Title:
Air processor and system for heating and cooling
Kind Code:
A1


Abstract:
A heating and cooling system including an air processor, a compression subsystem, a heat box, a recuperator, and an operating system. The air processor includes a pre-conditioner, a drenched coil and a post conditioner. The heat box includes a refrigerant line in fluid communication with the compression subsystem, a heat exchange line, and a series of motorized shutters. The recuperator includes a thermal storage means, a supply pump and at least two heat exchange lines.



Inventors:
Sporie, George (Strafford, NH, US)
Application Number:
12/218861
Publication Date:
01/21/2010
Filing Date:
07/18/2008
Primary Class:
Other Classes:
165/104.34, 126/569
International Classes:
F25B29/00; F24J2/00; F28D15/00
View Patent Images:
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Primary Examiner:
RUBY, TRAVIS C
Attorney, Agent or Firm:
Lawson & Persson, P.C. (Laconia, NH, US)
Claims:
What is claimed is:

1. An air processor for use in a heating and cooling system, said air processor comprising: a housing comprising a top, a bottom, a coil section and an air output section; an air inlet in communication with said top of said housing; a bypass damper in communication with said air inlet and said air output section of said housing; a preconditioning coil chamber disposed within said coil section of said housing and proximate to said air inlet, said preconditioning coil chamber comprising a first portion of a refrigerant coil in communication with a source of refrigerant and a first portion of a thermal return coil; a coil drenching spray system disposed within said coil section of said housing between said at least one humidification nozzle and said bottom of said housing, said coil drenching spray system comprising a spray sump dimensioned to hold a volume of water, a recirculatory spray pump in fluid communication with said spray sump, a drenched coil comprising a refrigerant inlet in communication with said source of refrigerant and a refrigerant outlet, and at least one spray nozzle in communication with said recirculatory spray pump and disposed over said drenched coil such that water sprayed from said at least one nozzle contacts said drenched coil; a post-conditioning chamber disposed within said air output section between said bottom of said housing and said bypass damper, said post-conditioning chamber comprising a second portion of said thermal return coil and a first stage heating coil in communication with a source of heat transfer fluid; and a processed air outlet disposed within said air output section of said housing between said bypass damper and said post-conditioning chamber.

2. The air processor as claimed in claim 1 further comprising at least one ultraviolet emitter disposed within said coil section of said housing between said preconditioning coil chamber and said bottom or said housing.

3. The air processor as claimed in claim 1 further comprising at least one humidification nozzle disposed within said coil section of said housing between said at least one ultraviolet emitter and said bottom of said housing, said at least one humidification nozzle comprising a connector for connection to a supply of high purity water.

4. The air processor as claimed in claim 1 further comprising a filter section.

5. The air processor as claimed in claim 4 wherein said filter section comprises a pre-filter and a final filter.

6. The air processor as claimed in claim 1 further comprising at least one evaporative cooling nozzle disposed within said air output section between said bypass damper and said processed air outlet, wherein said at least one evaporative cooling nozzle comprises a connector for connection to a supply of high purity water.

7. The air processor as claimed in claim 1 further comprising a supply fan in fluid communication with said processed air outlet.

8. The air processor as claimed in claim 1 further comprising at least one electric heater.

9. The air processor as claimed in claim 8 comprising a first electric heater disposed within said coil section of said housing between said recirculatory spray system and said top of said housing and a second electric heater disposed within said processed air outlet.

10. The air processor as claimed in claim 1 wherein said spray sump further comprises a inlet control valve for attachment to a potable water line and a drain control valve for attachment to a drain line.

11. The air processor as claimed in claim 1 further comprising a fresh air inlet and an economizer damper disposed between said fresh air inlet and said air output section of said housing.

12. A heating and cooling system comprising: an air processor comprising: a housing comprising a top, a bottom, a coil section and an air output section; an air inlet in communication with said top of said housing; a bypass damper in communication with said air inlet and said air output section of said housing; a preconditioning coil chamber disposed within said coil section of said housing and proximate to said air inlet, said preconditioning coil chamber comprising a first portion of a refrigerant coil and a first portion of a thermal return coil; a coil drenching spray system disposed within said coil section of said housing between said at least one humidification nozzle and said bottom of said housing, said coil drenching spray system comprising a spray sump dimensioned to hold a volume of water, a recirculatory spray pump in fluid communication with said spray sump, a drenched coil comprising a refrigerant inlet and outlet, and at least one spray nozzle in communication with said recirculatory spray pump and disposed over said drenched coil such that water sprayed from said at least one nozzle contacts said drenched coil; a post-conditioning chamber disposed within said air output section between said bottom of said housing and said bypass damper, said post-conditioning chamber comprising a second portion of said refrigerant coil and a second portion of said thermal return coil; and a processed air outlet disposed within said air output section of said housing between said bypass damper and said post-conditioning chamber; a compression subsystem in communication with said air processor, said compression subsystem comprising and accumulator, a compressor, a reversing valve and at least one refrigerant line; a heat box comprising a refrigerant line in fluid communication with said at least one refrigerant line of said compression subsystem, a heat exchange line and a series of motorized shutters; a recuperator comprising a thermal storage means, a supply pump and at least two heat exchange lines, wherein a first heat exchange line is in fluid communication with said heat exchange line of said heat box and wherein said second heat exchange line is in communication with said air processor; and an operating system in electrical communication with said air processor, said compression subsystem, said heat box and said recuperator, wherein said operating system comprises at least one input from at least one user control, an internal temperature sensor and an external temperature sensor, a processor comprising a computer program product for processing user and temperature information and determining an appropriate system operating condition based upon said user and temperature information, and at least one output to each of said air processor, said compression subsystem, said heat box and said recuperator.

13. The heating and cooling system as claimed in claim 12 wherein said heat box further comprises a fan disposed such that air may be blown over said refrigerant line and said heat exchange line and wherein said output from said computer program product of said operating system controls an operation of said motorized shutters and said fan,

14. The heating and cooling system as claimed in claim 13 wherein said heat box further comprises a plurality of conductive plates attached to, and in heat conducting relation to, aid refrigerant line and said heat exchange line.

15. The heating and cooling system as claimed in claim 12 further comprising at least one of a potable water heater and a radiant heat water heater in communication with said heat exchange line of said heat box, wherein said output from said computer program product of said operating system controls a flow of heat transfer fluid from said heat box to at least one of said potable water heater and said radiant heat water heater when said system is in a cooling mode of operation.

16. The heating and cooling system as claimed in claim 12 wherein said recuperator further comprises at least one solar collector array in fluid communication with said thermal storage means.

17. The heating and cooling system as claimed in claim 12 further comprising an ice storage unit through which a heat transfer fluid line is disposed, wherein said heat transfer fluid line is in fluid communication with said air processor.

18. The heating and cooling system as claimed in claim 17 further comprising a coaxial chiller, wherein said heat transfer fluid line is disposed through said coaxial chiller and said ice storage unit and wherein said coaxial chiller is disposed relative to said ice storage unit such that a heat transfer fluid passing through said heat transfer fluid line passes through said coaxial chiller before passing through said ice storage unit.

19. The heating and cooling system as claimed in claim 12 further comprising a first check valve and a second check valve; wherein said first check valve is in communication with one of said at least one refrigerant line from said compression subsystem and said refrigerant coil of said preconditioning coil chamber and is disposed so as to control a flow of refrigerant to said refrigerant coil of said preconditioning coil chamber; wherein said second check valve is in communication with said refrigerant coil of said preconditioning coil chamber and said refrigerant inlet of said drenched coil of said coil drenching spray system; and wherein said output from said computer program product of said operating system controls said first check valve and said second check valve based upon whether said system is in a cooling mode of operation or a heating mode of operation.

20. The heating and cooling system as claimed in claim 12 wherein said spray sump of said coil drenching spray system comprises an inlet control valve in communication with a potable water supply line and a drain control valve in fluid communication with an overflow drain; wherein said inlet control valve and said drain control valve are computer controlled valves; and wherein said output from said computer program product of said operating system controls a position of said inlet control valve and said drain control valve based upon a signal from said external temperature sensor such that said spray sump is filled when an external temperature is at least 55° Fahrenheit and such that said spray sump is drained when said external temperature is below 50° Fahrenheit.

21. A heating and cooling system comprising: an air processor; a compression subsystem in communication with said air processor, said compression subsystem comprising and accumulator, a compressor, a reversing valve and at least one refrigerant line; a heat box comprising a refrigerant line in fluid communication with said at least one refrigerant line of said compression subsystem, a heat exchange line and a series of motorized shutters; a recuperator comprising a thermal storage means, a supply pump and at least two heat exchange lines, wherein a first heat exchange line is in fluid communication with said heat exchange line of said heat box and wherein said second heat exchange line is in communication with said air processor; and an operating system in electrical communication with said air processor, said compression subsystem, said heat box and said recuperator, wherein said operating system comprises at least one inputs from at least one user control, an internal temperature sensor and an external temperature sensor, a processor comprising a computer program product for processing user and temperature information and determining an appropriate system operating condition based upon said user and temperature information, and at least one output to each of said air processor, said compression subsystem, said heat box and said recuperator.

22. The heating and cooling system as claimed in claim 21 wherein said heat box further comprises a fan disposed such that air may be blown over said refrigerant line and said heat exchange line and wherein said output from said computer program product of said operating system controls an operation of said motorized shutters and said fan,

23. The heating and cooling system as claimed in claim 22 wherein said heat box further comprises a plurality of conductive plates attached to, and in heat conducting relation to, aid refrigerant line and said heat exchange line.

24. The heating and cooling system as claimed in claim 21 wherein said recuperator further comprises at least one solar collector array in fluid communication with said thermal storage means.

Description:

FIELD OF THE INVENTION

The present invention relates to systems for heating and cooling and, in particular, to air processors and forced air systems for heating and cooling an enclosed space.

BACKGROUND OF THE INVENTION

Systems for heating and cooling air in an enclosed spaced, such as a home or office building, have been used for many years. Traditionally, separate systems had been used for heating and for cooling. However, a number of systems have been developed to perform both functions. One such system is a heat pump.

A heat pump is a machine or device that moves heat from one location to another location using work. Many heat pumps move heat from a low temperature heat source to a higher temperature heat sink. One common type of heat pump works by exploiting the physical properties of an evaporating and condensing fluid known as a refrigerant. In heating, ventilation, and cooling (HVAC) applications, a heat pump normally refers to a vapor-compression refrigeration device that includes a reversing valve and optimized heat exchangers so that the direction of heat flow may be reversed.

According to the second law of thermodynamics heat cannot spontaneously flow from a colder location to a hotter area; work is required to achieve this. Heat pumps differ in how they apply this work to move heat, but they can essentially be thought of as heat engines operating in reverse. A heat engine allows energy to flow from a hot ‘source’ to a cold heat ‘sink’, extracting a fraction of it as work in the process. Conversely, a heat pump requires work to move thermal energy from a cold source to a warmer heat sink. Since a heat pump uses a certain amount of work to move the heat, the amount of energy deposited at the hot side is greater than the energy taken from the cold side by an amount equal to the work required.

One common type of heat pump works by exploiting the physical properties of an evaporating and condensing fluid known as a refrigerant. In such systems, the working fluid, in its gaseous state, is pressurized and circulated through the system by a compressor. On the discharge side of the compressor, the now hot and highly pressurized gas is cooled in a heat exchanger called a condenser until it condenses into a high pressure, moderate temperature liquid. The condensed refrigerant then passes through a pressure-lowering device, such as an expansion valve, capillary tube or a restrictor. This device then passes the low-pressure refrigerant in a saturated vapor state to the evaporator, where the refrigerant evaporates into a gas via heat absorption. The refrigerant then returns to the compressor and the cycle is repeated.

In HVAC applications, a heat pump normally refers to a vapor-compression refrigeration device that includes a reversing valve and optimized heat exchangers so that the direction of heat flow may be reversed. The reversing valve switches the direction of refrigerant through the cycle and therefore the heat pump may deliver either heating or cooling to a building. In the cooler climates the default setting of the reversing valve is heating. The default setting in warmer climates is cooling. Because the condenser and evaporator must swap functions, they are optimized to perform adequately in both modes. As such, the efficiency of a reversible heat pump is typically slightly less than two separately-optimized machines. Therefore, there is a need for a system for heating and cooling that operates at higher efficiencies than conventional reversible heat pump systems.

Conventional air-source heat pumps are relatively easy and inexpensive to install and, therefore, have historically been the most widely used heat pump type. Further, when the outside air is at sufficient temperature, air source heat pumps can typically produce three times the heating per kilowatt then electric heat systems. However, they suffer limitations due to their use of the outside air as a heat source or sink, as the higher temperature differential during periods of extreme cold or heat leads to a lower efficiency. Therefore, there is a need for a system for heating and cooling that operates at higher efficiencies than conventional heat pump systems at high temperature differentials.

Conventional air-source heat pumps also typically rely upon dry bulb temperature control for both heating and cooling. The dry bulb temperature refers to the ambient air temperature without regard to the moisture in the air. Conversely, wet-bulb temperature takes the amount of moisture in the air into account. As the amount of heat that can be absorbed the air is greatly impacted by its humidity, and as the humidity of air is greatly variable from day to day, the use of the dry bulb temperature for control of conventional systems during the cooling cycle leads to further inefficiency. Therefore, there is a need for a system for heating and cooling that controls the cooling mode based upon the wet-bulb temperature of the air and the heating mode based upon the dry bulb temperature of the air.

When used for cooling, the overall efficiency of conventional heat pumps is also reduced due to their failure to use the waste heat for useful purposes. Typically, waste heat is discharged to the atmosphere and not used for other purposes, such as heating residential water. Therefore, there is a need for a system for heating and cooling that will use this waste heat productively.

Another problem with any air conditioning processes is the need to add sensible heat back into the air after it has been de-humidified. The reason for this that lower temperature air has higher relative humidity and the failure to add sensible heat can result in excessively high relative humidity levels. Accordingly, most air conditioning process include a separate reheat process during the dehumidification cycle. This process is typically performed by an electric heater, or a hot refrigerant, which further reduces the efficiency of the system. Therefore, there is a need for a system for heating and cooling that has a more efficient reheat process than conventional systems.

There are a number of industrial cooling systems that utilize a flow of water over heated coils as the primary means of cooling in industrial processes. Such systems are often referred to as drenched coil or wet surface air coolers. These systems utilize banks of coils through which water or a refrigerant are pumped and a fluid, typically water, is sprayed over the coils and cools the fluid passing through the coils. Drenched coil cooling has a number of advantages. For example, the use of sprays acts to clean the process air being blown over the coils and also acts to clean the coils of dirt, scale and other buildup. However, as these systems are limited to cooling and operate most efficiently under certain ambient conditions, they have heretofore not been readily adapted for use in applications that require both heating and cooling. Therefore, there is a need for a system for heating and cooling that utilizes drenched coil cooling but that is adapted to automatically switch off the drenched coil cooling when conditions require it to do so.

Finally, evaporative cooling has been used to cool air in outdoor applications, such as livestock barns and along the sidelines at sporting events, as well as in industrial applications where hot gasses must be quickly cooled. Evaporative cooling works by spraying a fine mist of a liquid into a flow of gas, which causes the liquid to evaporate and remove heat from the gas. As was the case with the drenched coil systems above, these systems are limited to cooling, operate most efficiently under certain ambient conditions, and have not heretofore been adapted for use in applications that require both heating and cooling. Therefore, there is a need for a system for heating and cooling that utilizes evaporative cooling but that is adapted to automatically switch to compression heating or cooling when conditions require it to do so.

SUMMARY OF THE INVENTION

The present invention is a unique heating and cooling system and a unique air processor for use in a heating and cooling system.

The air processor of the present invention includes a housing including a top, a bottom, a coil section and an air output section. An air inlet is in communication with the top of the housing and a bypass damper is in communication with the air inlet and the air output section of the housing.

A preconditioning coil chamber is disposed within the coil section of the housing and proximate to the air inlet. The preconditioning coil chamber includes a first portion of a refrigerant coil and a first portion of a thermal return coil.

A coil drenching spray system is disposed within the coil section of the housing between the humidification nozzles and the bottom of the housing. The coil drenching spray system includes a spray sump dimensioned to hold a volume of water, a recirculatory spray pump in fluid communication with the spray sump, a drenched coil including a refrigerant inlet and outlet, and at least one spray nozzle in communication with the recirculatory spray pump. The nozzles are disposed over the drenched coil such that water sprayed from the nozzles contacts the drenched coil.

A post-conditioning chamber is disposed within the air output section between the bottom of the housing and the bypass damper. The post-conditioning chamber includes a second portion of the thermal return coil and a first stage heating coil in communication with a source of heating medium.

Finally, a processed air outlet is disposed within the air output section of the housing between the bypass damper and the post-conditioning chamber and allows processed, or conditioned, air to pass into the room to be heated or cooled.

The preferred air processor includes at least one ultraviolet emitter disposed within the coil section of the housing between the preconditioning coil chamber and the bottom or the housing. The preferred air processor also includes at least one humidification nozzle, connected to a supply of high purity water, which is disposed within the coil section of the housing between the ultraviolet emitter and the bottom of the housing.

The preferred air processor includes a filter section having a pre-filter and a final filter, an economizer damper disposed between the air inlet and the air output section of the housing. The preferred air processor also includes at least one evaporative cooling nozzle disposed within the air output section between the bypass damper and the processed air outlet. The evaporative cooling nozzle includes a connector for connection to a supply of high purity water.

The preferred air processor includes a supply fan in fluid communication with the processed air outlet and at least one electric heater. The air processor preferably includes two electric heaters. A first electric heater disposed within the coil section of the housing between the recirculatory spray system and the top of the housing and a second electric heater disposed within the processed air outlet.

Finally, the spray sump of the preferred air processor also includes an inlet control valve for attachment to a potable water line and a drain control valve for attachment to a drain line.

The heating and cooling system includes an air processor, such as the air processor of the present invention, and a compression subsystem in communication with the air processor. The compression subsystem includes and accumulator, a compressor, a reversing valve and at least one refrigerant line. A heat box including a refrigerant line, which is in fluid communication with a refrigerant line of the compression subsystem, a heat exchange line, and a series of motorized shutters. A recuperator is provided, which includes a thermal storage means, a supply pump and at least two heat exchange lines. A first heat exchange line is in fluid communication with the heat exchange line of the heat box and the second heat exchange line is in communication with the air processor. Finally, an operating system is in electrical communication with the air processor, the compression subsystem, the heat box and the recuperator. The operating system includes at least one input from at least one user control, an internal temperature sensor and an external temperature sensor, a processor that includes a computer program product for processing user and temperature information and determining an appropriate system operating condition based upon the user and temperature information, and at least one output to each of the air processor, the compression subsystem, the heat box and the recuperator.

In the preferred heating and cooling system, the heat box also includes a fan disposed such that air may be blown over the refrigerant line and the heat exchange line and where the output from the computer program product of the operating system controls an operation of the motorized shutters and the fan. The preferred heat box also includes a plurality of conductive plates attached to, and in heat conducting relation to, aid refrigerant line and the heat exchange line. The preferred recuperator includes at least one solar collector array in fluid communication with the thermal storage means. The use of a solar collector array is unique and is preferred due to its ability act as a thermal flywheel for the system.

In some embodiments of the heating and cooling system, a potable water heater and/or a radiant heat water heater is in communication with the heat exchange line of the heat box. In such embodiments, the output from the computer program product of the operating system control a flow of heat transfer fluid from the heat box to the potable water heater and/or the radiant heat water heater when the system is in a cooling mode of operation.

Some embodiments of the heating and cooling system also include an ice storage unit through which a heat transfer fluid line is disposed. In some such embodiments, a coaxial chiller is also provided and the heat transfer fluid line is disposed through the coxial chiller and the ice storage unit. It is preferred that the coaxial chiller be disposed relative to the ice storage unit such that a heat transfer fluid passing through the heat transfer fluid line passes through the coxial chiller before passing through the ice storage unit.

The preferred heating and cooling system also includes a first check valve and a second check valve. The first check valve is in communication with a refrigerant line from the compression subsystem and the refrigerant coil of the preconditioning coil chamber and is disposed so as to control a flow of refrigerant to the refrigerant coil of the preconditioning coil chamber. The second check valve is in communication with the refrigerant coil of the preconditioning coil chamber and the refrigerant inlet of the drenched coil of the coil drenching spray system. In such embodiments, the output from the computer program product of the operating system controls a position of the first check valve and the second check valve. During the heating cycle, the check valves direct the refrigerant flow through the refrigerant coil of the preconditioning coil chamber for increased heating efficiency. During the cooling cycle, the check valves direct the flow around the preconditioning coil chamber, providing increased efficiency of the drenched coil.

In the preferred heating and cooling system, the spray sump of the coil drenching spray system includes an inlet control valve in communication with a potable water supply line and a drain control valve in fluid communication with an overflow drain. The inlet control valve and the drain control valve are preferably computer controlled valves and the output from the computer program product of the operating system preferably controls a position of the inlet control valve and the drain control valve based upon a signal from the external temperature sensor such that the spray sump is filled when an external temperature is at least 55° Fahrenheit and such that the spray sump is drained when the external temperature is below 50° Fahrenheit. Therefore, it is an aspect of the invention to provide a system for heating and cooling that operates at higher efficiencies than conventional reversible heat pump systems.

It is a further aspect of the invention to provide a system for heating and cooling that operates at higher efficiencies than conventional heat pump systems at higher temperature differentials.

It is a further aspect of the invention to provide a system for heating and cooling that is controlled based upon the wet-bulb temperature of the air.

It is a further aspect of the invention to provide a system for heating and cooling that will use waste heat productively.

It is a further aspect of the invention to provide a system for heating and cooling that automatically controls its operating mode to optimize efficiency and comfort.

It is a further aspect of the invention to provide a system for heating and cooling that maintains the coil leaving wet bulb temperature, thereby increasing system efficiency and comfort.

It is a further aspect of the invention to provide a system for heating and cooling that cleans the air during cooling mode.

It is a further aspect of the invention to provide a system for heating and cooling that utilizes drenched coil cooling but that is adapted to automatically switch off such cooling under conditions where such cooling is inefficient.

It is a further aspect of the invention to provide a system for heating and cooling that utilizes evaporative cooling but that is adapted to automatically switch to compression heating or cooling.

These aspects of the invention are not meant to be exclusive and other features, aspects, and advantages of the present invention will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the five sub-systems that make up the overall system of the present invention.

FIG. 2 is a schematic diagram of the preferred air processor of the system of the present invention.

FIG. 3 is a schematic diagram of the air processor of FIG. 2 showing the piping inputs from the compression sub-system.

FIG. 4 is a schematic diagram of the air processor of FIG. 2 showing the piping inputs from the compression sub-system and an optional ice storage device.

FIG. 5 is a schematic diagram of the preferred embodiment of the heat box and compression sub-system operating in cooling mode.

FIG. 6 is a schematic diagram of the preferred embodiment of the heat box and compression sub-system operating in heating mode.

FIG. 7 is a schematic diagram of a preferred embodiment of the heat box and recuperator sub-system that includes thermal storage, a potable water heater, and a radiant heating unit.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIG. 1, the system 50 of the present invention includes five primary sub-systems 100, 200, 300, 400, 500. The first sub-system 100 is referred to as the “air processor”. The air processor 100 conditions air for human comfort and hygiene and moves the conditioned air into the desired space. The second sub-system is the compression sub-system 200. The compression sub-system 200 moves heat in and out of the system 50. The third sub-system 300 is referred to as the “heat box”. The heat box 300 determines whether excess system heat is recovered for reuse or rejected to the atmosphere during the cooling cycle and whether the heat is taken into the system 100 from the atmosphere or from the thermal storage loop during the heating cycle. The fourth sub-system 400 is referred to as the “recuperator”. The recuperator 400 is a heat storage system that allows heat to be stored for use at a later time, both during heating and cooling, and transferred to the air processor subsystem 100 when it is needed. The recuperator 400 is preferably made up of a solar array, thermal storage, piping and special valving to provide proper system operation. The final sub-system is referred to as the operating system 500. The operating system 500 is the integrator for all other sub-systems and controls the other four sub-systems so that they operate efficiently.

Referring now to FIGS. 2-4, the preferred air processor 100 of the system 50 of the present invention is shown. The preferred air processor 100 includes a housing 129 that is divided into two sections; the coil section 130 and the air output section 131. All return air to be processed, whether fresh air or air returning from an air-conditioned space, first passes through the return air inlet 101 and into filter section 123. Filter section 123 preferably includes a pre-filter 124 and a final filter 125. The pre filter 124 is preferably a ten MERV filter that is dimensioned to gather larger particles, typically greater than 10 microns, and allows for a longer service life for the final filter 125, preferably a sixteen MERV filter, which is more costly to replace and requires more fan energy as it becomes loaded with particles. In some embodiments, both the pre-filter 124 and final filter 125 are made up of multiple filters, while in others each is a single filter. In still others, filtration is performed prior to the air reaching the air processor 100 and, in such embodiments, the filter section 123 is omitted.

Once the air passes through the filter section 123, it next passes by the bypass damper 102. The bypass damper 102 increases the efficiency of supply fan 113 and provides the option to partially or totally bypass the coil section 130 and flow directly into air output section 131 during certain phases of the conditioning process. As an example, during low sensible heat ratios, the bypass damper 102 would be used to minimize reheat requirements. Also, the bypass damper 102 is useful during conditions calling for evaporative cooling by the evaporative cooling nozzles 111, as it allows the components in the coil section 130 to be inoperative. However, although the preferred system includes the bypass damper 102, the bypass damper 102 is eliminated in some embodiments of the system and all air flows through the coil section 130 of the housing 129.

Air passing through the coil section 130 first passes through a preconditioning coil chamber 103. The preconditioning coil chamber 103 includes a preconditioning refrigerant coil 135A and a preconditioning thermal return coil 136A. The preconditioning refrigerant coil 135A is in fluid communication with the compression subsystem 200. The preconditioning thermal return coil 136A communicates with the post-conditioning thermal return coil 136B in the post-conditioning chamber 115 in the air output section 131 and is part of a closed loop in which a heat transfer fluid is circulated between the coils 135A, 135B by thermal recirculating pump 114.

The preconditioning coil chamber 103 acts both as a pre-conditioner, using cool liquid from the thermal return chamber 115 to pre-cool the return air for more effective dehumidification, and using the preconditioning refrigerant coil 135A as an extended heat exchange surface during the heat pump cycle. The preconditioning refrigerant coil 135A and preconditioning thermal return coil 136A are preferably plate fin coils with intertwined circuitry in which every other tube is either circuited for refrigerant or heat transfer fluid. The preferred heat transfer fluid is a mixture of water and glycol, which is used as an additive that acts as antifreeze. The preferred refrigerant is R410A, as this is the most commonly used refrigerant for heat pump applications. However, other environmentally safe refrigerants, such as R290, may be substituted to achieve similar results.

In FIGS. 2 and 3, the first tube bank, denoted by the solid color, is the preconditioning refrigerant coil 135A, which is in communication with the refrigerant flowing to and from the compressor sub-system 200 during the heating cycle, and the intermediate tube bank, denoted by hatching, is the preconditioning thermal return coil 136A. However, this arrangement of tubes is shown for illustrative purposes and other arrangements may be utilized to achieve similar results. As described below, other embodiments may include a third coil (not shown) that is in communication with the recuperator 400. Such embodiments are useful where solar heating is applicable.

Air next passes over electric heating coil 104. The electric heating coil 104 is normally turned off, but does function during the compressor-less humidification cycle, where the system is used solely to add humidity to the air when the compressor is not running. It is also used as a back-up heat source in the rare instance when defrosting of the outdoor coil of the heat box 300 is required.

Air next passes through a series of ultraviolet emitters 105, which act as a germicidal system to kill mold spores, bacteria and other germs. In so doing, the drenched coil 108 and housing 129 is kept clean and efficient. The ultraviolet emitters 105 are preferably in operation all times the supply air fan 113 is in operation.

Air next passes over a series of humidification nozzles 106, which are in communication with a source of high purity water. The humidification nozzles 106 spray a mist of water to maintain the desired wet bulb temperature of the process air during periods when the coil drenching spray system 107 is offline, which typically occurs at outdoor dry bulb temperatures consistently below 50° F. The humidification nozzles 106 are turned off when the coil drenching spray system 107 is online.

The air then passes over the coil drenching spray system 107 and the drenched coil 108. The coil drenching spray system 107 is preferably a re-circulatory spray system that is activated at outdoor temperatures above 55° F. and deactivated and drained at temperatures below 50° F. The coil drenching spray system 107 includes the recirculatory spray pump 117 that is disposed within the spray sump 116, and a series of spray nozzles 139 disposed over the drenched coil 108 such that water sprayed from the nozzles 139 contacts the entire drenched coil 108. The coil drenching spray system 107 is only operable during compressor operation in the cooling mode and preferably sprays approximately four gallons per minute of water per square foot of surface area of the drenched coil 108. The spraying of water over the drenched coil provides an extended heat transfer surface and increases the apparatus dew point temperature of the system. Further, the recirculation of water from the sump over the cooled coil 108 provides a flywheel effect and stabilized system operation as the water gives up energy to the coil 108, resulting in cooled water in the sump, which is then recirculated by the recirculatory spray pump 117. The use of the spray system 107 is a distinct advantage in cooling mode due to the greater ability of water to absorb heat, the ability to wash the air, and the ability to keep the heat transfer surfaces free of dirt and other contaminants.

The drenched coil 108 is a continuous coil through which refrigerant from the compression subsystem 200 is pumped. The drenched coil 108 is preferably manufactured of copper, but may be manufactured of any material commonly utilized for coils in the HVAC industry. The drenched coil 108 preferably has a substantially smooth cylindrical outer surface having an outer diameter of between one half inch and one inch with the bends of the coil 108 resulting in the tubes being spaced apart in a staggered arrangement. The spacing of the tubes is typically such that the space between each tube is slightly larger than the diameter of the tube.

The use of a coil drenching spray system 107 and drenched coil 108 provides a number of benefits. First, such a system 107 generates the atmosphere for wet-bulb control of the overall system. The wet-bulb (w.b.) temperature of air leaving the coil will generally be 20° F. above the spray water temperature. Such a system 107 also automatically provides consistent total heat (enthalpy) content of the conditioned air stream. The coil drenching spray system 107 continually cleanses the air and surfaces of the drenched coil 108. The smooth surfaces of the coil array 108 eliminate the inherent problems of finned surface coils; namely air blockage due to frosting, dirt and bacteria buildup, which are not only unhealthy but also require excessive fan energy while providing lower system efficiency. Excess humidity condensed from the air becomes surplus water that is added to water used by the spray system 107 and this surplus water is automatically drained away along with any particulates. This feature eliminates unsanitary drain pans used in contemporary air conditioning systems. Further, air having low entering air wet-bulb conditions can absorb moisture from the sprays, which raises the leaving wet-bulb temperature to the control set point. As each pound of moisture absorbed into the air removes approximately 1000 BTU of sensible heat, the humidification of the air acts to reduce the amount of heat that needs to be removed by the compression circuit. The spray system 107 also provides a continuous defrosting of the surface of the drenched coil 108 and an averaging of coil surface temperatures, ensuring a consistent temperature of the leaving air mass.

After leaving the coil outlet, the air is turned upward into the air output portion 131 and the water from the coil drenching spray system 107 falls by gravity into the spray sump 116. The use of gravity to remove the excess water from the air eliminates costly and energy robbing moisture eliminators and is another important feature of the air processor 100.

The spray sump 116 is in fluid communication with an inlet control valve 109, which controls a flow of potable water from a potable water supply line 119 and allows the spray sump 116 to be initially filled when outdoor temperatures are above 55° F. The spray sump 116 is also in fluid communication with a drain control valve 118 that allows spray sump 116 to be drained when outdoor temperatures are below 50° F. Finally, the spray sump 116 includes an overflow drain 141, which allows excess water to automatically drain from the sump.

Air that has passed through the coil section 130 of the housing 129 next passes upward through the post-conditioning chamber 115. Post-conditioning chamber 115 provides free reheat of return air when in cooling mode and pre-cooling of return air when in heating mode, which enhances dehumidification and system efficiency. As noted above, the coils 135B, 136B in the post-conditioning chamber 115 are in the same types of coils that pass through the preconditioning coil chamber 103. Post-conditioning coil 135B is in communication with piping from the recuperator system piping, thereby providing a first stage of heating without having to activate the compression subsystem 200 until second stage heat is required. Post conditioning thermal return coil 136B is in communication with the thermal recirculating pump 114, which causes the heat transfer fluid to flow through from the post-conditioning chamber 115 to the preconditioning coil chamber 103 and back again. The thermal recirculating pump 114 is preferably a relatively low pressure, low flow pump that is highly efficient and is selected and sized based upon the dimensions of the coils and the overall capacity of the system 50.

After passing through the post-conditioning chamber 115, the air is drawn into the supply fan 113, passes over an electric heater 112 and out through the processed air outlet 142 into the room to be heated or cooled. The supply fan 113 is preferably a variable speed supply air fan that may be automatically adjusted as the heating or cooling load changes and is preferably sized for 400 CFM per ton of system capacity. The electric heater 112 is included as an emergency back-up and typically functions only when the compressor 200 is offline due to malfunction or low ambient temperatures. The electric heater 112 is preferably sized to match the basic heating capacity of the system 50; i.e. if the system 50 is sized to produce 80,000 BTU of heating, the electric heater 112 would be selected to also produce 80,000 BTU of heating.

Return air that is diverted through the bypass damper 102 and directly into air output section 131 is referred to as “bypass return air”. Fresh air also passes through the economizer damper 110 in the fresh air inlet 145, which is also located at the top of the housing 129 proximate to the air output section 131. The economizer damper 110, in conjunction with the bypass damper 102, modulates fresh air and return air to provide free cooling when outdoor temperatures are low enough. The combined bypass return air and fresh air is next passed over evaporative cooling nozzles 110, which function during low wet-bulb economizer operation to lower the conditioned air temperature and provide enthalpy correction. Finally, the combined bypass return air and fresh air is drawn into the supply fan 13, where it mixes with air that has passed through the coil portion 131 of the housing 129.

FIG. 3 shows the refrigerant input to the air processor 100 from the compression system 200, the output of refrigerant from the air processor 100 back to the compression system 200 during the heating mode. Refrigerant is cooled or heated by the compression system 200 and is fed through pipes to the air processor 100. A first check valve 120 and second check valve 121 are one way valves that direct the flow of the refrigerant to the coils 108, 136 during the heating and cooling modes of operation.

FIG. 4 shows one embodiment of the system in which the air processor 100 is piped into an ice storage unit 160. The ice storage unit 160 takes advantage of lower night energy costs by operating in ice building mode during nighttime hours. The ice storage unit 160 includes four inlets for pumping heat transfer fluid into the unit, and an open chamber in which are disposed a plurality of four-inch diameter plastic balls that are filled with water, preferably those sold by Cryogel of San Diego, Calif., under the name Ice Ball™. The water within the plastic balls is frozen during ice building mode and act as an aid to cooling during daytime hours.

The embodiment of FIG. 4 includes a coaxial chiller 162 in addition to the ice storage unit 160. The coaxial chiller 162 is preferably a tube-and-shell type heat exchange in which the heat transfer fluid is pumped through the shell by chiller pump 161 during ice building mode, where it is cooled by refrigerant passing through the tubes. During ice building mode, the flow of air through the air processor 100 is greatly reduced, which results in the refrigerant passing through the drenched coil 108 to drop well below the freezing temperature of water. This low temperature refrigerant passes into the coaxial chiller 162 where it cools the heat transfer fluid to a temperature that is also below the freezing temperature of water. This low temperature heat transfer fluid is then pumped into the ice storage unit 160 where it surrounds and slowly freezes the water filled plastic balls for later during cooling mode when air cooling is required.

When the system switches from ice building mode to cooling mode, the chiller pump 161 is shut off and the thermal recirculating pump 114 and three way valve 164 are activated so as to pump heat transfer fluid through the ice storage unit 160 where it surrounds the plastic balls and gives up heat by melting the stored ice within the plastic balls. The heat transfer fluid then passes back to the air processor 100 where it may be mixed with warmed heat transfer fluid from the post-conditioning chamber 115, or be pumped by the thermal recirculating pump 114 directly back to the pre-conditioning chamber 103.

The preferred compression sub-system 200 is shown in FIGS. 5 and 6, with FIG. 5 showing the flow of refrigerant through the compression sub-system 200 when the system 50 is in cooling mode and FIG. 6 showing the flow of refrigerant through the compression sub-system 200 when the system 50 is in heating mode.

The compression subsystem includes compressor 202, which provides variable refrigerant flow to match compression requirements to load. Compressor 202 may be any industry available compressor that is sized to match the desired output and is adapted to work in variable speed mode. Refrigerant flows through the compressor discharge line 226 to the reversing valve 204, which works in concert with the manifold check valve 206 to redirect refrigerant flow as required for the cooling or heating cycle. The accumulator 208 stores excess liquid refrigerant from the air processor 50 during the cooling cycle and from the heat box 300 during the heating cycle. Condensed liquid is further sub-cooled by the internal heat exchanger 209 located within the accumulator 208, which increases overall cycle efficiency. The suction line heat exchanger 210 dries the saturated suction gas slightly such that only gas is fed to the compressor 202. A sub-cooling control valve 212, preferably an expansion valve, allows liquid refrigerant to flow from the heat exchanger 209 after being sub cooled slightly, generally by about ten degrees Fahrenheit. A liquid booster pump 214 is provided to increase liquid refrigerant pressure, thereby increasing the sub-cooling effect. The liquid booster pump 214 is a refrigerant pump and also provides motive pressure for actuation of the de-super heating function.

During compression, the inefficiencies of the cycle are added to the gas leaving the compressor. This results in the refrigerant going through three phases in the condenser subsystem 200. The first phase is de-superation, which is a sensible heat process that occurs through the de-superheater line 228 and de-super heater valve 216; preferably a solenoid valve that is closed during the heating cycle and open during the cooling cycle. The de-super heater valve 216 cools the hot refrigerant to its saturation temperature, thereby freeing up more surface of the condenser for condensing rather than de-superation. The second phase is condensation, which occurs after the refrigerant is de-superheated. While in a saturated state, without any temperature change the latent heat of condensation is removed from the gas by the condensing surfaces. The third phase is sub-cooling, which is another sensible heat process that uses a condensing surface to cool the liquid refrigerant below its saturation temperature. It is noted that, although this process is preferred, duperheating may also be accomplished via a heat recovery unit connected to the recuperator subsystem 300. Further, in lieu of the liquid booster pump 214 for subcooling and de-superheating, an evaporatively cooled sub-cooling coil could be applied.

As shown in FIG. 5, when the system 50 is operated in cooling mode, the compression sub-system 200 takes warmed refrigerant from the air processor 50 and moves it into the accumulator 208. Refrigerant in a gaseous state is then taken from the accumulator 208, passes through the suction line heat exchanger 210 and moves into the compressor 202 where it is compressed. The compressed refrigerant then moves through the heat box 300 and into the manifold check valve 206, which directs the refrigerant through the liquid booster pump 214 and back upward through the suction line heat exchanger 210. The refrigerant passes through the heat exchanger 209 within the accumulator 108 through the filter drier 218 and subcooling valve 212 and back through the manifold check valve 206 where it is directed to the air processor 100.

As shown in FIG. 6, when the system 50 is operated in heating mode, the compression sub-system 200 takes cooled refrigerant from the air processor 100 and passes it through the manifold check valve 206, which directs the refrigerant through the liquid booster pump 214 and back upward through the suction line heat exchanger 210. The refrigerant passes through the heat exchanger 209 within the accumulator 108 through the filter drier 218 and subcooling valve 212 and back through the manifold check valve 206 where it is directed to the heat box 300. The refrigerant passes from the heat box 300 into the accumulator 109. Gaseous refrigerant is then drawn from the accumulator 208 through the suction line heat exchanger 210 and into the compressor 202, where it is compressed and fed through the discharge line to the reversing valve 204. The reversing valve 204 reverses the flow of the refrigerant back through the discharge line to the air processor 100.

Referring now to FIG. 7, the heat box 300 and recuperator sub-system 400 are shown in detail. The heat box 300 is preferably a cross flow plate fin type heat exchanger that includes both a refrigerant line 310 and a heat exchange line 312 containing a heat exchange liquid, such as glycol. The refrigerant line 310 and heat exchange line 312 are preferably disposed in an intertwined circuit and are put into heat conducting relation by a series of aluminum plates (not shown) that are attached to and deposed between the lines 310, 312. A series of motorized shutters 314 are disposed on end of its housing 318 and a fan 316 is disposed on another end of the housing 316. The heat box 300 performs different functions depending upon whether the system 50 is in cooling or heating mode.

When the system 50 is in cooling mode, the heat box 300 routes heat as appropriate to atmosphere, to the recuperator 400, to a potable water heater 410, to a radiant heat water heater 420 or to a swimming pool heat exchanger (not shown) in order to use the waste heat from the process productively. During the heating cycle, the heat box 300 utilizes atmospheric or recuperator heat to provide increased operating efficiency. Further, during extreme low ambient conditions the heat box fan 316 shuts down, the shutters 314 are closed and total heat is supplied from the recuperator 400, allowing efficient heat pump operation without the need to activate the defrost function. During daylight hours with mild temperatures, the heat box 300 is controlled to direct ambient heat for heat pump operation and the recuperator 400 is recharged by solar heating through the solar collector array 402.

The recuperator sub-system 400 improves the overall efficiency of the system 50, both on a daily and year round basis. This is accomplished by taking advantage of daytime heat energy and storing it for nighttime use, and/or by taking advantage of low nighttime electric energy rates to store additional heat for daytime use. Regardless of whether it is used in heating or cooling mode, thermal energy is stored in the thermal storage mass 404, which is the stabilizer required for efficient heat pump operation.

The thermal storage mass 404 is essentially a large water filled tank 406 through which a heat transfer line 408 is disposed. During the winter months, latent heat is available from the thermal storage mass 404 of the recuperator 400 for cold weather heat pump operation. Effectively, it allows the heat pump to operate at 20° F. below zero as if it was 30° F. above zero. During the summer months the solar collector pump 416 runs a nocturnal cooling cycle in which the heat transfer fluid is pumped through the heat transfer line 408 and through the solar collector array 402, which acts as a heat sink that releases excess stored heat to the atmosphere. This maintains the glycol below degradation temps and lowers the temperature of the thermal storage mass 404 to assist with daytime cooling. During winter months, the unique hydronic piping arrangement allows utilization of special nighttime electric rates to charge the thermal storage with low cost heat for daytime use, thereby allowing first stage heating, which improves the overall efficiency of the system.

The operating sub-system 500 is preferably a direct digital control (DDC) system, such as a properly configured EXCELL 5000 system as manufactured by Honeywell International, Inc., of Golden Valley, Minn., which provides seamless management and integration of all sub-systems 100, 200, 300, 400 to capitalize on inherent design flexibility, while providing truly automatic and energy efficient operation. The operating sub-system 500 utilizes algorithms that perform a number of different functions. One algorithm resets parameters due to changing ambient conditions i.e. as the ambient wet-bulb temperature increases, unit operating wet-bulb temperature is reset to a lower level. Others police system operation: ensuring, integrity and continuous efficiencies. Still others provide notification and automatic switching to backup systems.

The operating sub-system 500 is similar in many respects to those utilized to control current HVAC systems and there are a number of DDC systems currently on the market that are readily adapted to perform the control functions required of the operating sub-system 500. The primary requirements of the operating sub-system 500 are that it accept inputs from at least one user control, an internal temperature sensor and an external temperature sensor, that it include a processor that will process the user and temperature information and determine the appropriate system operating conditions based upon this processing, and that it include outputs that control the operation of the various system components.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions would be readily apparent to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.