AU770746B2 - Underfloor climate control apparatus - Google Patents

Description

Wr AUSTRAL IA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant 'LA T 7% M M WT V'V UfM VtV TM -r T7 0 Invention Title: UNDERFLOOR CLIMATE CONTROL APPARATUS The following statement is a full description of this invention, including the best method of performing it known to me/us: EDITORIAL NOTE APPLICATION NUMBER 61382/00 The first page of the specification is page 2.

2 The present invention relates to underfloor climate control apparatus.

It is well known that building-wide 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.

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 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.

In one particularly preferred arrangement, the fluid is heated in tubes in the roof space of the dwelling and passes through a closed circulation system to an 2 arrangement of tubes installed in the hardfill or go 25 foundation block of the building. Preferably, a polystyrene is used to insulate at least part of the S" tubing..

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

Most preferably, the heating arrangement comprises a *oe *35 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 H:\lauraw\Keep\Speci\61382-OO.doc 10/12/03 3 of the roofing material to gain a maximum solar heating effect, 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. 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, a 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 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 o 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.

*oo H:\lauraw\Keep\Speci\61382-OO.doc 10/12/03 4 Desirably, the hardfill or heating block foundation is surrounded on its sides and base by a suitable insulation system. For example, a suitable polystyrene insulating material could be used.

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 S. 10 drawings, in which: Figure 1 illustrates, schematically, a heating apparatus of the invention installed within a domestic dwelling; Figure 2 illustrates the heating network of the apparatus installed within the rafters of a standard tiled roof; Figure 3 illustrates, schematically, the recirculating fluid network; Figures 4 5 illustrate possible arrangements of radiating tubes within the hardfill/foundation block of a building; Figure 6 illustrates the provision of alternative selectable circulation loops; Figure 7 illustrates, schematically, a possible manifold arrangement for selecting the circulating loops of Figure 6.

Referring to Figure 1, an underfloor heating apparatus is generally indicated at 1. The apparatus 1 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 indicated at 6. A supply of heating fluid 7 is held within a containment tank 8, supported in \\melbfies\home\Lind\Kee\sec\P39711.doc 28/09/00 5 the upper part of the roof space 5. A pump, illustrated schematically at 9, pumps fluid 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 illustrated by the broken line 10 in Figure 1.

It will be appreciated that, in an average domestic dwelling, between 100 and 200 tons of hardfill provide a S" 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 S" tubes are positioned within the top 25 mm 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 block.

Tubes made from a medium density alkathene material having a diameter of 20-25 mm 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 alkathene has been found to be particularly suitable. The size according to requirements.

This does not preclude a purpose built pipe system.

Further aspects of the system will be described in more detail later. However, it may be helpful now to consider in more detail the operation of the system.

The main principle underlying the invention is to provide an underfloor heating system that is capable of heating the hardfill to a temperature of from 20 to 250 C. By passing fluid heated in the heating tubes in the roof space through the network of radiating tubes, slow heating of the \\melbfiles\home\Linda\Keep\spec\P39711.doc 28/09/00 6 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.

°1 Figures 2 and 3 illustrate, in more detail, the arrangement of heating tubes in the roof space. As illustrated, a network of heating tubes 4 is formed in the upper part of o the roof space. Figure 2 illustrates two common forms of roofing, corrugated panel roofing and tiled roofing 13.

If a corrugated iron roofing material 12 is used, the network of heating tubes is positioned to lie between the rafters and adjacent roofing paper 14 which underlies the roofing panels 12. If a tiled roofing material is used, the heating tubes 4 may be positioned to lie adjacent the tiles, between the tiles and the roofing paper 15. In practice, a network of heating tubes will be provided only on the sun-facing side of the dwelling, in New Zealand the north-facing side of the roof.

Turning to Figure 3, one possible circulation arrangement is illustrated. The containment tank 8, which is preferably a pressurisable or "bubble" tank, connects with the network of heating tubes 4. A thermostat 15 monitors the temperature of the fluid in the uppermost part of the heating tube network. Figure 3 also illustrates an \\melb_files\home$\Linda\Keep\spec\P39711.doc 281/09/00 7 alternative positioning of the circulation pump.

Irrespective of the whereabouts of the pump 9, the operation of the pump is preferably to control feedback from the thermostat 15 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 3.

Figure 3 illustrates, schematically, the connection to the radiating tubes 2 and the provision of a return pathway The heating fluid may be any suitable fluid. For example, a polypropylene glycol heating transfer fluid may be used.

e. This is particularly advantageous as this will ensure that fluid does not freeze within the tubes during winter.

Figures 4 to 7 illustrate possible arrangements of the radiating tubes within the hardfill/block foundation. As illustrated in Figure 4, 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, indicated at 16, 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 2 is required. As is illustrated in Figures 5 and 6, the 25 radiating network 2 may be provided in a single series of interconnected loops or in two or more separated loops, illustrated as 19, 20, 21 in Figure 6. Where independent loops are provided, a manifold 22, carrying a number of on/off valves 23, may be used to control flow independently to the various loops. Figure 4 also illustrates, schematically, an additional loop 24 that is desirably provided in a lower region of the filler material. The loop 24 is connectable to the circulation system and is used to take excess heat away from the surface of the filler material, for example during hot parts of summer.

\\melbfiles\home\Linda\Keep\spec\P39 7 11.doc 28/09/00 8 Returning to Figure 1, another feature of the invention will now be described. A swimming pool 25 is provided with a heating arrangement 26 comprising a further network of radiating tubes 27. The tubes 27 are connected to the outlet tube 3 via manifold 28 and flow may be selected to pass to the swimming pool before entering the network of heating tubes 2 in the hardfill 11. This again allows excess heat to be used to heat water in the swimming pool during summer months, and also provides a system with an ability to provide a cooling effect to the dwelling during the summer by passing fluid that has been cooled to the temperature of the swimming pool throughout the circulation system.

15 In operating a system in accordance with the invention, it 006 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 0 "colder part of the dwelling.

As discussed above, it may be desirable for the hardfill or 25 foundation block to be insulated, at least on its side

S.

o edges and on the lower base. For example, a polystyrene insulating material could be used. The insulating material could then be placed underground before the fill or foundation block is positioned.

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.

\\.elb files\homeS\Linda\Keep\spec\P39711.doc 28/09/00 9 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 S.i to run in an almost completely solar-powered arrangement.

S: 15 In a further advantageous development, polystyrene sheeting •i 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 may also be provided under tubes in the roof space to provide enhanced heating of the circulating fluid.

25 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 \\melb~files\homeS\Linda\Keep\spec\P39711.doc 28/09/00 10 '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.

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 plastics tank, could be buried in the fill under a central part of the house. The tank receives circulating fluid from the roofmounted collectors and replaces the radiating tubes 2 S* 15 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 20 modifications to the system could be made without departing from the spirit of the invention.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but 25 not limited to", and that the word "comprises" has a corresponding meaning.

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.

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Claims (23)

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 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.

2. Apparatus according to claim 1, wherein the fluid is heated in the tubes in the roof space of the dwelling and passes through a closed circulation system to an arrangement of tubes installed in the hardfill or foundation block of the building.

3. Apparatus according to claim 1 or 2, wherein a polystyrene is used to insulate at least part of the tubing.

4. Apparatus according to claim 1, 2 or 3, wherein 25 the fluid is a suitable liquid.

5. Apparatus according to claim 4, wherein the fluid is water.

6. Apparatus according to claim 4, wherein the fluid is a specialised heat exchange liquid.

7. Apparatus according to claim 6, wherein the fluid contains an anti-freeze component such as ethylene glycol. 35

8. Apparatus according to any one of claims 1 to 7, .wherein the heating arrangement comprises a storage containment tank that is installed in the upper part of H:\lauraw\Keep\Speci\61382-OO.doc 10/12/03 12 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 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.

9. Apparatus according to claim 8, wherein the storage containment tank is a pressurisable tank.

Apparatus according to claim 8, 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.

11. Apparatus according to claim 8 or claim wherein a network of radiating tubes is provided to cover substantially the entire area of the hardfill/foundation block.

12. Apparatus according to claim 11, wherein the 25 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 the building.

13. Apparatus according to any one of claims 8 to 12, wherein the network of radiating tubes is arranged so that heated fluid first enters the network in the hardfill on the side of the building remote from the direct action of the sun. H:\lauraw\Keep\Speci\61382-OO.doc 10/12/03 13

14. Apparatus according to any one of claims 8 to 13, further comprising a manifold and valve system to separate circulation networks.

15. Apparatus according to claim 14, wherein a separate circulating network in outbuildings, or for heating a swimming pool or other building, is provided.

16. Apparatus according to any one of claims 1 to 14, wherein a voltaic kit is provided to power the circulation system.

17. Apparatus according to any one of claims 1 to 16, wherein the hardfill or heating block foundation is surrounded on its sides and base by a suitable insulation system.

18. 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.

19. A method according to claim 18, wherein the apparatus has a thermostat set to ensure the floor is not g 25 overly cooled. :o

20. A method of heating a building using apparatus according to any one of the previous claims.

21. Apparatus according to claim 1 substantially as herein described or exemplified.

22. A method of heating a building according to claim 20 substantially as herein described or exemplified. H:\1auraw\Keep\Speci\61382-OO.doc 10/12/03 14

23. A method of cooling a building according to claim 18, substantially as herein described or exemplified. Dated this 10 th day of December 2003 ALTERNATIVE HEATING LIMITED By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia oeooe oo ee e L H:\lauraw\Keep\Speci\61382-OO.doc 10/12/03