WO2000033000A1

WO2000033000A1 - Heating and cooling system

Info

Publication number: WO2000033000A1
Application number: PCT/US1999/028762
Authority: WO
Inventors: Steven S. Leighton
Original assignee: The Trustees Of The Leighton Family Trust
Priority date: 1998-12-04
Filing date: 1999-12-03
Publication date: 2000-06-08
Also published as: WO2000033000B1; AU1750600A

Abstract

A heating and cooling system (10) comprised of tubes (40) placed within channels (16) of support members (12) and panels (30) mounted to the support members (12).

Description

HEATING AND COOLING SYSTEM

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/101,072 filed September 18, 1998, fully incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to heating and cooling systems, and in particular, to a solar heating and cooling system that can be structurally integrated into a building.

BACKGROUND OF THE INVENTION

Environmental concerns and the depletion of non-renewable energy resources, such as fossil fuels, have created an on-going need for viable alternative energy sources. Solar energy was once considered to be the ideal alternative energy source. Using radiation from the sun to generate heat or other forms of energy is not harmful to the environment and provides a seemingly unlimited supply of energy. Further, any individual or business, in theory, can utilize solar energy, for example, by installing solar panels on residential and non-residential buildings. Various types of solar collector panels have been designed to maximize the efficient conversion of solar radiation to heat or other forms of energy.

Despite these advantages, however, the use of existing solar energy systems has been limited. The solar collector panels typically used to provide solar energy are expensive and often difficult to install. Further, incorporating solar energy systems into a building often requires significant structural changes in the building. As a result of the increased costs in building solar heated structures, many individuals and businesses have opted not to include solar panels but, instead, to use the conventional energy sources. Also, many of the existing solar heating systems have limited use in colder climates, for example, where the solar panels are covered by snow.

Accordingly, a need exists for a system that efficiently utilizes solar energy and that can easily and inexpensively be integrated into a building using existing building materials. A need also exists for a system that reverses the heat transfer process in colder climates to provide cooling, for example, to refrigerators and the like.

SUMMARY OF THE INVENTION

The present invention features a solar heating and cooling system that can be structurally incorporated into a building. The system comprises one or more structural support members for attachment to the building. The structural support members are made of a heat conducting material and include heat receiving surfaces and heat carrying surfaces extending from the heat receiving surfaces to form a channel or slot. The system further comprises one or more structural panels mounted to the structural support members such that an inner surface of the panel is in contact with the heat receiving surfaces of the structural support members. The panels are made of a heat conducting material and have an outer radiation absorbing surface for absorbing solar radiation. The system further comprises a radiant heat tube disposed in each channel or slot in contact with the heat carrying surfaces of the support members, for conveying a heated or cooled medium. The system further comprises insulation for placement beneath the panels and around the support members. The system is preferably sold as a kit to be assembled into the roof and/or wall of the building.

The present invention also features a method of installing a heating and cooling system in a building. The method comprises the steps of: mounting at least one support member to an outer region of a building; laying at least one radiant heat tube within a channel disposed in the support member; mounting at least one panel over the support member such that the panel holds the radiant heat tube in place; and placing insulation underneath and around the support member. In one method, the support members are purlins mounted to rafters of the building in a spaced relationship and the panels are metal roofing panels fastened to the purlins. According to one method, laying the radiant heat tube includes laying a continuous length of the radiant heat tube through the channel in each of the purlins. According to another method, laying the heat tube includes laying one or more heat tubes in each of the channels and coupling a feeder tube and return tube to opposite ends of the radiant heat tubes in each channel. The present invention further features a method of retrofitting an existing building with a heating and cooling system. The method of retrofitting includes removing existing insulation from beneath roofing panels in the building; assembling a plurality of support members to a plurality of sub- support members to form a grid structure; laying at least one radiant heat tube within channels disposed in the support members; securing the grid structure beneath the roofing panels such that top surfaces of the support members and the radiant heat tube are in contact with the roofing panels; and placing insulation underneath and around the support members.

The present invention also features a method of heating using a heating and cooling system structurally incorporated into a building. The method comprises the steps of: absorbing solar radiation at an outer radiation absorbing surface on a panel at an outer region of the building to heat the panel; conducting heat in the panel to a heat receiving surface on a support member mounted to the building beneath the panel; conducting the heat from the heat receiving surface to a heat carrying region of the support member; and transferring heat from the heat carrying region of the support member to a heat carrying medium flowing through a radiant heat tube disposed against the heat carrying region of the ^■ structural support member. The present invention also features a method of cooling using a heating and cooling system structurally incorporated into a building. The method comprises the steps of: transferring heat from a heat carrying medium in a radiant heat tube to a heat carrying region of a support member mounted to the building; conducting the heat from the heat carrying region of the support member to a panel mounted to the support member; and transferring the heat from the panel to a colder region outside of the building, whereby the heat carrying medium within the radiant heat tube is cooled.

DESCRIPTION OF THE DRAWINGS These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein: Fig. 1 is a schematic cross-sectional view of a heating and cooling system, according to the present invention;

Figs. 2A and 2B are side views of support members (or purlin) used in the system, according to two embodiments of the present invention; Fig. 3 is a schematic representation of the heating and cooling system incorporated into a roof of a building, according to one embodiment of the present invention;

Fig. 4 is a schematic cross-sectional view of the heating and cooling system illustrating the heat transfer during a heating application, according to the present invention;

Fig. 5 is graphical illustration of the temperature readings of the panel and water in the system when used as a solar heating system, according to one application of the present invention; and Fig. 6 is a schematic cross-sect ional view of the heating and cooling system illustrating the heat transfer during a cooling application, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The solar heating and cooling system 10, Fig. 1, according to the present invention, utilizes solar radiation and outside temperature conditions to provide heating or cooling. The system 10 is preferably structurally integrated into a building using existing building materials and without requiring separate solar collector panels. According to the exemplary embodiment, the system 10 is incorporated into the roof of the building, for example, as a conventional metal roof placed over rafters 2. Alternatively, the solar heating and cooling system 10 of the present invention can be incorporated into the walls of a building or other locations exposed to the outside environment.

The solar heating and cooling system 10 includes one or more support members 12. In the exemplary embodiment, the support members 12 are purlins, such as the type available from Leighton Mining, mounted to rafters 2 in place of the plywood commonly used in metal roofing. The support members (or purlins) 12 are preferably made of steel or another rigid, heat conducting material.

Each of the support members 12, Fig. 2A, includes heat receiving regions or surfaces 14 and heat carrying regions or surfaces 16 extending from the heat receiving surfaces to form a channel or slot 18. The support members 12 further include fastening strips 20 for fastening the support members 12 to the rafters 2 using fasteners 22. In one example, the heat receiving surfaces 14 have a length of about 1.5 in., the heat carrying surfaces 16 have a length of about 3/4 in., the fastening strips have a length of about 1 in., and the purlins have a height in the range of about 1-3 in.

According to one alternative embodiment, each of the support members (or purlins) 12', Fig. 2B, include one heat receiving surface 14a wider than the other heat receiving surface 14b. In one example, the heat receiving surface 14a (e.g., about 3 in.) is about twice as wide as the heat receiving surface 14b (e.g., about 1.5 in.) Although the exemplary embodiment shows support members (or purlins) 12, 12' having a particular shape, the present invention contemplates other possible shapes, configurations and dimensions.

One or more panels 30 are mounted to the support members 10, for example, using fasteners 32 extending through the panels 30 into the support members 10. One example of the fasteners 32 includes wood/sheet metal pan head screw type fasteners. In the exemplary embodiment, the panels 30 are metal roofing panels, such as the type manufactured by L.F. Leighton Enterprises, Inc. The panels 30 are preferably made of steel or another type of rigid, heat conducting materials and have a thickness of about 24 gauge (GA) .

Each of the panels 30 includes an outer radiation absorbing surface 34 exposed to the outside environment for absorbing solar radiation from the sun, thereby generating heat in the panels 30. The radiation absorbing surface 34 preferably has a darker color with a high solar absorbtivity . An inner surface 36 of each panel 30 is mounted against the heat receiving surfaces 14 of the support members 12, allowing the panels 30 to conduct heat to the heating receiving surfaces 14 and vice versa .

A radiant heat tube 40 is disposed in each of the channels or slots 18 within the support members 12. In one example, the radiant heat tube 40 is a cylindrical tube, such as the type available from Rahau. In another example, the radiant heat tube 40' (see Fig. 4) has a shape that conforms with the channel or slot 18, such as a triangular shape. The radiant heat tubes 40 are preferably made of a plastic material that facilitates radiation of heat. The present invention also contemplates metal tubing or other materials capable of radiating or otherwise transferring heat. The radiant heat tube 40 includes an internal channel 42 for carrying a medium, such as air, water, or any other gaseous or liquid medium capable of transferring heat.

Insulation 44 is disposed beneath the panels 30 and around the support members 12 to prevent heat loss. The insulation 44 prevents heat loss from the panels 30 and support members 12, thereby causing the heat to be conducted between the panels 30 and support members 12 where the inner surface 34 of the panels 30 are in contact with the heat receiving surfaces 14. In the exemplary embodiment, the insulation 42 is a rigid insulation, such as the type manufacture by Johns Manville, Inc. The present invention contemplates any rigid spray or batten insulation that can be specified to code.

One example of assembling the solar heating and cooling system 10 begins by mounting the support members 12 to the rafters 2 using the fasteners 22. In one example, the support members 12 are preferably spaced at a distance of about 12 in. on center. One or more lengths of radiant heat tube 40 are then laid into the channel or slot 18 in each of the support members 12. The panels 30 are then placed over the support members 12 and mounted to the support members 12 using the fasteners 32. Once installed, the panels 30 will then hold the tube 40 in place. The rigid insulation 44 is placed underneath and between the support members 12 according to methods known to those of ordinary skill in the roofing industry.

According to another method of installation, the system 10 can be retrofitted into a roof of an existing building. In this example, the existing insulation is removed from within the building essentially leaving the roofing panels 30 in place. The support members (or purlins) 12 are laid across and fastened to a plurality of sub-support members (or sub-purlins), such as steel C-channels, at a generally 90 degree angle to form a grid structure. The radiant heat tube 40 is then laid in the channels of the support members 12. The entire grid structure formed by the support members 12 and sub-support members is then raised up against the existing roofing panels 30, the sub- support members are secured to the carrying rafters or other existing building structure, and the insulation 44 is re- applied.

When installed, the one or more radiant heat tubes 40, Fig. 3A, preferably form a continuous length of tubing having an input end 46 through which the medium enters the system 10 and an output end 48 through which the heated or cooled medium leaves the system 10. A conventional pumping mechanism 49 can be used to pump the medium through the system 10. The heated or cooled medium is thereby circulated to the desired system or location 43 and then back to the system 10.

Alternatively, one or more lengths of radiant heat tubes 40a-40d, Fig. 3B, are placed in each channel of the support members to form a manifold construction. A feeder tube 45 is coupled to one end of each of the radiant heat tubes 40a-40d for feeding the heat carrying medium to the system, and a return tube 47 is coupled to an opposite end of each of the radiant heat tubes 40a-40d for returning the heat carrying medium to the desired system or location 43. The pumping mechanism 49 is used to pump the heat carrying medium to through the system 10. In use as a heating system as shown in Fig. 4, solar radiation 50 from the sun hits the radiation absorbing surface 34 of the panel 30, thereby heating the panel 30. Heat 52 from the panel is conducted through the panel to the heat receiving surfaces 14 of the support members 12. The insulation 44 prevents heat loss from the panel 30, causing the heat to be directed to the heat receiving surfaces 14. The heat 52 is conducted from the heat receiving surfaces 14 to the heat carrying surfaces 16 adjacent the radiant heat tube 40. The insulation 44 prevents heat loss from the support members 12, causing the heat to be directed to the radiant heat tube 40. The heat 52 is then transferred to the medium flowing through the channel 42 in the tube 40 by radiation and/or convection.

In one example, water was used as the medium and the system 10 was exposed to the sun for 8 hours during clear weather conditions. The temperature readings for the ambient air, the panel, and the water were recorded as shown in Fig. 5.

The heated medium within the radiant heat tube 40 can be pumped or otherwise conveyed to any area or region inside or outside of the building that requires heat. For example, the heated medium can be directed to a hot water heater within the building, to a heat exchanger, or to a swimming pool or hot tub. The present invention contemplates any other applications for using the heated medium to provide energy. In use as a cooling system as shown in Fig. 6, the outside temperature against the panel 30 is lower than the temperature of the medium within the radiant heat tube 40 and the process is reversed, thereby drawing cold from the outside air. Heat 54 is transferred from the medium to the radiant heat tube 40, through the heat carrying surfaces 16 and heat receiving surfaces 14, and into the panel 30. The heat is then transferred from the panel 30 into the outside air or into snow or ice 56 on the panel 30. As a result, the medium within the radiant heat tube 40 is cooled. The cooled medium within the radiant heat tube 40 can then be supplied to any area or region in need of cooling, for example, in a refrigerator. The cooling system is intended for use in cold temperatures and in an area with no direct sunlight . Accordingly, the solar heating and cooling system of the present invention efficiently utilizes solar radiation and the outside temperature to provide heating or cooling to any area inside or outside of a building. The solar heating and cooling system can also be easily integrated into a building to provide an alternative energy source. When incorporated into a metal roof, for example, the heating and cooling system is virtually concealed.

Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention which is not to be limited except by the claims which follow.

What is claimed is:

Claims

1. A heating and cooling system capable of being structurally incorporated into a building, said heating and cooling system comprising: at least one support member made of a heat conducting material, each said at least one support member including at least one heat receiving surface and including at least one heat carrying region extending from said heat receiving surface to form a channel; at least one panel mounted to the support members, wherein at least a portion of an inner surface of said panel is in contact with said heat receiving surface of said at least one support member, and wherein said panel is made of a heat conducting material and has an outer radiation absorbing surface for absorbing radiant heat; at least one radiant heat tube disposed in each said channel formed by said heat carrying regions; a heat carrying medium carried in said radiant heat tube, for carrying heat; and insulation placed beneath said panel and around said support members.

2. The heating and cool ing system of claim 1, wherein said at least one support member includes at least one purlin.

3. The heating and cooling system of claim 2, wherein said purlin includes first and second heat receiving surfaces and first and second heat carrying regions extending from respective first and second heat receiving surfaces to form said channel .

4. The heating and cooling system of claim 3, wherein said channel has a generally triangular shape.

5. The heating and cooling system of claim 4, wherein said radiant heat tube has a generally triangular shape corresponding to said channel such that sides of said radiant heat tube contact said heat carrying regions forming said channel .

6. The heating and cooling system of claim 1, wherein said radiant heat tube has a shape generally corresponding to a shape of said channel.

7. The heating and cooling system of claim 3, wherein each said purlin includes at least one fastening strip, for fastening said purlin to an outer region of said building.

8. The heating and cooling system of claim 1, wherein said at least one panel include at least one metal roofing panel .

9. The heating and cooling system of claim 8, wherein said radiation absorbing surface of said at least one panel has a darker color having a high solar absorbtivity .

10. The heating and cooling system of claim 1, wherein said radiant heat tube is made of a plastic material.

11. The heating and cooling system of claim 1, wherein said at least one support member includes a plurality of support members attached to an outer region of said building, and wherein said at least one panel includes a plurality of panels secured to said support members.

12. The heating and cooling system of claim 11, wherein said at least one radiant tube forms a continuous length of tubing running through said channels in said plurality of support members, and wherein said continuous length of tubing includes an input end and an output end such that said heat carrying medium enters said system through said input end and leaves said system through said output end.

13. The heating and cooling system of claim 11, wherein said at least one radiant tube includes at least one radiant tube in each of said channels in said plurality of support members, and includes at least one feeder tube coupled to one end of each of said radiant tube and at least one return tube coupled to an opposite end of each said radiant tube in each of said channels, and wherein said heat carrying medium enters said system through said feeder tube and leaves said system through said return tube.

14. A heating and cooling system capable of being structurally incorporated into a building, said heating and cooling system comprising: at least one support member adapted to be secured to an outer region of said building, wherein each said support member is made of a heat conducting material, and wherein each said support member includes at least one heat receiving surface and at least one heat carrying region extending from said heat receiving surface to form a channel; at least one panel adapted to be mounted to the support members such that at least a portion of an inner surface of said panel is in contact with said heat receiving surface of said support member, and wherein said panel is made of a heat conducting material and has an outer radiation absorbing surface for absorbing radiant heat; at least one radiant heat tube adapted to be disposed in each said channel formed by said heat carrying regions, for conveying a heat carrying medium; and insulation adapted to be placed beneath said panel and around said support members.

15. The heating and cooling system of claim 14, wherein said at least one support member includes at least one purlin.

16. The heating and cooling system of claim 15, wherein said purlin includes first and second heat receiving surfaces and first and second heat carrying regions extending from respective first and second heat receiving surfaces to form said channel .

17. The heating and cooling system of claim 16, wherein said channel has a generally triangular shape.

18. The heating and cooling system of claim 17, wherein said radiant heat tube has a generally triangular shape corresponding to said channel such that sides of said radiant heat tube contacts said heat carrying regions forming said channel when said radiant heat tube is disposed in said channel.

19. The heating and cooling system of claim 14, wherein said radiant heat tube has a shape generally corresponding to a shape of said channel.

20. The heating and cooling system of claim 14, wherein said at least one panel include at least one metal roofing panel .

21. The heating and cooling system of claim 20, wherein said radiation absorbing surface of said at least one panel has a darker color having a high solar absorbtivity.

22. The heating and cooling system of claim 1, wherein said radiant heat tube is made of a plastic material.

23. A method of installing a heating and cooling system in a building, said method comprising the steps of: mounting at least one support member to an outer region of a building; laying at least one radiant heat tube within a channel disposed in said support member; mounting at least one panel over said at least one support member such that said at least one panel holds said radiant heat tube in place; and placing insulation underneath and around said at least one support member.

24. The method of claim 23 wherein said at least one support member includes a plurality of purlins, and wherein the step of mounting said purlins includes mounting said purlins to rafters of said building in a spaced relationship.

25. The method of claim 24, wherein said at least one panel includes a plurality of metal roofing panels, and wherein the step of mounting said at least one panel includes fastening said metal roofing panels to said purlins.

26. The method of claim 24, wherein the step of laying said at least one radiant heat tube includes laying a continuous length of said at least one radiant heat tube through said channel in each of said plurality of purlins.

27. The method of claim 24, wherein said at least one radiant heat tube includes a plurality of radiant heat tubes, wherein the step of laying said at least one radiant heat tube includes laying at least one of said plurality of radiant heat tubes in each said channel of said plurality of purlins, and further including the step of coupling a feeder tube and a return tube to opposite ends of said at least one of said plurality of radiant heat tubes in each said channel.

28. A method of heating using a heating and cooling system structurally incorporated into a building, said method comprising the steps of: absorbing solar radiation at an outer radiation absorbing surface on a panel at an outer region of said building, wherein said panel is heated; conducting heat in said panel to a heat receiving surface on a support member mounted to said building beneath said panel; conducting said heat from said heat receiving surface to a heat carrying region of said support member; and transferring heat from said heat carrying region of said support member to a heat carrying medium flowing through a radiant heat tube disposed against said heat carrying region of said structural support member.

29. A method of cooling using a heating and cooling system structurally incorporated into a building, said method comprising the steps of: transferring heat from a heat carrying medium in a radiant heat tube to a heat carrying region of a support member mounted to said building; conducting said heat from said heat carrying region of said support member to a panel mounted to said support member; and transferring said heat from said panel to a colder region outside of said building, whereby said heat carrying medium within said radiant heat tube is cooled.

30. A method of retrofitting an existing building with a heating and cooling system, said method comprising the steps of: removing existing insulation from beneath roofing panels in said building; assembling a plurality of support members to a plurality of sub-support members to form a grid structure; laying at least one radiant heat tube within channels disposed in said support members; securing said grid structure beneath said roofing panels such that top surfaces of said support members and said radiant heat tube are in contact with said roofing panels; and placing insulation underneath and around said support members .