Patent Publication Number: US-11022345-B1

Title: Ground source heat pump heat exchanger

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Pat. No. 10,345,051 entitled “GROUND SOURCE HEAT PUMP HEAT EXCHANGER” filed on 15 Mar. 2013, which claims the benefit of U.S. Provisional Application Ser. No. 61/657,898 entitled “Horizontal Ground Source Heat Pump Heat Exchanger” filed on 11 Jun. 2012, the contents of both of which are incorporated herein by reference in their entirety. 
    
    
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document may contain material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     The principle of the heat pump was initially proposed by Nicholas Carnot in 1824. Thirty years later, Lord Kelvin suggested refrigerating equipment could be used for heating. Although several manufacturers built heat pumps in the 1930s, it was not until the 1950s that heat pumps began to be mass produced. Conventionally, the heat was exchanged with the ambient outside air, and refrigerants, e.g., hydrocarbons or fluorocarbons, were used in the process. The use of refrigerants, such as hydrocarbons, proved to have a negative environmental impact. Today, numerous types of heating and cooling systems are used for controlling the temperature of various thermal loads, and efforts are made to minimize pollutants in the environment. Many existing heating and cooling systems, including heat pumps, air conditioners, refrigeration units, and the like, operate on the same thermodynamic principles and utilize the same basic components. 
     Most commonly, these basic components include a compressor, an expander, a load heat exchanger, and an external heat exchanger. Each of these components is connected with a piping system which carries a circulating fluid, e.g., a refrigerant (liquid or gas) or water (or an antifreeze or alcohol water solution) throughout the system. In order for this type of system to operate, heat must be exchanged with the environment. This heat exchange with the environment may be accomplished by directing the circulating fluid to an outdoor coil, e.g., an external heat exchanger, where thermal energy is exchanged between the water/refrigerant contained in the coils and the outside air. 
     Using outside air as the sink or source for a heat exchange process is problematic due to the variability of air temperature. A heat pump operating during the winter requires the external heat exchanger to absorb thermal energy from the outside air. The heating system, however, loses its efficacy and efficiency as the outside temperature falls because less thermal energy can be extracted from the outside air, and therefore, these heating systems must have a secondary heat back up, e.g., electric heating strips. Similarly, a cooling system, such as an air conditioner, encounters the same efficacy and efficiency problems when the outside temperature rises. 
     A ground source heat pump works like other heat pumps in that it has a basic refrigerating circuit but, instead of extracting energy from the air, it uses the heat stored in the ground. Ground source heat exchange is a potentially more efficient and effective way to perform the external heat exchange required by many heating and cooling systems. Unlike air temperatures, the ground temperature is a relatively constant temperature that ranges from about 44° F. to about 76° F. at a depth below the local frost line. Additionally, the ground can act as a virtually limitless energy source or heat sink. 
     Currently, plastic pipe is typically used with ground source heat pumps, and is buried in the earth, or disposed in lakes, rivers, ponds, water wells, and the like. Copper coils containing refrigerants, and flat steel plates disposed in rivers, lakes, and ponds, are also used. In using plastic tubing, or pipes, one method is to install the pipes horizontally with a trencher or backhoe. This requires 350′ per ton of heat pump, e.g., a five-ton heat pump needs 1750′ of pipe and trench. Examples contained herein regarding pipe length and pipe and trench length figures throughout are for the average annual ambient temperatures of Charleston W. Va. These figures will vary for other locations based upon average annual ambient temperature. In general, two basic types of connecting horizontal loop arrangements are utilized, which include connecting a closed loop in series so that only one long loop is present and in parallel so that several loops are disposed to use the same input/output pipes. Vertical loops are also installed by a drilling machine in either a parallel or series configuration, which requires a 150′ to 225′ of borehole per ton of heat pump which requires a pipe length of 300′ to 450′ per ton of heat pump. 
     Although, ground source heat pump heating and cooling systems generally include many of the same essential components as other heat pump heating and cooling systems, except that the external heat exchanger operates in a different manner. The external heal exchange process of a ground source heat pump heating or cooling system is generally accomplished by one of two methods. One method is simply to extend the refrigerant fluid carrying coil into the soil, thereby directly exchanging heat with the ground, e.g., a direct expansion (DX) refrigerant loop. The second method utilizes a circulating heat exchange fluid, e.g., water or other aqueous solution, to carry thermal energy between the ground and the refrigerant heat exchanger and on the thermal load. Typically, this circulating heat exchange fluid travels in a piping system between a subterranean heat exchanger, where heat is exchanged with the ground, and the refrigerant heat exchanger and on to the thermal load, where heat is exchanged with the heating or cooling system. When the water/refrigerant carrying coil of the heating or cooling system contacts this circulating heat exchange fluid, heat is exchanged directly with the circulating heat exchange fluid and, thereby, indirectly with the ground. 
     Most existing ground source heating and cooling systems use a circulating heat exchange fluid to transfer heat between the system and the ground. Heretofore, geothermal systems of this type typically employ small size polyethylene pipe(s), and a dedicated loop field to service each individual thermal load. Most of these heat exchange loops are oriented vertically extending down into the earth. This limits the contractors who can install these systems and creates a muddy water mess at the ground surface which is unacceptable at many locations potentially increasing the cost of the installation. Where horizontal loops are used, they tend to require a large surface area. The heat exchangers with small sized polyethylene pipe loops that are oriented horizontally are typically buried four or more feet beneath the ground surface, and take up a great deal of surface area. Many locations are inadequate in surface area size to accommodate these horizontal loops. 
     Direct exchange geothermal heat pumps use a single loop circulating refrigerant through tubes that are in direct contact with the ground. The refrigerant circulates through a loop of copper tube buried underground, and exchanges heat with the ground. Water-source, and water loop, heat pumps are considered different because they use water or a water antifreeze mixture. Most such systems have two loops, including a primary refrigerant loop that is contained in the heat pump cabinet where it exchanges heat with a secondary water loop that is buried. The secondary loop is typically made of high-density polyethylene pipe containing a mixture of water and anti-freeze, such as propylene glycol, monopropylene glycol, denatured alcohol, methanol, or the like. After leaving the internal heat exchanger, the water flows through the secondary loop outside the building to exchange heat with the ground before returning. The secondary loop is placed below the frost line, or submerged in a body of water, or well, if available. Ground moisture aids in the heat exchange, and therefore, where the ground is naturally dry, sprinkler (or soaker) hoses may be buried with the ground loop to keep it wet. 
     Efforts to devise modular geothermal heat exchangers have been made in the past, but these devices tend to be too large for small homebuilders, do-it-yourself homeowners, for temporary or seasonal habitats, or the like because these devices typically require deep/long trenches or large bodies of water in which to place the heat exchanger. U.S. Pat. No. 5,224,357 teaches a ground source heat exchanger having modular tube bundles adapted to be placed within narrow excavation in the group that also utilizes thermal conductive materials such as metals, and more specifically, copper or aluminum; however, that device is quite different from the present invention having many more coils of tubing in each modular bundle, and the bundles requiring much deeper trenches. A source of water, such as a soaker hose, is disclosed to maintain proper moisture levels directly above the modular bundles. 
     Similarly, U.S. Pat. No. 5,339,890 teaches a modular ground source heat pump system with subterranean piping installation constructed of a plurality of modular heat exchange units, which utilizes a tube within an insulated tube structure that requires deep holes, long trenches, wells, or bodies of water. Another patent along the same design is U.S. Pat. No. 5,533,355 which teaches a ground source heat pump system wherein modular heat exchange units are utilized. These systems are limited to using a parallel connection system to the inlet/outlet piping instead of having the option of the modular units generating a single coil with the separate modules operating in series. 
     U.S. Pat. No. 5,651,265 teaches a more conventional ground source heat pump system with an internal heat exchanger and an arrangement of check valves to permit a single direction of refrigerant flow in both the heating and cooling modes. The system charge is the same for heating and cooling and the ground coil consists of a plurality of three pipe units—one pipe for inflow and two for out flow. US Patent Application No. 2010/0258266 teaches a modular system with dual loops, an inner loop disposed within a contained cylinder. 
     Each of these inventions require a great deal of space, a large body of water, or at least one very deep borehole, and as such, are difficult for your average consumer to utilize. As such, conventional ground source heat pumps tend to be used by businesses or property owners with lots of resources and large lots, because of the extra space required, and the high cost of installing conventional ground source heat exchangers. 
     SUMMARY OF THE INVENTION 
     The present invention relates to the field of ground source heat pump heating and cooling systems, and more specifically, to a compact circulating heat exchanger loop component, a ground source heat pump in fluid communication with at least one compact circulating heat exchanger loop component, and method of installation and use. 
     Alternative designs of the invention include a ground source heat pump earth heat exchanger that is a horizontally oriented water/fluid loop ground heat exchanger having a pipe bundle containing two or more layers of horizontally oriented long pipes, which upon assembly are in closed fluid communication with an output and an input. The output and input form a closed loop when attached to the corresponding output and input of the heat pump. Water, or an antifreeze/water solution, is pumped through the closed loop to alternatively exchange heat with the ground or heat pump as appropriate. 
     The long pipes are composed of highly thermal conductive materials, such as metal, e.g., aluminum, copper, or alloys thereof, or steel or other alloys. This loop component may be combined with additional loop components to create a larger loop system with more than one loop component in fluid communication with one another in series or in parallel. The thermally conductive long pipes are spaced a minimum of about two (2′) feet apart from one another under all circumstances to prevent undesirable thermal interference between adjacent pipes. 
     In an embodiment of the present design, a first layer of horizontally oriented pipes are spaced a minimum of about two (2′) feet apart from one another, and about twenty (24″) to about thirty (30″) inches from the surface of the ground. In very cold climates, the distance required beneath the surface may be greater due to a deeper frost line, but typically about the same level as the local requirements for the depth of the foundation of a structure or a house. 
     Alternatively, a heat exchanger loop component may be disposed vertically with long pipes oriented up and down with short tubes disposed at least two (2′) feet under the ground surface. Although a greater total depth will be required, the vertically oriented heat exchanger will have an even smaller footprint. Multiple components disposed vertically, horizontally, or combinations thereof may be utilized for large heat pump loads. 
     Since the heat exchanger loop components are modular, they can be more easily installed by a do-it-yourself homeowner, construction workers during the construction of a home or other building, remodelers, or the like without drilling equipment. 
     An embodiment of the present design permits installation along the periphery of the foundation of a house with the conventional version or a single level of one pipe (the components are distributed around the periphery of a small footprint structure with the input and output being from opposite directions), or two adjacent pipes disposed apart two (2′) feet minimum (the components are disposed in two lengths which return to the same location, see  FIG. 1 ), where the house water down spouts may be used as soakers to maintain the moisture about the heat exchanger tubes. 
     The basic heat exchanger loop components and heat pump are compact enough that they could be utilized for heating/cooling temporary structure, e.g., military camps, refugee camps, and emergency hospital facilities. An embodiment of the present design permits the heat exchanger loop component to be merely covered by two (2′) feet of fill allowing the unit to be placed on the ground and then buried. 
     The present invention makes ground source heat exchangers more economical, feasible, and accessible. Another aspect of the present design is to maximize the energy acceptance/rejection, and to minimize land area required for a ground source heat pump earth heat exchanger. The present design does not require the area or footprint of conventional ground source heat exchangers or of other conventional heat exchanger designs, and does not require the land or drilling resources for conventional excavations. 
     Yet another aspect of the present design takes advantage of the shallower depths, e.g., from twenty four (24″) inches to thirty (30″) in Charleston, W. Va., inches to provide more optimum thermal conductivity, convection, radiation, diffusivity, temperature gradients, moisture migration, evaporation, and to some extent biological transpiration (depending on soil vegetation). 
     Furthermore, the design of the present invention has a potential coefficient of performance (COP) of three (3) to five (5), and an energy efficiency ratio (EER) of eighteen (18). COP is the total Btu required to heat the building divided by the total Btu to run the heat pump. The EER is equal to the total Btu required to cool the building divided by 3.14 times 1000. 
     The heat exchangers of the present designs are low maintenance, will endure for a long time, and can be used to make all necessary domestic hot water. Additionally, the hot air produced at a heat register is 95° F. to 110° F., and the design can be used to heat indoor or outdoor swimming pools. 
     These and other aspects of the present invention will become readily apparent upon further review of the following drawings and specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the described embodiments are specifically set forth in the appended claims; however, embodiments relating to the structure and process of making the present invention, may best be understood with reference to the following description and accompanying drawings. 
         FIG. 1A  is an environmental view of alternative embodiments of present design showing a building with the component configured as a U-shape. 
         FIG. 1B  is an environmental view of alternative embodiments of present design shows a home with heat exchanger component disposed in a hill. 
         FIG. 2  shows a basic configuration of the components of the heat exchanger according to alternative embodiment of the present invention. 
         FIG. 3  shows a heat exchanger coil according to the present design composed of a combination of basic components of the heat exchanger. 
         FIGS. 4A through 4D  show a basic heat exchanger component coil and supports according to an alternative embodiment of the present design. 
         FIGS. 5A through 5C  show perspective, side, and exploded views respectively of connector and pipe components according to an embodiment of the present design. 
         FIGS. 6A through 6C  show side and perspective views of connector and short pipe components according to an embodiment of the present design. 
         FIG. 7  is a pipe connection having internal threads to mate with a pipe having external threads. 
         FIG. 8  is a pipe connection having external threads to mate with a pipe having internal threads, e.g.,  FIG. 7 . 
         FIG. 9  is a side view of a long to short pipe with connector. 
         FIG. 10  is a side view of another long to short pipe with connector mechanism shown. 
         FIGS. 11A-11C  shows an elevated environmental view, an environmental view from the bottom, or a side view respectively of an alternative cylindrical HDPE insert for socket or butt fusing the long pipe to the U-shaped short pipe or to the connectors of the short pipe. 
         FIGS. 12A-12B  show an exploded view and a side view of the HDPE insert of  FIGS. 11A-11C  in position between a long pipe and a connector or an end of a U-shaped short pipe. 
         FIGS. 13A and 13B  show elevated environmental views of the short pipe, corner connectors and long pipes as fused together using an HDPE insert according to  FIGS. 11A-11C . 
         FIGS. 14A and 14B  show an alternative embodiment in which the corners and short pipes are replaced with a single U-shaped short pipe having the corners molded into the short pipe, and the ends thereof are fused together with the HDPE insert according to  FIGS. 11A-11C . 
       FIGS.  FIGS. 15A-15D  show a die mold used to clamp the HDPE insert used for socket or butt fusing. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention is directed in part to a ground source heat pump heat exchanger  12  utilizing one or more small vertically or horizontally oriented water or antifreeze water mixture ground loop heat exchanger component(s)  12  which is disposed in the ground adjacent to a building as shown in  FIG. 1A , or in close proximity to the ground surface adjacent to a house as shown in  FIG. 1B . The embodiment of the heat exchanger  12 , shown in  FIG. 1A , is the simplest arrangements of the present invention in which two vertical layers of multiple long pipes  14  connected end to end by a straight connector  13  with a short pipe  18 , and two corners  16  disposed at the distant end. All of the pipes  14 ,  18 , connectors  13 , and corners  16  are in fluid communication therethrough. The long pipes  14  are disposed of thermally conductive materials, e.g., aluminum, copper, iron and alloys thereof, or appropriate thermally conductive plastic/polymers. 
     The heat pump  10  may include any suitable heat pump design which are well known in the art, and may be a conventional ground source heat pump. The present heat pump system, encompassing the heat pump  10  and the in ground heat exchanger  12  as shown in  FIG. 1A  utilizes two loops. The ground heat exchanger  12  is disposed underground or under packed down fill. In operation, the cooling mode disperses heat into the ground, while in heating mode heat is absorbed from the ground. A ground source heat exchanger  12  has two or more layers of horizontally oriented long pipes  14 , which upon assembly are in closed fluid communication with output  17  and an input  15  terminuses. The output  17  and input  15  terminuses form a closed loop when attached to the corresponding output O and input I of the heat pump  10 . Water, or antifreeze/water solution, is pumped through the closed loop to alternatively exchange heat with the ground or heat pump as appropriate. Alternatively, the pipes are spaced about two (2′) feet apart to moderate undesirable heat transfer interference between pipes  18 . 
     A desirable basic embodiment of the present invention, used in the example of  FIG. 2 , incorporates six (6) twenty (20′) foot long aluminum pipes with 3.5″ outer diameter, and larger than about a three inch (3.0″) inner diameter.  FIG. 3  shows two basic embodiments of  FIG. 2  combined for a larger unit, and  FIGS. 4A through 4D  show a basic structure in more detail. The long pipes  14  are placed two (2′) feet apart on center, and connected together by two corners  16  and one short pipe  18  in series flow. Aluminum welded, and/or fuse welded High Density Polyethylene (HDPE) may be utilized as corner connectors  16  and short pipes  18  disposed between pipes  14 . The piping system is then stabilized using supports placed to give maximum structural strength, the supports being two (2′) long. 
     An embodiment has a pipe basket, or component  12 , placed in an excavated ditch or a hole in the ground at a depth to allow the top of the basket to be twenty-four (24″) inches to thirty (30″) inches below the surface of the earth for conditions similar to those in Charleston, W. Va. The excavated ditch or hole, containing the pipe basket  12  disposed therein, is refilled with earth well compacted to insure maximum contact with the earth/pipe interface. A small perforated sprinkler, or soaker hose, may be placed at the top of the basket  12 , and connected to a heat pump condensate line, house downspout, and/or other water supply, to ensure proper soil/moisture concentrations that enhance heat transfer especially in the cooling season. 
     The fluid flowing through the heat exchanger  12  may be an antifreeze and water mixture, sufficient to protect from freezing down to fifteen (15° F.) degrees Fahrenheit or lower. The velocity will be such as to maintain turbulent flow at all times that maximizes heat transfer between the fluid and the pipe. Since most heat pump systems are two or three tons in size more than one of these baskets can be connected together in series to provide adequate heat transfer. 
     The bundle  12  is fitted together at a manufacturer as a discrete all-in-one basket, in a shop, or in the field from the components. The components may be sold separately or as a bundle in a kit to be put together in a shop or in the field. If not assembled at the manufacturer, the long pipes, short pipes, polyethylene fittings, connectors, corner connectors, and flexible pipes are fused together in a shop or in the field. The pipes and fittings are connected to each other using fitted ends, the sections may be butt connected, complimentary male/female threading, and the like, including any other well-known or conventional means of connecting or fusing two pipes together to prevent leakage. Threaded connections and/or pipe ends plus a binder may be used. 
     The present design is not restricted to the particular dimension relationship shown in the figures, but may be arranged however is appropriate for the location. The long pipes  14  in the bundle may simply be disposed with one short pipe and two corner connectors, or no short pipes and four corner connectors (to circumnavigate a building and return to the heat pump  10  from opposing sides)—with straight connectors  13  disposed between long pipes  18 . 
     The thermally conductive composition of the long pipes  14  is essential to shortening the overall length of the heat exchanger  12 . For example, aluminum thermal conductivity is about one hundred twenty BTU/hr ° F. ft, while conventional plastic, e.g., for a HDPE pipe, is an insulator having a thermal conductivity of about 0.25 Btu/hr ° F. ft. A three (3″) inch internal diameter and 3.5″ outer diameter aluminum pipes may be optimum. The outside diameter of the pipes  14  is not particularly limited. Smaller size pipes will work. In some embodiments, the outside diameter of the pipes may range from about 0.75 inches to more than four (4) inches. 
     Pipes of a twenty (20′) foot length are desirable for convenience of handling and transport, construction, and economy and because such pipes are standard sizes. A four (4′) foot by four (4′) foot trench that is twenty (20′) feet long is desirable for the most compact version of the present invention. Three (3″) inch internal diameter marine grade aluminum alloy pipes are also standard, and assure turbulent flow at twelve (12) GPM, and in some cases a mechanical or permanent fixture to assure turbulent flow (not shown), to provide a maximum heat flow rate from the fluid to the pipe. In some cases, a mechanical or permanent fixture to increase turbulent flow may be present. A condensate line may also be attached to the heat pump  10  to return water to the ground, and may be attached to a soaker line (not shown) disposed above or along the pipes  14  to assure moist soil in direct contact with the conductive pipe  14 . In an embodiment of the present design, the pipes  18  have a 3.33″ internal diameter. 
     The required heat flow between the ground and the heat exchanger  12  can be realized with multiple aluminum alloy pipes, but little additional benefits are realized with more than six (6) pipes per basket. Calculations show that comparatively, a two (2) pipe heat exchanger requires the shortest pipe length (168′) but the longest trench (84′) length, while a six pipe heat exchanger basket requires the longest pipe length (260′) but the shortest trench length (43′) for the ambient conditions in Charleston, W. Va. 
     Each long pipe  14  is connected to an adjacent long pipe  14  by two corner connectors  16 , and one short pipe  18 . The shorter pipes  18  may be composed of a thermally conductive material, or they may be composed of HDPE piping, or other flexible piping material that may or may not be thermally conductive. The corner connectors  16 , and the shorter pipes  18 , are preferably flexible so that upon placement in the ground G, the entire heat exchange component  12  may be malformed without leaking or breaking. This feature not only prevents the danger of breaking as ground settles, it facilitates filling in the space about the pipes  14  and  18  without fear of breaking them or having the fill be perfect. Settling of the fill dirt will not rupture the heat exchanger&#39;s  12  pipes  14  since the constructed line of pipes  14 ,  18  is flexible. With the relatively shallow depth of the pipes, the basket will not be damaged by the weight of the ground above them. In some embodiments of the present invention, the short pipes  18  will be composed of a more rigid thermally conductive material like the long pipes  14 . 
     The heat exchanger  12  may be placed against the bottom of a cliff, hill, or other incline, and then be covered with fill instead of being buried, as shown in  FIG. 1B . Furthermore, the heat exchanger  12  may be buried in the side of an incline, e.g., mountainside, hill, or the like, as long as the fill dirt covers the pipes  14 ,  18  to a minimum of about two (2′) feet on all sides. It is also preferable for the heat exchanger  12  to be placed in a moist area. In more arid environments, underground sprinklers (not shown) may be used to maintain the moisture level about the exchanger  12  pipes  14 ,  18 . Alternatively, or additionally, the heat exchanger  12  may be placed under the eaves of the roof line along the path of the down spouts, which may also be connected to or allowed to drain above the heat exchangers  12 . 
     The heat exchanger  12  comprises a pipe bundle, which may be sold as a kit, containing a plurality of long pipes  14 , which upon construction are in fluid communication with one another. The horizontal long pipes  14  may be configured in one or more layers positioned below one another, and are spaced a minimum of about two (2′) feet apart. The long pipes  14  may be placed alternatively in a horizontal or vertical arrangement. The vertical installation requires a deeper area to be excavated, but would represent a smaller foot print on the ground surface. A further alternative arrangement involves, simply placing the heat exchanger component against a geological feature and burying it with at least two (2′) feet on all sides. 
     With reference to  FIG. 2 , there is illustrated a horizontally oriented ground loop heat exchanger component  12  in accordance with alternative designs of the present invention having an upper and lower layer of long pipes  14 , as shown. The horizontally oriented ground loop heat exchanger  12  includes a first layer of horizontally oriented long pipes  14  in fluid communication with one another. The first layer of long pipes  14  is positioned or installed about twenty-four (24″) inches to about thirty (30″) inches from the surface of the ground G. Further, the long pipes  14  are positioned at least about two (2′) feet from one another, and may have a brace  24  between them as shown in  FIG. 2 . This spacing maximizes heat transfer with the ground G, while moderating thermal interference with adjacent long pipes  14 . 
     Additional layers of horizontally oriented pipes  14  may be used.  FIG. 2  illustrates two layers of three horizontally oriented long pipes  14  with a second layer positioned below the first layer of three horizontally oriented pipes  14 . The first layer of horizontally oriented pipes  12  and the second layer of three horizontally oriented pipes  14  are in fluid communication with one another, altogether having a single input terminus  15  and single output terminus  17 . The second layer of horizontally oriented pipes  14  is spaced at least about two (2) feet from the first layer of horizontally oriented long pipes  14 . 
     While the  FIG. 2  illustrates two layers of three horizontally oriented long pipes  14 , more layers of horizontally oriented pipes may be utilized.  FIG. 1A  shows a single layer of long pipes  14 , while  FIG. 3  shows two components or baskets  12  of  FIG. 2  depicted on top of one another in series so that one input terminus  17  and one output terminus  15  is present. It should be understood that the embodiments shown in  FIGS. 2 and 3  may also be rotated ninety (90°) degrees so that the long pipes  14  are disposed vertically, and that combinations of vertical, horizontal, and diagonally (at an angle) disposed long pipes  14  are also possible. The out pipe  20  and the in pipe  22  are shown in  FIGS. 2 and 3 , and may be a nonconductive pipe  20 ,  22 . An expansion tank (not shown) is typically provided to remove air from the closed tubing loop of the heat exchanger  12  and to facilitate the change in fluid volume due to thermal expansion and contraction. 
     The long pipes  14  making up the first and second layer of horizontally oriented long pipes  14  provide for a high rate of heat transfer between the fluid inside the pipe and the ground. In some embodiments, the pipes  14  are made of metal, including but not limited to, copper, aluminum, alloys of iron, such as steel, stainless steel, and combinations or alloys thereof. In other embodiments, the pipes may be made of carbon composites or polymer composite materials that provide for a high rate of heat exchange between the fluid inside the pipe and the ground. 
     The length of the horizontal long pipes  14  is not particularly limited and may be based upon the anticipated heat transfer requirements. In some embodiments, the horizontal long pipes  14  may range from about ten (10) feet to about forty (40) feet in length. In other embodiments, the length of the horizontal pipes  14  may be about twenty (20) feet in length. The short pipes  18  may be two (2) or three (3) feet long. 
     There will be a minor component of vertically extending short pipes  18  to fluidly connect the two or more layers of horizontal long pipes  14 . It is anticipated that the overwhelming majority of ground loops will be oriented horizontally in typical applications, but the present invention is not limited thereby as there are embodiments of the current design in which the heat exchange component is merely placed upon the ground, hillside, or mountainside, and buried under two (2) feet of ground G cover or fill. In some embodiments, the horizontally oriented water/fluid ground loop heat exchanger  12  includes about one hundred twenty-eight (128′) feet of horizontal pipe which is about sixty-four (64′) feet in each layer, and about two (2′) feet of vertical pipe, excluding the fluid inlet and fluid outlet piping leading to the horizontally oriented water/fluid ground loop heat exchanger  12 . 
     In some embodiments, the installed long pipes  14  are a horizontally oriented water/fluid ground loop heat exchanger  12  exhibiting a ratio of horizontal piping to vertical piping ranging from about 32:1 to about 128:1. In other embodiments, the ratio of horizontal piping to vertical piping ranging is about 64:1. It is to be understood that in alternative embodiments, the long pipes  14  are vertically oriented and the short pipes  18  are horizontal. Furthermore, in some circumstances, such as temporary structures for camp facilities, temporary medical facilities, or the like, the pipes  14  may be oriented simply according to the lay of the land so that they are neither horizontal nor vertical, and covered by fill to the proper local specs for the season or seasons to be used. The inlet and outlet pipe  22  and  20  locations and lengths must clearly be adjusted accordingly. 
     In the simplest embodiment composed of two layers with one line of pipe(s) each, the horizontal long piping  14  is connected on end to other horizontal long piping  14  by a straight in line connection and may simply encircle the structure at least two (2) feet from the foundation in a well moistened area, at least two (2′) feet from the surface of the ground G, in climates similar to Charleston, W. Va. In the embodiment depicted in  FIG. 2 , however, the horizontally oriented water/fluid ground loop heat exchanger  12  includes a fluid inlet  22  which may be a reducer to accommodate the use of smaller polyethylene pipe to convey the fluid from the heat pump  10  heat exchanger (not shown) to the ground heat exchanger  12  in which heat exchanging fluid such as water or other heat exchanging fluid enters the second layer of horizontally oriented pipes  14 . The fluid travels through the second layer of horizontally oriented pipes  14  and then through the first layer of horizontally oriented pipes  14  and on through the outlet pipe  15  to the heat pump  10 . 
     Heat is transferred between the heat exchanging fluid and the ground G as the fluid travels through the layers of horizontally oriented long pipes  14 . The heat exchanging fluid then exits through a fluid outlet  20  which may be a reducer to accommodate the use of smaller polyethylene pipe to convey the fluid from the ground heat exchanger  12  to either additional bundles of heat exchangers  12  and then on to the heat pump  10  heat exchanger loop C 2 , or directly to the heat pump  10  heat exchanger loop C 2  where the heat exchanging fluid contacts the refrigerant carrying coil C 1  of the heating or cooling system thereby exchanging heat between the heat exchanging fluid flowing through the heat exchanger C 2  and the refrigerant coil C 1  (using the appropriate ASHRAE standard 34 refrigerant) The heat exchanger  12  has an input terminus  17  and an output terminus  15  for fluid communication with the input/output I/O of the heat pump  10 . 
       FIGS. 4A through 4D  show a plan schematic of a favorite embodiment of the present design, representing a bundle, in which the basic ground loop heat exchanger  12  has two levels of long pipes  14  and short pipes  18  with six (6) lengths of long pipe  14  and five (5) lengths of short pipe  18 . The bundles can be packaged and sold as a kit, with a heat pump  10  or as individual bundles. The three lengths of long pipe  14  are seen most clearly in  FIG. 4A , while  FIG. 4B  shows the two levels.  FIG. 4C  shows the view from the end which demonstrates the location of the short lengths of pipes  18  and the braces  26 . The corners  16  are omitted from  4 C through  4 D. 
     Braces  26  may be disposed regularly along the length to maintain the two (2′) foot space between long pipes  14 . The length of the long pipes  14  relative to the short pipes  18  are not drawn to scale with the long pipes  14  shown as much shorter. In a favorite embodiment of the present design, the long pipes  14  are twenty (20′) feet long, and the short pipes  18  are two (2′) feet long. The braces  26  are disposed every three (3′) feet to four (4′) feet along the length of the long pipes  14  from end to end. 
     Alternative embodiments of the present design may use longer or shorter lengths of long pipe  14 , and the short pipe  18  may also be longer, but preferably not shorter unless the long pipes  14  are not disposed parallel to one another but instead are splayed so that the distance between long pipes  14  is at least two (2′) feet apart (for Charleston, W. Va.) up to being disposed end to end in a substantial line. 
     It may be desirable to have the corner connectors  16  pre attached to, or configured from, the short pipes  18 .  FIGS. 5A and 5B  show two views of an alternative corner connection  16  arrangement.  FIG. 5A  is a perspective view of a butt joint.  FIG. 5B  is a side view in which the pipes are joined butt together fitting in which the fitting is crimped to hold the pipe  14 ,  18  sections together. There is a space of about twenty (20″) between the ends of the crimping clamp.  FIG. 5C  is a side exploded view of a pipe  14 ,  18  with an connector  13  that is an HDPE insert  19  which fits into each end of the pipe  14  or  18 . Each end shows that the pipe diameter is enlarged due to the insert  19  being forcibly shoved mechanically into the pipe  14  or  18 . One end shows the pipe crimped and the other end show the pipe and insert  19  without being crimped. Alternatively, the insert  19  can be installed into the pipe by cooling the insert  19  sufficiently to shrink its outside diameter so that it will fit into the inside diameter of the pipe and will be tightly sealed when the insert&#39;s  19  diameter expands due to the increased diameter of the insert  19  as it warms up to the ambient temperature. 
     Alternatively, the insert  19  may be installed into the end of the large  14  and small 18 aluminum pipe, or other pipe fitting or length of pipe, by cutting threads onto the outside of one end of the insert  19 , cutting threads in the inside of an aluminum pipe end and screwing the HDPE insert  19  pipe into the threaded aluminum pipe end. Any HDPE pipe or fitting, such as, but not limited to, an elbow, reducer, tee, straight connector, or any other type of fitting, can be attached to the insert  19  by any type of joint connection device, including but not limited to butt fusion welding and threads, that seals the joint so that it won&#39;t leak under twice the operating pressure of the exchanger  12  fluid system. 
     In an embodiment of the present design, the horizontal three-inch (3″) aluminum ground heat exchanger long pipes  14  are connected in one of two alternative configurations, each using alternative physical connection methods. In the first, the pipes  14  are connected in an end to end line of long pipes  14 . Alternative physical connection methods include, but not limited to, butt welding the ends of the aluminum long pipes  14  together, and installing an internal HDPE pipe insert  19  into each end of the aluminum long pipe  14  and connecting them to HDPE pipes. In the second, parallel long pipes  14  utilize the alternative physical connection methods that includes miter welding the ends of the long pipes  14  to two foot (2′) long vertical or horizontal short pipes  18  to make the transition from one horizontal long pipe  14  pipe to another horizontal long pipe  14 , or installing an internal HDPE pipe insert  19  into each end of the aluminum long pipe  14  and connecting them to HDPE pipes. 
       FIGS. 6A through 6C  are elevated and environmental view of the short pipes  18  and corner connectors  16  relative to the ends of the thermally conductive long pipes  14 . In detail,  FIG. 6A  shows a flexible short pipe  28 , such as flexible high-density polyethylene tubes  28 , which can be bent to mate with the ends of the long pipes  14 . The ends of the long pipes  14  are narrower than along the length of the pipe  14  which may be about three (3″) inches in diameter, as shown in the embodiment depicted therein. 
     The flexible short pipe  28  mates at  30  with the ends of the long pipes  14  over a space, six (6″) inches in the embodiment shown, and then are bent into the proper shape. A clamp  32  may be used to secure the flexible pipe  28  about the end of the long pipe  14 , as shown.  FIG. 6B  shows an alternative embodiment in which a reducer coupling connector  13  is provided upon the end of a long pipe  14  which a reducer coupling connector  13  is disposed on the end of each pipe  14 , and  18  as shown in  FIG. 6B .  FIG. 6C  shows the reducer coupling  13  by itself. The flexible short pipe  18  is then bent to the proper position or the bends can be prefabricated into the shape of the short pipe  18 . 
       FIGS. 7 and 8  shows a threaded transition adaptor connector  13 , U.S. Pat. No. 5,211,429 the contents of which are incorporated herein in their entirety and are available from Poly-Cam (Anoka, Minn.), in which the ends of the pipes  14 ,  18  have complementary inner and outer threads designed to mate by rotating one or the other pipe  14 ,  18 . These mates are typically composed of metal or metal alloys, and may be disposed on the ends of either metal/metal alloy pipes used with the long pipes  14  or high-density polyethylene pipes used with the short pipes  18 . A binder composition may be added to seal and bind the pipes  14 ,  18  and connectors  13  together. This transition adaptor connector  13 , shown in  FIGS. 7 and 8 , is disposed where similar sized high-density polyethylene pipes  18  to metal pipes  14  are mated. The aluminum pipe  14  has a wall thickness of 0.83″ with up to 20′ long. A high-density polyethylene pipe connector  13  to connect to selected size of high-density polyethylene butt weld pipe or socket weld fittings which are well known in the art. Seal joints with either friction fit or pipe crimp stainless steel pipe clamp are also options as are well known in the art. Well known alternative sealing connectors between adjacent pipes, and corner connectors, may be utilized. 
       FIG. 9  shows yet another alterative in which the corner connectors  16  are flexible, such as a flexible high-density polyethylene that is connected to another element which can then be butt welded in position, or the like.  FIG. 10  shows another embodiment of a butt-welded pipe. The flayed ends are a demonstration of the malformation of the pipe once it is fitted over the adjacent pipe. 
       FIGS. 11A-11C  shows an elevated environmental view, an environmental view from the bottom, or a side view respectively of an alternative cylindrical HDPE insert  119  for socket or butt fusing the long pipe  14  to the U-shaped short pipe  118 , shown in  FIGS. 14A and 14B  or to connectors  19  extending from the corners  16  of the short pipe  18  shown in  FIGS. 13A and 13B . The HDPE insert  119  is used to socket or butt fuse the HDPE short pipe  18  or  118  to the aluminum/aluminum alloy long pipe  14 , as shown. A sleeve  123  is provided through the cylindrical insert  119 , and has an inner diameter of about one and five-eighths (1⅝) inches with the outer diameter of the cylindrical insert  119  being about three (3) inches in outer diameter and about three and a half (3½) inches long. The outer diameter of the lip  121  of the cylindrical insert  119  is about three and one-quarter (3¼) inches. 
     A heating iron may be used to socket or butt fuse the pipes or connectors to the cylindrical HDPE insert. In installation, the cylindrical HDPE insert  119  is heated until it combines with the HDPE corner piece at the sleeve  123  and the ends of the aluminum long pipes  14  to fuse the long and short pipes  14  and  18 , or  114  and  18  together. Heat fusing is used to join the pipes requires tools and is a known process described in “Heat Fusion Joining Procedures” copyrighted by 2012 by Polypipe, Inc., the contents of which are incorporated herein by reference. 
       FIGS. 12A-12B  show an exploded view and a side view of the HDPE insert  119  of  FIGS. 11A-11C  in position between a long pipe  14  and an end  116  of a U-shaped short pipe  118 . The same configuration may be used with a connector  16 . A lip  121  provided on the cylindrical HDPE insert  119  to prevent the insert  119  from extending further into the long pipe  14  then desired, and keeps the insert  119  at the end of the long pipe  14 . The connector  16  or the end  116  of the U-shaped short pipe  118  are inserted through a sleeve  123  of the cylindrical insert  119 , as shown in  FIG. 12B . The part of the connector or end of the U-shaped short pipe should extend six (6) to eight (8) inches and should not extend past the insert  119 , but it may extend past the insert  119 . The long pipe may have an outer diameter of three and a half (3½) inches such as an alloy 6063 schedule  10  pipe. 
       FIGS. 13A and 13B  show elevated environmental views of the short pipe  18 , corner connectors  16 , and long pipes  14  as fused together using a cylindrical HDPE insert  119  according to  FIGS. 11A-11C . The short pipe  18  is about one and five-eights (1⅝) inches outer diameter and is about two (2) feet long. The corner connector  16  is one and a half (1½) inches inner diameter and is a 90-degree HDPE coupling. 
       FIGS. 14A and 14B  show an alternative embodiment in which the corner connectors  16  and short pipes  18  are replaced with a single U-shaped short pipe  118  having the corners molded into the U-shaped short pipe  118  at the end  116 , and the ends thereof are fused together with the HDPE insert  119 . 
     The U-shaped short pipe  118  corner part  116  will be called a U-shaped shorter pipe with a corner section. The U-shaped pipe  118  can be anywhere from three feet to six feet long the ends  116  are six inches to two feet long so that the long pipes  14  are two feet apart when installed. As an alternative to the U-shaped pipe shown with two ends at 90 degrees from each other, we may use a curved radius pipe having a smooth curved U-shaped pipe on a one (1) foot radius with the ends being about two (2) feet apart. 
       FIGS. 15A-15D  show a die mold  134  used to make the HDPE insert  119  used for socket or butt fusing. The die mold  134  has a top part  136  and a bottom part  138 . The die mold  134  is used to press the HDPE inserts into the three (3″) inch diameter of the ends of the long pipe  14 . The corner connector  16  and  19  or ends  116  of the U-shaped short pipe  118  sticking out of the cylindrical HDPE insert  119  can be anywhere from six (6) inches to eight (8) inches long. 
     Without intending to be bound by theory, it is believed that several physical processes interact positively with a ground heat exchanger  12  at a depth relatively close to the ground surface, i.e., conduction, convection, radiation, moisture migration, evaporation, and to some extent biological transpirations (depending on type of soil vegetation), and combinations thereof. 
     Another embodiment of the present design may include one or more of a plurality of water soaker or sprinkler pipes to enhance the heat exchange process, and to assure ground containing water. The water soaker pipes are positioned between the surface of the ground and the water/fluid ground loop heat exchanger, or simply along the length of the heat exchanger pipes  14 . The water soaker pipes may be installed to facilitate saturating the ground around the heat exchanger bundle with water during the short period of the maximum heating load, and particularly during the short periods of the maximum cooling load, when moisture migrates away from the pipes, to maximize the thermal conductivity of the soil, and the heat transfer capacity of the bundle. Installation of the ground loop exchanger  12  of the present invention is simple and only requires simple earth moving equipment. Due to the horizontal orientation in most applications, and close proximity of the ground loop heat exchanger  12  to the surface of the ground, specialized drilling equipment and associated muddy water ground surface pollution is avoided. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.