GROUND-TO-AIR HEAT PUMP SYSTEM
A ground to air heat pump unit operable to receive a first working fluid and transfer heat between the first working fluid and a second working fluid. The ground to air heat pump unit is operable to return the first working fluid to a channel and further operable to return the second working fluid to a living space.
The present application claims the benefit of U.S. Provisional Patent Application No. 61/243,445, filed Sep. 17, 2009, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTIONThe present application relates generally to energy transfer to or from a living space and/or to heat water. More particularly, but not exclusively, the present application relates to using the ground as a heat source and/or heat sink in a HVAC system to condition the living environment.
BACKGROUNDIn modern buildings heating, ventilating, and air conditioning (“HVAC”) systems are common to maintain the temperature inside the building at a comfortable level. These HVAC systems can be designed in a variety of ways including using the outside air or the Earth as a heat source or heat sink. The technical community recognizes that certain inefficiencies and cost constraints exist in prior art HVAC systems.
SUMMARYOne embodiment of the present invention includes a unique technique involving heating and/or cooling for buildings and/or water heaters. Other embodiments include unique methods, systems, devices, and apparatus involving heating and/or cooling. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
The heat pump 12 includes a heating unit 24 and a conditioning unit 26. Although the heat pump 12 of
The operation of a heat pump is well known to one of ordinary skill in the art. A typical heat pump includes four stages. In the first stage, a working fluid, such as a refrigerant, is compressed by a compressor into a relatively high pressure, superheated gas. In the second stage, the relatively high pressure superheated gas is condensed by a condenser, which is a heat exchanger. After passing through the condenser, the refrigerant is in a relatively high pressure subcooled liquid form. In the third stage, the refrigerant passes through an expansion valve, which lowers the pressure and raises the temperature of the refrigerant. In the fourth stage, the relatively low pressure superheated gas passes through another heat exchanger, such as coils, called an evaporator in which the refrigerant evaporates into a gas through heat absorption. The cycle is then repeated.
A working fluid channel/plenum 30 is formed between an outer wall 32 and an inner wall 34. In one embodiment, the outer wall 32 is the concrete basement wall 20. The inner wall 34 may be formed from insulated wall material, drywall, fiberglass board or other suitable material know to one of skill in the art for making interior wall structures. It is also contemplated that the basement walls 32 may be lined with a material as long as the material allows heat/energy to be transferred between wall 32 and the working fluid/air in the channel 30. In one form of the present application the distance between the outer wall 32 and inner wall 34 is about four (4) inches. However, in another form of the present application the distance between the outer wall 32 and inner wall 34 may be in a range from about one (1) inch to about six (6) inches. However, the present application contemplates other wall spacing unless specifically provided to the contrary. The present application contemplates a variety of types and dimensions associated with inner wall 34 and it one non-limiting form the inner wall 34 is approximately two (2) inches thick.
In one form the channel/plenum 30 defines a substantially sealed environment and in another form the channel/plenum 30 is a sealed environment. Many means to create a sealed environment are contemplated herein and in one form the channel/plenum is sealed on at the top 36 and the bottom 38 using headers 40, which may be formed from the same or different materials as used to fabricate the inner wall 34. The headers 40 seal the channel 30 such that air generally cannot enter or escape the channel 30. An opening 42 in the channel/plenum 30 allows air to flow through the heat pump 12 and back inside the channel 30. Thus, the air inside the channel 30 flows in a closed loop through the heat pump 12. As previously discussed, in one embodiment the channel 30 is hermetically sealed. While, in another embodiment, the channel 30 is not hermetically sealed, but it is substantially sealed such that little, if any, air enters or escapes the channel 30. Keeping the channel 30 sealed maintains the temperature of the air inside the channel 30 near or at the same temperature as the ground 18 and basement wall 20. It is contemplated that from time-to-time the air inside the channel 30 may be purged either outside or into the basement.
At a depth of about 1.5 to 3 meters (6 to 10 feet) below the surface, the ground 18 remains at a relatively constant temperature between 45° F. (7° C.) to 73° F. (23° C.). Thus, the heat/energy from the ground 18 will be transferred through the concrete walls 20 to heat the cooled air from the heating unit 24. As discussed previously, the present application fully contemplates the direction of heat/energy being transferred from the ground 18 to the walls 32 and/or from the walls 32 to the ground 18. A person of ordinary skill in the art will understand that convective heat transfer is a mechanism for transfer of energy/heat between the working fluid/air within the channel/plenum 30 and the walls 32.
During the heating mode, a refrigerant in a relatively low pressure superheated gas state 52 flows from the coils 46 in the heating unit 24 into a four-way reversing valve 54. The four-way reversing valve 54 allows the heat pump 12 to operate either in a heating mode or a cooling mode by routing the refrigerant to the proper components of the heat pump 12. It is contemplated that other valves or devices may be used to allow the heat pump 12 to operate in either a heating mode or a cooling mode as known by those skilled in the art. The four-way reversing valve 54 routes refrigerant into the compressor 59 where the relatively low pressure superheated gas 52 is compressed into a relatively high pressure superheated gas 56. The four-way reversing valve 54 then routes the refrigerant 56 (in its high pressure superheated gas state) to the coils 58 in a conditioning unit 26.
The conditioning unit 26 receives relatively cool air from a source, such as but not limited to the living space 60 of the building 16 or from external to the building 16. As the relatively cool air flows over the coils 58, the refrigerant 56, in its relatively high pressure superheated gas state, is condensed into a relatively high pressure subcooled liquid 62. Heat/energy is given off by the refrigerant 56 and is transferred from the refrigerant in the coils 58 to the air, which increases the air's temperature. The relatively high pressure subcooled liquid 62 refrigerant then flows out of the coils 58 in the conditioning unit 26 and through the check valve 64. In the heating mode, the coils 58 in the conditioning unit 26 are operating as a condenser.
As the relatively high pressure subcooled liquid 62 flows from the conditioning unit 26 into the heating unit 24, it passes through a thermal expansion valve 66, metering device, or capillary tubes that allow the relatively high pressure subcooled liquid 62 to expand. The refrigerant then flows into the coils 46 of the heating unit 24. In the heating unit 24, as warm air flows over the coils 46, the refrigerant inside the coils 46 absorbs heat/energy from the warm air and is evaporated into a relatively low pressure superheated gas 52 and the process repeats itself. In the heating mode, the coils 46 in the heating unit 24 are operating as an evaporator.
One of ordinary skill in the art will recognize that he relatively high pressure superheated gas 56, the relatively high pressure subcooled liquid 62, and the relatively low pressure superheated gas 52 are all different phases of a refrigerant.
Turning to the conditioning unit 26 in
As described above, the air flowing through the plenum/channel 30 is in a closed loop and sealed off from ambient air in the basement 14, the living space 60, or from outside 70. The closed loop maintains the air temperature in the plenum/channel 30 at a more consistent temperature as heat is transferred between the ground 18 the walls 20 and the air inside the channel 30.
Once the heated air is in the channel 30, the basement walls 20 absorb heat/energy from the air and transfer the heat/energy to the ground 18. As in the heating mode, the basement walls 20 are in geothermal communication with the ground 18. The operation of the heating unit 24 and conditioning unit 26 is similar to the previous heating mode. However, in the cooling mode, the coils 46 of the heating unit are operating as a condenser and the coils 58 of the conditioning unit 26 are operating as an evaporator.
In the cooling mode, the refrigerant, in its relatively high pressure subcooled liquid state 62, flows out of the coils 46 in the heating unit and through a check valve 72. The refrigerant then flows into the conditioning unit 26. In the conditioning unit 26, the relatively high pressure subcooled liquid 62 flows through a thermal expansion valve 74 which lowers the pressure of the refrigerant.
The refrigerant flows through the coils 58 in the conditioning unit 26. During this time relatively warm air from the living space 60 flows over the coils 58 allowing heat to be transferred from the air to the refrigerant in the coils 58. The refrigerant then becomes a relatively low pressure superheated gas 52 as it exits the coils 58. This relatively low pressure superheated gas 52 flows from the conditioning unit 26 into the four-way reversing valve 54 where it is routed to the compressor 59.
The compressor 59 compresses the relatively low pressure superheated gas 52 into a relatively high pressure superheated gas 56 which then flows into the four-way reversing valve 54. The four-way reversing valve 54 routes the relatively high pressure superheated gas 56 to the coils 46 in the heating unit 24. As the refrigerant, in its relatively high pressure superheated gas state 56, flows through the coils 46, relatively cool air flows over the coils 46 from the channel 30. This allows heat/energy to be transferred from the refrigerant in the coils 46 to the relatively cool air flowing over the coils 46. As the refrigerant leaves the coils 46, the refrigerant is now in the form of a relatively high pressure subcooled liquid 62 and the process repeats itself. In the conditioning unit 26, after the heat laden air flows over the coils 58 the air temperature is lowered and the cooled air is returned to the living space 60 using a blower 68.
The heat pump 28 includes a blower 48 in order to move air through the heat pump 28 and throughout the channel 30. Blower 48 is specifically used to provide the necessary motive force to move the air throughout the channel 30.
The heating unit 24 operates in the same manner as it does in the heating operation mode as described with reference to
By using a three-way valve 84 as in the embodiment shown in
The heat pumps described in this application operate as air-to-air heat pumps. This is because the heat pumps absorb heat from the air in the channel 30 and transfer that heat to air in the living space 60. The concrete basement walls 20 operate as a geothermal heat source and heat sink depending on the mode of operation. In the heating mode, the walls 20 operate as a geothermal heat source because heat from the ground 18 is transferred from the ground 18 through the basement walls 20 by conduction and then to the air in the channel 30 by convection. During the cooling mode, the basement walls 20 are operating as a geothermal heat sink because heat from the air in the channel 30 is transferred by convection to the basement walls 20 and then by conduction to the ground 18 from the basement walls 20.
The valves in this application may be actuated in any manner including by hydraulic, pneumatic, manual, solenoid, or motor. It is contemplated that other valves or other fluid regulation devices may be used in place of the four-way reversing valve 54 or the three-way ball valve 84 as known to those ordinarily skilled in the art.
One aspect of the present application contemplates the following:
The method of utilizing a masonry or concrete exterior wall of a building as a condensing heat exchange medium in a vapor compression cycle, wherein condensing air circulating in a closed loop flows through condensing coils absorbing heat and across the interior surface of a masonry or concrete wall giving up heat to the wall mass, whereby heat is absorbed by the wall mass and conducted to the wall's exterior surface in thermal continuity with the earth and absorbed therein.
The present application relates to heretofore unknown method of utilizing a masonry or concrete exterior wall of a building as a condensing heat exchange medium in a vapor compression cycle, wherein condensing air circulating in a closed loop flows through condensing coils absorbing heat and across the interior surface of a masonry or concrete wall giving up heat to the wall mass, whereby heat is absorbed by the wall mass and conducted to the wall's exterior surface in thermal continuity with the earth and absorbed therein.
The method provides a relatively constant moderate temperature heat exchange medium wherein the vapor compression cycle operates at lower condensing temperature/pressure reducing compressor motor electrical power consumption. The higher the pressure to which a gas is compressed the more power required by the compressor motor to motivate the gas thereby consuming more energy.
Conventional air-cooled refrigeration and air conditioning condensers utilize outdoor ambient air as a heat exchange medium. Although this method has been in use since inception of air-cooled condensers it is nevertheless extraordinarily inefficient. The reason being that in order for there to be an exchange of heat from a condensing unit's condensing coils to outdoor ambient air there must be a temperature differential, that is, the condensing coils must be at a higher temperature than outdoor ambient air flowing over them, thus, the higher the outdoor ambient air temperature the higher the necessary condensing temperature. The consequence of higher condensing temperature is higher condensing pressure (head pressure) resulting in greater the energy consumption.
In one aspect conventional air-cooled condensers are capable of operating within a wide outdoor ambient air temperature span, typically between 70° F. (21° C.) to 110° F. (43° C.). Consider a conventional air-cooled condensing unit (utilizing refrigerant R-410A) operating at 70° F. (21° C.). At 70° F. the corresponding condensing pressure (head pressure) is 201 psig. The same condensing unit operating at 110° F. (43.3° C.), which is the standard design condition, the corresponding condensing pressure is 365 psig. Operating at 201 psig head pressure is more efficient than at 365 psig, in fact 45% more efficient. This is merely one non-limiting example of aspects of a conventional air-cooled condenser.
At a depth of about 1.5 to 3 m (6 to 10 feet) the earth remains at a relatively constant temperature between 45° F. (7° C.) to 73° F. (23° C.) which at its worst will provide 70° F. condensing temperature. The method may also be applicable to air-source heat pumps provided certain technical issues relating to frosting and icing can be overcome.
Referring to
Wall surface mounted heat exchange enclosure 800 comprises elements 120, 150, 170, 210 and space 140. Element 120 is a substantially rigid insulation board or similar material forming the outer wall surface of said wall surface mounted heat exchange enclosure 800. Element 170 and 170a is constructed of sheet metal, or equivalent material, formed to provide a top, bottom and end cap, wherein in combination with element 120 and wall surface 1000 form a substantially air tight space 140, air space 140 depth about 1 to 2 inches. Element 210 is a metallic material formed to function as a thermal heat sink to promote efficient heat transfer between air circulating through air space 140 and in thermal continuity contact with wall surface 100. Wall surface mounted heat exchange enclosure 800 air space 140 being further subdivided top to bottom by partition 150 into upper air flow chamber 180a and lower air flow chamber 180b said partition 150 being open at end 190 to allow air flow to crossover from said upper chamber 180a to lower chamber 180b as depicted by arrow 160.
Referring to
The required surface area of wall 1000 per unit of cooling capacity is calculated based on the thermal conductivity of concrete and earth (ground). Thermal Conductivity is the specific travel rate that heat moves through a material. The travel rate is dependent upon the material itself. Some materials allow heat to move quickly through them while others very slowly. When heat is applied to a portion of a material, that heat will move through the material. The composition of the atoms of that material will determine the rate of travel. For instance, heat moves very quickly through a metal spoon. Placing one end of the spoon in boiling water will make the entire spoon hot very quickly. Additionally, according to the Second Law of Thermodynamics, when two objects of different temperature contact one another there is an exchange of thermal energy. This exchange is known as heat of conduction, wherein heat flows from the warmer object into the cooler object.
The thermal energy of an object is a measure of the speed of the object's particles. When two objects of different temperatures come into contact with one another, the faster moving particles collide with the slower moving particles, and energy is exchanged. The faster moving particles give up some energy and therefore slow down and the slower moving particles gain some energy and therefore speed up. This process, known as heat conduction, continues until temperature equilibrium is reached. This equilibrium temperature must be somewhere in between the two objects' original temperatures. Therefore, the warmer object cools and the cooler object warms. The thermal current is directly proportional to a material's coefficient of thermal conductivity.
The Coefficient of Thermal Conductivity of concrete stated in the ‘Trane Air Conditioning Manual’ is 12 Btu/in/hr/° F. Generally, concrete and the ground have about the same coefficient of thermal conductivity. Thus, at 10° F. delta-T we get 12 Btu/lin/hr/° F./10° F.=120 Btu/ft°/hr wherein thickness factor (in) in the formula is ignored because wall (110) in contact with the ground (220) combines to form a heat sink of infinite thickness. Thus, dividing a unit of cooling capacity, i.e. 12,000 Btu/hr by 120 Btu/hr/ft2 we get 100 ft2 of required wall surface area (1000) per ton of capacity. Dividing 100 ft2 by 7 foot high wall (typical) equals 14.3 linear feet of wall (110) per ton of cooling capacity.
At a depth of about 1.5 to 3 m (6 to 10 feet) the earth remains at a relatively constant temperature between 45° F. (7° C.) to 73° F. (23° C.) for an average of about 59° F. Thus, adding 10° F. delta-T would provide 69° F. air flowing across wall surface mounted heat exchange enclosure (800). Referring to an R-41OA P/T chart (Pressure/Temperature) we find that 69° F. equates to 200 psig condensing pressure. In contrast, a conventional air-cooled condenser at 110° F. design condensing temperature will be operating at 365 psig. Thus, 200 psig divided by 365 psig equals a significant 45% reduction in compressor load and corresponding reduction in energy consumption.
Of course, as outdoor temperature drops the percent of decrease in energy consumption diminishes accordingly until equal with ground temperature where there is no further decrease. However, at outdoor ambient temperatures even a few degrees above ground temperature there is a worthwhile reduction in percent, i.e., per the above example: at 79° F. outdoor ambient temperature the conventional unit condensing pressure would be 234 psig, thus, dividing 200 psig (from above) by 234 psig would still yield a worthwhile 15% reduction in electrical energy.
In one embodiment, an apparatus for removing heat of condensation from the discharge air of an air-cooled refrigeration condenser is provided which includes a air-cooled refrigeration condensing unit adapted to include an air inlet plenum and air outlet plenum for connecting to a heat exchange means; and a heat exchange means adapted to include an air-inlet means and air-outlet means for connecting to said air-inlet plenum and air-outlet plenum of said air-cooled refrigeration unit. The heat exchange means may further includes an outer wall means. Furthermore, the outer wall means may be a substantially ridged material. The substantially ridged material may be a substantially insulating material. The heat exchange means may include a top and bottom cover means and side cover means. The top and bottom cover means and side cover means may be substantially ridged material. The heat exchange means may include a heat sink means. The heat sink means may be a metallic material. The heat exchange means may further include a partition dividing the heat exchange means into at least two interconnected parts. The partition may be open at one end. The partition is optional. Another embodiment includes a method of removing heat of condensation from the discharge air of an air-cooled refrigeration condenser.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.
Claims
1. A climate control system for a building, comprising:
- a closed loop fluid flow channel containing a first gaseous working fluid in geothermal communication with ground proximate the building; at least a portion of the channel disposed beneath the ground and proximate an outer wall of the building foundation; and
- a heat exchange unit operable to receive the first gaseous working fluid from the channel and transfer heat between the first working fluid and a second working fluid, the unit operable to return the first working fluid to the channel and the second working fluid to a living space for conditioning the air in the living space.
2. The system of claim 1, wherein the unit is a heat pump.
3. The system of claim 1, wherein the channel is formed between an inner wall and the outer wall, said outer wall disposed in a conductive heat transfer relationship with the ground, and wherein the first working fluid in a convective heat transfer relationship with said outer wall.
4. The system of claim 3, wherein said outer wall defines at least a portion of the perimeter of a basement.
5. The system of claim 4, wherein the channel is located within the basement of the building.
6. The system of claim 4, wherein said the inner wall includes one of an insulated wall, a drywall sheathed structure and a fiberglass board.
7. The system of claim 4, wherein the inner wall and the outer wall are separated by approximately one to six inches.
8. The system of claim 1, wherein the first and second working fluids are air.
9. The system of claim 2, wherein the heat pump is operable to heat and/or cool the second working fluid.
10. The system of claim 1, further comprising a hot water tank.
11. The system of claim 10, wherein the hot water tank is in fluid communication with the unit and the unit transfers heat to water within the hot water tank.
12. The system of claim 10, further comprising:
- a hot water heat pump operable to receive the first working fluid from the channel, transfer heat to the first working fluid, and return the first working fluid to the channel; and
- the hot water heat pump operable to transfer heat to the water within the hot water tank.
13. The system of claim 1, wherein the unit is a heat pump having a heating mode and a cooling mode;
- wherein the channel is formed between an inner wall and the outer wall and located within the basement of the building, said outer wall disposed in a conductive heat transfer relationship with the ground;
- wherein the first and second working fluids are air; and
- wherein said heat pump is located within the basement of the building.
14. The system of claim 1, wherein the channel defines a hermetically sealed fluid flow path.
15. The system of claim 1, which further includes an access for selectively purging a quantity of the first working fluid from the channel.
16. A ground to air heat pump apparatus, comprising:
- a heat pump including an inlet port, an outlet port and a blower for moving air between the inlet port and the outlet port;
- the inlet port is structured to be coupled to a closed-loop, air-flow channel disposed in geothermal communication with a ground; and
- the outlet port is structured to be coupled to the air-flow channel.
17. The apparatus of claim 16, further comprising a hot water tank, wherein a heat exchanger in the hot water tank is in fluid communication with the heat pump and the heat pump transfers heat to the heat exchanger to heat water within the hot water tank.
18. A method, comprising:
- flowing air within a closed-loop, air-flow channel that is in geothermal communication with ground proximate a building;
- transferring energy between the air and the ground;
- flowing air from the channel to a heat pump;
- operating the heat pump to transfer energy between the air and a working fluid utilized to condition a living space within the building;
- returning the air to the air-flow channel; and
- returning the working fluid to the living space to condition the environment within the living space.
19. The method of claim 18, wherein said flowing occurring between a concrete basement wall and an inner wall; and
- wherein said transferring includes convective heat transfer between the basement wall and the air and conductive heat transfer between the basement wall and the ground.
20. The method of claim 18, wherein said operating includes the capability to cool and/or heat the working fluid.
21. The method of claim 18, further comprising placing the heat pump in fluid communications with a hot water tank;
- further operating the heat pump to transfer energy via a heat exchanger within the hot water tank to water within the hot water tank.
22. An apparatus, comprising:
- channel means for retaining channel air and transferring heat between the channel air and ground adjacent a portion of a foundation of a building; and
- environmental conditioning means for receiving the channel air and transferring heat between the channel air and a living space air within the building, and returning the channel air to the channel means.
23. The apparatus of claim 24, wherein the channel means and environmental conditioning means are all substantially underground.
24. The method of claim 23, further comprising:
- means for transferring heat to water inside a hot water tank, wherein the means is in fluid communication with the heating means.
Type: Application
Filed: Sep 9, 2010
Publication Date: Mar 17, 2011
Inventor: Luther D. Albertson (Sellersburg, IN)
Application Number: 12/878,699
International Classification: F24J 3/08 (20060101); F24F 7/00 (20060101); F24F 3/00 (20060101);