NZ520049A - Underfloor heating and cooling using solar and auxilary power sources - Google Patents

Abstract

An underfloor climate control apparatus (1), for heating/cooling a building (6) that is constructed on a foundation of hardfill or on a block foundation, the climate control apparatus comprising a network of tubes (4) in the roof space (5) of the building for heating a fluid, a supplementary heat source (12-15) and a circulation system (2) for conducting fluid through the hardfill or foundation block of the building so that the heated fluid (7) can act to heat the hardfill/foundation block, wherein the supplementary heat source can be selected to operate in combination with the heating provided by circulation of the fluid through the network of tubes in the roof space. (61) Addition to 338087

Description

New Zealand Paient Spedficaiion for Paient Number 520049 Patents Form 5 520049 N.Z. No. 520049 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION <L UNDERFLOOR CLIMATE CONTROL APPARATUS - IMPROVEMENTS/MODIFICATIONS We, Alternative Heating Limited, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement intellectual property office of n.z 1 5 JAN 2003 received - 1 - (Followed by 1 A) Underfloor Climate Control Apparatus - Improvements / Modifications The present invention relates to underfloor climate control apparatus.

It is well known that underfloor heating systems can be a convenient and effective way of heating a building. However, known systems tend to be expensive to operate and, for this reason, have often been ignored as a suitable heating source in domestic and commercial buildings.

Our earlier New Zealand Patent No. 338087 discloses an alternative underfloor heating system.

According to the invention, there is provided an underfloor climate control apparatus, for heating/cooling a building that is constructed on a foundation of hardfill or on a block foundation, the climate control apparatus comprising a network of tubes in the roof space of the building for heating a fluid, a supplementary heat source, and a circulation system for conducting fluid through the hardfill or foundation block of the building so that the heated fluid can act to heat the hardfill/foundation block, wherein the supplementary heat source can be selected to operate in combination with the heating provided by circulation of the fluid through the network of tubes in the roof space.

The supplementary heat source may be isolated from the heating provided by circulation of the fluid through the network of tubes in the roof space and used to provide the main source of heat to the fluid in the circulation system.

In one particularly preferred arrangement, the fluid is heated in tubes in the roof space of the dwelling by heat energy in the roof space, supplemented by heat from the supplementary heat source and passes through a closed circulation system to an arrangement of tubes installed in the hardfill or foundation block of the building. 1A Most preferably, the heating arrangement comprises a storage containment tank that is installed in the upper part of the roof space of a building, a network of heating tubes that are positioned closely adjacent the inner side of the roofing material to gain a maximum solar heating effect, a supplementary heat source, a pump for circulating fluid from the containment tank and through the network of heating tubes and subsequently to a network of tubes in the hardfill/foundation block, from where the fluid is returned to the containment tank.

The supplementary heat source may be one or more sources selected from the group including solar heating panels, a heating element that may be electric, oil or gas, a flue jacket, a flue coil or a wetback.

Preferably the supplementary heat source is in contact with the heating tubes. Alternatively, the supplementary heat source may act directly on the fluid in the tubes or in the containment tank.

The heating tubes in contact with the supplementary heating source may be in series in a continuous network that circulates the fluid from the containment tank through the hardfill/foundation block and back. Alternatively, a separate loop of tubing may circulate fluid from the containment tank, to the supplementary heat source and back to the containment tank.

In a further aspect of the invention the hardfill/foundation block may be insulated with polystyrene surrounding the base and sides of the hardfill/foundation block and the polystyrene is surrounded by a moisture proof material.

The polystyrene is preferably laid before the construction of the foundation, lining a hole, preferably the same area of the foundation, and a depth suitable to fill with around 900mm of hardfill or foundation block.

The moisture proof material is preferably polythene that surrounds the polystyrene to prevent moisture seeping into the hardfill/foundation block below the building. 2 The hardfill/foundation block absorbs excess heat during the summer. The hardfill/foundation block cools during the winter, the heat stored over summer provides extra energy to aid heating during the winter months.

Preferably, the depth of the hardfill/foundation block is thin in hot areas, for example the north of the North Island of New Zealand. There is no need for a large heat sink beneath the house to store energy for winter as the winter is not that long or extreme in the far north of New Zealand. In some cases the insulating polystyrene lining may not be required.

Preferably, the depth of the hardfill/foundation block is thick in cooler areas, for example the south of the South Island in New Zealand. The deep hardfill provides a large storage facility for excess heat energy during summer to be used in the winter months.

In a further aspect of the invention, the circulation system comprises at least two alternative circuits of tubes within the hardfill/foundation block.

Preferably, one of the circuits of tubes in the hardfill/foundation block is a winter circuit of tubes located in close proximity to the floor of the building, and another second circuit of tubes is a summer circuit of tubes located deeper in the hardfill/foundation block. A manifold and valve system may be used to separate the summer and winter circuits.

Preferably, a control switch within the building is used to select which circuit the fluid flows through.

Advantageously the flow through each alternative circuit of tubes may be governed by thermostatically controlled pumps. Preferably, one thermostatically controlled pump controls flow into the summer circuit of tubes. The thermostat of the summer circuit pump may be set to 25°C, for example, so that the pump is activated when the temperature of the fluid in the heating tubes reaches 25°C or above allowing fluid to circulate through the summer circuit.

Preferably another thermostatically controlled pump (a winter pump) controls flow to the heating tubes in the roof space. The thermostat of the winter pump may be set to around 20°C, for example, so that the pump is activated when the temperature of the fluid in the heating tubes reaches 20°C or above, allowing fluid to circulate through the system. The winter pump ensures that the floor temperature remains at the temperature set on the winter pump thermostat, for example 20°C. The thermostatically controlled summer pump increases the summer flow in comparison to a manual control switch.

The winter circuit of tubes may be placed in sand rather than hardfill for both protection of the tubes and to facilitate radiation of heat into the building in the winter months.

Preferably, at least some of the winter circuit tubes are insulated, for example with polystyrene beneath them to provide directional heating to the floor of the building.

The summer circuit tubes may be set in hardfill or in gravel which retain excess heat energy.

Preferably the winter tubes lie within the top 25mm of hardfill/foundation block. The summer tubes are preferably laid near the bottom of the hardfill/foundation block, which is preferably up to 900mm deep.

Preferably, the network of winter radiating tubes is provided to cover the entire area of the hardfill/foundation block. The winter network may be constructed to provide a higher concentration of radiating tubes in different parts of the hardfill/foundation block corresponding to different living areas of the building.

The length of the circuit of radiating tubes is dependent on the size of the building that the system is installed in. For a standard installation, the winter circuit tubing is about 100 metres in length, the summer circuit tubing is about 200 metres in length and the circuit of heating tubes in the roof space is about 300-400 metres in length. 4 Preferably the containment tank used in the apparatus is a pressurisable tank.

Desirably, a thermostat is provided to control operation of the pump so that circulation can be suspended if the temperature of the fluid falls below a preset temperature and to restart the pump when the temperature rises above a preset temperature.

Preferably, the network of radiating tubes is provided to cover the entire area of the hardfill/foundation block. The network may be constructed to provide a higher concentration of radiating tubes in different parts of the hardfill/foundation block corresponding to different living areas of the building.

Desirably, the network of radiating tubes is arranged so that heated fluid first enters the network in the hardfill/foundation block on the side of the building remote from the direct action of the sun (for example, in New Zealand, on the south side of the dwelling).

Using a manifold and valve system, separate circulation networks can be established, for example allowing fluid to be diverted to a circulating network in outbuildings, or for heating a swimming pool or other building. The provision of a swimming pool within the circulating system can be particularly advantageous, the pool providing an outlet for excess heat, particularly in the summer.

The circulation system may be operated using a solar voltaic kit.

Preferably, a polystyrene is used to insulate at least part of the tubing. The polystyrene may be placed under the network of tubes in the roof space to increase the heating effect.

The polystyrene may be placed directly beneath at least some of the tubes in the hardfill/foundation block for directional heating. The tubes will be insulated by the polystyrene below, so that heat will radiate from them in an upward direction, thus heating the floor directly above without losing too much energy to the hardfill/foundation block.

Preferably the tubing is polyethylene tubing having a diameter of 20-25mm, most preferably 25mm.

The fluid may be any suitable liquid, including water, or a specialised heat exchange liquid, for example one containing an anti-freeze component such as ethylene glycol.

The apparatus may be used to cool the building at night by radiating heat from the network of tubes in the roof space. The apparatus may be provided with a thermostat set to ensure the floor is not overly cooled.

In order that the invention may be more readily understood and so that further features thereof may be appreciated, an embodiment of the invention will now be described, by way of example, and with reference to the accompanying drawings, in which: Figure 1 illustrates a climate control apparatus of the invention with supplementary heat sources.

Figure 2 illustrates a climate control apparatus of the invention with an insulated pool of hardfill and two alternative circuits of tubes in the hardfill.

Figure 3 illustrates a climate control apparatus of the invention with two alternative circuits of radiating tubes in the hardfill/foundation block wherein the flow through each circuit is governed by two thermostatically controlled pumps.

With reference to figure 1, there is depicted an underfloor climate control apparatus 1. The apparatus comprises a network of radiating tubes 2 that receive fluid via an inlet tube 3 from a network of heating tubes 4 in the roof space 5 of a dwelling 6. A supply of heating fluid 7 is held within a containment tank 8, supported in the upper part of the roof space 5. A pump 9 pumps fluid 7 from the containment tank 6 8 through the heating network 4 and, via the inlet 3, to the radiating network 2 that is installed in the hardfill or foundation block of the dwelling. Fluid 7 is then returned to the containment tank 8 via a return line 10.

It will be appreciated that, in an average domestic dwelling, between 100 and 200 tons of hardfill provide a foundation 11 for the building. In using the arrangement of the invention, the network of radiating tubes 2 is installed within the hardfill. Preferably, the radiating tubes are positioned within the top 25mm of filler material. The filler material may be any suitable hardfill material, for example pea metal. These tubes may also be pre-installed within a concrete or other solid foundation.

Tubes made from a medium density polyethylene having a diameter of 25mm or equivalent have been found to be particularly suitable for use as radiating tubes in the invention. The network of heating tubes 4 in the roof space may be formed of any suitable material, for example black polybutylene or heavy walled medium density polyethylene has been found to be particularly suitable. The size according to requirements. This does not preclude a purpose built pipe system.

Alternative supplementary heat sources 12, 13, 14, 15 provide extra heat energy to heat the fluid 7. The underfloor climate control apparatus may comprise one or more supplementary heat sources, for example, solar panels 12, a flue coil or jacket 13, a wetback 14 or a gas, oil or electrical element, 15.

The heating tubes 4 may contact the supplementary heat sources, for example solar panels 12, or flue coil or jacket 13 as illustrated, or the supplementary heat source may act directly upon the fluid 7, for example wetback 14 or element 15 as illustrated.

The heating tubes 4 in contact with the supplementary heat sources may be separate loops of heating tube 4 that run from the containment tank and back as illustrated, or they may form part of a continuous heating tube.

When the supplementary heat source acts directly on the fluid 7, it is preferably the fluid 7 in the containment tank 8 that is acted on. 7 Thus, the underfloor climate control apparatus 1 may advantageously make use of energy from extra heating used in cooler periods, such as fires by circulating fluid through a jacket or tube 13 coiled around the flue 17. Direct solar energy may also supplement heating through solar panels 12 on the exterior roof connected to heating tubes 4 in the inner roof space 5.

With reference to figure 2, there is illustrated an underfloor climate control apparatus 1. The apparatus comprises a network of radiating tubes 2a, 2b that receive fluid via an inlet tube 3 from a network of heating tubes 4 in the roof space 5 of a dwelling 6. A supply of heating fluid 7 is held within a containment tank 8, supported in the upper part of the roof space 5. A pump 9 pumps fluid 7 from the containment tank 8 through the heating network 4 and, via the inlet 3, to the radiating network 2 that is installed in the hardfill or foundation block of the dwelling. Fluid is then returned to the containment tank via a return line 10. Hardfill provides a foundation 11 for the building.

The network of radiating tubes 2a, 2b comprise two separate circuits of tubing, 2a and 2b. The first circuit of radiating tubes 2a is suitable for use in winter months and is located in close proximity to the floor of the building, preferable within the top 25mm of fill. The winter tubes may be embedded in sand rather than hardfill.

The second circuit of radiating tubes 2b is suitable for use in the summer months and is located deep within the hardfill, preferably around 900mm below the floor of the building.

The length of the circuit of radiating tubes 2 is dependent on the size of the building that the system is installed in. For a standard installation, the winter circuit tubing 2a is about 100 metres in length, the summer circuit tubing 2b is about 200 metres in length and the circuit of heating tubes 4 in the roof space is about 300-400 metres in length.

A control 18 is preferably located within the building 6 to allow selection between the winter 2a and summer 2b circuit of tubes. 8 A manifold and valve system may be used to control flow independently to the circuits.

The winter circuit of tubes 2a are preferably insulated with a layer of polystyrene sheeting 19 below the tubes. This advantageously provides directional heating to the floor of the building 6 as the polystyrene sheeting prevents heat radiating to the hardfill below.

The winter circuit of tubes 2a may be placed in sand rather than hardfill for both protection of the tubes 2a and to facilitate radiation of heat. The winter circuit of tubes 2a are preferably utilised during the winter months. The tubes 2a heat only the top of the fill, the heat may then radiate through the floor of the building 6 relatively quickly to heat the building 6.

The summer circuit of tubes 2b is preferably used during the summer months. The tubes 2b heat the hardfill lower down, directing excess heat energy away from the building 6. Thus the building 6 may be cooled in this way. The hardfill may store the excess energy which may be used in the winter months. The summer circuit tubes 2b are preferably set in hardfill or gravel which will retain heat energy.

The hardfill foundation beneath the building 6 is preferably lined with polystyrene 20, or other suitable insulating material. The polystyrene lines the bottom and sides of the hardfill foundation.

Preferably a layer of polythene 21 surrounds the outside of the polystyrene to prevent moisture from seeping into the hardfill foundation. It will be appreciated that other suitable moisture proof materials may be used in place of the polythene.

The polystyrene 20 aids the foundation 11 to retain excess heat energy stored over the summer months.

The underfloor climate control apparatus 1 may be adapted to suit the climate of the location of the building 6. In hot areas, for example the north of the North Island 9 of New Zealand the hardfill foundation below the building may be relatively shallow, or the radiating tubes 2 may be placed relatively shallow. There is no need for a large heat sink beneath the building to store energy for the winter as the winter is not that extreme in the far north of New Zealand. In some cases the insulating polystyrene lining 20 may not be required.

In cooler areas, for example the south of the South Island, the hardfill foundation 11 below the building 6 may be relatively deep. The deep hardfill 11 provides a large storage facility for excess heat energy during summer to be used in the winter months. The hardfill 11 is preferably insulated 20 in areas with cool climates. The climate control apparatus 1 in these cooler areas also preferably has summer circuit tubes 2b located deep in the hardfill 11 to dissipate excess heat into the fill for storage for winter.

Figure 3 shows a schematic of an underfloor climate control apparatus 1 according to the invention. The apparatus comprises a network of radiating tubes, circuits 2a and 2b that receive fluid 7 via an inlet tube 3 from a network of heating tubes 4 in the roof space of a dwelling (not shown in figure 3). A supply of heating fluid 7 is held in a containment tank 8, supported in the upper part of the roof space.

As in figures 1 and 2, the two separate circuits of radiating tubes 2a and 2b are suitable for use in winter and summer months respectively. There are provided two thermostatically controlled pumps Ps and Pw that control the flow of fluid through the system.

Thermostatically controlled pump Ps controls flow into the summer circuit of tubes 2a. The thermostat of Ps may be set to 25°C for example so that pump Ps is activated when the temperature of the fluid in the heating tubes reaches 25°C or above, allowing fluid to circulate through the summer circuit. An advantage of the second pump Ps instead of a manual control for flow to the summer and winter circuits is that summer flow is increased.

Thermostatically controlled pump Pw preferably controls flow from the inlet tube 10 to the heating tubes 4. (Pump Pw is essentially equivalent to pump 9 in figures 1 and 2). The thermostat of the winter pump Pw may be set to around 20°C, for example, so that the pump Pw is activated when the temperature of the fluid in the heating tubes 4 reaches 20°C or above, allowing fluid to circulate through the system. The winter pump Pw ensures the floor remains at the temperature set on the thermostat, for example 20°C. When the temperature of the fluid in the heating tubes 4 is between the temperatures set on the thermostats of Pw and Ps, for example 20°C and 25°C, the fluid is pumped through the winter circuit 2a. When the temperature of the fluid in the heating tubes 4 is above that set on the thermostat of Ps the fluid is pumped through the summer circuit 2b. Some fluid may backflow through the winter circuit 2a producing an advantageous cooling effect.

The main principle underlying the invention is to provide an underfloor climate control system that is capable of heating the hardfill to a temperature from 20°C to 25°C. By passing fluid heated in the heating tubes in the roof space through the network of radiating tubes, slow heating of the hardfill throughout the summer months allows this temperature to be achieved. Insulation of the hardfill material, in combination with the bulk of the material itself, has been found to enable the system to operate effectively to heat the dwelling throughout a winter period. Using the system of the invention to heat a dwelling has been found to provide a temperature which is highest at floor level, with air cooling gradually as it rises. This has been established to be a particularly comfortable way of heating a dwelling. As the floor area is relatively large, the maximum temperature of the system can operate at a relatively low level, thus requiring less energy to be pumped into the system to provide the heated hardfill. The system of the invention may advantageously use excess energy from supplementary heat sources, generally used in winter to warm the building.

In practice, a network of heating tubes 4 will be provided only on the sun-facing side of the dwelling, in New Zealand the north-facing side of the roof.

The containment tank 8 is preferably a pressurisable or "bubble" tank that connects with the network of heating tubes 4. ll Preferably a thermostat monitors the temperature of the fluid in the uppermost part of the heating tube network. The operation of the pump 9 is preferably to control feedback from the thermostat so that circulation of fluid within the system is halted if the fluid temperature falls below a preset minimum. The circulation system 4 may be a continuous convolved loop of tubing or may comprise a plurality of interlinked tubes connecting with an outlet pipe 3.

The radiating tubes 2 may be provided in different densities throughout the floor space. For example, tubes may be provided in a greater density in a zone which may correspond to a major living or working zone of the building, and in a lower density in other regions of the building where less heating is required.

The radiating network 2 may be provided in a single series of interconnected loops or in two or more independent loops. Where independent loops are provided, a manifold carrying a number of on/off valves may be used to control flow independently to the various loops.

The radiating tubes may be used to heat other buildings or structures such as swimming pools. This is also an advantageous way that excess heat can be directed away from the building and may provide a cooling effect on the building during the summer by passing fluid that has been cooled to the temperature of the swimming pool throughout the circulation system.

In operating a system in accordance with the invention, it has been found that the system operates to keep a relatively even temperature throughout the dwelling. For example, it has been found that when the sun shines on to the floor of a room on one side of the dwelling, the system acts as a heat exchanger and fluid within the system is heated in that area, with the heat being released in a colder part of the dwelling.

It will also be appreciated that the fluid contained in the heating system can be used for other heating tasks within the dwelling. For example, the inlet supply tube 3 or the outlet return tube 10 could be passed through cupboard spaces or used to provide heated towel rails, etc.

In a typical installation, it may take some months to warm the 100 or more tons of hardfill from the typical 5-6°C temperature at installation to the desired 20-22°C. However, the advantage of the system is that it also takes many months for the hardfill to cool again and it is believed this is why the system is, in fact, so effective.

The circulatory pumps and valves are preferably electrically operated. In a further improvement to the system, the pumps may be operated using a solar voltaic kit, which generates electricity using this solar power, which may be stored in batteries, and will allow the system to run in an almost completely solar-powered arrangement.

Polystyrene sheeting can be arranged to provide enhanced heating effects in selected areas. For example, sheeting could be provided under tube sections located beneath a tiled room to provide additional heating in that area.

Polystyrene sheeting 22 may also be provided under tubes in the roof space to provide enhanced heating of the circulating fluid.

Although the system has been described in relation to a single storey building, it will be appreciated that the system can be readily adapted for use in multi-storey buildings by providing loops in the circulating network. In such an arrangement, control valves would be provided to allow particular floors to be selected for heating. A timing arrangement could be incorporated to control operation of the valves to permit automated heating of different floors at selected times of the day.

During periods of warmer weather, the system may be operated during the coolest times of the day, usually at night, to allow heat to be radiated from the network of heating tubes in the roof space. This provides a very effective cooling ability. A thermostat is provided to ensure that the floor is not overly cooled. 13 Other alternative arrangements are possible. For example, it may be desirable to incorporate one or more layers of a spacer material within the hardfill/foundation block to improve air flow around the radiating tubes.

To enable the system to be incorporated into existing buildings, a tank, for example a copper or plastic tank, could be buried in the fill under a central part of the house. The tank receives circulating fluid from the roof-mounted collectors and replaces the radiating tubes 2 described above. Such a system could also include a buried radiator system (a cast iron radiator has been found to be suitable).

It will be appreciated that many variations or modifications to the system could be made without departing from the spirit of the invention. intellectual property office of n.z JAN 2003 received 14

Claims (59)

WHAT WE CLAIM IS:

1. An underfloor climate control apparatus, for heating/cooling a building that is constructed on a foundation of hardfill or on a block foundation, the climate control apparatus comprising a network of tubes in the roof space of the building for heating a fluid, a supplementary heat source and a circulation system for conducting fluid through the hardfill or foundation block of the building so that the heated fluid can act to heat the hardfill/foundation block, wherein the supplementary heat source can be selected to operate in combination with the heating provided by circulation of the fluid through the network of tubes in the roof space

2. Apparatus according to claim 1, wherein the supplementary heat source can be isolated from the heating provided by circulation of the fluid in the roof space and used to provide the main source of heat to the fluid in the circulation system.

3. Apparatus according to claim 1, wherein the fluid is heated in the tubes in the roof space of the dwelling by heat energy in the roof space, selectably supplemented by heat from the supplementary heat source and is circulated to an arrangement of tubes installed in the hardfill or foundation block of the building.

4. Apparatus according to any one of claims 1 to 3, wherein the heating arrangement comprises a storage containment tank that is installed in the upper part of the roof space of a building, a network of heating tubes that are positioned closely adjacent the inner side of the roofing material to gain a maximum solar heating effect, a supplementary heat source, a pump for circulating fluid from the containment tank and through the network of heating tubes and subsequently to a network of tubes in the hardfill/foundation block, from where the fluid is returned to the containment tank. 15

5. Apparatus according to any one of claims 1 to 4 wherein the supplementary heat source is one or more sources selected from the group including solar heating panels, an electric, oil or gas element, a flue jacket, a flue coil or a wetback.

6. Apparatus according to claim 5 wherein the supplementary heat source is in contact with the heating tubes.

7. Apparatus according to claim 5 wherein the supplementary heat source acts directly on the fluid.

8. Apparatus according to claim 7 wherein the supplementary heat source acts directly on the fluid in the containment tank.

9. Apparatus according to claim 8 wherein the heating tubes are in series in a continuous network of tubes.

10. Apparatus according to claim 6 wherein the heating tubes in contact with the supplementary heat source are a separate loop of tubes that circulate the fluid from the containment tank to the supplementary heat source and back to the containment tank.

11. Apparatus according to any one of the preceding claims wherein the hardfill/foundation block is insulated with polystyrene surrounding the base and sides of the hardfill/foundation block and the polystyrene is surrounded by a moisture proof material.

12. Apparatus according to claim 11 wherein the polystyrene lining is of a depth to be filled with 900mm of hardfill or foundation block.

13. Apparatus according to any one of claims 11 or 12 wherein the moisture proof material is polythene. 16 INTELLECTUAL PROPERTY OFFICE OF N.Z. 5 1 7 APR 2003 RECEIVED

14. Apparatus according to any one of claims 11 to 13 wherein the hardfill/foundation block absorbs heat energy during summer.

15. Apparatus according to any one of claims 11 to 14 wherein the hardfill/foundation block cools during winter, radiating stored heat energy into the building.

16. Apparatus according to any one of claims 11 to 15 wherein the depth of the hardfill is determined according to the climate of the location of the

17. Apparatus according to claim 16 wherein the depth of the hardfill is thin in hot climates.

18. Apparatus according to claim 16 wherein the depth of the hardfill is thick in cool climates.

19. Apparatus according to any one of the preceding claims, wherein the circulation system comprises at least two alternative circuits of tubes within the hardfill/foundation block.

20. Apparatus according to claim 19 wherein the circuits of tubes in the hardfill/foundation block consist of a first winter circuit of tubes located in close proximity to the floor of the building, and a second summer circuit is located deeper in the hardfill/foundation block.

21. Apparatus according to claim 20 wherein a manifold and valve system is used to separate the summer and winter circuits.

22. Apparatus according to claim 21 wherein a control within the building may be used to select between the winter or summer circuit.

23. Apparatus according to claim 20 wherein the flow through each alternative circuit of tubes is governed by a thermostatically controlled pump. building. 17

24. Apparatus according to claim 23 wherein a thermostatically controlled pump controls flow into the summer circuit of tubes.

25. Apparatus according to claim 24 wherein the pump allows fluid through the summer circuit when the temperature of the fluid in the heating tubes is above 25°C.

26. Apparatus according to any one of claims 23 to 25 wherein a thermostatically controlled winter pump controls flow to the heating tubes in the roof space.

27. Apparatus according to claim 26 wherein the thermostatically controlled winter pump allows fluid into the heating tubes in the roof space when the temperature of the fluid in the heating tubes exceeds 20 °C.

28. Apparatus according to any one of claims 20 to 27 wherein the winter circuit of tubes is laid in sand.

29. Apparatus according to any one of claims 20 to 28 wherein at least some of the winter circuit tubes are insulated.

30. Apparatus according to claim 29 wherein the winter circuit tubes are insulated with polystyrene beneath the tubes.

31. Apparatus according to any one of claims 20 to 30 wherein the summer circuit tubes are laid in gravel.

32. Apparatus according to any one of claims 20 to 31 wherein the winter circuit tubes are within the top 25mm of filler material.

33. Apparatus according to any one of claims 20 to 32 wherein the summer circuit tubes are laid 900mm below the floor of the building. 18

34. Apparatus according to any one of claims 20 to 33 wherein the winter circuit of tubes covers substantially the entire area of the hardfill/foundation block.

35. Apparatus according to claim 34 wherein the winter circuit of tubes is constructed to provide a higher concentration of radiating tubes in different parts of the hardfill/foundation block corresponding to different living areas of the building.

36. Apparatus according to any one of claims 20 to 35 wherein the winter circuit of tubing is about 100 metres in length.

37. Apparatus according to any one of claims 20 to 36 wherein the summer circuit of tubing is about 200 metres in length.

38. Apparatus according to any one of the preceding claims wherein the containment tank is a pressurisable tank.

39. Apparatus according to any one of the preceding claims further comprising a thermostat provided to control operation of the pump so that circulation can be suspended if the temperature of the fluid falls below a preset temperature and to restart the pump when the temperature rises above a preset temperature.

40. Apparatus according to any one of the preceding claims wherein the network of radiating tubes is provided to cover substantially the entire area of the hardfill/foundation block.

41. Apparatus according to claim 38 wherein the network is constructed to provide a higher concentration of radiating tubes in different parts of the hardfill/foundation block corresponding to different living areas of he building.

42. Apparatus according to any one of the preceding claims wherein the network of radiating tubes is arranged so that heated fluid first enters the network in 19

43

44,

45

46

47

48

49

50

51

52 the hardfill/foundation block on the side of the building remote from the direct action of the sun. Apparatus according to any one of the preceding claims further comprising a manifold and valve system to separate circulation networks. Apparatus according to claim 43, wherein a separate circulating network in outbuildings, or for heating a swimming pool or other building, is provided. Apparatus according to any one of the preceding claims wherein a voltaic kit is provided to power the circulation system. Apparatus according to any one of the preceding claims wherein polystyrene is used to insulate at least a part of the tubing. Apparatus according to claim 46 wherein the polystyrene is placed under the network of tubes in the roof space to increase the heating effect. Apparatus according to claim 46 wherein the polystyrene is placed directly beneath at least some of the tubes in the hardfill/foundation block for directional heating. Apparatus according to any one of the preceding claims wherein the tubes are polyethylene tubes having a diameter of 25mm. Apparatus according to any one of the preceding claims, wherein the fluid is a suitable liquid. Apparatus according to claim 50, wherein the fluid is water. Apparatus according to claim 50, wherein the fluid is a specialised heat exchange liquid. 20

53. Apparatus according to claim 52, wherein the fluid contains an anti-freeze component such as ethylene glycol.

54. A method of cooling a building using apparatus according to any one of the previous claims at night wherein heat is radiated from the network of heating tubes in the roof space.

55. A method according to claim 54 wherein the apparatus has a thermostat set to ensure the floor is not overly cooled.

56. A method of heating a building using apparatus according to any one of claims 1 to 53.

57. An apparatus according to claim 1 substantially as herein described or exemplified.

58. A method according to claim 54 substantially as herein described or exemplified.

59. A method according to claim 56 substantially as herein described or exemplified. ;m i>u-ECTL)AL property 1 OFFICE OF N.Z. I 1 7 APR 2003 I received I ALTERNATIVE HEATING LIMITED By Their Attorneys HENRY HUGHES Per: 21 Figure 1 6 ~ Figure 3 IT ■v. C c c Pw- 20°c -10 OJ o3 c c r