US20070151704A1

US20070151704A1 - Geothermal heat exchange system

Info

Publication number: US20070151704A1
Application number: US11/325,403
Authority: US
Inventors: Gregory Elmore
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-04
Filing date: 2006-01-04
Publication date: 2007-07-05

Abstract

A geothermal heat exchange system for use in cooperation with a foundation wall of a building. The geothermal heat exchange system includes a heat exchange unit for transferring heat between a building and the earth, a foundation wall that is at least partially buried in the earth, and a ground loop. The heat exchange unit includes an inlet and an outlet for a working fluid. The ground loop includes a loop of piping connected to the inlet and the outlet of the heat exchange unit, and is at least partially imbedded in the foundation wall.

Description

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to the field of geothermal heat exchange systems. In particular, the invention relates to a geothermal heat exchange system that can be used in cooperation with a foundation wall of a building.
A geothermal heat exchange system is a system that uses the earth to provide energy for heating or cooling. The earth absorbs almost 50% of all solar energy and remains a nearly constant temperature of 50° F. to 70° F. depending on geographic location. The geothermal heat exchange system utilizes this constant temperature to exchange energy between a building and the earth as needed for heating and cooling.
To take advantage of the earth's energy, a geothermal heat exchange system uses a series of pipes called a “loop” in combination with an indoor heat exchange unit, such as a heat pump. The loop is typically buried in the ground near the building to be heated or cooled. In the winter, a fluid is circulated through the loop to absorb heat from the earth and carry the heat energy to the heat exchange unit for heating the building. In the summer, the heat exchange unit absorbs heat from the building and expels the heat into the earth via the loop. Once installed, the loop in a geothermal heat exchange system remains out of sight beneath the earth's surface.
Most loops for residential geothermal heat exchange systems are installed either horizontally, FIG. 1, or vertically, FIG. 2, in the ground. Horizontal loops are typically installed by digging trenches three to six feet below the ground, and laying a series of parallel pipes in the trenches. Once the loop is positioned in the trenches, the trenches are backfilled. Horizontal loops are usually easy to install and cost effective when installed with new construction. However, a typical horizontal loop is 400 to 600 feet long per ton of heating and cooling capacity, and thus requires the availability of substantial yard space. Additionally, because of the yard space required, installing a horizontal loop for an existing building results in the yard being disturbed. Vertical loops are used when yard space is insufficient to permit horizontal loops to be used, for buildings with large heating and cooling loads, when the earth is rocky close to the surface, or for retrofit applications where minimum disruption of the landscaping is desired. Vertical loops are installed by boring vertical holes in the ground 150 to 450 feet deep and inserting pipe into those holes. After the pipe is inserted, the holes are backfilled. Each vertical pipe is then connected to a horizontal pipe, which is also concealed underground. The horizontal pipe carries fluid to and from the geothermal heat exchange unit. Vertical loops are expensive to install due to the depths at which the holes must be drilled.
Accordingly, there is a need for a geothermal heat exchange system that can be installed easily without disturbing a yard, that does not require substantial yard space, and that is cost effective to install.

SUMMARY OF THE INVENTION

Therefore it is an object of the invention to provide a geothermal heat exchange system that can be installed without digging trenches or boring holes in a yard.
It is another object of the invention to provide a geothermal heat exchange system that can be installed with new construction and existing buildings.
It is another object of the invention to provide a geothermal heat exchange system that can be installed in a foundation wall of a building.
It is another object of the invention to provide a geothermal heat exchange system that can be installed along a foundation wall of a building.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a geothermal heat exchange system. The heat exchange system includes a heat exchange unit for transferring heat between a building and the earth, the heat exchange unit having an inlet and an outlet for a working fluid. The heat exchange unit further including a foundation wall which is at least partially buried in the earth, and a ground loop adapted to receive a flow of working fluid therethrough. The ground loop includes a loop of piping connected to the inlet and the outlet. The ground loop being at least partially imbedded in the foundation wall.
According to another preferred embodiment of the invention, the loop of piping is continuous.
According to another preferred embodiment of the invention, the loop of piping is coiled.
According to another preferred embodiment of the invention, a geothermal heat exchange system includes a heat exchange unit for transferring heat between a building and the earth, the heat exchange unit having an inlet and an outlet for a working fluid. The heat exchange unit further includes a ground loop adapted to receive a flow of a working fluid therethrough. The ground loop including a loop of piping connected to the inlet and the outlet. The ground loop is adapted for being positioned adjacent an outside surface of a foundation wall which is at least partially buried in the earth.
According to another preferred embodiment of the invention, the ground loop is secured to the outside surface of the foundation wall.
According to another preferred embodiment of the invention, the ground loop further includes at least one piping support for being secured to the outside surface of the foundation wall.
According to another preferred embodiment of the invention, the loop of piping is secured to an outside surface of the piping support between the piping support and the earth.
According to another preferred embodiment of the invention, the loop of piping is imbedded in the piping support.
According to another preferred embodiment of the invention, a geothermal heat exchange system includes a heat exchange unit for transferring heat between a building and the earth, the heat exchange unit having an inlet and an outlet for a working fluid. The heat exchange unit further includes a ground loop adapted to receive a flow of working fluid therethrough and connected to the inlet and the outlet. The ground loop includes a plurality of interconnected modular ground loops. Each of the modular ground loops include a loop of piping adapted for being positioned adjacent an outside surface of a foundation wall which is at least partially buried in the earth.
According to another preferred embodiment of the invention, the modular ground loops are positioned adjacent to each other on an outside surface of the foundation wall to allow the modular ground loops to be interconnected.
According to another preferred embodiment of the invention, the modular ground loops further include a piping support.
According to another preferred embodiment of the invention, the loop of piping is secured to the piping support.
According to another preferred embodiment of the invention, the piping support is secured to the outside surface of the foundation wall.
According to another preferred embodiment of the invention, the loop of piping is secured to an outside surface of the piping support and positioned between the piping support and the earth.
According to another preferred embodiment of the invention, the piping support is a panel.
According to another preferred embodiment of the invention, the panel is a rigid closed cell insulation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be best understood by reference to the following description in conjunction with the accompanying drawing figures in which:
FIG. 1 is a prior art horizontal geothermal heat exchange system;
FIG. 2 is a prior art vertical geothermal heat exchange system;
FIG. 3 is a heat exchange system according to an embodiment of the invention;
FIG. 4 is a heat exchange system according to another embodiment of the invention; and
FIG. 5 is a heat exchange system according to yet another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE

Referring now specifically to the drawings, a geothermal heat exchange system according to an embodiment of the invention is illustrated in FIG. 3 and shown generally at reference numeral 10. The heat exchange system 10 includes piping 11 imbedded in a foundation wall 12 to form a “loop.” The piping 11 may be made of any non-reactive material, such as high-density polyethylene, that can be encased in concrete and that does not substantially retard the exchange of heat between a fluid in the pipe 11 and the foundation wall 12. The piping 11 may be coiled, as shown, or installed in sections using fittings.
The system 10 is particularly suited for use with poured foundation walls. The piping 11 is installed along with any rebar or other support-type structures within a form before any concrete is poured to form the foundation wall 12. The piping 11 is connected to a heat exchange unit 13, such as a heat pump, for extracting energy from the fluid circulating within the piping 11. Examples of a suitable fluid include water, antifreeze, or a mixture thereof. Because the foundation wall 12 extends below the surface of the earth, the system 10 is able to absorb heat energy from the earth through the foundation wall 12 in the winter and expel heat into the earth via the foundation wall 12 in the summer.
In operation, the fluid is circulated within the piping 11 and absorbs the heat energy from either the earth or from the building, depending on whether the system 10 is cooling or heating the building. In the summer, the heat exchange unit 13 captures the heat from within the building and transfers it to the fluid in the piping 11. The fluid then transfers the heat from the building to the piping 11 and into the earth, thereby decreasing the temperature of the fluid in the piping 11 and providing air-conditioning. In the winter, the fluid in the piping 11 absorbs heat energy from the earth and delivers it to the heat exchange unit 13 where it is extracted and transferred to the building.
Referring to FIG. 4, a heat exchange system 110 according to another embodiment of the invention is shown. The heat exchange system 110 includes piping 111 affixed to an outside surface 112 of a foundation wall 113 to form a loop. The foundation wall 113 may be made of concrete blocks, poured concrete, or other suitable materials. Like the piping 11, the piping 111 may be made of high-density polyethylene or other suitable material that does not substantially retard the exchange of heat between a fluid in the piping 111 and the earth.
Once the foundation wall 113 is constructed, the piping 111 is positioned between the outside surface 112 of the wall 113 and the earth and affixed to the foundation wall 113 using suitable fasteners. The wall 113 is pierced above the earth's surface to allow ends of the piping 113 to enter the building and be connected to a heat exchange unit 114. This allows the fluid in the piping 111 to transfer heat energy to the earth in the summer and to the building in the winter.
FIG. 5 illustrates a heat exchange system 210 in modular form to allow ease of installation. As shown, piping 211, forming a loop, is affixed to or imbedded in a piping support, such as panel 212. The panel 212 is preferably made of a rigid closed cell insulation, but other suitable materials for providing a support and insulating characteristics may be used. The panel 212 is sized, such as 4 feet by 8 feet, for use with a foundation wall 214.
The heat exchange system 210 is installed during the waterproofing stage of the foundation wall 214. Once the waterproofing has been applied to an outside surface 213 of the wall 214, individual panels 212 are imbedded into the waterproofing before it dries with the piping 211 positioned between the panel 212 and the earth. Each panel 212 is placed below the earth's surface. The loop formed by the piping 211 on each panel 212 is joined with the loop of an adjacent panel 212 by a suitable connection means 218 to create a continuous loop. Examples of suitable connection means include welding, gluing, and pipe fittings such as couplings and unions. Ends of the loop are inserted through an opening of the wall 214 to allow the loop to be connected to a heat exchange unit 216. A drain 217 is provided along the bottom of the panel 212 to prevent moisture buildup around the panel 212 and foundation wall 214.
A geothermal heat exchange system is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.

Claims

1. A geothermal heat exchange system, comprising:

(a) a heat exchange unit for transferring heat between a building and the earth, the heat exchange unit having an inlet and an outlet for a working fluid;

(b) a foundation wall which is at least partially buried in the earth; and

(c) a ground loop adapted to receive a flow of working fluid therethrough, the ground loop comprising a loop of piping connected to the inlet and the outlet, the ground loop being at least partially imbedded in the foundation wall.

2. The heat exchange system according to claim 1, wherein the loop of piping is continuous.

3. The heat exchange system according to claim 1, wherein the loop of piping is coiled.

4. A geothermal heat exchange system, comprising:

(a) a heat exchange unit for transferring heat between a building and the earth, the heat exchange unit having an inlet and an outlet for a working fluid; and

(b) a ground loop adapted to receive a flow of working fluid therethrough, the ground loop comprising a loop of piping connected to the inlet and the outlet, the ground loop adapted for being positioned adjacent an outside surface of a foundation wall which is at least partially buried in the earth.

5. The geothermal heat exchange system according to claim 4, wherein the loop of piping is continuous.

6. The geothermal heat exchange system according to claim 4, wherein the loop of piping is coiled.

7. The geothermal heat exchange system according to claim 4, wherein the ground loop is secured to the outside surface of the foundation wall.

8. The geothermal heat exchange system according to claim 4, wherein the ground loop further includes at least one piping support for being secured to the outside surface of the foundation wall.

9. The geothermal heat exchange system according to claim 8, wherein the loop of piping is secured to an outside surface of the piping support between the piping support and the earth.

10. The geothermal heat exchange system according to claim 9, wherein the loop of piping is imbedded in the piping support.

11. A geothermal heat exchange system, comprising:

(b) a ground loop adapted to receive a flow of working fluid therethrough and for being connected to the inlet and the outlet, the ground loop comprising a plurality of interconnected modular ground loops, each of the modular ground loops comprising a loop of piping adapted for being positioned adjacent an outside surface of a foundation wall which is at least partially buried in the earth.

12. The geothermal heat exchange system according to claim 11, wherein the modular ground loops are positioned adjacent to each other on an outside surface of the foundation wall to allow the modular ground loops to be interconnected.

13. The geothermal heat exchange system according to claim 11, wherein the modular ground loops further include a piping support.

14. The geothermal heat exchange system according to claim 13, wherein the loop of piping is secured to the piping support.

15. The geothermal heat exchange system according to claim 13, wherein the loop of piping is imbedded in the piping support.

16. The heat exchange system according to claim 13, wherein the piping support is secured to the outside surface of the foundation wall.

17. The heat exchange system according to claim 13, wherein the loop of piping is secured to an outside surface of the piping support and positioned between the piping support and the earth.

18. The heat exchange system according to claim 13, wherein the piping support is a panel.

19. The heat exchange system according to claim 18, wherein the panel is a rigid closed cell insulation.

20. The heat exchange system according to claim 11, wherein the loop of piping is coiled.