EP1954991A1

EP1954991A1 - Geothermal cooling device

Info

Publication number: EP1954991A1
Application number: EP06846910A
Authority: EP
Inventors: Lynn Mueller; John Graham
Original assignee: Free Energy Solutions Inc
Current assignee: Free Energy Solutions Inc
Priority date: 2005-11-14
Filing date: 2006-11-14
Publication date: 2008-08-13
Also published as: US20080053130A1; CA2642204A1; CA2530560A1; WO2007065247A1

Abstract

A geothermal cooling device (110, 120,130,140,150,160) is adapted to be coupled to a ground coil (32) formed from a thermal superconductor material and located in a ground hole (34) to allow passive thermal conduction to an earth source The geothermal cooling device (110,120,130,140,150,160) includes a thermally superconducting air exchanger (20) and a blower (18) placed in the vicinity of the heat exchanger (20) The air heat exchanger (20) is connected to the ground coil (32) via a superconductor segment (26) and a coupler (28) m order to conduct the heat from the heat exchanger (20) and to discharge it to the earth source The geothermal cooling device (110,120,130,140,150,160) actively operates when the blower (18) is activated in response to the difference between a set point and a measured temperature The geothermal cooling device (110,120,130,140,150,160) may be enclosed in a housing (10) adapted to be mounted in structural spaces, and the blower (18) can be activated with a manual switch ( 40) or controlled by a thermostat(14).

Description

GEOTHERMAL COOLING DEVICE

TECHNICAL FIELD

The present invention relates generally to geothermal cooling systems, and more particularly to a geothermal cooling device coupled with a superconducting heat transfer element for use as an air conditioner.

BACKGROUND OF THE INVENTION

Limitations of current art

Ground source heat pump systems, also known as geothermal or geoexchange systems, have been used for cooling and heating homes for more than half a century. In 1993, the Environmental Protection Agency evaluated all

commercially available technologies and concluded that ground source heat pumps were the most energy efficient systems available to the consumer.

Conventional ground source heat pump systems operate on a simple principle. In the cooling mode, heat from the building is collected at a heat exchanger and transferred to the heat pump, which concentrates the heat and transfers it to a ground source loop, which transfers the heat to the ground. In the heating mode, heat energy is absorbed from the ground and transferred to a heat pump which concentrates the heat and transfers it to the building's heat distribution system which in turn heats the building. In both modes, only a small amount of the heat energy comes from the electricity that runs the compressor; most of the energy comes from the air (in the cooling mode) and the ground (in the heating mode). This allows ground source heat pump systems to achieve more than 100% efficiency: every unit of energy consumed by the heat pump produces more than a unit of useful energy in the form of heat. Even though ground source heat pump systems achieve efficiencies of up to 350% compared to less than 100% for most conventional systems, they have achieved a very low level of adoption in the commercial marketplace because their capital costs and installation costs have always been much higher than conventional 5 systems.

These high capital and installation costs have largely been due to fundamental inefficiencies in the ground loop subsystem. In a typical installation, the ground loop consists of hundreds or thousands of feet of looped plastic piping buried in

0 deep trenches or deep holes drilled into the ground. An antifreeze solution such as glycol is pumped through this loop to transfer heat energy to the ground (in the cooling mode) or to absorb heat energy from the ground (in the heating mode). Few

installations have sufficient available land for trenching so loops are most commonly installed in deep holes and this makes them relatively expensive for several reasons.

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First, each loop consists of a supply and return line, which must fit down the same hole. With an outer diameter of an inch or more for each pipe and a tendency for these pipes to bow away from each other due to the plastic material's memory of being coiled for shipment, the hole typically needs to have a diameter of 4 to 6 inches to

0 allow the loop to be installed. Holes of this size are relatively expensive to drill and

require heavy equipment that disrupts landscaping, making it expensive to retrofit existing homes. Holes of this size also leave large voids around the loop that must be filled with materials such as bentonite clay in order for heat to transfer from the ground to the loop, which adds significantly to the cost of installation.

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Second, having both supply and return lines in the same hole results in thermal "short circuiting" which reduces the efficiency of the loop. In the cooling mode, for example, heat absorbed by the building's cooling system is transferred to the fluid in the ground loop system and pumped down a supply line into a bore hole. As it goes i0 down the hole it loses heat to the cool ground, causing the ground to warm up - more at the top of the hole because the fluid in the pipe is hottest as it enters the top of the hole. As the fluid goes down the tube it cools. When the cooled fluid comes back up the hole in the return line, it passes through the ground that was just heated, so the fluid in the pipe reabsorbs some of the heat it lost on the way down. This lowers the efficiency of the loop so the loop must be made longer to compensate, adding to the cost of drilling and piping.

Third, for the ground loop to function, the antifreeze solution must be pumped through hundreds or thousands of feet of small diameter piping. This consumes a significant amount of electric energy, lowering the overall efficiency of the system.

In recent years, a new ground source heat pump technology has evolved to overcome some of the inefficiencies of conventional systems. This technology, called "direct geoexchange," replaces the conventional plastic ground loop with a small- diameter copper loop. Instead of an antifreeze solution, direct geoexchange systems pump a refrigerant through the loop to pick up heat from the ground or give off heat to the ground in the same way that conventional ground loops function.

Direct geoexchange has some significant advantages over conventional systems. First, the direct geoexchange loop runs directly to and from the heat pump's compressor, eliminating the heat exchanger that is required by conventional systems to transfer heat from the loop to the heat pump. Second, the small diameter of the direct exchange loop makes it possible for loops to be installed in smaller diameter holes in the ground; this reduces the cost of drilling and backfilling the holes and reduces the size of the drill rig required to drill the holes decreasing damage to landscaping in retrofit applications. Third, the copper pipes used in direct geoexchange transfer heat more efficiently to and from the ground so the total length of loop required is typically less than conventional systems. Because of these improvements, direct geoexchange systems can be cheaper to install than conventional ground source systems and more energy efficient. In spite of these inherent advantages, direct geoexchange also has some significant disadvantages. First, both supply and return pipes run in the same hole, so the thermal short circuit problems of conventional systems remain. Second, the loop system pumps much more refrigerant through many more feet of piping past many more connections than conventional systems, so the potential for refrigerant leaks is increased.

Both direct geoexchange and conventional ground source heat pump systems have additional limitations that affect their usefulness. First, they are designed to heat and cool whole buildings, so neither can efficiently be installed on the

incremental room-by-room basis on which most of the world - particularly the

developing world - installs air conditioning. Second, they require significant amounts of electrical energy to operate pumps and compressors; this power is not often available or reliable in many parts of the world.

Most of the world either does without air conditioning (where money and electricity are in short supply), or uses refrigerant-based room air conditioners to cool individual rooms. Like geothermal systems (in the cooling mode), room air conditioners use a refrigeration circuit to absorb heat from room air and intensify it so it can be dissipated outside the building. Unlike geothermal systems, room air conditioners dissipate this heat into the outside air instead of the ground. Because air conditioning is usually used when the outside air is hot - often more than 40 degrees Fahrenheit hotter than the ground in a geothermal installation - the process of dissipating heat to the air requires air conditioners to work much harder and use much more energy than geothermal heat pumps to produce the same amount of cooling.

In spite of their high electrical power consumption, room air conditioners have dominated world markets because they are inexpensive to buy and simple to install. Rising demand for energy, however, is changing these markets. Rising demand is causing the cost of electricity to rise, making inefficient systems such as room air conditioners much less attractive to consumers. Rising demand is also causing shortages of power. Metropolitan areas such as Shanghai are finding that room air conditioners are consuming as much as two thirds of the capacity of the entire electrical grid on hot summer days, destabilizing the grid and leaving too little power for the manufacturing sector to operate during the day.

There is a need for a cooling device that consumes significantly less power than conventional air conditioners and is cheaper to buy, easier to install and has fewer moving parts than ground source heat pump systems.

SUMMARY OF THE INVENTION

Cooling devices are provided that use a thermal superconducting transfer medium to absorb heat from a room and transfer that heat to the ground where it can be dissipated. The thermal superconducting transfer medium in these devices allows heat to move between building and ground without the assistance of a compressor or refrigeration circuit, and without the assistance of a ground loop and associated pumps, valves and circulating fluids. This reduces the power required to operate these cooling systems, and also eliminates refrigerant leaks and reduces cost and system complexity. According to one aspect of the present invention, there is provided a cooling device suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source. The cooling device includes a thermal superconductor having a first end couplable to said thermal superconductor geothermal ground coil and a second opposing end configured as a thermal superconductor exchange segment, and a blower positioned in the region of said thermal superconducting exchange segment, and a thermostat controller associated with an indoor space and programmable to a desired temperature set point and for measuring temperature of said indoor space and further having a blower controller connected to said blower. The blower controller operates the blower in response to the difference between the set point and the measured temperature, for the purpose of operating in a cooling mode to efficiently cool an indoor space.

According to another aspect of the present invention, there is provided a cooling device operable without a thermostat and suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source. The cooling device includes a thermal superconductor having a first end couplable to said thermal superconductor geothermal ground coil and a second opposing end configured as a thermal superconductor exchange segment, and a blower positioned in the region of said thermal superconducting exchange segment, and a power connection for providing operating power to said blower when connected, and a switch connected to the power connection and the blower for controlling the blower. The blower may be manually controlled for the purpose of operating in a cooling mode to efficiently cool an indoor space.

According to another aspect of the present invention, there is provided a simple cooling device not requiring a thermostat or switch that is suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source and for connecting to a power source. The cooling device includes a thermal superconductor having a first end couplable to said thermal superconductor geothermal ground coil and a second opposing end configured as a thermal superconductor exchange segment, and a blower positioned in the region of said thermal superconducting exchange segment, and a power connection for providing operating power to said blower when connected. The blower may be powered by connecting the external power connector to the power source, for the purpose of operating in a cooling mode to efficiently cool an indoor space.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 : A GEOTHERMAL COOLING DEVICE: This figure shows a schematic of an efficient geothermal cooling device couplable to a ground source.

Figure 1a shows an alternate embodiment with multiple ground source loops.

FIGURE 2: COOLING DEVICE POWERED BY ALTERNATIVE ENERGY SOURCE: This figure shows a schematic of an embodiment of an efficient geothermal cooling device powered by an alternative energy source and having a power

conditioner.

FIGURE 3A,B: GEOTHERMAL COOLING SYSTEM INTEGRATED INTO AN INTERIOR SPACE: This figure shows a a) perspective and b) sectional view of an embodiment of an efficient geothermal cooling device formed of a thermal

superconductor extending to the ground source.

FIGURE 4: A GEOTHERMAL COOLING SYSTEM WITH A PLURALITY OF AIR EXCHANGE SEGMENTS: This figure shows a schematic of multiplexed cooling segments couplable to a single ground loop and connected to a power and sensor control box.

FIGURE 5: A GEOTHERMAL COOLING DEVICE WITH BLOWER

POWER SWITCH: This figure shows a schematic of a geothermal cooling device with a power switch for operating the blower for additional air heat transfer. FIGURE 6: A GEOTHERMAL COOLING DEVICE: This figure shows a schematic of a geothermal cooling device with a power connector for manually powering the blower for additional air heat transfer. DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, new and improved cooling devices and systems for improved cooling embodying the principles and concepts of the present 5 invention will be described. In particular, the devices and systems are operable in the conditions where an earth source temperature is lower than an above ground

temperature associated with an interior space to be cooled. The earth source may alternatively be a ground source or a body of water effectively below ground level.

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Recent advances in thermal superconducting materials can now be considered for use in novel energy transfer applications. For example, US patent 6132823 and continuations thereof, discloses an example of a heat transfer medium with extremely high thermal conductivity, and is included herein by reference.

5 Specifically the following disclosure indicates the orders of magnitude improvement in thermal conduction; "Experimentation has shown that a steel conduit 4 with medium 6 properly disposed therein has a thermal conductivity that is generally 20,000 times higher than the thermal conductivity of silver, and can reach under laboratory conditions a thermal conductivity that is 30,000 times higher that the thermal conductivity of silver."

0 Such a medium is thermally superconducting. Throughout the disclosure, the term

superconductor shall interchangeably mean thermal superconductor or thermal superconductor heat pipe. The available product sold by Qu Energy International Corporation is an inorganic heat transfer medium provided in a vacuum sealed heat conducting tube.

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Alternate thermal superconductors may be equivalently substituted, such as thermally superconducting heat pipes. Heat pipes typically include a sealed container(pipe),working fluid and a wicking or capillary structure inside the container. Heat is transported by an evaporation-condensation cycle when a thermal differential is IO present between opposing ends. Working fluids can be selected with high surface

tension to generate a high capillary driving force such that the condensate can migrate back to the evaporator portion, even against gravity. Some working fluids useful for the geothermal operating temperature range include ammonia, acetone, methanol and ethanol. Inside the tube, the liquid enters and wets the internal surfaces of the capillary structure. Applying heat at one segment of the pipe, causes the liquid at that point to

5 vaporize picking up latent heat of vaporization. The gas moves to a colder location

where it condenses, giving up latent heat of vaporization. The heat transfer capacity of a heat pipe is proportional to the axial power rating, the energy moving axially along the pipe. For maximum energy transfer the heat pipe diameter must be increased and the length shortened, making it operable but less preferred than a non-liquid

0 superconductor such as the Qu product. In particular with respect to the ground loop, scaled up heat pipe designs have been disclosed for geothermal heating applications such as for PCT publication WO 86/00124, "Improvements in earth heat recovery systems", these designs partially overcome the length to diameter ratio problem but preferably require a recirculation pump for the fluid. A two way heat pipe design for

5 ventilation heat-exchanger is disclosed in US patent 4896716, and could be used for non-ground loop transfer as a two way thermal superconductor.

When suitably configured for geothermal cooling, thermal superconductors of this kind result in many significant advantages. In particular, because they transfer

0 heat at a very high rate, they are able to absorb heat in a building, transfer it quickly and efficiently out of the building over relatively long distances of hundreds of feet with little loss of energy, and then dissipate this energy into the cool ground, without the mechanical pumping of circulating fluids required to move heat in conventional geothermal systems.

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Figure 1 illustrates an embodiment of the invention. Geothermal cooling device 110 is positioned above ground level 30 and couplable to a geothermal heat exchange element 32 formed from thermal superconductor and positioned in a ground loop hole 34. The thermal superconductor 32 extends above ground level where it is iO covered by insulation and terminated in a coupler 28. For illustrative purposes, this superconductor may be in the form of a sealed metal tube as currently available from Qu Corporation and will be considered to be in tube form. Alternatively other available thermal superconductors could be similarly substituted that may have various forms and cross sections such as flexible conduits, thin laminate, thin film coated metal etc.

Optionally, the superconducting transfer segments maybe formed from discontinuous discrete sections of superconducting material separated by small gaps of a non- superconducting material.

In the preferred case, the depth of hole 34 is selected in combination with the transfer properties of geothermal heat exchange element 32, the heat absorbing properties of the ground at the hole and the quantity of heat required by the system to be dissipated into the ground. As per conventional geoexchange systems, the depth of hole 34 may be greater than is practicable for a single hole, so a plurality of holes may be substituted to receive a plurality of geothermal heat exchange elements 32 and 32a with an aggregate depth equal to or greater than the required depth of a single hole. As shown in Figure 1 a, this plurality of geothermal heat exchange elements 32 and 32a can be joined at or below coupler 28 in such a manner that they are equally able to transfer heat to the ground. Due to the superior thermal transfer properties of the thermal superconductor element and the fact that the element is not looped so thermal "short-circuiting" is avoided, the hole size and depth can be considerably less than conventional geoexchange loops, saving installation costs and enabling installation in places where the large holes required by conventional geoexchange are not practical. In the example of a body of water being the earth source, the superconducting ground coil can be either suspended in the body of water, or in indirect thermal contact with the body of water. The latter example is specifically useful for marine applications.

The coupler 28 couples between the ground loop superconductor 32 and a cooling device superconductor segment 26, providing for ease of installation and conduit routing into an interior location prior to connection. The cooling device superconductor segment 26 extends inside a housing 10. As obvious to one skilled in the art, the coupler 28 could equivalently be alternatively positioned under the ground, above ground outside a building, inside the building but outside the housing 10, or even inside the housing 10, as selected for best ease of installation. Housing 10 includes two

5 vented regions (not shown), an inlet region to draw hot air in, and an outlet region to push cool air out. Positioned within housing 10 and between the two vented regions is a thermally superconducting air exchanger 20 connected to or integral with the cooling device superconductor segment 26, which is further insulated by insulation 25 up to the air exchanger 20, and further includes power line 36. A blower 18 is positioned in

0 proximity to the superconducting air exchanger to pull or push air through the exchanger for cooling, the preferred position being near the outlet vent region such that air is pulled over the air exchanger 20. Due to the superior heat transfer properties of the

exchanger, the fan can be a low power, low throughput fan to conserve energy, or alternatively a variable speed fan. The fan is powered by powerline 36 coupled through

5 controller 14 to external power line 12. The preferred fan has operating noise less than 45 dB and the external power line 12 can be DC powered by an alternative energy source (not shown). Superconducting air exchanger 20 may be configured in many possible designs provided sufficient net surface area is exposed to the air flow through cooling device 110, the illustrated design of an array of bars substantially corresponding

,0 to the fan diameter is a preferred example. Blower 18 is connected to controller 14 and power line 12 for control of fan operation. In some atmospheric conditions, condensate will form on the superconductor heat exchanger 20, and an optional drip tray 22 is shown positioned below to catch condensate and an optional water drain line 24 is shown connected to drip tray for runoff disposal.

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The controlled operation of the geothermal cooling device 110 is essential for user comfort and control of cooling. Controller 14 may be programmed as a thermostat controller responding to a temperature sensor 16 (such as a thermocouple) associated with the space to be cooled, or as a cooling device controller that receives

>0 input from a remote thermostat and sensor associated with the space (not shown). The controller is shown within the housing 10, but may alternatively be in any location provided it is in communication with the blower and temperature sensor. While the simplest implementation is one temperature measurement, to one skilled in the art, multiple temperature measurements could be weighted or averaged for the purpose of feedback set points in the controller 14. In the case of a multi-speed fan, alternatively a second temperature sensor could be positioned on or near the air exchanger 20 to determine the initial fan speed for faster cooling. Unlike conventional central geothermal heat pumps, which are large, noisy and require greater power than available from a standard household outlet, the geothermal cooling device 110 can be operated from a standard outlet connected to power line 12, anywhere in the house, very quietly and in a small form factor housing. The housing 10 for geothermal cooling device 110, may be positioned anywhere within the interior room to be cooled; it does not have to be near or in a window region. Preferably the housing is positioned to provide optimum air mixing and cooling for the room.

With the controller 14 set to a desired room temperature T1 via a manual input (not shown), or a remote control input or a second remote thermostat (not shown) in communication with the controller 14, the controller senses existing room temperature T2 and if higher than T1 , operates the blower 18 to circulate air until the temperature reaches T1. Alternatively, as common in the art, various thresholding or smoothing processes can be programmed to avoid jitter and to determine when to switch the blower 18 on or off. In the example of a multi-speed blower, the blower speed can be programmed to change proportional to the rate of change of existing temperature T2, in addition to on or off. The geothermal cooling device 110 can be programmed to operate for any input that acts as a related proxy for associated interior temperature and has a known characterized relationship to temperature.

The geothermal cooling device 110 of figure 1 has many advantages that solve the problems described in the background, due to the substantial efficiency increase relative to existing cooling solutions. First, the geothermal earth source element is not looped so it is not subject to thermal short-circuiting, so hole depth can be less than conventional ground loop depth, reducing costs and increasing qualifying sites. Second, by eliminating a compressor and heat intensifying circuit or circulating pumps, the power requirements of the geothermal cooling device are an order of magnitude less than conventional geothermal exchange units, whether central or for a single room, and permit the installation and operation on low power electrical systems such as conventional 15 Ampere residential circuits. Third, the generated noise is orders of magnitude better than compressor driven geothermal exchange units. Fourth, the lightweight and small size of the geothermal cooling device 110 relative to existing solutions, permits easy installation in a wide range of locations and even installations of individual geothermal cooling devices 110 in multiple rooms of a residence interior. Fifth, eliminating refrigerant and reducing moving parts extends system lifetimes and reduces system maintenance. The geothermal cooling device may operate from an alternative energy power source for even more economical sustainable operation, as shown in Figure 2. This embodiment is similar to Figure 1 with the addition of a power converter 11 inside the enclosure and connected to power line 12, for the purpose of processing alternative energy from an alternative power source (not shown), such as a hydrogen fuel cell, a solar cell array, or a wind turbine and the like, resulting in DC power requiring

conditioning by power converter 11 to supply controller and fan power. Due to the efficient thermal transfer of the configuration, low voltage components (12V) can be used in an embodiment, permitting alternate energy sources to be used without conditioning. Preferably the alternative power source would supply continuous power, but controller 14 may be adapted to use intermittent power operation.

Alternatively, for reducing potential thermal losses through coupler 28 shown in Fig's 1 and 2, a geothermal cooling system can be designed where the thermal superconductor is formed as one integral loop from earth source segment 32 through to superconductor air exchanger 20, by eliminating coupler 28. In this example, installation is done differently. The housing 10 is installed in position in the interior space, and both the above ground insulated thermal superconductor segment 26 and uninsulated segment 32 are routed through openings from the interior to the ground 30, and uninsulated segment 32 is seated in the ground loop hole. The interior openings 5 may be either through a sidewall and out to an uncovered hole, or in the case of new building may be positioned in the foundation of the building and fed into ground loop holes underneath the building.

Due to the advantages of lightness and compactness, interior mounting

0 can be considered for geothermal cooling devices that was previously not feasible. In Figure 3 and 3a, an example is shown for a wall-integrated geothermal cooling device 130 mounted on interior wall 52, in perspective view to show air circulation and in sectional view to show installation assembly. In Figure 3a, necessary connections are shown as coming up from below the interior wall 52 for illustration. Thermal

5 superconductor earth source loop 32 extends into the ground 30 and terminates in

coupler 28 above ground. The three connections to the cooling device 130 include a water drain line 24, a cooling device thermal superconductor segment 26 couplable to coupler 28, and power line 36 couplable to a controller (not shown) or power

supply/mains (not shown); the three are shown supported in conduit 38 that serves for

0 protection when exteriorly mounted, and fastening through wall opening 55. Thermal superconductor 26 may have insulation (not shown for clarity). Optionally controller (not shown) may be housed in housing 10 and powerline 36 is replaced by external powerline 12 (not shown). The conduit 38 is terminated at housing 10 and delivers the 3 services to the internal components. It will be obvious to one skilled in construction

!5 that the conduit could be routed or positioned at any point on the wall or routed partially on the interior side of the wall, or interior to the wall within the scope of the

embodiments, or alternatively, that the services contained in the conduit could be separately routed within or outside the structure. It will also be obvious from the disclosure of this invention that water drain line 24 could be eliminated in installations i0 where environmental conditions do not result in condensation sufficient to require collection and drainage. Housing 10 is secured to the wall, either by conduit 38 or by separate fasteners such as wall-anchors not shown, in a manner that meets building codes.

Housing 10 has inlet vents 53 underneath and outlet vents 54 at the room facing side, such that cooled air is circulated as shown by the arrows in Fig 3a. The fan 18 and thermal superconductor air exchanger 20 are positioned preferably at the outlet vent 54 and operated to pull the air from the inlet. Any arrangement of inlet and outlet can be configured on the exposed sides of the housing, but the preferred arrangement is shown. Additionally the controller 14 (not shown) and thermostat (not shown) can be enclosed in housing 10 and connected to power line 36 for operation, and as discussed previously various user controls may be provided on the housing exterior or by way of a remote control. Alternate versions may have the coupler 28 moved inside the housing 10, or along the conduit path between the ground 30 and housing 10. Alternatively, for ease of installation the conduit may have a conduit coupler (not shown) such that the geothermal cooling device 130 can be installed in stages. The integrated cooling device provides safety in that all wires and supply lines are less accessible and reduces installation costs as normal power wiring can be used, and the housing can be safely and quickly wall-mounted with common mechanical fasteners, without requiring reinforced supports or cutaways in the wall.

Figure 4 demonstrates a multiplexed version of the geothermal cooling device 140. A thermal superconductor ground loop 32 is coupled to two or more superconductor air exchangers 20 and 20a though two or more cooling device superconductor segments 26 and 26a with insulation 25 (as shown generally on above- grade superconductor transfer segments). Housings 42 and 42a respectively enclose the air exchangers 20, 20a, associated blowers 18, 18a and optional drip trays 22, 22a and optional drain lines 24,24a, and have inlet and outlet vents (not shown in schematic view). The controller 14, temperature sensor 16 and power line 12, while shown externally, can alternatively be housed in either of the housings 42, 42a, and connects to both blowers 18, 18a through power lines 37, 37a. The configuration as described allows for distributed cooling through a single thermostat, for example in a large interior space where one cooling device is inadequate. The operation would be as described previously. Alternate embodiments could have separate thermostat in each enclosure with separate set points for controlling each blower individually, or separate thermostat controller and sensor for each blower integrated into housings 42 and 42a.

In all the examples of geothermal cooling devices thus far, a thermostat has been used to control operation. The superconducting air exchanger can be effectively "cool" with no power and doesn't have to be "disconnected" from the ground loop. Therefore, for further parts reduction it may be desired to remove the thermostat and provide manual controls only, as shown in Figures 5, 6. In Figure 5, a geothermal cooling device 150 consists of enclosure 1C), cooling device superconductor segment 26 with insulation 25, superconductor air exchanger 20, blower 18, power line 12 to exterior power supply (not shown) and user operable switch 40 in series with power line 12 and power line 37 to switch fan off or on. When cooling device superconductor segment is coupled to thermal superconductor ground loop at coupler 28, heat is transferred from air exchanger 20 to earth 30 through the thermal superconductor, at a rate determined by blower operation and temperature differential. It will be appreciated in an alternate arrangement that blower 18 could be a multi-speed blower and switch 40 could be a variable control switch such that the user could control various speed settings.

Figure 6 varies from Figure 5 in that the switch 40 has been removed. External power line 12 is terminated in an electrical connection such as a plug, so that user operates the geothermal cooling device 160 by plugging or unplugging direct power to the blower of the geothermal cooling device 160.

Throughout these examples and embodiments described, insulation has been shown on superconductor segments designed for low thermal loss transfer (that is, not the ends of the superconductor segments), and is the preferred example, whether or not explicitly stated in figure descriptions or numbered on drawings. However, as noted previously, the cooling device described will operate with no insulation or with some transfer lines insulated or any combination of insulated or uninsulated portions of the superconductors thereof. Throughout these examples housing has been described as split housing in a preferred case, however it will be appreciated that the various embodiments can be integrated into existing structures or enclosed in a single housing.

Although particular embodiments of the invention have been described by way of example, it will be appreciated that additions, modifications and alternatives thereto may be envisaged. The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigates any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during the prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in the specific combinations enumerated in the claims.

Claims

What is claimed is:

1. A cooling device suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source, the device comprising:

(a) a thermal superconductor having a first end couplable to said thermal superconductor geothermal ground coil and a second opposing end configured as a thermal superconductor exchange segment; (b) a blower positioned in the region of said thermal superconducting

exchange segment;

(c) a thermostat controller associated with an indoor space, programmable to a desired temperature set point and for measuring temperature of said indoor space and further having a blower controller connected to said blower;

wherein said blower controller operate said blower in response to the difference between said set point and said measured temperature, for the purpose of operating in a cooling mode to efficiently cool an indoor space.

2. The cooling device of claim 1 , further comprising at least one geothermal ground coil formed from a thermal superconductor material and extending below ground level allowing passive thermal conduction to the earth source and thermally coupled to said above ground thermal superconductor segment.

3. The cooling device of claim 1 , wherein said thermal superconductor material is an inorganic high heat transfer medium.

4. The cooling device of claim 1 , wherein said high heat transfer medium is applied in a sealed heat transfer pipe.

5. The Cooling device of claim 4, wherein said thermal superconductors are heat transfer pipes containing said high heat transfer medium, and insulated along at least a portion of heat transfer segment, said heat transfer pipes having thermal conductivity greater than 100 times the thermal conductivity of silver and substantially negligible heat loss along said heat transfer segment.

6. The cooling device of claim 1 , further comprising a power conditioner connected to said blower and said thermostat controller.

7. The cooling device of claim 6, wherein said power conditioner is a power converter couplable to an alternative energy source, one selected from the group of photovoltaic arrays, wind generators and fuel cells.

8. The cooling device of claim 7, wherein said power conditioner is a power converter couplable to 110V AC power and converting AC to DC supply for operating said cooling device.

9. The cooling device of claim 7, wherein said power converter includes a power conditioning circuit for converting low grade alternative power from an alternative energy source to conditioned power suitable to operate said blower.

10. The cooling device of claim 1 , wherein said blower operates in one of a variable or multispeed mode as controlled by said blower controller.

11. The cooling device of claim 1 , wherein at least a portion of said thermal superconductors are formed in discrete segments joined by substantially short thermally conducting joiners.

12. The cooling device of claim 1 , wherein said first thermal superconductor exchange segment is arranged as a condenser array with area substantially

corresponding to said blower area for increased air heat exchange.

13. The cooling device of claim 1 , further comprising a receiver connected to said thermostat controller and a remote control in communication with said receiver such that thermostat set points and operations are wirelessly controllable.

14. The cooling device of claim 1 , wherein a segment of said heat exchange coil is arranged as a thermal conductor bus with a plurality of said first thermal superconductor segments.

15. The cooling device of claim 14, further comprising a plurality of blowers positioned proximal to each of said first thermal superconductor exchange segments and connected to said blower controller, such that said cooling device provides a plurality of exchanges associated with a plurality of locations within a structure.

16. The cooling device of claim 15, further comprising multiple thermal sensors associated with said plurality of locations and connected to said thermostat controller to provide temperature measurements associated with each location.

17. The cooling device of claim 1 , further comprising an enclosure which houses said controller, said heat exchanger, said thermal superconductor exchange segment, a blower positioned proximal to said segment, said enclosure having venting near said blower.

18. The cooling device of claim 2, wherein said earth source is a body of water.

19. The cooling device of claim 18, wherein said geothermal ground coil is suspended in said body of water.

20. The cooling device of claim 18, wherein said geothermal ground coil is in indirect thermal contact with said source water.

21. The cooling device of claim 15, wherein said thermostat controller is programmable to independently vary the speed or operation of individual blowers.

22. A cooling device suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source, the device comprising; (a) a thermal superconductor having a first end couplable to said thermal superconductor geothermal ground coil and a second opposing end configured as a thermal superconductor exchange segment,

(b) a blower positioned in the region of said thermal superconducting

exchange segment;

(c) a power connection for providing operating power to said blower when connected; and

(d) a switch connected to said power connection and said blower for

controlling said blower;

wherein said blower may be manually controlled for the purpose of operating in a cooling mode to efficiently cool an indoor space.

23. The cooling device of claim 22, wherein said blower operates in one of an off or on mode.

24. The cooling device of claim 23, wherein said blower operates in a variable speed mode and said switch is a variable switch.

25. The cooling device of claim 22, further comprising a receiver connected to said switch and a remote control in communication with said receiver such that blower operation is wirelessly controllable.

26. The cooling device of claim 22, further comprising at least one geothermal ground coil formed from a thermal superconductor material and extending below ground level allowing passive thermal conduction to the earth source and thermally coupled to said above ground thermal superconductor segment.

27. The cooling device of claim 22, wherein said thermal superconductor material is an inorganic high heat transfer medium.

28. The cooling device of claim 22, wherein said high heat transfer medium is applied in a sealed heat transfer pipe.

29. The cooling device of claim 28, wherein said thermal superconductors are heat transfer pipes containing said high heat transfer medium, and insulated along at least a portion of heat transfer segment, said heat transfer pipes having thermal conductivity greater than 100 times the thermal conductivity of silver and substantially negligible heat loss along said heat transfer segment.

30. The cooling device of claim 22, further comprising a power conditioner connected to said blower.

31. The cooling device of claim 30, wherein said power conditioner is a power converter couplable to an alternative energy source, one selected from the group of photovoltaic arrays, wind generators and fuel cells.

32. The cooling device of claim 31 , wherein said power conditioner is a power converter couplable to 110V AC power and converting AC to DC supply for operating said cooling device.

33. The cooling device of claim 31 , wherein said power converter includes a power conditioning circuit for converting low grade alternative power from an alternative energy source to conditioned power suitable to operate said blower.

34. The cooling device of claim 22, wherein at least a portion of said thermal superconductors are formed in discrete segments joined by substantially short thermally conducting joiners.

35. The cooling device of claim 22, wherein said first thermal superconductor exchange segment is arranged as a condenser array with area substantially

corresponding to said blower area for increased air heat exchange.

36. The cooling device of claim 22, wherein a segment of said heat exchange coil is arranged as a thermal conductor bus with a plurality of said first thermal superconductor segments.

37. The cooling device of claim 36, further comprising a plurality of blowers positioned proximal to each of said first thermal superconductor exchange segments and connected to said switch and power connection, such that said cooling device provides a plurality of exchanges associated with a plurality of locations within a structure.

38. The cooling device of claim 22, further comprising an enclosure which houses said switch, said heat exchanger and said thermal superconductor exchange segment, a blower positioned proximal to said segment, said enclosure having venting near said blower.

39. The cooling device of claim 26, wherein said earth source is a body of water.

40. The cooling device of claim 39, wherein said geothermal ground coil is suspended in said body of water.

41. The cooling device of claim 38, wherein said geothermal ground coil is in indirect thermal contact with said source water.

42. A cooling device suitable for coupling to a thermal superconductor geothermal ground coil extending below a ground level allowing passive thermal conduction to an earth source and for connecting to a power source, the device comprising;

exchange segment;

(c) a power connection for providing operating power to said blower when connected; wherein said blower is capable of being powered by connecting said external power connector to said power source, for the purpose of operating in a cooling mode to efficiently cool an indoor space.

43. The cooling device of claim 42, further comprising an enclosure which houses said thermal superconductor exchange segment, a blower positioned proximal to said segment, and a power connection, said enclosure having venting near said blower and wherein said power connection has at least one connector disposed external to said housing for connecting to an external power supply.

44. The cooling device of claim 42, further comprising at least one geothermal ground coil formed from a thermal superconductor material and extending below ground level allowing passive thermal conduction to the earth source and thermally coupled to said above ground thermal superconductor segment.

45. The cooling device of claim 42, wherein said thermal superconductor material is an inorganic high heat transfer medium.

46. The cooling device of claim 45, wherein said high heat transfer medium is applied in a sealed heat transfer pipe.

47. The cooling device of claim 46, wherein said thermal superconductors are heat transfer pipes containing said high heat transfer medium, and insulated along at least a portion of heat transfer segment, said heat transfer pipes having thermal conductivity greater than 100 times the thermal conductivity of silver and substantially negligible heat loss along said heat transfer segment.

48. The cooling device of claim 42, further comprising a power conditioner connected to said blower.

49. The cooling device of claim 48, wherein said power conditioner is a power converter couplable to an alternative energy source, one selected from the group of photovoltaic arrays, wind generators and fuel cells.

50. The cooling device of claim 49, wherein said power conditioner is a power converter couplable to 110V AC power and converting AC to DC supply for operating said cooling device.

51. The cooling device of claim 49, wherein said power converter includes a power conditioning circuit for converting low grade alternative power from an alternative energy source to conditioned power suitable to operate said blower.

52. The cooling device of claim 42, wherein at least a portion of said thermal superconductors are formed in discrete segments joined by substantially short thermally conducting joiners.

53. The cooling device of claim 42, wherein said first thermal superconductor exchange segment is arranged as a condenser array with area substantially

corresponding to said blower area for increased air heat exchange.

54. The cooling device of claim 42, wherein a segment of said heat exchange coil is arranged as a thermal conductor bus with a plurality of said first thermal superconductor segments.

55. The cooling device of claim 54, further comprising a plurality of blowers positioned proximal to each of said first thermal superconductor exchange segments and connectable to said power connection, such that said cooling device provides a plurality of exchanges associated with a plurality of locations within a structure.

56. The cooling device of claim 42, further comprising an enclosure which houses said heat exchanger, said thermal superconductor exchange segment, a blower positioned proximal to said segment, said enclosure having venting near said blower.

57. The cooling device of claim 44, wherein said earth source is a body of water.

58. The cooling device of claim 57, wherein said geothermal ground coil is suspended in said body of water.

59. The cooling device of claim 58, wherein said geothermal ground coil is in indirect thermal contact with said source water.