when moving from the first air chamber 562 towards the tent 501, a second heat exchanger 540 located within the second air chamber 563 such that air from the tent 501 is drawn over the second heat exchanger 540 when being discharged from the air handling system 502, and a compressor 530 and an expansion device 510 in fluid communication with the first heat exchanger 520 and the second heat exchangers 540 to impose a change of state on a working fluid therein, wherein the air handling system 502 is configured to operate in a first cooling mode to reduce an initial temperature of the air source within the treatment zone, and a second heating mode to increase the initial temperature of the air source within the treatment zone.

Portable thermal chamber 500 comprises the tent 501 and the air treatment unit 502. The portable thermal chamber 500 serves as a treatment zone for altering the body temperature of a person or animal. The portable thermal chamber 500 is designed as a fully transportable system which can easily be transported and plugged in for heat stress recovery. For example, an athlete or sportsman can use the thermal chamber 500 to cool down after physical exertion. Similarly, the thermal chamber 500 can be used to rapidly warm a person, for example to treat hypothermia. Use of the thermal chamber 500 for short periods of time can help a user avoid heatstroke, reduce the risk of muscle cramps, and reduce the onset of a fever.

Figure 16A shows an embodiment of the thermal chamber 500. The tent is an inflatable tent 501, constructed of a lightweight and durable material such as Nylon 210. The material is non-porous, such that it provides an enclosed treatment zone into which treated air is be pumped. The tent 501 can be formed of a flexible sheeting over a rigid frame. Alternatively, the embodiment of tent 501 as illustrated in the figures can be inflated under fan pressure. The inflatable tent 501 comprises inflatable vertical tubes 512 with a tubular ring 513 located both at the top and the bottom of the vertical tube 512, which when inflated give a uniform shape to the tent 501. As shown in Figure 16B, the tubular ring 513 located at a top of the assembled inflatable tent 501 may be U-shaped.

The tent 501 is connectable to the air treatment unit 502, to be inflated by a fan 521 therein. This allows the inflatable tent 501 to inflate within 2-30 seconds. As the tent 501 is a small volume in comparison to the cooling power of the unit 501, the air within the tent 501 (treatment zone) can be brought to a desired temperature within about 2 minutes. The air inlet is 100% fresh air. Once the tent is inflated the air volume to cool is about 1100 -1200 litres (having an approximate internal volume of 2.1m x 1m x 1m).

As illustrated in Figures 16A and 16B, the inflatable tent 501 is sized to fit a single person. The tent 501 can also be configured as a larger, multi-person, chamber housing multiple occupants simultaneously. The tent 501 has a zipper style door 510. The tent 501 has at least one remote access point 509 to pass in liquids and snacks to a person within the tent 501. The tent can have imbedded light strips that are flexible to offer an illuminated environment.

A de-humidifier 511 , shown in Figure 16A mounted in a top portion of the tent 501 adjacent the upper tubular ring 513, and can be included within the thermal chamber 500 for optimising the air within the treatment zone for breathing by the person within the tent to remove excess moisture. This can improve the comfort and recovery and/or reduce the treatment time for the person. The de-humidifier 511 can alternatively be floor mounted within the tent 501.

As shown in Figure 16B, air treatment unit 502 is connected to the inflatable tent 501 via a hose 504. In one embodiment, the hose 504 is a 150mm long flexible hose. The air treatment unit 502 provides treated air to the inflatable tent 501 being either warmer or cooler that the external air outside of the chamber 500. The air treatment unit 502 comprises electricity via a power-in line 506. The electricity can be a mains (240V) electricity or a portable (24V) power supply. A power-out line 505 from the air treatment unit 502 to the inflatable tent 501 can provide a power outlet inside of the inflatable tent 501. This power outlet can be used to charge mobile devices by the subject within the inflatable tent 501.

In reference to Figure 16C and 16D, it is understood that the components of air treatment system 1 are arranged in such a manner that they are contained within housing 503 of the air treatment unit 502. The compressor 530, evaporator 520 and condenser 540 are all packaged within the housing 503. As shown in the figures, the housing 503 can be a carry case. A heating means, such as lamp assembly 566, can also be fitted within the unit 502.

Non-porous baffle 561 divides an interior of the air treatment unit 502 into two chambers, 562 and 563. The baffle 561 is effectively Ύ” shaped dividing the interior of the unit 502 into first air chamber 562, second air chamber 563, and a supplementary chamber 564. The first chamber 562 is upstream of the tent 501. Evaporator fan 521 sucks air from an ambient environment into the first chamber 562. Air within the first chamber exchanges heat with evaporator 520, cooling the air. The cooled air is then pumped into the thermal chamber 501 through hose 504. The second chamber 563 is downstream of the tent 501. Condenser 540 is located within the second chamber 563. A condenser fan 542 sucks air out of the treatment zone within the tent 501 into the second chamber 563. Air within the second chamber 563 then exchanges heat with the condenser 540, before being discharged to the ambient environment external of the housing. The fans 521 and 541 are mounted within the supplementary chamber 564.

The condenser 540 can be fan forced. Condenser fan 542 can be an axial style low noise fan. The evaporator 520 can be an induced draft evaporator and comprise evaporator fan 521. The evaporator fan 521 can be an in-line blower style fan. The evaporator fan 521 can serve a dual purpose: first, the evaporator fan 521 can force air to pass over the evaporator 521 , cooling the air through heat exchange; and secondly, the evaporator fan 521 can be used to inflate the tent 501.

An electronic controller 570, in the form of a PLC based micro-controller controls operation of the air treatment unit 502. A touch screen, integrated into the electronic controller 570, provides a human-machine interface. The electronic controller 570 can be mounted on an outside surface of the casing 503. Portable casing 503, as illustrated, has a set of wheels 508, enabling the air treatment unit 502 to be easily transported and set-up immediately adjacent the sports field or track where treatment is to be administered. Both heat exchangers 520 and 540 can generate condensate. In air treatment unit 502, there is a small reservoir leading to a pump (not shown) that can be used for heating the condensate to evaporate the condensate. Alternatively, a hose can be connected to the reservoir to drain the condensate conveniently into a nearby drain, in situ. It will be appreciated by persons skilled in the art that numerous variations and modifications may be made to the above-described embodiments, without departing from the scope of the following claims. The present embodiments are, therefore, to be considered in all respects as illustrative of the scope of protection, and not restrictively.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the example methods and materials are described herein.

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

In the claims which follow and in the preceding description of the disclosure, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is 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 disclosure.