HK1190782A - Method and apparatus for conditioning air - Google Patents

Abstract

An apparatus and a method for conditioning air has a quantity of liquid desiccant. A first portion of a first airflow is received in a first contact volume such that it contacts a first portion of the liquid desiccant. A second contact volume is in parallel with the first contact volume and receives a second portion of the first airflow. At least a portion of a second airflow is brought into contact with a second portion of the liquid desiccant in a third contact volume. A first heat exchanger is associated with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and a first medium. A second heat exchanger is associated with the second portion of the liquid desiccant and configured to transfer heat between the second portion of the liquid desiccant and a second medium.

Description

Method and apparatus for conditioning air

Technical Field

Various embodiments of the present invention relate to dehumidification and humidification in heating, ventilation and air conditioning systems.

Background

Heating, ventilation and air conditioning (HVAC) systems provide temperature and humidity controlled air to residential, commercial and industrial buildings. The air provided by the HVAC system may need to be at a specified temperature or humidified or dehumidified to meet comfortable occupancy levels, or within a range for the electronics, and so forth. Typically, if an air conditioning system is used, the outdoor air is dehumidified and cooled, and if a heating system is used, the outdoor air is humidified and heated. The temperature and humidity mechanisms may be integrated or separate.

For example, with some conventional air conditioning systems, air is cooled below its dew point by passing the air over a cooling coil, which causes water to condense out of the air. This typically results in the air being at a temperature below the temperature of a comfort zone. The air is then heated by mixing it with warmer air already present in the space being cooled or by passing it over a heating coil to bring the air to the desired comfort zone temperature. The excess cold used to dehumidify the air reduces efficiency.

If a desiccant type dehumidifier is used in the air conditioning system, the desiccant removes moisture in a dehumidification section to dehumidify the air. The dried air may then be cooled to a desired comfort zone temperature by using a cooling coil. The desiccant is regenerated in a regeneration zone where water is removed from the desiccant. The desiccant can then be reused in the dehumidification section. Depending on the capacity and type of the dehumidification and regeneration sections, desiccant can be blown out of these sections at high air flow rates. The high flow rate of air flowing through the chamber containing the desiccant contacts the desiccant, entrains desiccant droplets or vapor, and causes the desiccant to be lost from the HVAC system. Loss of desiccant by blowing out of the chamber during high air flow conditions (if insufficient desiccant is present) may impair the function of the dehumidifier or may cause other problems.

SUMMARY

In some embodiments of the invention, an apparatus for conditioning air is provided with a quantity of liquid desiccant. A first contact volume is provided in which a first portion of a first airflow is received such that it contacts a first portion of the liquid desiccant. A second contact volume is parallel to the first contact volume in which a second portion of the first air flow is received. A third contact volume is provided in which at least a portion of a second airflow is in contact with a second portion of the liquid desiccant. A first heat exchanger is associated with the first portion of the liquid desiccant and is configured to transfer heat between the first portion of the liquid desiccant and a first medium. A second heat exchanger is associated with the second portion of the liquid desiccant and is configured to transfer heat between the second portion of the liquid desiccant and a second medium.

In another embodiment, an apparatus for conditioning air is provided with a first chamber having an inlet and an outlet for a first flow of a first fluid. The first chamber contains a first portion of a liquid desiccant for removing water from the first stream moving through the chamber. A second chamber has an inlet and an outlet for a first flow of a second fluid and contains a second portion of the liquid desiccant for evaporating water in the desiccant into the second fluid. The second chamber is in fluid communication with the first chamber such that the desiccant is able to flow between the first chamber and the second chamber. A third chamber has an inlet and an outlet for the second flow of the second fluid and is parallel to the second chamber.

In yet another embodiment, a method of regulating fluid using a system having a first chamber, a second chamber, and a third chamber is provided. A first portion of a first fluid flows through the first chamber. The first portion of the first fluid interacts with a portion of a desiccant and transfers water between the first portion of the first fluid and the portion of the desiccant. A second portion of the first fluid flows through the second chamber. The second portion of the first fluid bypasses the first chamber. A second fluid flows through the third chamber. The second fluid interacts with at least a portion of the desiccant and transfers water between the second fluid and the at least a portion of the desiccant. The first and second portions of the first fluid are merged after the first portion of the first fluid exits the first chamber and the second portion of the first fluid exits the second chamber.

In another embodiment, an apparatus for conditioning air is provided with: a quantity of liquid desiccant; a first contact volume in which a first portion of a first air stream is received such that it contacts a first portion of the liquid desiccant; a second contact volume parallel to the first contact volume in which a second portion of the first air flow is received; and a third contact volume in which at least a portion of a second airflow is in contact with a second portion of the liquid desiccant. A first heat exchanger is in contact with the first portion of the liquid desiccant and is configured to transfer heat between the first portion of the liquid desiccant and a first medium. A second heat exchanger is in contact with the second portion of the liquid desiccant and is configured to transfer heat between the second portion of the liquid desiccant and a second medium. A vapor compression system includes a compressor, a third heat exchanger not in contact with the liquid desiccant, and a refrigerant.

Brief description of the drawings

FIG. 1 is a schematic view of a unit for conditioning air according to one embodiment of the present invention; and is

Fig. 2 is a schematic view of a unit for conditioning air according to another embodiment of the present invention.

Detailed Description

As required, detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various and alternative forms. The figures are not necessarily to scale and certain features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.

A heating, ventilation and air conditioning (HVAC) system 10 is schematically illustrated in fig. 1. The system 10 has a dehumidification section or side 14 and a regeneration section or side 16 and uses a desiccant system 12 to change the humidity level of the air flowing through the system 10. The dehumidification side 14 may be used as a dehumidifier to provide drier air or as an air conditioner to provide drier, cooler air. Alternatively, the regeneration side 16 may be used as a heating system to provide warmer, higher humidity air. The drying agent is a lithium chloride salt solution. Alternatively, the desiccant comprises lithium bromide, magnesium chloride, calcium chloride, sodium chloride, and the like.

The desiccant system 12 has a dehumidification chamber 18 on the dehumidification side 14 of the system 10, wherein the desiccant within the chamber 18 absorbs water from air flowing through the chamber 18 and contacting the desiccant. Air flowing through the chamber 18 is provided to the dehumidifying side 14 through an air inlet 20. Only a portion of the air entering through the inlet 20 flows through the dehumidification chamber 18 and the remaining air bypasses the chamber 18 and flows through ducts parallel to the dehumidification chamber 18, allowing either a higher flow rate required to achieve the desired cooling in a given space or better control of the humidity level of the air exiting the dehumidification side 14. Alternatively, all air entering through the inlet 20 flows through the dehumidification chamber 18.

The desiccant system 12 also has a regeneration chamber 22 on the dehumidification side 16 of the system 10, wherein water is removed from the desiccant by absorption into the air flowing through the chamber 22. Air flowing through the chamber 22 is provided to the regeneration side 16 through an air inlet 24. Only a portion of the air entering through the inlet 24 flows through the regeneration chamber 22 and the remaining air bypasses the chamber 22 and flows through a duct parallel to the chamber 22, allowing a higher air flow rate or better control of the humidity of the air leaving the regeneration side 16. Alternatively, all air entering through the inlet 24 flows through the regeneration chamber 22.

The dehumidification chamber 18 and the regeneration chamber 22 are connected such that a liquid desiccant can flow between the two. The desiccant with the higher water content from the dehumidification chamber 18 is exchanged with desiccant with a lower or no water content from the regeneration chamber 22. The desiccant is delivered by diffusion flow from desiccant concentration differences, pumped flow when one or more pumps are used, gravity flow when a controlled overflow is used, and the like.

Moist air flows through the inlet 20 and through the dehumidifying or process side 14. The inlet 20 draws air from the interior of the building or draws outside air for addition to the building HVAC system. A fan (not shown) or other device is used to create a pressure differential to flow the air across the side 14. A set of dampers or additional fans divide the air flow from the inlet 20 into two air streams and control.

One of the air streams from inlet 20 flows through the dehumidification chamber 18 where water is removed from the air by the desiccant. The desiccant is a liquid desiccant and may be sprayed, contained on a sponge-like material or used to dehumidify an air stream as is well known in the art. The air stream flowing through the dehumidification chamber 18 exits the chamber 18 with a lower moisture content as a dry air portion.

Another portion of the air from the inlet 20 is cooled by a heat exchanger 26, such as a chilled water coil or glycol coil. The heat exchanger 26 may be directly connected to a source of ground water, or may be integrated into a larger cooling system 28 or thermodynamic system 29 such as a vapor compression circuit. The dry air portion and the other cooled air portion are recombined before exiting the dehumidification side 14. The heat exchanger 30 is part of the vapor compression circuit 29, or alternatively is connected to a source of ground water and integrated into the cooling system 28. The heat exchanger 30 is located at the regeneration side 16 to maintain the lines in the vapor compression circuit 29 at the regeneration side 16 and out of the dehumidification side 14. The air flow of the dehumidifying side 14 is regulated by cooling and removing moisture. The vapour compression circuit 29 has a compressor 31 for circulating a refrigerant fluid through the circuit 29, and additionally has a throttle valve (not shown). The heat exchangers described within the system 10 are associated with a medium (e.g., air, desiccant, various flows of circulating fluid), meaning that there is direct heat transfer between a fluid flowing through the heat exchanger and the medium, or indirect heat transfer between a fluid flowing through the heat exchanger and the medium when an intermediate heat exchanger or additional medium is used.

Alternatively, after water is removed in the dehumidification chamber 18, the dry air portion and another air portion from the inlet 20 are recombined, then flow over and cooled by a medium flowing in the heat exchanger 26.

By providing a bypassed portion of air to reduce the air flow through the chamber 18, the desiccant is prevented or reduced from blowing out of the chamber 18 and higher flow rates are achievable. The flow rate through the chamber 18 is limited based on when the air flowing through the chamber begins to entrain desiccant. The air flow rate through the dehumidification side 14 is increased by bypassing air around the chamber 18, thereby providing a greater air flow than can be achieved using the chamber 18 alone.

If a cooling system 28 is present, a flow of cooling fluid (e.g., glycol or another refrigerant) exits the heat exchanger 30 and flows in parallel or in series with the heat exchanger 26 and the heat exchanger 32. The cooling fluid in the heat exchanger 32 cools the desiccant before it is used in the dehumidification chamber 18, which additionally cools the air.

A second flow of air enters through the inlet 24 and passes through the regeneration side 16 of the system 10. If the system 10 is used as an air conditioning system, the inlet 24 may draw air from outside the building. A fan (not shown) or other device is used to create a pressure differential to flow air across the side 16. The air is preheated by a medium in a heat exchanger 34 before entering the regeneration chamber 22 containing the desiccant. The air is preheated to increase the amount of water that may evaporate from the desiccant into the air. The heat exchanger 34 is part of the vapour compression circuit 29, or alternatively is connected to an external heat source. The air flows through the regeneration chamber 24 where water is removed from the desiccant. The desiccant may be sprayed, contained on a sponge-like material, or used in other ways well known in the art. The desiccant is heated by a medium in exchanger 36 prior to entering the regeneration chamber 22 to promote evaporation of water from the desiccant. The heat exchanger 36 is connected to the vapour compression circuit 29 or alternatively to an external heat source. The heated air flowing through the regeneration chamber 22 exits the chamber 22 as humid air having an increased water content.

In one embodiment, a set of dampers or additional fans generally divide the air flow through the inlet 24 into two air streams after the heat exchanger 34. One of the air streams flows through the regeneration chamber 22, while the other air stream bypasses the chamber 22. By restricting the flow of air through the chamber 22, blowing of the desiccant out of the chamber 22 is prevented or reduced. The air flow rate through the regeneration side 16 is increased by bypassing air around the chamber 22, thereby providing a greater air flow than can be achieved using the chamber 22 alone. The two air streams may be recombined in a mixing chamber or the like downstream of the regeneration chamber 22.

The system 10 is described above as an air conditioning unit in which the dehumidification side 14 provides a high flow rate of cooler air at an appropriate humidity level to the building, and the regeneration side 16 is used to circulate desiccant for reuse in the desiccant system 12. In other embodiments, the system 10 as described above is used as a heating unit, where the regeneration side 16 provides a high flow rate of warmer air at an appropriate humidity level to the building, and the dehumidification side circulates the desiccant for reuse in the desiccant system 12. The system 10 may be used to provide air as an HVAC system using sides 14, 16 corresponding to HVAC purposes or requirements.

FIG. 2 illustrates another HVAC system 50 having a dehumidification chamber 52 and a regeneration unit 54. The dehumidification chamber 52 and the regeneration unit 54 provide chambers or contact volumes in which air interacts and contacts a desiccant. In one embodiment, the system 50 provides cooler, drier conditioned air from the dehumidification chamber 52, while the desiccant is regenerated for reuse in unit 54. In another embodiment, the system 50 provides warmer, more humid conditioned air from the regeneration unit 54, and the desiccant is regenerated for reuse using the chamber 52. The system 50 is described hereinafter as an air conditioning unit; however, the use of the system as a heater or ventilator is contemplated and will function as described below. The difference between the system 50 as an air conditioner and as a heater is the source of inlet air for the chamber 52 and the unit 54, and is for the air from the chamber 52 and the unit 54 after exiting the system 50.

Moist air enters the dehumidification chamber 52 through a moist air inlet 56 and cooler, dried air or partially dried air exits the chamber 52 through a dry air outlet 58. A bypass duct 60 allows a portion of the air entering through the inlet 56 to bypass around the dehumidification chamber 52. The bypass duct 60 serves as a chamber or contact volume for the bypassed air portion. A series of fans or dampers 62 control the relative air portions flowing through the chamber 52 and the duct 60. The respective air portions may be recombined through the use of the chamber 52 and a mixing chamber 64 downstream of the conduit 60. The bypass duct 60 allows a relatively high flow rate (cubic feet per minute, cfm) of air to be provided by the outlet 58 and to flow through the system 50. The addition of the conduit 60 provides a mechanism to obtain a higher total flow rate at the outlet 58 while maintaining a lower flow rate of air through the chamber 52. The flow rate through the chamber 52 is limited by when the air flowing through the chamber 52 begins to entrain desiccant. Without the bypass conduit 60 and at high flow rates, the desiccant from the chamber 52 is blown out of the chamber and entrained in the exiting air at the outlet 58.

Desiccant 66 is pumped from a desiccant reservoir 70 using pump 68 through a conduit 72 to a series of nozzles 74. The nozzles 74 spray the desiccant into the interior of the chamber 52. The chamber 52 may be filled with a cellulose sponge material, the desiccant permeating the material down into the reservoir 70. A portion of the humid air entering the chamber 52 through the inlet 56 contacts the desiccant droplets. The hygroscopic desiccant absorbs water vapor of the humid air. The drier air exits the chamber 52, mixes with the bypass air from the duct 60 and exits through the outlet 58.

As the air is dried, the moisture content of the desiccant in the sump 70 connected to the chamber 52 increases. The desiccant is regenerated for reuse by removing water from the desiccant in a regeneration unit 54. Air enters through an inlet 76 of the regeneration unit 54 and exits through an outlet 78. The air flow may be divided into two portions, with one portion flowing through the regeneration unit 54 and the other portion flowing through a bypass conduit 80. The bypass conduit 80 serves as a chamber or contact volume for the bypassed air portion. A series of dampers 82 or fans are used to control the relative air portions between the unit 54 and the duct 80. The portion of the air flowing through the unit 54 carries away the moisture evaporated from the desiccant through the outlet 78. The air portions flowing through the unit 54 and the bypass duct 60 may recombine in a mixing chamber 84 before exiting the outlet 78.

The desiccant 66 is pumped from a desiccant reservoir 88 by a pump 86 through a conduit 90 to a series of nozzles 92. The nozzles 92 spray the desiccant into the interior of the unit 54, which may be filled with a cellulose sponge material, which the desiccant permeates through into the reservoir 88. The portion of the air entering the unit 54 through the inlet 76 contacts these moisture-laden desiccant droplets. Water vapor evaporates from the desiccant into the drier air, and the moist air exits the chamber 54, mixes with the bypass air, and exits through outlet 78. By reducing the water content in the desiccant, the desiccant 66 is regenerated for reuse in the dehumidification chamber 52.

The bypass duct 80 allows a relatively high flow rate (cubic feet per minute, cfm) of air to be provided through the outlet 78. The addition of the conduit 80 provides a mechanism to obtain a higher total flow rate at the outlet 78 while maintaining a lower flow rate of air through the unit 54, which prevents the desiccant from becoming entrained in the air flowing through the unit 54. Without the bypass duct 80 and at high air flow rates, the desiccant may blow out of the unit 54 and become entrained in the exiting air.

There is typically a heat transfer mechanism between the desiccant flowing through the dehumidification side and the regeneration side. For example, a vapor compression circuit 94 (e.g., a heat pump or refrigeration circuit) is used for heat transfer between the high-moisture content desiccant and the low-moisture content desiccant and is additionally used to cool or heat air flowing through the system 50. Of course, other circuits or heat exchanger operations using independent operation of the heat source and the heat sink are also contemplated. The heat exchangers described within the system 50 are associated with one medium (e.g., air, desiccant, different flows of circulating fluid), meaning that there is direct heat transfer between the two media flowing through the heat exchanger, or indirect heat transfer between the two media flowing through the heat exchanger via an intermediate heat exchanger or additional medium.

The vapor compression circuit 94 includes a compressor 96, a first condenser 98, a second condenser 100, a throttle or expansion valve 102, and an evaporator 102. The heat pump 94 uses a refrigerant such as R-134a, R-1234, or other refrigerants known in the art. The compressor 96 circulates the refrigerant through the circuit 94. The first condenser 98 acts as a heat exchanger to heat the desiccant in the conduit 98. By preheating the desiccant prior to regenerating it in unit 54, water is more easily evaporated from the desiccant. The second condenser 100 functions as a heat exchanger to heat the air flowing through the inlet 76. Warmer air flowing through the unit 54 is able to maintain a higher level of moisture or humidity at a higher temperature, which additionally facilitates regeneration of the desiccant 66. The evaporator 104 provides a heat exchanger that acts as a heat sink to directly or indirectly cool the desiccant and air on the dehumidification side of the system 50.

The order of the first and second condensers 98, 100 may be reversed depending on the heating requirements of the air and desiccant. Additionally, the second heat exchanger 100 may be positioned to heat only a portion of the air flowing through the unit 54, rather than heating the air flowing through the inlet 76.

The evaporator 104 can be a two-stage evaporator or two evaporators in series for directly cooling the desiccant and air on the dehumidification side of the system 50. Alternatively, the evaporator 104 is connected to a cooling loop 106 that contains glycol, water, or another fluid. The flow within the cooling loop 106 exits the evaporator 104 and splits at valve 108. A line in the cooling loop 106 flows through a heat exchanger 110 which is in direct or indirect contact with the desiccant in the conduit 72 to pre-cool the desiccant before it enters the chamber 52. The other line in the cooling loop 106 flows through a heat exchanger 112 that is parallel to the first heat exchanger 110. The medium in the heat exchanger 112 cools the air in the bypass duct 60. By cooling the air in the bypass duct, the cooler humid air from the duct 60 is mixed with the drier air from the chamber 52 in the mixing chamber 64, which allows the air temperature and humidity level at the outlet 58 to be controlled by using the dampers 62, fans and a controller (not shown). A heat exchanger 112 may also be positioned at the inlet 56 to cool all air flowing through the dehumidification side of the system 50. Other cooling loops 106 are also contemplated, such as those having multiple heat exchangers in series.

Cooling the desiccant on the dehumidification side with heat exchanger 110 lowers the temperature of the desiccant in chamber 52, which contacts the air being dried in chamber 52 and additionally lowers the temperature of the dried air.

Alternatively, the heat exchangers and cooling loops 106 in the vapor-compression circuit 94 may be piped directly to a radiator or heat source, such as ground water or waste heat from an associated air conditioner or other system.

Desiccant may be transferred between the two reservoirs 70, 88 by using a diffusion orifice 114, pumps, a floatation system, or the like. The desiccant in the reservoir 70 has an increased moisture content compared to the desiccant in the reservoir 88 when the dehumidification chamber 52 is in operation, which corresponds to a higher concentration of desiccant in the reservoir 88 than in the reservoir 70. For the efficiency and drying capacity of the dehumidification chamber 52, the desiccant needs to be regenerated.

In the system 50 shown in fig. 2, the desiccant is transferred between the dehumidification reservoir 70 and the regeneration reservoir 88 by diffusion transport. Alternatively, pumping or another system may be used. The aperture 114 allows ions of water and desiccant salt to transfer between the reservoirs while minimizing the amount of heat transfer between the reservoirs. The dehumidification chamber 52 continuously adds water content to the desiccant 66 of the reservoir 70. The regeneration unit 54 continuously removes water from the desiccant. During operation, the concentration of salt ions in the reservoir 88 is generally higher than in the reservoir 70 because the desiccant in the regeneration reservoir 88 is concentrated and the desiccant in the reservoir 70 is diluted. This concentration difference causes the salt ions to flow from the reservoir 88 to the reservoir 70 via the aperture 114 by diffusive transport, which is balanced by the flow of water ions from the reservoir 70 to the reservoir 88 caused by the flow of solution in this direction. This results in a steady-state level of desiccant concentration, but during changes in air flow, start-up conditions, or other system 50 transients, there will be corresponding transient periods of desiccant concentration.

In one embodiment, the system 50 has a dehumidification chamber (or contacting volume) 52 and a regeneration chamber 54. A bypass conduit (or contact volume) 60 is provided parallel to the dehumidification chamber 52. A liquid desiccant 66 is used in the chambers 52, 54 to change the humidity level of the air flowing through the chambers 52, 54. A portion of the airflow entering the inlet 56 flows into the chamber 52 such that it contacts the first portion of the liquid desiccant 66 and is dehumidified. A second portion of the air flow entering the inlet 56 flows through the bypass duct 60. At least a portion of the second airflow entering the inlet 76 flows into the chamber 54 such that it contacts the second portion of the liquid desiccant 66 and removes water from the desiccant to regenerate the desiccant. The system 50 has a heat exchanger 110 in contact with a first portion of the liquid desiccant 66. Another heat exchanger 98 is in contact with a second portion of the liquid desiccant 66. Yet another heat exchanger 112 is not in contact with the liquid desiccant 66. In one embodiment, the heat exchanger 112 is in contact with a second portion of the first air stream in the bypass duct 60. In some embodiments, the system has a vapor compression system 94 that includes a plurality of heat exchangers 110, 98, 112, a compressor 96, and a refrigerant. In other embodiments, the heat exchangers 110, 112, 98 may be connected to separate heat sources or radiators. Alternatively, the heat exchangers 110, 112 are part of a cooling loop 106 in communication with the vapor compression circuit 94. The heat exchangers 110, 112 are arranged in parallel such that the refrigerant or cooling fluid flows in parallel to the heat exchangers 100, 112.

A heat exchanger 110 transfers heat from the desiccant 66 to the vapor compression circuit 94. A heat exchanger 112 transfers heat from the bypass air in conduit 60 to the vapor-compression circuit 94. This provides two heat sources to the vapor compression circuit 94: the bypass air in the duct 60 and the desiccant flowing through the duct 72. The increased energy transferred into the vapor compression circuit results in additional energy (or heat) being transferred or used on the regeneration side, increasing the heat capacity available for regeneration. This additionally increases the efficiency of the system 50 and allows for higher air flow through the system 50. By arranging the heat exchangers 110, 112 in parallel, a higher airflow can be achieved through the inlet 56 and outlet 58 without the desiccant 66 blowing out of the chamber 52.

While various embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. In addition, features of the various implementing embodiments may be combined to form further embodiments of the invention.

Claims (24)

1. An apparatus for conditioning air, comprising:

a quantity of liquid desiccant;

a first contact volume within which a first portion of a first air stream is received such that it contacts a first portion of the liquid desiccant;

a second contact volume parallel to the first contact volume, a second portion of the first air flow being received within the second contact volume;

a third contact volume within which at least a portion of a second airflow is received such that it contacts a second portion of the liquid desiccant;

a first heat exchanger associated with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and a first medium; and

a second heat exchanger associated with the second portion of the liquid desiccant and configured to transfer heat between the second portion of the liquid desiccant and a second medium.

2. The apparatus of claim 1, further comprising a fourth contact volume parallel to the third contact volume, a second portion of the second air flow being received within the fourth contact volume.

3. The apparatus of claim 1, further comprising at least one damper for controlling the relative amount of the first and second portions of the first air flow flowing to the first and second contact volumes, respectively.

4. The apparatus of claim 1, wherein the first heat exchanger is also associated with the second portion of the first air stream in the second contact volume and is configured to transfer heat between the second portion of the first air stream and the first medium.

5. The apparatus of claim 1, further comprising a vapor compression system comprising the first heat exchanger, the second heat exchanger, and a compressor;

wherein the first medium is the same as the second medium.

6. The apparatus of claim 1, further comprising a cooling loop having a cooling fluid circulating therein, the cooling loop being in communication with the first heat exchanger, the cooling loop having:

a third heat exchanger in communication with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and the cooling fluid; and

a fourth heat exchanger in communication with the second portion of the first air stream and configured to transfer heat between the second portion of the first air stream and the cooling fluid.

7. The apparatus of claim 1, further comprising a mixing chamber downstream of the first and second contacting volumes for combining the first portion and the second portion of the first air stream.

8. The apparatus of claim 1, further comprising a third heat exchanger in communication with the at least a portion of the second air stream prior to flowing into the third contact volume, the third heat exchanger configured to transfer heat between the at least a portion of the second air stream and a third medium.

9. The apparatus of claim 1, further comprising a third heat exchanger associated with the second portion of the first air stream and configured to transfer heat between the second portion of the first air stream and a third medium.

10. An apparatus for conditioning air, comprising:

a first chamber having an inlet and an outlet for a first flow of a first fluid, the first chamber containing a first portion of a liquid desiccant for removing water from the first flow flowing through the chamber;

a second chamber having an inlet and an outlet for a first flow of a second fluid, the second chamber containing a second portion of the liquid desiccant for evaporating water from the desiccant into the second fluid, the second chamber being in fluid communication with the first chamber such that the desiccant is able to flow between the first chamber and the second chamber; and

a third chamber having an inlet and an outlet for a second flow of the second fluid, the third chamber being parallel to the second chamber.

11. The apparatus of claim 10, further comprising a common inlet for the second fluid; and

a flow divider positioned within the common inlet for the second fluid and adapted to divide the second fluid between a first flow of the second fluid flowing through the inlet to the second chamber and a second flow of the second fluid flowing through the inlet to the third chamber.

12. The apparatus of claim 10, further comprising a fourth chamber having an inlet and an outlet for the second flow of the first fluid, the fourth chamber being parallel to the first chamber.

13. The apparatus of claim 12, further comprising a common inlet for the first fluid; and

a flow divider positioned within the common inlet for the first fluid and adapted to divide the first fluid between a first flow of the first fluid flowing through the inlet to the first chamber and a second flow of the first fluid flowing through the inlet to the fourth chamber.

14. The apparatus of claim 12, further comprising a mixing chamber in communication with the outlet of the first chamber and the outlet of the fourth chamber for combining the first and second streams of the first fluid.

15. The apparatus of claim 10, further comprising:

a first heat exchanger associated with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and a first medium; and

a second heat exchanger associated with the second portion of the liquid desiccant and configured to transfer heat between the second portion of the liquid desiccant and a second medium.

16. The apparatus of claim 15, further comprising a cooling loop containing a cooling fluid circulating therein, the cooling loop being associated with the first heat exchanger, the cooling loop having:

a third heat exchanger associated with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and the cooling fluid; and

a fourth heat exchanger in communication with the second flow of the first fluid and configured to transfer heat between the second flow of the first fluid and the cooling fluid.

17. The apparatus of claim 16, wherein the fourth heat exchanger is in parallel with the third heat exchanger in the cooling loop.

18. The apparatus of claim 16, wherein the cooling loop has a valve configured to vary an amount of cooling fluid flowing into the third and fourth heat exchangers.

19. The apparatus of claim 16, further comprising a fifth heat exchanger associated with the first and second flows of the second fluid and configured to transfer heat between the first and second flows of the second fluid and a third medium.

20. A method of regulating fluid using a system having a first chamber, a second chamber, and a third chamber, the method comprising:

flowing a first portion of a first fluid through the first chamber, the first portion of the first fluid interacting with a portion of a desiccant and transferring water between the first portion of the first fluid and the portion of the desiccant;

flowing a second portion of a first fluid through the second chamber, the second portion of the first fluid bypassing the first chamber;

flowing a second fluid through the third chamber, the second fluid interacting with at least a portion of the desiccant and transferring water between the second fluid and the at least a portion of the desiccant; and is

The first and second portions of the first fluid are combined after the first portion of the first fluid exits the first chamber and the second portion of the first fluid exits the second chamber.

21. An apparatus for conditioning air, comprising:

a quantity of liquid desiccant;

a first contact volume within which a first portion of a first air stream is received such that it contacts a first portion of the liquid desiccant;

a second contact volume parallel to the first contact volume, a second portion of the first air flow being received within the second contact volume;

a third contact volume in which at least a portion of a second airflow is in contact with a second portion of the liquid desiccant;

a first heat exchanger in contact with the first portion of the liquid desiccant and configured to transfer heat between the first portion of the liquid desiccant and a first medium;

a second heat exchanger in contact with the second portion of the liquid desiccant and configured to transfer heat between the second portion of the liquid desiccant and a second medium; and

a vapor compression system including a compressor, a third heat exchanger not in contact with the liquid desiccant, and a refrigerant.

22. The apparatus of claim 21, wherein the third heat exchanger is in contact with the second portion of the first air stream and is configured to transfer heat between the second portion of the first air stream and the refrigerant.

23. The apparatus of claim 21, wherein the vapor compression system comprises the first heat exchanger and the second heat exchanger;

wherein the refrigerant is the first medium and the second medium.

24. The apparatus of claim 23, wherein the refrigerant flows in parallel with the second heat exchanger and the third heat exchanger.