AU2014305638B2 - Improved air source heat pump and method - Google Patents

Abstract

The present invention provides an improved air source heat pump (ASHP) system and method which relies on using scavenged and/or stored heat to change the temperature of ambient air used by the ASHP thereby increasing efficiency. The heat is carried via a fluid medium.

Description

PCT/AU2014/000776 WO 2015/017880

Title: Improved Air Source Heat Pump and Method

Field of Invention [0001] The present invention relates to the field of heating of residential and commercial buildings via air source heat pumps (ASHP).

Background Art [0002] ASHP commonly referred to as a reverse cycle air-conditioner is a refrigeration device which can operate in heating and cooling modes. An ASHP transfers heat from one environment having a lower temperature (such as outdoors) to another environment where a higher temperature is desired (such as indoors).

[0003] The operating cycle of an ASHP during heating proceeds as follows: a compressor compresses refrigerant gas which raises the gas temperature forming hot gas vapour which is directed towards a condenser coil in the indoor environment where heat is transferred to the indoor air by induction of indoor air over the condenser coil. The refrigerant gas condenses into warm liquid as a result of having rejected the heat and is directed to an expansion device adjacent an outdoor evaporator coil by a reversing valve. After expanding to a lower temperature and pressure, the relatively cold liquid refrigerant absorbs heat from the relatively warm ambient air and expands rapidly into a gaseous state from where it is introduced into the suction side of the compressor for the cycle to be repeated.

[0004] A number of proposals for ASHP have been put forward. These include US patent application 2012/0247134 in the name of Gurin which discloses a heat pump with integral solar collectors. US patent application 2011/0067437 in the name of Song discloses an air sourced heat exchange system comprising an extensive evaporator area. US patent application 2010/0077779 in the name of Pearson discloses use of a gas fired burner or waste heat from flue gas to prevent frost from forming on the evaporator surfaces. In 2004 American Solar Inc published an article "Pentagon Solar Heating, Air Conditioning, Lighting and Power" which describes an integrated heating and cooling system for a building which utilizes solar warmed air.

[0005] Other proposals (not in the ASHP art) do not use ambient air as a source of heat. These include China patent application 103335454 in the name of Anhui Cheari Zhirui Technology Co Ltd which requires an artificial heat source in an ammonia heat absorption system to benefit hot water system operation.

[0006] Although ASHP provide reasonable means for heating a building they do not operate optimally under all conditions and some require extensive installation or alteration to an existing building. In particular, existing ASHP do not operate well in conditions where there is a low ambient temperature outside. Further, another of the non optimal conditions that occurs under low ambient 1 PCT/AU2014/000776 WO 2015/017880 air temperatures is the deposition of ice/frost on the evaporator surfaces during heating mode. This detrimentally affects the heat transfer capacity of the evaporator due to the insulating effect of the ice/frost on the heat transfer surfaces. The industry standard remedy for this is to activate a defrost cycle, whereby a reversing valve is activated to reverse refrigerant flow in order to collect heat from the indoor environment in order to increase gas pressure in the outdoor unit coil and therefore temperature of the outdoor unit coil in order to remove the deposited ice/frost.

[0007] The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In addition the China patent application mentioned above is not considered to be part of the prior art for the present invention.

Disclosure of the Invention [0008] The present inventors set out to improve the functioning of ASHP during non-optimal conditions. In particular the present inventors sought to address the problem of load mismatch between ambient conditions during the coldest periods and the requirement for heat by consumers wishing to use an ASHP for heating.

[0009] In one aspect the present invention provides an improved ASHP system comprising: a) an evaporator capable of extracting heat from ambient air in one space; b) a condenser capable of rejecting heat into air another space to provide a desired temperature in one of the spaces; c) a heat collecting means able to collect heat via a fluid medium; said heat collecting means associated with d) an ambient air preconditioning means, said preconditioning means for bringing the temperature of the ambient air adjacent the evaporator closer to said desired temperature by allowing heat exchange between the fluid medium and the ambient air; said collecting means and said preconditioning means operably linked with e) a regulating means for regulating the treatment of ambient air.

[0010] The present invention is partly predicated on the inventors’ surprising realization that readily available heat could be scavenged or harvested to address the natural mismatch between demand for heat indoors at the coldest times of day and its lack of availability outdoors (and vice versa). Freely available ambient heat can be scavenged or harvested when and/or where it is most abundant and then put to good use. Specifically the inventors realized that the heat could be used to precondition ambient air and increase the coefficient of performance (COP) of the ASHP.

[0011] The term "ASHP system" refers to the physical device and its components.

[0012] The term “a heat collecting means” includes a heat collection and a heat scavenging component able to collect or scavenge heat from any convenient heat source. Preferably the heat 2 PCT/AU2014/000776 WO 2015/017880 is from the outdoor ambient environment not heat generated for the specific purpose of raising the temperature of the ambient air utilized by the evaporator (such as heating by an electric element or by a gas burner). In this way the COP is improved.

[0013] The term “fluid medium” refers to any fluid suitable for transferring heat. Preferably the fluid is a liquid. Even more preferably the fluid is water or a water glycol mixture.

[0014] The term “ambient air preconditioning means” refers to one or more components able to transfer heat to the ambient air. These components function together to change the temperature of the ambient air such that the ASHP requires less energy to achieve a desired temperature in the space being heated. Preferably the ambient air preconditioning means includes a heat exchanger coil. More preferably the fluid in the heat exchanger coil is a liquid. Even more preferably the heat is delivered by a water/glycol mixture-to-air heat exchanger in an air induction chamber.

[0015] The term “regulating means for regulating the treatment of ambient air” refers to components which control the flow of the fluid including the rate and timing of fluid flow. The regulating means include controllers, pumps, temperature sensors and related circuitry which operate to certain predetermined parameters.

[0016] Preferably the ambient air preconditioning means of the system comprises a heat exchanger and an air induction chamber adjacent the evaporator and the fluid medium is a liquid.

[0017] Preferably the system additionally comprises a heat storage means such as a domestic hot water cylinder.

[0018] In another aspect the present invention provides an improved air source heat pump (ASHP), said ASHP comprising: an evaporator capable of extracting heat from ambient air in one space and a condenser capable of rejecting heat into air in another space to provide a desired temperature, the improvement comprising providing: a) a heat collecting means able to collect heat via a fluid medium; said collecting means associated with b) an ambient air preconditioning means for bringing the temperature of the ambient air adjacent to the evaporator closer to said desired temperature by allowing heat exchange between the air and the fluid medium; said collecting means and preconditioning means operably linked with c) a regulating means for regulating the treatment of ambient air.

[0019] In another aspect the present invention provides a method of increasing the efficiency of an air source heat pump (ASHP), said ASHP including an evaporator capable of extracting heat from ambient air in one space and a condenser capable of rejecting heat into air in another space; said method comprising providing a) a first heat exchange means able to gather heat via a fluid 3 PCT/AU2014/000776 WO 2015/017880 medium; and b) a second heat exchange means adjacent said evaporator able to dissipate heat via said fluid medium; said first and second heat exchange means operatively associated with c) a pumping means to convey said fluid; and d) a control means to control flow of said fluid wherein one of said heat transfer means is able to collect and/or scavenge available heat from a heat source and the other is able to alter the temperature of the ambient air adjacent to the evaporator such that the coefficient of performance of the ASHP is increased.

[0020] The term “heat exchange means” refers to one or more components able to transfer heat from one medium to another medium.

[0021] The term “pumping means” refers to one or more mechanisms for moving or conveying fluid.

[0022] The term “control means” refers to any means suitable for controlling the flow of the fluid such as programmable thermal control units.

[0023] The term “available heat from a heat source” refers to any convenient heat such as a nearby river, dam or other body of water.

[0024] The term “alter the temperature of the ambient air” refers to increasing the temperature of the ambient air such that it reduces the temperature gradient between ambient air and the desired indoor temperature.

[0025] The term “coefficient of performance” refers to the ratio of the heating provided over the electrical energy consumed (accounting for losses) by the ASHP.

[0026] In a further aspect the invention provides a method of increasing the efficiency of an ASHP by raising the temperature of ambient air taken up by the ASHP said method comprising providing: a) a supplementary heat gathering means for gathering heat in the vicinity of the ASHP; b) a supplementary heat storage means associated with said gathering means; c) a heat transfer means for transferring supplementary heat to the ambient air; d) a pump means and; e) a control means for regulating flow of said fluid under predetermined conditions wherein said supplementary heat is carried by a fluid medium circulatable between the heat gathering means, the heat storage means and/or the heat transfer means.

[0027] The term "increasing the efficiency" refers to the ASHP using less energy to obtain the desired temperature in a space compared to the amount of energy it would use under normal operating conditions. 4 PCT/AU2014/000776 WO 2015/017880 [0028] The term “supplementary” refers to additional heat available from the environment other than heat in the ambient air and includes heat from solar collectors.

[0029] The term “vicinity of the ASHP” refers to an area around where the ASHP is installed and includes the building, plot of land or countryside.

[0030] The term “supplementary heat storage means” refers to a heat battery such as a hot water system including a domestic hot water tank, any suitably sized insulated water/glycol storage vessel or the like.

[0031] The supplementary heat gathering means, supplementary heat storage means and heat transfer means may be provided separately from the ASHP. For example the heat transfer means may be a “bolt-on system” connected to the supplementary heat gathering means and supplementary heat storage means by appropriate piping or the heat transfer means may be integral with the ASHP (i.e. included at the time of manufacture). If the heat transfer means is integral with the ASHP it may be provided with or without a kit for connection to the supplementary heat gathering means and supplementary heat storage means.

[0032] In another aspect the present invention provides auxiliary system for improving energy efficiency of an ASHP capable of providing a desired temperature in a space, by preconditioning ambient air contactable by an outdoor heat exchanger of the ASHP said system comprising: a) a heat collection and/or scavenging means; b) a heat storage means; c) an air preconditioning means; and d) a pumping means, wherein heat collected /scavenged and stored is in a fluid medium circulated by said pumping means which medium is exposed to ambient air adjacent said outdoor heat exchanger thereby bringing the air closer to the desired temperature and thus increasing coefficient of performance (COP).

[0033] In yet a further aspect the present invention provides a kit for making an auxiliary system for improving the energy efficiency of an ASHP, said kit comprising: a) an air induction chamber suitable for fixing adjacent an outdoor evaporator on an ASHP; b) a heat exchanger suitable for mounting in the air induction chamber said heat exchanger able to allow transfer of heat collected by a liquid from a heat collecting means to ambient air entering the evaporator and thereby raise the temperature of the ambient air; c) a pumping means to convey liquid to and from the heat exchanger; and d) a control means to control flow of the liquid; wherein a), b), c) and d) may be assembled so that liquid is transportable from said heat collecting means to said heat exchanger in said air induction chamber.

[0034] Preferably the kit also includes a heat storage means in the form of a heat battery, hot water tank or the like. 5 PCT/AU2014/000776 WO 2015/017880

Brief Description of the Drawings [0035] The invention will now be described with reference to the following non limiting illustrative drawings.

[0036] Figure 1 is a schematic drawing of a generalized embodiment of the system.

[0037] Figure 2 is a schematic drawing of another embodiment of the system showing details of sensor controls.

[0038] Figure 3 represents data of a test run of an ASHP during standard operation and with the system of the present invention operating.

[0039] Figure 4 is data recorded during a test run which shows a pre-treated air temperature of 18°C achieved during ambient air temperature conditions of 5°C.

Modes of carrying out the Invention and Illustrative Embodiments [0040] It will be understood by those skilled in the art that the following description relates an ASHP in heating mode.

[0041] The system of the invention 300 comprises a standard ASHP 100, ambient air preconditioning means in the form of air induction chamber 40 and heat transfer coil 240; heat collector 150 and heat storage 200.

[0042] ASHP 100 comprises outdoor unit 20 with heat exchanger coil 30 which functions as an evaporator during heating mode, fan 45 and compressor 50 and; indoor unit 60 with heat exchanger coil 65 and fan 70. Coil 65 functions as a condenser during heating mode.

[0043] Outdoor unit 20 and indoor unit 60 are connected via piping 15 through which refrigerant gas is circulated.

[0044] ASHP 100 has the ability to be operated in both cooling and heating modes due to four way or reversing valve 55. In heating mode the coil 65 in the indoor unit 60 becomes the condensing coil which rejects heat into the room via airflow across the coil (produced by fan 70), thus increasing the temperature to a desired level. Under standard operating conditions (i.e. when the system of the invention is not in operation) evaporator coil 30 in the outdoor unit 20 absorbs or collects heat from the outdoor untreated ambient air 10. It is able to do this due to the basic principles of refrigeration and the relationship between pressure and temperature that exists. The refrigerant gas within the system is passed through expansion device 18 which lowers the pressure 6 PCT/AU2014/000776 WO 2015/017880 and therefore the temperature of the gas and delivers it to the evaporator 30 via piping 15.The combination of the reduction in pressure and the heat transfer from the warmer ambient air causes the refrigerant to boil rapidly. As it does this the gas absorbs heat from the surrounding air. The gas then travels to the compressor 50 where it is compressed into a hot gas vapour; this process concentrates the heat held within the gas and also adds heat created by the process of compression and creates a hot gas vapour. The “hot” gas vapour then travels to indoor unit 60 where the heat is rejected by the condenser coil 65 into the environment being heated, the rejection of heat causes the gas to condense into a high pressure liquid. The liquid then travels back to the outdoor unit 20 via four way valve 55 then on to expansion device 18 which delivers it to evaporator 30 and the whole process starts again.

[0045] In the system of the invention heat collector 150 comprises heat exchanger coils 155 which contain a fluid medium in above ground piping 165 which gathers heat and transfers it into heat storage 200 via heat exchange coil 170. Heat collector 150, heat exchanger coil 155, piping 165, heat exchange coil 170 and the fluid medium form part of the system which corresponds to the heat collecting means, first heat exchange means, supplementary heat gathering means and the heat collection and/or scavenging means referred to in the claims.

[0046] Heat collected by heat exchanger coil 220 is transferred from storage 200 via pump 225 by above ground piping 215 to ambient air 10 via pre-treatment heat exchanger coil 240 located in air intake chamber 40 attached to outdoor unit 20. Storage 200 comprises the supplementary heat storage means and heat storage means referred to in the claims. Heat exchanger coil 220, piping 215, heat exchanger coil 240 and air intake chamber 40 comprise the ambient air preconditioning means, second heat exchange means, heat transfer means and air preconditioning means referred to in the claims.

[0047] The fluid medium is water or a water/glycol mixture which carries heat to and from various parts of the system.

[0048] The problem addressed by the present invention is that when there is abundant ambient heat available (typically the middle of the day), there is not much demand for the added heat of an ASHP in the target environment. Conversely, when the ambient heat levels are low (typically at night and early morning), there is relatively high demand for heat from the ASHP. There thus exists a mismatch between ambient heat availability and customer demand for heat - this is in fact a natural mismatch since customers demand heat when it is cold outside, which is exactly when the ASHP is least efficient.

[0049] One solution provided by the present invention to this mismatch problem is to harvest ambient heat when it is most beneficial to do so (typically around the middle of the day), then store 7 PCT/AU2014/000776 WO 2015/017880 this heat (in a fluid) for later delivery to the ASHP when demand for heat is high. In this way the ASHP is still drawing on the heat source in the conventional way but the inventors have provided a system which simply scavenges heat at its optimal availability, stores it and then re-delivers it when most needed to the ambient air so that the ASHP can continue to operate as designed albeit under improved conditions. This heat is delivered by means of a water/glycol-to-air heat exchanger in the upstream side of the outdoor heat exchanger (evaporator coil) of the ASHP.

[0050] While there are a number of systems designed to eliminate icing/frosting of the evaporator, none store heat for delivery when most needed or raise the COP. No-one has designed an add-on system which can be attached to any existing or new ASHP with the correct coil/induction chamber design and sufficient heat scavenging/storage (dependant on make, model and capacity of ASHP). Instead the prior art has been directed at purpose built units.

[0051] Figure 2 illustrates an embodiment of the invention where an existing ASHP 2100 is fitted with an air induction chamber 2040 where pre-treatment heat exchanger (referred to as HE1 in the assembly instructions) 2240 draws heat from domestic hot water tank 2200 which has solar collectors 2250 (referred to as HE2 in the assembly instructions). Fan 2045 draws untreated ambient air 10 over heat exchanger 2240 located in air induction chamber 2040 and allows delivery of homogenous tempered pre-treated air 5 to ASHP 2100.

[0052] Air induction chamber 2040 is essentially a tunnel, passage or duct-like structure through which ambient air 10 is drawn. Ambient air 10 is exposed to heat exchanger 2240 and converted into pre-treated air 5 by transfer of heat from the liquid in heat exchanger 2240. Air induction chamber 2040 may be made of any suitable material such as sheet metal or foam lined sheet metal. In situations where unacceptable heat loss from heat exchanger 2240 is likely to occur then material with low heat transfer properties would be used.

[0053] Domestic hot water tank 2200 functions as a thermal battery for on-demand heat delivery to ASHP 2100 during heating.

[0054] Controllers C1 and C2, pumps P1 and P2 and associated piping and valves are used to control flow in the system. Temperature sensors (T1 to T6) are placed throughout the system.

[0055] Temperature sensor T1 constantly samples the ambient air temperature adjacent to the air intake of pre-treatment heat exchanger 240 positioned on the air intake side of ASHP outdoor unit 2100. Sensor T2 samples pre-treated air temperature in air induction chamber 2040. Sensor T3 samples heat available in the thermal battery (2200). Temperature sensor T4 samples temperature at bottom of thermal battery (2200). Sensor T5 samples the temperature of the hot gas vapor pipe connecting ASHP indoor and outdoor units. Temperature sensor T6 samples the temperature of 8 PCT/AU2014/000776 WO 2015/017880 the heat scavenging heat exchanger (2250). Pump P1 circulates stored heated fluid within the heat delivery circuit of the system. Pump P2 circulates collected/scavenged heat in the collection circuit of the system.

[0056] Controllers C1 and C2 and pumps P1 and P2 comprise the “regulating means” referred to in the claims.

[0057] Pumps P1 and P2 comprise the “pumping means” and “pump means” referred to in the claims and controllers C1 and C2 refer to the “control means” in the claims.

[0058] An example of operational logic of controller C1 as follows assumes ample heat collection and storage capacity. The guiding principle is thus to maximise COP. Heat delivery rate is controlled by pump speed. When ambient air temperatures are high, less auxiliary heat is required, conversely when ambient air temperatures are low additional auxiliary heat is required.

[0059] Operational logic of controller C1: Start pump P1 at “high” speed when T5 exceeds 20°C and T1< 15°C (ASHP has just turned on in heating mode). Slow pump P1 to “intermediate” speed when T2 > 10°C (to conserve heat, favourable COP already exists), conversely increase pump speed by one step if this condition is no longer met. Slow pump P1 to “low” speed when T2 > 15°C (to conserve heat, high COP already exists), conversely increase pump speed by one step if this condition is no longer met. Stop pump P1 when T2 > 20°C (for ASHP protection reasons). Stop pump P1 when T3-T1< 4°C (not economical to run pump). Stop pump P1 when T5 < 30°C (ASHP has turned off).

[0060] Operational logic of “C2” controller: Start pump P2 at “slow” speed when T6 - T4 > 4°C (economical to run pump). Increase speed of pump P2 to “intermediate” when T6 - T4 > 7°C (to increase heat scavenging), conversely reduce pump speed by one step if this condition is no longer met. Increase speed of pump P2 to “high” when T6 - T4 > 9°C (to maximize heat scavenging), conversely reduce pump speed by one step if this condition is no longer met. Stop pump P2 when T6 - T4 < 5°C (not economical to run pump).

[0061] The guiding principle is to maximize scavenging when economical to do so and this is achieved by controller C2.

[0062] One of the major problems with ASHP is icing of the outdoor unit heat exchanger during ambient temperatures below about 7°C. The present invention addresses the problem by pretreating the ambient air to conditions above which ice/frost deposition is reduced or eliminated (depending on ambient conditions and or heat storage). The example logic outlined above caters 9 PCT/AU2014/000776 WO 2015/017880 for ice/frost minimisation as well as COP maximisation. Maximising COP by air pre-treatment naturally minimises ice/frost deposition.

[0063] In designing the system illustrated in Figure 2, pre-treatment heat exchanger 2240 (referred to as HE 1 in the assembly notes) preferably has a cross-sectional area equal to customer heat pump external coil, with similar fin spacing. Solar collectors 2250 (referred to as HE 2 in the assembly notes) preferably have a cross-sectional area half of HE 1 or greater, depending on thermal battery capacity. The air induction chamber preferably has a minimum distance between HE 1 and customer external coil of 100mm. The thermal battery is preferably a 400 litre Hot Water cylinder or larger, with solar connections. The pumps are preferably 2 X variable speed pumps with a pumping capacity dependent on system size.

[0064] ASSEMBLY NOTES

The following instructions describe the assembly process: 1. Attach a custom built air induction chamber to air intake side of external unit of ASHP with the following requirements: 2. Minimum gap between ASHP coil and HE1 to be 100mm to allow for complete mixing of pretreated air. This gap can be reduced depending on correct design of HE1 coil so as to match flow distribution of refrigerant in ASHP evaporator/coil as would be the case for a coil integrated at time of manufacture. 3. Ensure no ambient air is induced through any gaps other than HE1. 4. Attachment by means of magnetic strips is recommended to avoid use of ASHP casing screws. 5. Fit T2 local to (within 15mm), but not in contact with, the ASHP coil. 6. Fit T5 to hot gas pipe. 7. Situate Thermal Battery in such a way as to minimize piping between HE1 and HE2. 8. Fit primary pump to HE1 supply line (off top of Thermal Battery) and complete supply and return piping runs. 9. Fit HE2 in selected location, fit secondary pump in HE2 supply line (off bottom of Thermal Battery) and complete supply and return piping runs. 10. Attach temperature sensors and wire to controllers. 10 PCT/AU2014/000776 WO 2015/017880

Example 1 [0065] Data of an actual test run is shown by the graph in Figure 3. The graph plots results of an ASHP initially operated without the system of the present invention as illustrated in figure 1 activated and then subsequently activated during the test run.

[0066] The ASHP used in this test is a circa 2004 Fujitsu non-inverter model installed in a standard suburban house in Tasmania. Rogerdini model No. DLH9097 temperature sensors and a pump with a flow circulation rate of 100 litres/hour were used.

[0067] Line 1 shows discharge air temperature off indoor unit 60 of ASHP, line 2 shows indoor room temperature, line 3 shows the water temperature into the pre-treatment heat exchanger 240, line 4 shows outdoor ambient temperature 10. Time point “A” 6.29am ASHP start up without system activated, time point “B” 6.40am maximum air discharge temperature on “un-boosted ASHP”, time point “C” 6.43am is reduced performance point due to heavily frosted evaporator coil 30 at which time the system was activated (note steep increase in curve 3 temperature at this time), time point “D” 7.26am shows end of test run (ASHP plus system switched off). Time periods A to B refers to un-boosted ASHP from start up to maximum discharge temperature over which time there was rapid frost build up on evaporator coil 30. B to C represents decreasing performance due to heavy frost build up on evaporator coil 30 prior to initiation of defrost cycle by ASHP logic. C to D represents “boosted” performance with system activated. NB note steadily increasing discharge temperature as a result of pre-treated air which rapidly cleared the frost build up on evaporator coil 30. Initial steep response in temperature is directly correlated to frost elimination. The more gradual increase over time is an indication of COP improvement.

Example 2 [0068] A Daikin system run in heating mode comprising indoor condenser FTXD25DVMA and outdoor unit evaporator RXD25DVMA fitted with the system of the invention including pretreatment heat exchange coil 240 and induction chamber 40 operating at outdoor ambient temperatures typically below 5°C prior to activation of system, achieved pre-treated air temperatures (onto outdoor unit evaporator coil) of 10°C to 18°C depending on pump speed and ambient temperatures.

[0069] Temperature data was collected using a Daikin Dchecker™ which reported temperatures as sensed by the ASHP’s own temperature sensors. Figure 4 shows data recorded during one such test run where line 1 shows compressor discharge pipe temperature, line 2 shows temperature in air induction chamber 40 and line shows 3 temperature on evaporator coil 30 (in ° C). Figure 4 shows a pre-treated air temperature of 18°C achieved during ambient air temperature conditions of 5°C. This is an increase of 13°C. By comparing to Daikin’s performance chart as 11 PCT/AU2014/000776 WO 2015/017880 shown in Table 2 at various ambient temperatures it can be shown that an increase in output would be achieved. This table clearly demonstrates the relationship between ambient temperature and performance.

[0070]

Table 1 C.O.P. And Percentage Gain Calculation*

No. Outdoor Temp (°C) A1 - A4 Output (kW) B1-B4 Input (kW) C.O.P. Percentage Gain(from No.1 as baseline) 1 -5 4.51 1.34 3.37 2 0 5.19 1.4 3.71 10% 3 6 6 1.47 4.08 21% 4 10 6.54 1.52 4.30 28% [0071] ‘Percentage gain in Table 1 was calculated using Table 2 as follows:

Table 2 A1 B1 A2 B2 A3 B3 A4 B4 Indoor Outd oor Temperature (°CWB) EDB -5 0 6 10 O 0 O CM 4.51 1.34 5.19 1.40 6.00 1.47 6.54 1.62 [0072] Where the airflow rate was 19.4 m3/min, EDB refers to entering dry bulb temperature °C, EWB refers to entering wet bulb temperature °C, A1 to A2 refer to total power capacity (heating) of heat pump in kilowatts, B1 to B4 refer to input electrical power to operate heat pump in kilowatts and COP = A/B = total heat output in kW divided by input electrical power in kW. Data used in Table 2 is from published tables relating to a Daikin system run on heating mode comprising indoor condenser FTXS50LVMA and outdoor evaporator RXS50LVMA.

[0073] Table 1 shows that if the system of the present invention is used to bring the ambient air temperature up to 10 °C the COP gain will be 28%.

[0074] The following advantages are provided by the invention:

• Saves energy by raising COP/energy efficiency rate of an ASHP • Increases serviceable life of heat pump by reducing run time due to increased COP. • Allows for heat pump shut down overnight, with cold start capability during low ambient conditions without compromising the heat pump, as would be the case with an unassisted heat 12 PCT/AU2014/000776 WO 2015/017880 pump. The pre-treatment of the ambient air raises its temperature to allow the heat pump to start and operate as if during favourable ambient conditions. By enabling the overnight shutdown of a heat pump, substantially more energy is saved. • Further energy efficiency is achieved by avoiding frosting of heat pump outdoor unit heat exchanger coil during heating mode due to ambient air pre-treatment. This is due to the elimination of the defrost cycle as well as the improved air flow over an unfrosted heat exchanger coil. • Many consumers buy ASHP’s based on price. These units are primarily designed as reverse cycle air conditioners specifically for use in warmer climates with heating mode only suitable for those times when ambient temperatures drop below 15°C. These units are incapable of performing adequately at ambient temperatures below 5°C. Clearly the present invention now allows such ASHP’s to perform at ambient temperatures below 5°C, greatly expanding their operational range. • Energy saving can be further increased by harvesting heat from varying sources such as drain heat recovery, solar water heating technology, ceiling heat recovery. This heat is stored in the thermal battery. • Pre-heating of cold water supply to hot water storage cylinder, washing machine, dishwasher, etc in thermal battery during summer, thus saving further energy. • The present invention turns the ASHP into an “on demand” system rather than its current recommended use of being always on, thus further reducing energy consumption.

[0075] The present application claims priority from Australian provisional patent applications No. 2013902918 and 2013904000 filed 4 August 2013 and 17 October 2013 respectively, the specifications of which are herein incorporated by reference.

[0076] From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.

[0077] Throughout this specification and the claims that follow, unless the context requires otherwise the words "comprise", "comprises", "comprising" will be understood to mean the inclusion of the stated integer, step or group of integers or steps but not the exclusion of any of other integer, step or group of integers or steps. 13 PCT/AU2014/000776 WO 2015/017880

Table 3: Parts List

Number/Designation Feature C1 Controller 1 C2 Controller 2 P1 Pump 1 P2 Pump 2 T1-T6 Temperature sensors 5 Pre-treated air 10 Ambient air 15 Refrigerant piping 18 Expansion device 20 Outdoor unit 30 Evaporator coil 40 Air induction chamber 45 Fan 50 Compressor 55 Reversing valve 60 Indoor unit 65 Condenser coil 70 Condenser Fan 100 air source heat pump (ASFIP) 150 Heat collector 155 Heat exchangers 165 Heat gathering piping 170 Battery heat exchanger 200 Heat storage/heat battery 215 Heat transfer piping/heat transfer means 225 Pump for liquid in pre-treatment heat exchange coil 240 220 heat exchange coil 240 Pre-treatment heat exchange coil 300 System of the invention 2040 Air induction chamber 2100 customer ASHP 2200 Hot water tank 2240 Pre-treatment Heat exchanger 1 2250 Heat exchanger 2 14

Claims (15)

1. An ASHP system comprising: a) an evaporator capable of extracting heat from ambient air in one space; b) a condenser capable of yielding heat into air to heat another space towards a desired temperature; c) a heat collecting means able to collect heat via a fluid medium and being associated with d) an ambient air preconditioning means for bringing the temperature of the ambient air adjacent the evaporator closer to said desired temperature by allowing heat exchange between the fluid medium and the ambient air; said heat collecting means and said preconditioning means being operably linked with e) a regulating means for regulating the treatment of ambient air; wherein said ambient air preconditioning means comprises a heat exchanger through which said fluid medium flows and which is associated with an,-pir induction chamber adjacent said evaporator whereby said ambient air includes air within the air induction chamber heated by said heat exchanger; and wherein said fluid medium is a liquid which remains in liquid phase.

2. The ASHP system of claim 1 wherein the heat exchanger comprises a coil suitable for water/glycol-to air heat exchange, said coil associated with the air induction chamber adjacent said evaporator.

3. The ASHP system of claim 2 having an associated heat storage means.

4. The ASHP system of any one of claims 1 to 3 where the heat exchanger and ah- induction chamber are incorporated at the point of manufacture of the ASHP.

5. A method of increasing the efficiency of an air source heat pump (ASHP), said ASHP including an evaporator capable of extracting heat from ambient air in one space and a condenser capable of yielding heat into air to heat another space; said method comprising providing a) a first heat exchange means able to gather heat via a fluid medium; and b) a second heat exchange means adjacent said evaporator able to dissipate heat via said fluid medium; said first and second heat exchange means operatively associated with c) a pumping means to convey said fluid medium and d) a control means to control flow of said fluid medium, wherein said fluid medium is a liquid which remains in liquid phase throughout its flow through and between the first and second heat exchange means, and wherein said first heat exchange means is able to collect and/or scavenge available heat from a heat source and the second heat exchange means is able to alter the temperature of the ambient air adjacent to the evaporator such that the coefficient of performance of the ASHP is increased.

6. The method of claim 5 wherein said second heat exchange means comprises a heat exchanger and an air induction chamber adjacent said evaporator.

7. The method of claim 6 wherein the heat exchanger comprises a coil suitable for water/glycol-to-air heat exchange, said coil associated with the evaporator.

8. The method of claim 7 wherein said ASHP has an associated heat storage means.

9. A method of increasing the efficiency of an ASHP by raising the temperature of ambient air taken up by the ASHP said method comprising providing: a) a supplementary heat gathering means for gathering heat in the vicinity of the ASHP; b) a supplementary heat storage means associated with said gathering means; c) a heat transfer means for transferring supplementary heat to the ambient air; d) a pump means; and e) a control means for regulating flow of a fluid medium under predetermined conditions; wherein said supplementary heat is carried by the fluid medium circulatable between the heat gathering means, the heat storage means and the heat transfer means; wherein the fluid medium is a liquid which remains in liquid phase throughout its flow through and between the heat gathering means, the heat storage means, and the heat transfer means.

10. The method of claim 9 wherein said heat transfer means comprises a heat exchanger and an air induction chamber adjacent an evaporator of the ASHP.

11. The method of claim 9 wherein the heat transfer means comprises a coil suitable for water/glycol-to-air heat exchange, said coil associated with an evaporator of the ASHP.

12. An auxiliary system for improving energy efficiency of an ASHP capable of providing a desired temperature in a space, by preconditioning ambient air contactable by an outdoor heat exchanger of the ASHP said system comprising: a) a heat collection and/or scavenging means; b) a heat storage means; c) an air preconditioning means; and d) a pumping means, wherein heat collected/scavenged and stored is in a fluid medium circulated by said pumping means which fluid medium is exposed to ambient air adjacent said outdoor heat exchanger thereby bringing the air closer to the desired temperature and thus increasing coefficient of performance (COP); wherein said fluid medium is a liquid which remains in liquid phase.

13. The auxiliary system of claim 12 wherein said air preconditioning means comprises a heat exchanger and an air induction chamber adjacent said an evaporator of the ASHP.

14. The auxiliary system of claim 13 wherein the heat exchanger comprises a coil suitable for water/glycol-to-air heat exchange, said coil associated with the evaporator.

15. An improved air source heat pump (ASHP), said ASHP comprising: an evaporator capable of extracting heat from ambient air in one space and a condenser capable of rejecting heat into air in another space to provide a desired temperature, the improvement comprising providing: a) a heat collecting means able to collect heat via a fluid medium; said collecting means associated with b) an ambient air preconditioning means for bringing the temperature of the ambient air adjacent to the evaporator closer to said desired temperature by allowing heat exchange between the air and the fluid medium; said collecting means and preconditioning means operably linked with c) a regulating means for regulating the treatment of ambient air; wherein said fluid medium is a liquid which remains in liquid phase.