LOOP IN-GROUND INSTALLATION AND SOIL

PENETRATING HEAD THEREFOR

TECHNICAL FIELD

A geothermal, in-ground, conduit system and a method of constructing and installing same, to capture thermal energy stored in soil and wherein the conduits are at least partly in direct contact with the soil.

BACKGROUND ART

With the high cost of electricity and gas, more and more interest is directed to the use of other sources of energy and in recent years particular attention has been given to tapping the geothermal energy stored in the ground. Such energy is renewable as it comes from the sun, but more important such energy does not produce any harmful gas emission which is released in the atmosphere as is the case with combustible products. The use of such energy also results in a cost-saving to heat and cool a building structure. It has been calculated that by using geothermal energy, as opposed to combustible energy, an average house prevents the emission of 2.5 to 5 tons of carbon dioxide into the atmosphere, each year. Accordingly, there is a need to improve the technology to extract this geothermal energy and to develop new methods to tap this energy for existing building structures as well as new building structures.

Nearly half of the thermal energy which comes from the sun is stored in the earth and water on the planet. At a depth of approximately 2 meters, the temperature of the earth is constant during winter months, as well as summer months, and depending on the geographical location of the building it varies between 5 to 12 ⁰ C. This is the energy that a geothermal system taps into. Also, a geothermal system produces heat which is more uniform than an electrical or gas heating system. The most popular geothermal system is a close-circuit vertical system wherein tubes are disposed in bore holes or tubes driven into the soil and in which a conduit loop is disposed. The spacing of the tubes that form the conduit loop are very close to one another and usually spaced about 3 inches apart. The tube is then filled with Bentanite ^™ cement. Because the conduits are closely spaced and located within a hole bored in rock or in tubes, the heat exchange with the surrounding soil is poor and consequently it is often necessary to have to bore many holes and install many pipes to extract sufficient amount of heat from the ground. Accordingly, these systems have been found to be expensive.

Usually, for an average household of about 1200 square feet, there is required approximately 750 linear feet of in-ground tubing interconnected in series and into a thermo pump. The thermo pump circulates a heat exchange liquid in the closed loop circuit disposed in the ground and the liquid is used to extract and convect the heat from the soil to the thermo pump which compresses the liquid to extract heat therefrom. During hot summer months, the thermo pump operates in reverse and the geothermal circuit is used to cool the liquid convected through the closed circuit with the liquid extracting heat from inside the building by the thermo pump. It is pointed out that these tubes can extend from 100 to 400 feet into the ground. Often it is necessary, at those depths, to drill through the bedrock and this adds considerably to the cost of the installation of the system. A vertical installation is preferred over a horizontal installation due to the fact that in a horizontal installation it is necessary to have a very large terrain and usually the tubing is installed in the ground in the form of continuous overlapped loops. A big advantage of using a geothermal energy heating/cooling system is that the cost of the installation can be recovered within a period of 5 to 10 years and thereafter comes the economy wherein the heating and air-conditioning costs are greatly reduced.

DISCLOSURE OF INVENTION

It is a feature of the present invention to provide a geothermal in-ground conduit system and method of installation which greatly reduces the disadvantage of the prior art mentioned hereinabove. Another feature of the present invention is to provide a soil penetrating head for use in a geothermal in-ground conduit system to position a flexible tubing loop in the soil and which greatly facilitates the installation of the loop into the soil. Another feature of the present invention is to provide a geothermal in-ground conduit system comprised of a loop of flexible tubing and a soil penetrating head secured at a lower end of the loop and wherein the head is driven into the soil by a static or dynamic force transmitting shaft which is retractable or which may be utilized as a foundation support pile or a conduit for convecting a heat exchange liquid therein and wherein the soil penetrating head remains imbedded in the soil with the loop of flexible tubing. Another feature of the present invention is to provide a geothermal in-ground conduit system comprised of a loop of tubing material which is connectable to a soil penetrating head to position the loop of tubing material at a predetermined depth into the soil and wherein the soil penetrating head is retractable after the loop of tubing material has been positioned.

Another feature of the present invention is to provide a geothermal in-ground conduit system which can be installed under the footings of new building structures and to make it accessible to the proprietors of such building structures for future use.

Another feature of the present invention is to provide a geothermal in-ground conduit system which can be installed into the ground from inside a foundation of an existing building and which can be placed into the soil surrounding the building at a multitude of desired angles.

Another feature of the present invention is to provide a geothermal in-ground conduit system which does not require drilling through the bedrock.

Another feature of the present invention is to provide a geothermal in-ground conduit system comprised of at least one loop of flexible tubing and wherein the elongated side sections of the loop are spaced-apart a distance sufficient to permit extraction of heat from its surrounding areas without interfering from the surrounding area of the adjacent elongated side sections and wherein there are no tubes required for housing the loop as the side sections are each in direct contact with the surrounding soil thereby greatly increasing the efficiency of such closed loop conduit systems.

Another feature of the present invention to provide a soil penetrating plate assembly which greatly facilitates the installation of conduit loops into the soil and which permits easy retrieval of the said penetrating plate and which is inexpensive to fabricate.

Another feature of the present invention is to provide a pile which is casted from concrete or other suitable material and formed in sections and wherein the sections are adapted to position one or more geothermal conduit loops at different depths along a sidewall of the pile .

According to the above features, from a broad aspect, the present invention provides a geothermal in- ground conduit system comprising at least one loop of flexible tubing material adapted to convect a heat exchange liquid therein. The loop has a lower end section and opposed spaced-apart elongated side sections communicating with the lower end section to form the loop. The lower end section is adapted to be driven in the soil for permanent burial therein with at least a major portion of the side sections and in direct contact with the soil for heat exchange therewith. According to a further broad aspect, the present invention provides a geothermal in-ground conduit system which comprises at least one loop of flexible tubing adapted to convect a heat exchange liquid therein. The loop has a lower end section and opposed spaced-apart elongated side sections communicating with said lower end section to form the loop. The lower end section of the loop is secured to a soil penetrating head. The soil penetrating head has a leading soil penetrating face formation. Coupling means is provided with the soil penetrating head to receive a force transmitting shaft to transmit a pushing force against the soil penetrating head to displace the head in the soil while pulling the loop and guiding the loop into the soil as the soil penetrating face formation forms passages in the soil. According to a further broad aspect of the present invention there is provided a soil penetrating head for use in a geothermal in-ground conduit. The soil penetrating head has a leading soil penetrating face formation. Coupling means is secured to the soil penetrating head rearwardly of the leading soil penetrating face formation and adapted to receive a force transmitting shaft. The leading soil penetrating and ramming face formation has a convex shaped forward sharp edge and opposed symmetrical shaped side walls tapering outwardly from an apex of the convex forward sharp edge. It also has passage means to receive a lower end section of at least one loop of flexible tubing from a rear end of the soil penetrating head. According to a still further broad aspect of the present invention the soil penetrating head is detachably secured from the loop of flexible tubing after the loop has been positioned in the soil at a predetermined depth whereby the soil penetrating head is retractable with the loop of flexible tubing remaining buried in the soil.

According to a still further broad aspect of the present invention there is provided a method of constructing an in-ground conduit system to capture thermal energy stored in the ground. The method comprises the steps of securing a lower end section of at least one loop of flexible tubing to a soil penetrating head. The loop has opposed spaced-apart elongated side sections. The soil penetrating head has a leading soil penetrating face formation. The soil penetrating head is engaged by a lower end of a force transmitting shaft supported at a desired angle with respect to a soil surface adjacent a foundation of a building structure. A pushing force is applied to the force transmitting shaft to displace the soil penetrating head in the soil with the opposed elongated side sections maintained spaced-apart. The soil penetrating head pulls the loop and guides it into the soil as the penetrating face formation forms passages for burial of at least a major portion of the loop. According to a further broad aspect, the present invention provides a soil penetrating plate to position a flexible geotherraal conduit loop in soil. The soil penetrating plate has a leading soil penetrating formation. Hook means is provided in the soil penetrating plate assembly and adapted to hook an end loop portion of the conduit loop. Attachment means is provided to secure the soil penetrating plate to a force transmitting means for displacing same in the soil to position the conduit loop thereinto.

According to a still further broad aspect of the present invention there is provided a pile which is adapted to be driven into the ground to position one or more geothermal conduit loops adjacent the pile and wherein a guide collar is positioned about the pile over a top surface of the ground whereby to guide opposed longitudinal conduit sections of the conduit loops with respective attachment means secured to the pile to precisely position the conduit sections with respect to the pile sidewalls.

According to the above features, from a broad aspect, the present invention provides a pile adapted to be driven into the ground and having retaining means to retain one or more geothermal conduit loops. Each conduit loop is formed by opposed longitudinal conduit sections interconnected at a lower end by an interconnecting section. The conduit loops are adapted for flow of a heat exchange fluid therein. The retaining means retains the one or more conduit loops in close proximity to the pile through the attachment means as the pile is driven into the ground.

According to a further broad aspect of the present invention the pile is casted pile constructed of a solid mass material and the retaining mean is formed by channels casted in the outer side face of the pile.

According to a further broad aspect of the present invention the pile is hollow steel pile and the retaining means is constituted by guide channel elements secured to the outer surface of the hollow steel pile

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a fragmented schematic view illustrating the construction of the geothermal in-ground conduit system of the present invention; FIG. 2 is a perspective view, partly exploded, showing the construction of the soil penetrating head and its connection to a loop of flexible tubing as well as to a force transmitting shaft;

FIG. 3 is a side view showing a modification of the soil penetrating head of Figure 2;

FIG. 4 is a top, rear view showing a further modification of the soil penetrating head;

FIG. 5 is a further rear view showing a still further modification of the soil penetrating head; FIG. 6 is a schematic illustration of a still further modification of the soil penetrating head;

FIG. 7 is a schematic illustration showing the interconnection of loops of flexible tubing and the use of the force transmitting shaft as a conduit integrated with the loops of flexible tubing and for convecting the heat exchange liquid therein;

FIG. 8 is a fragmented side view illustrating the construction of spacing elements connectable with the force transmitting shaft for maintaining the elongated side sections of the flexible tubing loop in spaced-apart relationship as it is drawn into the soil;

FIG. 9 is a simplified perspective view of a pneumatic force applying device utilized to drive the soil penetrating head and the flexible tubing loop into the soil from inside a foundation of an existing building;

FIG. 10 is a perspective view illustrating the construction of a pneumatic force applying device utilized to drive shaft sections of the force transmitting shaft into the soil;

FIG. 11 is a top view of the pneumatic force applying device;

FIG. 12 is a further perspective view of the pneumatic force applying device illustrating an assembly of protection plates secured about the clamping jaws of the device;

FIG. 13 is a fragmented sectional view showing the in-ground conduit system installed under a footing of a foundation structure; FIG. 14 is a simplified section view illustrating various orientations of the flexible tubing loops that can be installed from inside an existing foundation structure.

FIG. 15 is a schematic illustration of a heavy equipment used to apply a dynamic force against the force transmitting shaft to drive the soil penetrating head and loop of flexible tubing into the soil;

FIG. 16A is a perspective view of a further example of the construction of a soil penetrating head which is adapted to be retracted after the loop of flexible tubing has been positioned into the soil for burial thereinto;

FIG. 16B is a side view of Figure 16A; FIG. 16C is a fragmented side view of the soil penetrating head showing the curved section of the loop of flexible tubing material engaged therewith;

FIGs. 17A to 17C are side views of the soil penetrating head of Figure 16A illustrating how the lower end section of the loop of tubing is positioned into the soil and the soil penetrating head retracted therefrom;

FIG. 17D is a side view similar to Figure 17A but showing a modification of the soil penetrating head wherein a soil penetrating nose member is detachably connected to the leading edge of the soil penetrating head;

FIG. 17E is a side view showing a soil penetrating nose member secured to the lower end section of the loop and engageable by the leading edge of the soil penetrating head;

FIG. 18 is a simplified perspective view showing the construction of the loop of flexible tubing material; FIGs. 19A and 19B are perspective views showing a further embodiment of a soil penetrating head with a detachable force transmitting shaft engageable therewith;

FIG. 20 is a perspective view showing the construction of the force transmitting shaft lower end; FIG. 21 is a simplified side view showing how the loop of flexible tubing, as shown in Figure 18, is positioned within the soil; and

FIG. 22A is a top view of a hole made in a concrete floor slab of a building structure illustrating a plurality of loops driven in the soil below the slab in different directions;

FIG. 22B is a schematic side view illustrating the position of loops driven into the ground at different angles and with the property boundaries of a building lot; FIGs. 22C and 22D are similar illustrations of different loop patterns of tubing loops driven in the soil of a building lot;

FIG. 23 is a schematic view illustrating how the flexible geothermal conduit loop is positioned into the soil by the use of a soil penetrating plate assembly which is secured to a force transmitting shaft;

FIG. 24 is a fragmented section view showing the soil penetrating plate assembly in the form of a rigid metal soil penetrating wing welded to a steel shaft;

FIG. 25 is a side view of the soil penetrating plate showing a different configuration thereof and also showing a soil deflector secured thereto or to the metal shaft; FIG. 26 is a fragmented view showing a metal shaft having two opposed parallel rigid soil penetrating plates welded thereto in parallel relationship;

FIGs. 27A and 27B are top views showing different configurations of the soil penetrating plate and attachment to a shaft;

FIG. 28 is a transverse section view showing a detachable connection of a soil penetrating plate to a shaft;

FIGs. 29 and 30 are schematic illustrations showing different force transmitting means for driving the soil penetrating plate into the soil;

FIG. 31 is a schematic illustration showing a soil penetrating plate secured spaced from a penetrating end of a force transmitting shaft; FIG. 32 is a perspective view showing a V- shaped soil penetrating plate having hooking means to secure two flexible geothermal conduit loops simultaneously into the soil; FIG. 33 is a simplified perspective view showing a further embodiment of the soil penetrating plate and wherein the plate is pulled into the soil to pull a flexible geothermal conduit loop thereinto,- FIG. 34 is a side view of a further embodiment of the soil penetrating plate of the present invention which is secured to a tubular connector which is detachably securable to a drive shaft;

FIGs. 35A to 35C are side vies showing the manner in which a flexible geothermal conduit loop is hooked onto the soil penetrating lead edge of the soil penetrating plate;

FIG. 36A is a side view of a detachable coupling to which the soil penetrating plate is secured; FIG. 36B is a front view of Figure 36A;

FIG. 37 is a top section view showing a further embodiment of the soil penetrating plate of the present invention;

FIG. 38 is an exploded view showing a further embodiment for positioning the flexible geothermal conduit loop into dense soil conditions;

FIG. 39 is a side view illustrating a casted concrete pile formed by pile sections and wherein the pile sections are provided with retaining channels adapted to retain therein opposed longitudinal conduit sections and a lower interconnecting section of one or more geothermal conduit loops;

FIG. 40 is an enlarged view of two pile sections adapted to be connected together and illustrating a conduit loop bottom section secured and retained in the conduit retaining channels of one of the pile sections;

FIG. 41 is a transverse cross-section view showing a casted concrete pile having four opposed flat surfaces casted with loop retaining channels and wherein there are four conduit loops retained in the sidewalls of the concrete pile,-

FIG. 42 is a transverse section view similar to Figure 41 but showing a pile having conduit retaining channels which are lined with a metal liner to receive a portion of a longitudinal conduit section of two conduit loops and wherein a thermally conductive protection cover is secured over the conduit to provide protection to the conduit while permitting thermal conductivity; FIG. 43 is a simplified fragmented side view showing a conduit loop being positioned into the ground as a pile is driven into the ground and wherein a guide collar is positioned about the pile over the top surface of the ground and adapted to guide the conduit longitudinal side sections in respective channels as the pile is driven into the ground;

FIG. 44A is a transverse cross-section view showing a pile which is formed as a hollow steel pile and provided with guide channel elements welded to the outer sidewalls of the pile to guide and retain the longitudinal conduit sections of the geothermal conduit loops, herein two loops disposed at 90 degrees to one another,-

FIG. 44B is a simplified fragmented side view showing the lower end of the pile of Figure 6A and wherein the interconnecting sections of the conduit loops crisscross in a protective head secured to the bottom end of the pile;

FIG. 45A is a fragmented perspective view of the guide channel elements of Figure 44A; FIG. 45B is a cross-section view showing a modification of the guide channel elements of Figure 7A;

FIG. 46 is a transverse cross-section view of a hollow steel pile showing a further embodiment and wherein two geothermal conduit loops are secured to the pile in substantially parallel relationship and extending diagonally across two adjacent sidewalls;

FIG. 47 is a transverse section view showing a hollow steel pile and wherein the conduit retaining means is provided by hook members permanently secured to one or more of the sidewalls of the pile for retaining a plurality of conduit loops thereto;

FIG. 48 is a transverse section view of hollow steel pile of circular cross-sections having guide channel elements secured to the outer sidewall thereof for retaining one or more geothermal conduit loops thereto and herein illustrating different types of guide channel elements and hook members;

FIGs. 49 to 51 are cross-section views of extruded force transmitting shafts or piles; and

FIGs. 52 and 53 are cross-section views of aluminum extruded force transmitting shafts or piles.

MODES FOR CARRYING OUT THE INVENTION Referring now to the drawings, and more particularly to Figure 1, there is shown a schematic illustration of a building structure 10, herein a residential home, equipped with the geothermal in-ground conduit system 11 of the present invention. Essentially the system comprises of at least one, herein a plurality of flexible tubing loops 12, each loop being connected in series to form a closed loop conduit circuit which is connected to a thermo pump 13 adapted to circulate a heat exchange liquid within the circuit to extract heat from the soil 14 surrounding the loops for heating the building 10. The pump 13 is conveniently installed inside the building structure 10 or an attached structure 10 '. By reversing the operation of the pump 13, heat from inside the building can be cooled by heat exchanging the heat with the heat exchange liquid and circulating into the earth where the soil surrounding the loop cools the heat exchange liquid within the tube thereby extracting heat therefrom. The operation of the thermo pump is well known in the art .

Each of the loops 12 has a pair of elongated, spaced-apart, side sections 15 and 15' and a lower end section 16, hereinshown in phantom line, which is secured to a soil penetrating head 17. The loop is formed of HDPE (high density polyethylene) . The loops 12, as well as the soil penetrating head 17, are embedded within the ground at a convenient location, herein close to the foundation wall 17 of the building 10, but they could of course be located further away. The soil penetrating heads 17 of the loops are driven into the ground by a force transmitting shaft, as will be described later, to a predetermined depth or until the soil penetrating head is arrested by the bedrock 18 or otherwise. Accordingly, the depth of the bedrock could determine how many loops are to be placed into the ground to provide heat for the square footage area of the building structure 10 to be heated. Usually, for a residential building structure of about 2,000 square feet, there is a requirement to dispose approximately 750 feet of tubing into the ground. However, because, as shown in Figure 1, the flexible tubing is in direct contact with the surrounding soil, it is more efficient in absorbing heat or releasing heat into the ground as opposed to conventional systems and less tubing may be required as compared with the prior art methods where the elongated side sections 15 of the loops are closely spaced and often disposed in a bore hole in a rock surface or in a metal tube driven into the ground.

With reference now to Figure 6, there will be described the construction of the soil penetrating head 17. As hereinshown the head 17 has a leading soil penetrating and ramming face formation 18 which has a convex-shaped forward sharp edge 19 and opposed symmetrically shaped bowed side walls 20 and 20' extending outwardly from an apex of the convex forward shape edge 19. Coupling means, as hereinshown in the form of a hollow tube section 21, is secured between the symmetrically shaped side walls 20 and 20' and is positioned along a straight central axis 22 which passes through the apex of the sharp edge 19 and at mid- length of the opposed symmetrical shaped side walls and mid- length of the opposed end edges 23 and 23' of the soil penetrating heads 17. The hollow tube section 21 is dimensioned whereby to receive therein a lower end section 24 of a force transmitting shaft 25.

The soil penetrating head 17 is further provided with a curved passage therein to permit the passage of the flexible tubing to form a curved lower end section 16, as hereinshown. Alternatively, as shown in Figure 3, a curved conduit 27 of high density polyethylene may be secured inside the soil penetrating head 17 and be provided with extension portions 27' for connection with a respective one of the elongated side sections 15 and 15' of the loop by socket fusion, butt fusion or electrofusion. Further, as shown in Figure 3, the tubular connector 21' , as hereinshown, is in the form of a pipe section having an engageable formation, herein an inner thread 28 for detachable connection with the threaded end 29 of the force transmitting shaft 25' . For the installation of the loops 12 into the ground surface 14', a trench 30 may be dug out from the top surface 14' of the ground and in which each loop 12 is driven into the ground by connecting or placing the free end of a force transmitting shaft 25 into the coupling tube 21 for transmitting a directional pushing force against the soil penetrating head to displace the soil penetrating head 17 into the soil 14. As the head is driven into the soil, the leading soil penetrating and ramming face formation 18 displaces the soil and obstacles in its path whereby to form a passage for the loop side sections 15 and 15' as it is pulled into the soil for permanent burial once the soil penetrating head reaches a predetermined depth or is arrested against the bedrock or other hard sub- strata. It is pointed out that the elongated side sections 15 and 15' of the loop are spaced- apart about 18 inches from one another and adjacent loops are positioned about three feet apart. After each of the loops 12 are installed below the ground surface, the loops are interconnected to one another by connectors, such as the connectors 31 shown in Figure 7 and intermediate pipe sections 32, as shown in Figure 1. Because the tubes are formed from high density plastics, it is preferable to secure the connectors and intermediate tube sections 32 by heat fusing them together or using a melting adhesive whereby there are no leaks in the joints. Once the joints are all interconnected and the free end sections 33 are brought above ground level 14, the trench 30 may be refilled with soil. As shown in Figure 2, the soil penetrating head

17 is preferably formed of steel or any other suitable hard material such as structural PVC material . The bowed side walls 20 and 20' are also reinforced by transverse rib formations or braces 35. If the soil penetrating head is constructed of a plastic material then a hard metal blade 19' is rigidly secured in the head 17 during the molding of the head 17.

As shown in Figure 4, the soil penetrating head 17 may also be provided with transverse guide flanges 36 to add stability to the head as it penetrates into the soil.

Figure 5 shows a further modification of the soil penetrating head, herein head 17' . As shown, the head 17 is in the form of a cross defined by transverse soil penetrating and ramming face formations 18 and 18' whereby to house a pair of hollow tube sections 27 and 37 which are superimposed under the coupling tube 21 whereby two of the loops can be installed into the ground surface with a single soil penetrating head 17' .

Figure 6 is a schematic illustration showing a further design of the soil penetrating head wherein the head is provided with three elongated flexible tubing sections 40 which are in communication with a hollow coupling tube 21" through conduits 41. With such an arrangement, the force transmitting shaft 25" is a hollow shaft permanently secured to the head for convecting the heat exchange liquid therein and into the opposed side sections 40 of the loop. The inner transverse surface area of the force transmitting shaft 25" is equal to the totality of the inner transverse surface area of the three opposed side sections 40 of the loop.

Figure 7 illustrates an arrangement which is similar, wherein the force transmitting shaft is a hollow shaft with the two elongated side sections 15 and 15' interconnected thereto by conduit connection 15", also illustrated in phantom lines in Figure 2. The heat exchange liquid is convected into the hollow shaft 25" and out through the elongated side sections 15 and 15' whereby to feed the adjacent force transmitting hollow shaft 25''' with the circulation liquid flow repeating with the next section and so on until the liquid convection circuit is complete . Referring now to Figure 8, there is shown generally at 10 a spacer element 42 which is securable to the force transmitting shaft 25. The force transmitting shaft 25 is a composite shaft consisting of shaft sections 43 interconnected end-to-end by a threaded end section at the end of one shaft section and a threaded bore 45 at the other end of each section 43. In order to maintain the elongated side sections 15 and 15' of the flexible tubing loop in a spaced-apart arrangement as it descends into the soil, the spacer element 42 is connected at selected ones of the connecting joints between the shaft sections 43. As hereinshown the spacer element 42 has projecting arms 46 which are flat with sharp edges and oriented to cut through the soil. The arms 46 are axially aligned with one another and extend transversely of the force transmitting shaft 25 for supporting a guide tube 47 at opposed free ends thereof. Each of the guide tubes 47 are disposed to receive a respective one of the spaced-apart side sections 15 and 15' of the flexible tube therethrough to maintain the side sections spaced-apart as they are drawn into the soil. The spacer element 42 has a connecting hub 48 also formed with a threaded spigot 49 and a threaded bore 50 whereby to be coupled to the threaded end section 44 and threaded bore 45 of the opposed shaft sections 43.

With reference again to Figure 1, there is shown another use of the force transmitting shaft 25 after the loops have been installed into the soil and the soil penetrating head 17 has reached the bedrock or a solid soil strata. As hereinshown, these force transmitting shafts 25 can be used as a pile which is connected to a bracket 55 immovably secured to the foundation wall 17 to support the foundation should this be desired due to the quality of the soil, i.e., clay or other unstable soils on which the foundation rests .

With reference now to Figures 13 and 1, there is shown another version of the installation of the in-ground conduit circuit or system 11. As shown in these Figures, a series of loops 12', see the right-hand side of Figure 1, are disposed into the ground surface after the excavation hole has been made to build the foundation 55. After the excavated hole has been surveyed for the footing implantation, the loops of flexible tubing 11 are installed into the ground along a straight line calculated to lie under the foundation footing 56 and offset from the center line 57 of the footing on an interior side 17' of the footing side wall 17. These loops 12 may be interconnected under the top surface 58 of the excavated hole 59 with the free ends of the loop circuit, or of the serially connected loops, extending above the top surface 58. One of these free end sections are herein designated by reference numeral 60. These tube open end sections 60 are disposed in an insulated protective sleeve 61 about which concrete 62 is to be poured and set to form the footing 56. Accordingly, the entire circuit of a geothermal in-ground conduit system is available to the building to be erected on the foundation from the two free end sections 60 of the circuit ready to be connected by piping to a thermo pump. Preferably, these two free end sections 60 are located at a location where the mechanical room is to be built.

With reference now to Figures 9 to 12, there will be described how the geothermal in-ground conduit system of the present invention is installed under an existing building structure. Figure 9 illustrates an existing building structure foundation, herein constituted by the foundation wall 17, the footing 56 and the concrete floor slab 65. It also shows the joist 66 of an upper floor and these joists 66 form a ceiling 67 which is usually 8 to 9 feet above the concrete floor slab 65. Accordingly, there is very limited space in which to install equipment capable of installing drive piles to install the flexible tubing loops and their associated soil penetrating heads into the ground surface under the foundation. This is accomplished in this restricted space by a pneumatic force applying device 70 which is secured to a foundation anchor plate 71 which is temporarily secured by anchor bolt 72 onto the inner surface 17' of the foundation wall 17 or on the outer surface 65' of the concrete floor slab 65. The anchor plate 71 is provided with a pair of parallel connecting flanges 73, each having a hole 74 for connection to the pneumatic force applying device 70.

As shown in Figures 10, 11 and 12, the pneumatic force applying device has a pair of pistons 75 each having a piston cylinder 76 and a piston rod 77. The piston rods have a piston rod end 78 in the form of a fork adapted to be engaged with a respective one of the holes 74 of the plate 73 by a lock pin 79. The piston cylinders 76 are coupled together in spaced parallel relationship by a force transmission shaft engaging assembly 80. The piston cylinders are connected to a pressurized fluid supply, not shown.

The shaft engaging assembly 80 is comprised of an attachment frame 81 immovably secured to the cylinders 76 to maintain them in spaced-apart parallel relationship. A pair of clamping jaws 82 is slidingly displaceable on a respective angulated side plate 81. The slide plates 81 are retained stationary in spaced-apart facial relationship to support the clamping jaws 82 in a spaced- apart relationship to define a shaft passage 83 therebetween and extending parallel to the cylinders . The clamping jaws 82, when at a lower end of the slide plates, as hereinshown, are spaced further away from one another to define a non-engaging position with the shaft section 43 of the composite force transmitting shaft as previously described. The clamping jaws 82, when moving to an upper end of the slide plates by downward displacement of the cylinders 76 by the application of fluid pressure, converge towards one another and clamp the shaft section 43 in the shaft passage 83 to impart a downward pushing force on the shaft section to drive the soil penetrating head and the flexible tubing loop into the ground surface. Of course, as shown in Figure 9, a hole 90 of sufficient size is first made into the concrete floor slab at an appropriate location where the flexible tubing assembly is to be installed.

With further reference to Figures 10 to 12, the attachment frame 81 is further comprised of a first bridge plate 84 which extends between the cylinders. An aperture 85 is provided in the first bridge plate intermediate the cylinder 76 and dimensioned for receiving the shaft section 43 in close sliding fit therein. A further bridge plate 86 is secured at the top end of the cylinders 76 and extends between the cylinders above the first bridge plate and is provided with a guide edge formation 87 aligned with the aperture 85 whereby to position the shaft intermediate the cylinders and in substantially parallel relationship therewith. Accordingly, by reciprocating the pistons 75, the cylinders move up and down causing the clamping jaws to engage and disengage the pipe sections thereby driving the pipe sections 43 within the soil under the foundation. Because the pipe sections are short pipe sections, approximately 5 feet in length, it is easy to manipulate them in the space above the concrete floor slab 65 of the foundation and by adding shaft sections and spacer elements 42, the solid penetrating head can be driven deep underground, as previously described.

In order to provide protection to the people operating the pneumatic force applying device the clamping jaws are protected by side protecting plates 89 and a top plate 88 interconnected together by fasteners extending through loops 91 of these plates. It also keeps foreign matter out of the clamping surfaces of the clamping jaws.

Because the piston rod ends 78 are in the form of a fork connected to the connecting flanges 73 of the anchor plates 71, the pneumatic force applying device can be hinged onto the anchor plate whereby the soil penetrating head and associated loops can be positioned into the soil at any angle, such as the angle indicated by axis 93 in Figure 14. Of course, the anchor plate 71 can also be secured to the top surface 65' of the concrete floor slab 65, as also shown in Figure 14, whereby the soil penetrating head and flexible tubing loop can be driven into the ground along a horizontal axis 94, as shown in Figure 14. Additionally, the pneumatic force applying device 70 could be secured at any location over the concrete floor slab top surface 65' by providing two anchor plates each having a single connecting flange and positioned to each side of a hole 95 formed in the concrete floor slab 65. This would be desirable for example, if the basement area has a dedicated mechanical room in which the thermo pump is to be installed. In such an installation the soil penetrating head 17 and its flexible tubing loop would be driven vertically down through the hole 95, as also illustrated in Figure 14. Therefore, it is possible to install the in-ground conduit system of the present invention from inside an existing foundation with the loops being directed at any desirable angle into the surrounding soil . With reference now to Figure 15 there is shown how the geothermal in-ground loop 12 of flexible tubing material can be inserted into the soil 14 from above ground by a heavy equipment 100 having a boom 101 to which is connected an impact device 102 capable of applying a dynamic force against the free end 103 of the force transmitting shaft 25, such equipment is well known in the art. As shown in Figures 18 and 21, the loop of flexible tubing is formed by two sections 104 and 104 ' of such plastic tubing cut a predetermined length and interconnected at a free end 105 and 105 ' thereof to a curved lower end section 106 of rigid plastic tubing or metal tubing and sealingly engaged therewith. This curved lower end section 106 is engaged by the soil penetrating head as illustrated in Figures 16A to 17D, namely soil penetrating head 107 and driven into the soil by the force transmitting shaft 25 as previously described. The soil penetrating head 107 is designed to be retracted from the soil 14 after the head has driven the loop to a predetermined depth or has reached the bedrock surface 18.

With reference now to Figures 16A to 17D there will be described the construction and operation of the soil penetrating head 107. Referring to Figures 16A to 16C, there is shown the basic construction of the soil penetrating head 107. It comprises a pair of spaced apart interconnected side walls 108 which are preferably, but not exclusively, constructed of steel and which are interconnected together in spaced parallel relationship by an internal recessed tube abutment member 109. A channel 110 is defined between the side walls 108 in an outer peripheral portion of the soil penetrating head 107. The channel extends along opposed side edges 107' and the leading edge 107" thereof to receive the lower end section 16 and immediate lower portions of the side sections 15 and 15' therein. As shown in Figure 16C, the tube abutment member 109 has an outer seating wall 111 which is configured to receive the lower end section 16 of the loop in facial contact therewith. The rear end portion of the soil penetrating head 107 is also provided with a transverse slot 112 to receive the free lower end 113 of the force transmitting shaft 25 in seated engagement therein, as better illustrated in Figure 16A. As shown in Figure 16A, the free end portion 114 of the force transmitting shaft 25 is retained captive between opposed transverse slots 112 of the opposed side walls 108.

The free end portion 114 of the force transmitting shaft can be welded to the opposed side walls 108 to retract the soil penetrating head 107 after it has been driven to its intended depth o leave the loop of flexible tubing material buried in the soil, as shown in Figure 22C. It can also be freely seated within the opposed slots 112 whereby the force transmitting shaft 25 can be retracted after the soil penetrating head 107 reaches its predetermined depth to be buried together with the lower curved end section of the loop. Figure 22A illustrates the loop buried in the soil together with the soil penetrating head 107. Figures 17A to 17C show how the lower section of the loop is buried into the soil by the displacement of the soil penetrating head, Figure 17C showing the head 107 being retracted by the force transmitting shaft 25. As herein shown, the lower section 16 of the loop is a U-shaped curved section which fits snuggly against the outer seating wall 111 which is convexly curved.

Referring now to Figure 17D, there is shown a soil penetrating nose member 120 which is detachably connected to the leading edge 107" of the opposed side walls 108 of the soil penetrating head 107 to provide ease of penetration of the soil penetrating head into the soil while protecting the curved lower end section 16 of the loop. The soil penetrating nose member is provided with a sharp leading edge 121 and a transverse locating pin 122 secured centrally behind the apex 123 of the head. A pair of articulated anchor wings 124 is pivotally connected by pivot connection 125 to the forward end portion 126 to hinge rearwardly as the soil penetrating head is driven into the soil. This soil penetrating nose member 120 remains in the soil under the lower curved section 16 of the loop after the soil penetrating head 107 is retracted. The soil penetrating nose member is retained captive in a slot 127 provided at the apex of the curved lower edge 107" of each of the opposed side walls 108. Figure 17A shows a further embodiment wherein the soil penetrating nose member 120' is provided with an attachment 130 to secure same directly onto the lower curved end section 16 of the loop of flexible tubing. Again, this lower section 16 could be fabricated from a metal pipe or hard industrial plastics material. The soil penetrating nose member 120' is retained in location by the abutment member 109. It is also made wider than the channel 110 to abut against the outer lower edge 107" of the side walls 108. Any pulling force in the direction of arrow 131 would cause the wings 124 to deploy outwardly, as illustrated in Figure 17E.

With reference now to Figures 19A, 19B and 20 there is shown a further soil penetrating head, herein soil penetrating head 135, and as herein shown, it is formed by a metal member 136 of V-shaped cross section 137 fabricated as a V-shaped soil penetrating head 135 defining a pointed leading end 138 and opposed tapered side walls 139 to provide ease of penetration in the soil. The lower end section 16 of the loop is formed by PVC tube sections 140 interconnected by connectors 141, as is well known in the art. The side sections 15 and 15' of the loop are formed from flexible plastic tubing such as PVC. As herein shown, the force transmitting shaft 25 is provided with a coupling 142, as better illustrated in Figure 20, which consists of opposed side walls 143, each provided with a slotted edge 144, configured to receive therein a rear edge portion 144 of the opposed side walls 139 of each side of the soil penetrating head 135 for removable engagement therewith. The coupling 142 remains in position by the provision of a channel 145 defined between the side walls 143 and which received therebetween the lower end section 16 of the loop. After the soil penetrating head 135 has been driven to a predetermined depth in the soil, the force transmitting shaft and the coupling 142 are retracted. Accordingly, it can be seen that the soil penetrating head may have a variety of designs while performing the function of positioning the loop of flexible tubing material into the soil with the head remaining in the soil or being retracted therefrom.

The method of constructing and installing the in- ground conduit system of the present invention whereby to capture thermal energy stored in the ground, will be briefly summarized. The method consists in securing a curved lower end section of at least one loop of flexible tubing 12 to the soil penetrating head 17. As previously described, each loop has opposed spaced-apart elongated side sections 15 and 15' and a curved end section 16. The side sections 16 are in the form of large coils of tubes located above ground and as the head is driven into the ground these coils unwind. A force transmitting shaft is secured to coupling means of the soil penetrating head and the force transmitting shaft is supported at a desired angle with respect to a soil surface adjacent a foundation of a building or spaced from the foundation of the building or inside the foundation of the building. The force transmitting shaft applies a pushing force to displace the soil penetrating head 17 in the soil with the opposed elongated side sections of the flexible tubing being maintained spaced-apart and being drawn into the soil by the soil penetrating head pulling the loop and guiding it into the soil as the head forms passages for burial of at least a major portion of the loop together with the soil penetrating head after the head is arrested. Depending on the material of the flexible tubing and its rigidity, the curved lower end section 16 of the loops 12 may be formed several ways as previously described. Further, in the method of installation, spacer elements 42 may be secured to the force transmitting shaft 25 between sections thereof. The force transmitting shaft 25 may have several forms and can also act as a conduit for the passage of the heat exchange liquid therethrough and in communication with the loop of flexible tubing. As above described, the soil penetrating head may have different configurations and be provided with guide flanges to prevent deviation as it penetrates into the soil. It may be formed of various materials such as steel, industrial plastics or composite materials that are rigid enough to displace small rocks as it is pushed within the ground. The force transmitting shaft 25 can be coupled to various impacting devices such as high frequency impactors acting on the top end of the force transmitting shaft sections or by a pneumatic force applying device as previously described. Such a device can exert from 5,000 to 75,000 pounds of pressure onto the force transmitting shaft sections. The soil conditions for the installation of the conduit system of the present invention must be such as to permit the displacement of the soil penetrating head therein.

Referring to Figure 22A, there is shown a top view of a hole made in a concrete floor slab, such as the slab 65 shown in Figures 13 and 14 and wherein several tubing loops 12 are driven into the soil under the building and at different radiating angles as well as vertically downwards whereby the flexible tubing loops can extend in the soil under the foundation and within the property lines of the building lot. Figure 22B is a side view showing some of the tubing loops installed in a foundation excavation or through a floor slab of an existing building at different angles and within the lot boundary lines 150. The length of the tubes can be calculated not to extend beyond the subterranean property lines 150 by calculating the angle of the loop and the distance to the property line.

Figure 22C is a further illustration showing an installation of the in-ground conduit system of the present invention and wherein the property lot is a small lot. As hereinshown all of the tubing loops 12 are disposed at different angles and radiate from a common area and at different angles. As previously described with reference to Figure 14, these flexible tubing loops can be driven horizontally and at different angles and can result in an installation such as shown in Figure 22D wherein the property lot is very large and therefore fewer loops may be used to extract heat from the soil.

Referring now to Figure 23, there is shown generally at 110 a schematic illustration of an equipment for installation of a flexible geothermal conduit loop 111 into the soil 112 using the soil penetrating plate 114 of the present invention. The flexible conduit loop is wound on a spool 113 and is drawn into the soil 112 by the soil penetrating plate 114 of the present invention. As hereinshown, the soil penetrating plate 114 is driven by a force transmitting shaft 115 which is connected thereto and driven into the soil by a dynamic force applied to the top end 115' of the shaft 115 by percussion blows of an impact element 116 of a pile driving machine 117. Although not shown the shaft 115 may be driven into the soil by a drilling machine converted to impact with the shaft. The shaft may comprise interconnected shaft sections.

The soil penetrating plate 114 may have many forms as will be described herein. As shown in Figure 24 the soil penetrating plate is in the form of a rigid metal wing 118 and it is provided with a leading soil penetrating formation, herein a profiled short straight leading edge 119 which is provided with hook means, herein in the form of a conduit retention notch 120, about which a curved end portion 111', see Figure 33, of the loop 111 is retained and drawn into the soil by the shaft 115. The rigid metal wing 118 is welded to the shaft 115 or a shaft section or a tubular connector along its inferior edge 121 and that constitutes an attachment means to secure the plate assembly to a force transmitting means, herein the shaft 115. Figure 25 shows the soil penetrating plate assembly having a different configuration, herein illustrated by reference numeral 118'. As hereinshown a leading soil deflector formation 122 is formed integral therewith whereby to loosen and deflect soil forwardly and outwardly as the soil penetrating plate assembly 118' is driven into the soil. Accordingly, the soil deflector formation 122 has a pointed end 122' and outwardly diverging side walls 122" and terminate in a wide top wall 122' ' ' . Referring to Figure 26, there is shown another embodiment of the construction of the soil penetrating plate assembly. As shown in Figure 26, the soil penetrating plate assembly has two plates 114 of the type as shown in Figures 24 and 25 or other configurations which are welded on opposed sides of the shaft 115, in parallel relationship, whereby to draw two flexible geothermal conduit loops 111 into the ground. Another arrangement of the soil penetrating plate assembly to draw two groups into the ground will be described later with reference to Figure 32.

Figures 27A and 27B are cross-section views showing further configurations of the soil penetrating plate 114 of the present invention. As hereinshown, there are two soil penetrating plates 114 removably secured or fixedly secured to a force transmitting shaft 115 and adapted at its opposed ends of its leading edges to secure a conduit loop 111 thereto. The two soil penetrating plates 114" of Figure 27A are secured at outwardly diverging angles and extend away from the force transmitting shaft 115 to maintain the conduit loop separated while they are driven or pulled into the soil. Figure 27B shows a further version wherein a large soil penetrating plate 114''' is a straight plate secured to a side of the force transmitting shaft 115. The straight soil penetrating plate 114''' is provided with conduit retaining notches similar to those as shown in Figures 24 and 25.

Figure 28 shows a still further embodiment of the soil penetrating plate assembly and as hereinshown the soil penetrating plate 114 is a straight rigid plate secured to a clamp wall 123 of a U-shaped clamp 124 whereby to be removably secured to the force transmitting shaft 115. The loop end portion 111' of the conduit loop is retained by a notch 120 formed in the leading edge 119 of the soil penetrating plate 114.

Figures 29, 30 and 31 are illustrations showing how the soil penetrating plate is positioned into the soil. As shown in Figure 29, the soil penetrating plate has a V-shaped leading edge 119' which is defined by- opposed slope edges diverging from an apex 126 thereof. The slope edges 119' are sharp edges to facilitate penetration into the soil. They are also provided with conduit retention notches 120. The V-shaped soil penetrating plate 114' is also coupled at a rear edge 127 thereof to a force transmitting shaft 115.

In the embodiment of Figure 33, the soil penetrating plate 114' is an assembly of two plates 113' separated by an insert 132 having a curved front end 132' on which the loop and portion 111' is supported when pulled through the soil is secured to a flexible pull cable 130 secured to the apex 126 of the V-shaped soil penetrating plate assembly 114' by a connector 131. The pull cable 130 pulls the V-shaped plate assembly 114' along a predetermined path into the soil and below a top surface thereof but in a curved path. Such conduit pulling devices are well known in the art.

As shown in Figure 35A, the hook means is constituted by a hook extension 133 formed in the top corners of the V-shaped soil penetrating plate 114' and it receives the loop end portion 111' of the conduit loop 111 whereby opposed loops may be drawn into the soil . Figure 35B shows another modification of the conduit loop retention means. As hereinshown, the retention means is provided by a pin connector 134 projecting laterally from the wing 118 or opposed sides of the V-shaped plate 114' as shown in Figure 33. Figure 35C shows a still further embodiment wherein the loop end portion 111' is secured to the retention 120 by connecting cable loop 142 of predetermined tensile strength calculated to break when subjected to a resistance force generated by the conduit loop being drawn in the soil. When cable loop 142 breaks, the conduit loop 111 is released and remains in the soil at a predetermined depth. This prevents the conduit loop to be subject to excessive force when drawn through the soil and therefore be damaged thereby resulting in the removal of the conduit loop and incurring further costs. As shown in Figures 30, 31 and 32, the soil penetrating plate, herein in the form of a V-shaped plate 114', is secured to the force penetrating shaft 115 but spaced from the end 115' thereof whereby to position the loops spaced above hard soil material 135 which is encountered as the force transmitting shaft 115 is driven into the soil or at a predetermined distance above bedrock. Figure 32 shows a modification of Figure 31 wherein the soil penetrating plate is provided with conduit retention notches 133 of the type shown in Figure 35A whereby to position two flexible geothermal conduit loops 111 simultaneously into the soil.

With reference now to Figure 34, there is shown a still further embodiment of the soil penetrating plate of the present invention. As hereinshown, there are two soil penetrating plates 140 and 140' each having a rearwardly sloped straight leading soil penetrating edge 141 which is somewhat sharper for ease of penetration into the soil. The plates 140 and 140' are immovably secured to a tubular coupling 142. Shaft coupling means in the form of an inner threaded rear section 143 in the coupling provide for threaded engagement with a threaded end 144 of a shaft section 145 of a force transmitting shaft assembly, not shown but well known in the art. Appropriate conduit attachment means is provided in the rear corner portions of the plates 140 and 140' . As hereinshown, these hook means are in the form of pins 134, as illustrated in Figure 35B, whereby to draw into the soil a flexible geothermal conduit loop in a manner as illustrated in Figure 33.

With reference now to Figures 36A and 36B, there are shown modifications to the soil penetrating plate of Figure 34. As hereinshown, the soil penetrating plate 152 is secured to the shaft 115 by attaching flanges 145 which are welded to the shaft 115 along welded edge 146 and to a rear of the soil penetrating plates 152 along weld line 147. The geothermal conduit loop is herein constituted by an end conduit section permanently secured in a trailing edge cavity 151 of the soil penetrating plate 152 which is herein in the form of a solid V-shaped plate projecting outwardly from the shaft 115 form its forward end connector 142. The end conduit section 150 has opposed free ends 153 and 153' adapted to be secured to opposed longitudinal conduit sections 154 to form the conduit loop.

Figure 37 shows a still further embodiment of the soil penetrating plate assembly. As hereinshown a pair of soil penetrates 155 is secured to a force transmitting shaft or connector 156 by plate connecting flanges 157 formed integral with the plates and welded on opposed sides of the shaft or tubular connector 156. The plates 155 have outwardly diverging plate sections 158 and have an angled end flange section 159 whereby a curved condition 160 may be permanently secured thereto. The curved conduit 160 is made of suitable material such as metallic tubular material and constitutes a loop end section such as the loop end section 150 as illustrated in Figure 36B. The curved conduit 160 has opposed free ends 161 adapted to be secured to opposed longitudinal conduit sections such as the sections 154 shown in Figure 36B to form the conduit loop. As shown in Figure 37, a further pair of soil penetrating plates 155' may also be secured to the shaft or tubular connector 156 and diametrically opposed to the pair of plates 155 whereby to connect a further flexible geothermal conduit loop thereto whereby two loops are driven into the soil at the same time.

Figure 38 shows a still further embodiment for positioning the conduit loop(s) 111 into dense soil conditions. As hereinshown the soil penetrating plate assembly 170 is constituted by two plates 170 secured to a drill rod 171 by a sleeve 172 having internal ball bearings 172' to maintain the assembly 170 substantially stable as the drill rod 171 rotates and advances in the soil. The sleeve 172 is retained in position as a collar ring 175 secured to the drill rod 171 and rotating therewith the sleeve 172 is located rearwardly of a drill head 173 provided with the usual carbide bit 174. The drill rod 171 is formed by interconnectable rod sections as well known in the art and illustrated herein. The drill head 173 is imparted rotation and/or percussion to advance in the dense soil. Once the drill head 173 has reached its predetermined depth, it is retracted to release the conduit loops in the soil, due to the taper or slope 170' of the plates 170 and the cone shape 173' of the drill head, the drill head 173 does not cause any damage to the conduit loops 11 when retracted. The cone shape 173' of the drill head flares outwardly towards the free end containing the carbide bit 174. Figure 38 illustrates the conduct loops 111 positioned spaced apart after having been disconnected from the plate assembly 170 and the drill head retracted.

Referring now to Figures 39 to 43, there is shown generally at 210 a pile, herein two pile sections 210', of the type adapted to be driven into the ground, such as the ground 211 illustrated in Figure 43. The pile 210, herein illustrated in Figure 41, is casted from concrete 212 or any other suitable solid mass material. As herein shown the sidewalls 213 of the pile are casted with conduit loop retaining means herein in the form of at least two channels 214, eight channels 214 being shown in the embodiment of Figure 41. These channels 214 have a straight channel section 214' and an interconnecting passage 215 formed across the straight channel section 214' whereby to receive therein an interconnecting lower end section 216 of a geothermal conduit loop formed by opposed longitudinal conduit sections 217 and 217' and the interconnecting end section 216, as illustrated in Figure 40.

As the pile 210 is driven into the ground by suitable impacting means, such as the percussion head 218' illustrated in Figure 43, the pile 210 draws the conduit loops into ground due to its attachment within the channels 214 as illustrated in Figure 40. As shown in Figure 39 the pile may be constructed of a plurality of pile sections 210' interconnected end-to-end by suitable interconnection means. As shown in Figure 40 this interconnection means may be constituted by locating pins 219' projecting from a bottom end 220 of a pile section 210' and a pin locating hole 221 formed in a top surface 222 of the pile section 210' so that these pile sections perfectly align with one another and remain in interconnected alignment as it is driven to the ground. Of course, other suitable interconnecting means or end connectors are contemplated.

As shown in Figure 43, a guide collar 223 may be positioned about the pile 210 over the top surface of the ground 211 to guide opposed longitudinal conduit sections 217 and 217', of rolls or conduit, into respective ones of the channels 214' formed in opposed sidewall of the pile 210 as the pile is driven into the ground. Guide rolls 223' guide the conduits 217 and 217' into their respective channel sections 214 and 214' . The channels may also be designed whereby the conduits are press -fitted therein by the guide rolls 223', similar to a zip-lock bag. This eliminates air from about the contact area between the conduits and the channels . The interconnecting passage 215 draws the opposed longitudinal conduit sections 217 and 217' with the pile as the pile is driven into the ground .

As shown in Figure 39 some or all of the pile sections may be provided with an interconnecting passage 215 thereby making it possible to locate a conduit loop at different depths within the ground by simply securing the conduit loop to sections above one or several lower ones of the pile sections. The lower one of the pile sections is shown in Figure 39 as having a ground penetrating head 225 secured thereto. This head 225 may have various configurations as obvious to a person skilled in the art and as described in my above-mentioned co-pending patent applications.

As shown in the embodiment of Figure 41 there can be four geothermal conduit loops secured to the pile, one in each of the sidewalls 213 thereof. Figure 42 shows an embodiment wherein there are two geothermal conduit loops secured to the pile and wherein the sidewalls 213 are provided with a single channel 214''. The conduit loops which have two opposed longitudinal conduit sections 217 and 217' may be disposed along transverse axes 226 with the lower interconnecting end section 216 of the two conduit loops crossing at right angles in the ground penetrating head 225 as shown in Figure 39 and Figure 44B. Alternatively, the conduit loops may be disposed along diagonal axes 227 with interconnecting lower end sections 216 of the conduit loops crossing at opposed diagonal corners of the pile. Figures 41 and 42 also illustrate that the channels 214 and 214'' may be provided with metal liners 230 permanently secured within the channels and adapted to be in flush contact with a portion of the other surface of the straight section of the geothermal conduits 217 and 217' to provide improved thermal conductivity for heat exchange therewith. A thermally conductive protective cover 231 may also be secured to the metal liner flanges 230' to encapsulate the opposed longitudinal conduit sections 217 and 217' therein to provide protection thereof while permitting thermal conductivity. An insulating liner 229 may also be interposed between the metal liner and the concrete 212.

These geothermal conduits are connected to heat exchange equipment which circulate a fluid therein whereby to extract heat from the ground for heating purposes or to release heat into the ground for cooling purposes. The channels 214 and 214'' are of U-shaped cross-sections with the channels of Figure 41 being much deeper whereby the conduits are recessed from the outer surfaces 213 of the concrete pile. Thus, the conduits are protected from the aggregate or other obstacles in the ground. The solid mass pile 210 is herein casted of concrete or reinforced concrete but it could also be made of metal, wood, structural plastics or any suitable hard material. The pile may also be square, rectilinear or circular or have any another suitable cross-sectional shapes.

With reference now to Figure 44A to 48 the piles as herein shown are constituted hollow steel piles and wherein the retaining means is differently formed. As shown in Figure 44A the hollow steel pile 240 is provided with guide channel elements 241 which are welded on the outer sidewall 242 of the steel pile 240. The guide channel elements 241 are better illustrated in Figure 45A and 45B. As shown in Figure 45A the guide channel 241 is an elongated metal strip provided flat wall 243 adapted to be welded to the outer sidewall 242 of the steel pile. A concave channel 244 is formed in the outer surface of the guide channel element 241 and dimensioned for close fit contact with a portion of the conduit sections 217 and 217'. As shown in Figure 44A the interconnecting end sections 216 of each of the two conduit loops cross at 90 degrees to one another in a lower end 240' of the pile in a ground penetrating head 245 formed with coupling means 246 and 246' to attach with a respective one of the interconnecting end sections 216 of the two geothermal conduit loops .

Figure 45B shows a guide channel element 241' wherein the connecting surface 247 is a curved surface whereby to secure same by welding to a circular hollow steel pile 250 as shown in Figure 48. The guide channel element 241' may also be provided with a pair of concave channels 244' in an outer surface thereof to receive both longitudinal conduit sections 217 and 217' of a geothermal conduit loop.

Referring now to Figure 47 there is shown a further modification of the hollow steel pile 240 as illustrated in Figure 44A. As herein shown, the retaining means for the geothermal conduit loops is provided by one or more hook members 251 secured to one or more of the sidewalls 242 of the pile 240 and such hooks are adapted to receive thereunder the interconnecting end section 216 of a conduit loop 260 as illustrated herein. These hook elements may have various shapes as described in my co- pending application serial number 12/497,560. As shown in Figure 47, and depending on the dimension of the pile, a sidewall, such as the sidewall 242', may have two hook elements 251 to secure two conduit loops 260 thereagainst . Of course, depending on the make-up of the ground in which the pile is intended to be driven and depths of the insertions of these conduit loops, the conduit retaining means may be suitably selected.

Figure 46 shows a further modification of the hollow steel pile 240 and, as hereinshown, it may be provided with guide channel elements 241 of different configurations and the conduit loops 216 may be disposed diagonally as previously described or transversely thereto as illustrated in Figures 44A and 44B. Figure 48 illustrates a still further embodiment herein a circular hollow steel pile 250, and it also illustrates various types of retaining means which may be welded to the outer sidewall of the pile 250. These retaining means are described hereinabove. The illustration in Figure 48 is simply to show that various ones of these retaining means may be welded to the outer sidewalls of a hollow circular metal pile to position geothermal conduit loops into the ground.

Figures 49, 50 and 51 show different embodiments of the pile. As hereinshown, these piles are conduit loop supporting piles and not adapted to support structures. These piles would be left in the ground with the conduit loops. The piles 270, 271 and 272 may be constructed of any suitable extruded material having sufficient rigidity to be driven into the soil and their purpose is to position the pile in the soil while also providing some protection to the conduit loop formed by the loop sections 217 and 217' . Metal inserts 273 may also be snap-fitted in the channels 274, if desirable, to provide better conductivity to provide thermal exchange between the fluid within the conduit sections 217 and 217' and the surrounding earth. The pile could be extruded from a combination of plastics material and wood fibers or recycled products. The pile can have various shapes, such as illustrated by Figures 49, 50 and 51. As shown in Figure 51, the conduit sections are only partly retained within the channel sections 274.

When the conduits are recessed, this eliminates friction between the conduits and the surrounding earth and thereby prevents the conduits from stretching when driven into the soil. The extruded material is inexpensive. These piles may also be very small in diameter, for example down to about 3 inch diameter. Of course, they could also be larger piles of 12 inches in diameter, for example.

With reference now to Figures 52 and 53, there is shown a still further embodiment of the piles wherein this pile 275 is formed of extruded aluminum. It is shaped whereby to form projecting fins 276 to provide a greater contact area with the surrounding ground to provide better thermal exchange therewith and with the conduit sections 217 and 217' fitted in the opposed channels 277 thereof. The hollow center core 278 also provides exposure to the soil but that area may also be completely filled, as shown in Figure 53, wherein the center core 279 is solid to provide more rigidity for driving the pile into the ground. The center core 279 may also be formed of a material which is more rigid permitting the application of a driving force thereon to drive the pile 275 into the ground. This center piece 279 is likely more expensive and therefore could be withdrawn after the pile is fully driven into the ground. It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein provide such modifications fall within the scope of the appended claims.