WO2024086914A1 - Systems and methods for modulating temperature and humidity of an enclosed space - Google Patents

Abstract

A system includes first and second conditioning systems and a liquid transport system. The first conditioning system can include a first plenum through which a first air stream is configured to be directed into an enclosed space, a pre-cooler dry coil in the first plenum, an evaporative cooler (EC) downstream of the pre-cooler, a wet coil downstream of the EC, and a reheater downstream of the wet coil in the first plenum. The second conditioning system can include an evaporative cooling based liquid cooler and trim chiller, which are able to supply one or more liquid streams with different temperature ranges at the same time to the first conditioning system. The liquid transport system is configured to transport the one or more liquid streams in and between the first conditioning system and the second conditioning system.

Description

SYSTEMS AND METHODS FOR MODULATING TEMPERATURE AND HUMIDITY OF AN ENCLOSED SPACE

BACKGROUND

[0001] The present application relates to conditioning systems and methods for modulating temperature and humidity of an enclosed space.

[0002] Heating, cooling, and air conditioning systems (HVAC) are employed in various applications and for various operational objectives. Many HVAC systems are employed to controllably modulate the conditions of an enclosed space. The particular type of spaces and its uses can affect the design of and performance targets of the HVAC system. Some enclosed spaces, the conditions of which are controlled by an HVAC system, require a set of conditions, e.g. a fixed air temperature and/or humidity, which do not vary over time (e.g. in a 24 hour, monthly, or annual cycle). Data centers are an example of such an application. Other types of enclosed spaces, however, have environmental condition requirements that vary with time.

[0003] Greenhouses are an example of a space, which may be conditioned using an HVAC system and which may require different target/set point temperatures and humidity levels from hour-to-hour in a 24-hour cycle, and/or in different months or seasons in an annual cycle. Greenhouse owners may, for example, design conditions to optimize the yield of crops or growth of plants within the space. Certain temperatures and humidity levels may be selected for certain plants, as well as the time of day in which to target those controlled environmental conditions. HVAC systems employed in such environments may require a design with more controlled flexibility in terms of system performance/capacity, hopefully while also improving efficiency and/or energy and/or other resource (e.g. water) usage.

SUMMARY

[0004] The inventors have devised, inter aha, a conditioning system that includes first and second conditioning systems and a liquid transport system. The first conditioning system can include a first plenum through which a first air stream is configured to be directed into an enclosed space, a pre-cooler dry coil in the first plenum, an evaporative cooler (EC) downstream of the pre-cooler, a wet coil downstream of the EC, and a reheater downstream of the wet coil in the first plenum. The second conditioning system can include an evaporative cooling based liquid cooler and trim chiller, which are able to supply one or more liquid streams with different temperature ranges at the same time to the first conditioning system. The liquid transport system is configured to transport the one or more liquid streams in and between the first conditioning system and the second conditioning system.

[0005] This summary is intended to provide an overview of subject matter in the present application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0007] FIG. 1 is a schematic depicting an example conditioning system in accordance with the present disclosure.

[0008] FIGS. 2A-2D are schematics depicting different modes of operation and/or configurations of an example conditioning system in accordance with the present disclosure.

DETAILED DESCRIPTION

[0009] FIG. 1 is a schematic depicting example conditioning system 100 in accordance with examples of this disclosure. Conditioning system 100 includes first conditioning system 102 and second conditioning system 104. First conditioning system 102 is configured to use one or more liquids to condition air that is supplied to an enclosed space as supply air (SA). As one example, first conditioning system 102 is configured to provide conditioned supply air to a greenhouse to modulate the environmental conditions therein. Second conditioning system 104 is configured to condition one or more liquids and supply the liquids to first conditioning system 102 for use in conditioning the supply air for the enclosed space. One example of the possible air and liquid flow paths of system 100 are depicted in FIG. 1. As described in detail with reference to FIGS. 2A-2D, however, in particular implementations and/or operational modes of system 100, not all of these air and liquid flow paths may be active.

[0010] First conditioning system 102 includes first plenum 110, wet coil 112, first liquid-to-air heat exchanger (LAHX1) 114, third liquid-to-air heat exchanger (LAHX3) 116, and evaporative cooler (EC) 118. First plenum 110 is configured to convey a first air stream through one or more of LAHX3 116, EC 118, wet coil 112, and LAHX1 114 and deliver the conditioned first air stream into the enclosed space as supply air. The first air stream can include one or more sources of air, including, for example outdoor air (OA) and/or return air (RA) from the enclosed space. First plenum 110 includes outdoor air (OA) damper 120, return air (RA) damper 122, and SA outlet 124. OA damper 120 is configured to be opened to allow outdoor air to enter first plenum 110 and RA damper 122 is coupled to ducting or other structure connected to the enclosed space to convey return air from the enclosed space into first plenum 110. One or both of OA damper 120 and RA damper 122 can be opened to constitute and deliver the first air stream as supply air to the enclosed space through SA outlet 124.

[0011] First plenum 110 may be referred to and act as a process plenum and the first air stream may be referred to as process air. Process air, as used in this disclosure, refers to air that is used to modulate the conditions of the enclosed space, i.e. air that is used as a working fluid on the functional target of system 100, the environmental conditions within the enclosed space.

[0012] In an example, LAHX3 116 is arranged in first plenum 110 and configured to precool the first air stream using a liquid circulating through the device. LAHX3 116 can include a variety of kinds of liquid-to-air exchangers, including, for example, cooling coils. Cooling coils are commonly formed of coiled copper tubes embedded in a matrix of fins. A variety of particular configurations, capacities, etc. can be employed in examples according to this disclosure. Other example LAHXs that can be used include micro-channel heat exchangers. The cooling liquid circulating through LAHX3 116 can include water, glycol, other hygroscopic liquids, other evaporative liquids, and/or combinations thereof. In an example, LAHX3 116 is a dry coil configured to directly and sensibly cool the first air stream using a cooling liquid.

[0013] EC 118 is arranged downstream (in a direction flow of the first air stream) of LAHX3 116 in first plenum 110. In an example, EC 118 is configured to evaporatively cool the first air stream using a cooling/evaporative liquid. EC 118 can use the cooling potential in both the first air stream and the liquid to reject heat. In an example, EC 118 can cool the first air stream to a temperature approaching the wet bulb (WB) temperature of the air leaving LAHX3 116. The cooling capacity and associated temperature reduction of first air stream can depend in part on the outdoor air conditions (temperature, humidity) and the EC type and its configuration.

[0014] EC 118 can be any type of evaporative cooler configured to exchange energy between an air stream and a cooling liquid through evaporation of a portion of the liquid into the air. Evaporative coolers can include direct-contact evaporation devices in which the working air stream and the liquid stream that is evaporated into the air to drive energy transfer are in direct contact with one another. In what is sometimes referred to as “open” direct-contact evaporation devices, the liquid may be sprayed or misted directly into the air stream, or, alternatively the liquid is sprayed onto a filler material or wetted media across which the air stream flows, in which case such devices are sometimes referred to as wet pads. As the relatively unsaturated air is directly exposed to the liquid, the liquid (e.g., water) evaporates into the air, and, in some cases, the liquid is cooled. [0015] Such direct-contact evaporation devices can also include what is sometimes referred to as a closed-circuit device. Unlike the open direct-contact evaporative device, the closed system has two separate liquid circuits. One is an external circuit in which, e.g. water is recirculated on the outside of the second circuit, which is tube bundles (closed coils) connected to the process for the relatively hot liquid being cooled and returned in a closed circuit. Air is drawn through the recirculating water cascading over the outside of the hot tubes, providing evaporative cooling similar to an open circuit. In operation the heat flows from the internal liquid circuit, through the tube walls of the coils, to the external circuit and then by heating of the air and evaporation of some of the water, to the atmosphere.

[0016] These different types of evaporative coolers can also be packaged and implemented in specific types of systems. For example, a cooling tower can include an evaporative cooling device such as those described above. A cooling tower is a device that processes working air and water streams in generally a vertical direction and that is designed to reject waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Cooling towers can transport the air stream through the device either through a natural draft or using fans to induce the draft or exhaust of air into the atmosphere. Cooling towers include or incorporate a direct-contact evaporation device/components, as described above.

[0017] Evaporative coolers can also include indirect evaporation devices in which the working air stream and the liquid stream that is evaporated into the air to drive energy transfer are in not in direct contact with one another. An example of such a device is a liquid-to-air membrane energy exchanger (LAMEE). As discussed in detail below, a LAMEE can transfer heat (sensible energy) and moisture (latent energy) between a liquid and an air stream to condition the temperature and humidity of the air flowing through the LAMEE and/or to condition the temperature and the constituent concentration of the liquid flowing through the LAMEE. A LAMEE can include one or more permeable membranes, which separate the air stream and the liquid stream and which allow water to evaporate on the liquid stream side of the membrane and water vapor molecules to permeate through the membrane into the air stream.

[0018] In examples according to this disclosure, EC 118 is configured to operate adiabatically, which is why EC 118 is not depicted as connected to a source of liquid. In an adiabatic operational mode, EC 118 can be configured to circulate water or another cooling liquid EC 118 in a closed liquid circuit (although, in some examples, a source of make-up water may be required). During adiabatic operation of EC 118, a temperature of the water (or other cooling liquid) can remain generally constant or have minimal temperature fluctuations. In examples, as the first air stream passes through EC 118, it can be cooled adiabatically such that its temperature is reduced, its humidity level increases, and its overall enthalpy remains approximately constant. In such adiabatic operation, the temperature of the liquid circulating through EC 118 can remain relatively constant and can therefore be recirculated through the device in a closed circuit. [0019] Wet coil 112 is arranged downstream of EC 118 and RA damper 122 in first plenum 110. Wet coil 112 is a type of LAHX that is configured to transfer sensible and/or latent energy between the first air stream and liquid circulating through the device. In examples, wet coil 112 is configured to cool and/or dehumidify the first air stream flowing through first plenum 110. For example, as the first air stream flows through wet coil 112 it is cooled by the liquid circulating through the device. Additionally, in some conditions, as the first air stream is cooled below the dew point temperature of the air, at which point moisture in the air condenses on the wet coil 112, which causes the humidity of the first air stream to decrease. The moisture that condenses on wet coil 112 can be collected and discarded or put to some use in another device of system 100 or some other component/ sy stem.

[0020] In an example, LAHX1 114 is arranged downstream of wet coil 112 in first plenum 110 and configured to heat the first air stream using a liquid circulating through the device. LAHX1 114 can include a variety of kinds of liquid-to-air exchangers, including, for example, heating coils. Heating coils are commonly formed of coiled copper tubes embedded in a matrix of fins. A variety of particular configurations, capacities, etc. can be employed in examples according to this disclosure. Other example LAHXs that can be used include micro-channel heat exchangers. The liquid circulating through LAHX1 114 can include water, glycol, other hygroscopic liquids, other evaporative liquids, and/or combinations thereof. In an example, LAHX1 114 is a dry coil configured to directly and sensibly heat the first air stream using a liquid.

[0021] In some examples, the target environmental conditions (e.g., set point temperature and humidity) may require cooling and dehumidifying the first air stream. As noted above, wet coil 112 can cool and dehumidify the first air stream by cooling the air to below its dew point temperature. However, in some cases, the set point temperature for supply air to the enclosed space is higher than the dew point. In such cases, LAHX 1 114 can be employed to increase the temperature of the first air stream leaving wet coil 112 before the air is conveyed to the enclosed space through SA outlet 122 as supply air.

[0022] Although not shown in FIG. 1, first conditioning system 102 can include one or more fans and filters to convey and filter the first air stream flowing through first plenum 110. For example, a fan can be positioned near OA damper 120 upstream of LAHX3 116 in the first plenum to push/blow air through first plenum 110. Alternatively or additionally, a fan can be positioned downstream of LAHX1 114 near SA outlet 122 in first plenum 110 to pull/draw air through first plenum 110. In examples, the speed of and associated flow rate generated by such fans can be controlled to improve the performance of first conditioning system 102 in conditioning the first air stream.

[0023] Second conditioning system 104 is configured to condition one or more liquids and supply the liquids to first conditioning system 102 for use in conditioning the supply air for the enclosed space. Second conditioning system 104 includes mechanical liquid chiller 130, an additional evaporative cooling based liquid cooling unit. In examples, the evaporative cooling based liquid cooling unit includes second plenum 132, liquid-to-air membrane energy exchanger (LAMEE) 134, and liquid-to-air heat exchanger (LAHX2) 136. In examples, mechanical liquid chiller 130 includes a compressor (not shown), condenser 138, an expansion valve (not shown) and evaporator 140. Additionally, second plenum 132 includes OA damper 142, bypass damper 144, and exhaust outlet 146.

[0024] Mechanical liquid chiller 130 is configured to cool and deliver a first liquid stream to wet coil 112. Liquid chiller 130 includes a compressor, condenser 138, an expansion valve and evaporator 140. Chiller 130 is configured to circulate a refrigerant through the compressor, condenser 138, expansion valve, and evaporator 140 and exchange heat between the refrigerant and the first liquid stream in evaporator 140. Liquid chiller 130 is fluidically connected to one or both of LAMEE 134 and LAHX2 136 and configured to exchange heat between the refrigerant and a second liquid stream in condenser 138.

[0025] Chiller 130 uses the vapor-compression cycle used by many refrigeration, air conditioning and other cooling applications and also heat pumps for heating applications. Chiller 130 includes two heat exchangers, condenser 138 and evaporator 140. In cooling applications, condenser 138 is hoter and releases heat, and evaporator 140 is colder and accepts heat. For applications which need to operate in both heating and cooling mode, a reversing valve can be employed to switch the roles of these two heat exchangers.

[0026] In the operation according to the vapor-compression cycle, a refrigerant enters the compressor of chiller 130 as a tow pressure and tow temperature vapor. The compressor compresses and thereby increases the pressure of the refrigerant, which leaves as a higher temperature and higher pressure superheated gas. This hot pressurized gas then passes through condenser 138 where it releases heat to the second liquid stream as it cools and condenses completely. The cooler high- pressure liquid refrigerant next passes through an expansion valve which reduces the pressure abruptly causing the temperature to drop dramatically. The cold low- pressure mixture of liquid and vapor refrigerant next travels through evaporator 140 where it vaporizes completely as it accepts heat from the first liquid stream, after which the refrigerant returns to the compressor as a tow pressure tow temperature gas to start the cycle again.

[0027] LAMEE 134 and/or LAHX2 136 are configured to cool the second liquid stream using a second air stream flowing through second plenum 132 and to deliver the second liquid stream to condenser 138 of chiller 130. LAMEE 134 is arranged downstream of OA damper 142 in second plenum and is configured to transfer sensible and latent energy between the second liquid stream and the second air stream. In an example, LAMEE 134 is configured to evaporatively cool the second liquid stream using the second air stream.

[0028] LAMEE 134 can transfer heat (sensible energy) and moisture (latent energy) between a liquid and an air stream to condition the temperature and humidity of the air flowing through the LAMEE and/or to condition the temperature and the constituent concentration of the liquid flowing through the LAMEE. In examples, LAMEE 134 separates the second air stream and the second liquid stream by a permeable membrane, which allows water to evaporate on the second liquid stream side of the membrane and water vapor molecules to permeate through the membrane into the second air stream. The water vapor molecules permeated through the membrane saturate the air stream and the associated energy caused by the evaporation is transferred between the second liquid stream and the second air stream. In examples, LAMEE 134 includes a stack of side-by-side air and liquid channels, adjacent ones of which are separated by a permeable membrane.

[0029] In examples, the permeable membrane(s) in LAMEE 134 can be a non- porous fdm having selective permeability for water, but not for other constituents that may be present in the liquid. The permeable membrane(s) in LAMEE 134 can also be semi-permeable or vapor permeable, and generally anything in a gas phase can pass through the membrane and generally anything in a liquid or solid phase cannot pass through the membrane. In examples, the permeable membrane(s) in LAMEE 134 can be micro-porous such that one or more gases can pass through the membrane. Moreover, the permeable membrane(s) in LAMEE 134 can be a selectively-permeable membrane configured to allow some compounds in a gas phase, but not others, to pass through the membrane. For example, a membrane that is selectively permeable to water will allow water vapor to pass through the membrane but will not allow vapor/gas of other molecules/compounds to pass through the membrane.

[0030] Many different types of liquids can be used as the second liquid stream flowing through LAMEE 134 (and/or LAHX2 136), including, for example, water, glycol, other hygroscopic or evaporative liquids, and/or combinations thereof.

[0031] LAMEE 134 may have some advantages over other types of evaporative coolers. For example, the LAMEE may eliminate or mitigate maintenance requirements and concerns of conventional cooling towers or other systems including direct-contact evaporation devices, where the liquid (e.g., water) is in direct contact with the air stream that is saturated by the evaporated water. For example, the membrane barriers of the LAMEE inhibit or prohibit the transfer of contaminants and micro-organisms between the air and the liquid stream, as well as inhibiting or prohibiting the transfer of solids between the water and air. Relative to other types of similar conditioning devices, the water flow rate and air flow rate through LAMEE 134 may not be limited by concerns such as droplet carryover at high face velocities. In addition, LAMEE 134 can operate with liquid flow rates that enable the transport of thermal energy at levels similar to a cooling tower, and elevated inlet liquid temperatures can boost the evaporative cooling power of the LAMEE.

[0032] In examples, the evaporative cooling process in LAMEE 134 causes the temperature of the liquid at a liquid outlet of the exchanger to be less than a temperature of the liquid at a liquid inlet of the exchanger. In other words, the second liquid stream flowing through LAMEE 134 is cooled by the device between the liquid inlet and the liquid outlet. The reduced-temperature, or “cooled” liquid from LAMEE 134 can be used to provide cooling to the refrigerant flowing through condenser 138 of chiller 130.

[0033] In an example, LAHX2 136 is arranged downstream of LAMEE 134 and bypass damper 144 in second plenum 132 and is configured to cool the second liquid stream using the second air stream circulating through the device. LAHX2 136 can include a variety of kinds of liquid-to-air exchangers, including, for example, cooling coils. Cooling coils are commonly formed of coiled copper tubes embedded in a matrix of fins. A variety of particular configurations, capacities, etc. can be employed in examples according to this disclosure. Other example LAHXs that can be used include micro-channel heat exchangers. The liquid circulating through LAHX2 136 can include water, glycol, other hygroscopic or evaporative liquids, and/or combinations thereof. In an example, LAHX2 136 is a dry coil configured to directly and sensibly cool the second liquid stream using the second air stream.

[0034] The second air stream can include one or more sources of air, including, for example outdoor air (OA). Second plenum 132 includes outdoor air (OA) damper 142, bypass damper 144, and exhaust outlet 146. OA damper 120 is configured to be opened to allow outdoor air to enter second plenum 132 upstream of LAMEE 134. In such cases, bypass damper 144 may be closed such that outdoor air as the second air stream flows through LAMEE 134 and LAHX2 136 and be exhausted out of exhaust outlet 146. Bypass damper 144 can be opened and OA damper 142 closed to bypass LAMEE 134 and allow outdoor air as the second air stream to enter second plenum 132 downstream of LAMEE 134 and upstream of LAHX2 136 and to flow LAHX2 136 and be exhausted out of exhaust outlet 146. [0035] Conditioning system 100 includes a liquid transport system including a plurality of liquid branches that are configured to convey one or more cooling (and/or heating, evaporative, etc.) liquids between first conditioning system 102 and second conditioning system 104. In an example, a cooled first liquid stream is delivered from evaporator 140 of chiller 130 to wet coil 112 via liquid branch 148 and a heated first liquid stream is returned from wet coil 112 to evaporator 140 via liquid branch 150.

[0036] The conveyance of the second liquid stream between first conditioning system 102 and second conditioning system 104 and within second conditioning system 104 includes a plurality of liquid transport branches and liquid junctions. In some operational modes and examples of system 100, a heated second liquid stream is delivered via liquid branch 152 from condenser 138 of chiller 130 to a liquid inlet of LAHX1 114, in which some of the heat in the second liquid stream is transferred to the first air stream. The pre-cooled second liquid stream is delivered from a liquid outlet of LAHX1 114 to valve 154.

[0037] The second liquid stream into which heat of the first air stream is rejected in LAHX3 116 is delivered from a liquid outlet of LAHX3 116 to valve 154 via liquid branch 156. The second liquid stream from the liquid outlet of LAHX1 114 and from liquid outlet of LAHX3 116 mixes at valve 154 and is delivered from valve 154 to a liquid inlet of LAHX2 136.

[0038] The second liquid stream is cooled by one or both of LAMEE 134 and LAHX2 136 using the second air stream and delivered to one or both of LAHX3 116 and condenser 138 of chiller 130. In some operational modes and examples of system 100, LAHX2 136 pre-cools the second liquid stream, which is then delivered to a liquid inlet of LAMEE 134 for further cooling by evaporation. In other operational modes and examples of system 100, LAHX2 136 cools the second liquid stream, which is then delivered to one or both of LAHX3 116 and condenser 138 of chiller 130, thereby bypassing LAMEE 134.

[0039] In examples, the second liquid stream circulates in LAHX2 136, which cools the liquid using the second air stream. The cooled second liquid stream is delivered from a liquid outlet of LAHX2 136 to valve 160. Valve 160 is configured to deliver the second liquid stream either to LAMEE 134 via liquid branch 162 or to valve 164 via liquid branch 166, which bypasses delivery of the liquid to LAMEE 134. Regardless of whether it comes from a liquid outlet of LAMEE 134 or from LAHX2 136 via valve 160 and liquid branch 166, the second liquid stream flows from valve 164 to valve 168, which is configured to deliver the cooled second liquid stream to one or both of LAHX3 116 via liquid branch 170 and condenser 138 of chiller 130 via liquid branch 172. The cooled liquid stream delivered to condenser 138 of chiller 130 is employed by the condenser to cool/absorb heat from the refrigerant circulating through the condenser, after which the heated second air stream is delivered to a liquid inlet of LAHX1 114 OR LAHX2 136 via liquid branch 174 (and, e.g., valves 176 and 154, respectively).

[0040] The liquid transport system of system 100 (and other systems in accordance with this disclosure) can include one or more pumps and one or more reservoirs to propel and store the first and/or second liquid streams. The pump(s) and/or reservoir(s) included in example systems according to this disclosure can be arranged at various locations in the liquid transport system, as appropriate or needed in the particular application of such systems. Additionally, the liquid branchjunctions, and associated control valve configuration shown in FIG. 1 may differ in different examples, while preserving the flow of the first and second liquid streams between components of system 100 as described above.

[0041] System 100 and other example systems in accordance with this disclosure can be used in a variety of cooling, heating, and/or humidifying/dehumidifying applications. One possible application for example systems in accordance with this disclosure is to modulate the environmental conditions in a greenhouse. As described above, controlling the environment of a greenhouse can present unique challenges, including designing the conditioning system for peak and off-peak conditions, as well as designing the conditioning system to adapt to target/set-point temperatures and/or humidity levels that may change multiple times in a 24 hour period.

[0042] FIGS. 2A-2D depict examples of conditioning system 100 in different operational modes and/or physical configurations, which are adapted to condition an enclosed space during different outdoor air/ambient conditions. FIGS. 2A and 2B depict operational modes and/or physical configurations of system 100 in off- peak conditions and FIGS. 2C and 2D depict operational modes and/or physical configurations of system 100 in peak conditions.

[0043] In some examples, including, for example, in some locations in which example conditioning systems according to this disclosure are employed, outdoor air (OA) enthalpy (compared with RA enthalpy) is employed to select the mode(s) of operation of conditioning system 100 (or other example systems in accordance with this disclosure). The mode of operation of conditioning system 100 depicted in FIGS. 2A and 2B can be employed, for example, when OA enthalpy is higher than a target/set point indoor air/RA enthalpy. In such situations, it can be more beneficial/ advantageous to condition RA rather than OA and OA damper 120 may be closed and RA damper 122 may be opened such that the air flowing through first plenum 110 is 100% RA. FIGS. 2C and 2D, on the other hand, depict a mode of operation of conditioning systems when OA enthalpy is lower than target/set point indoor air/RA enthalpy, in which case it can be more beneficial/advantageous to condition OA rather than rather than RA and OA damper 120 can be opened and RA damper 122 can be closed such that the air flowing through first plenum 110 is 100% OA. FIGS. 2C and 2D depict RA damper 122 as closed, but it should be noted that in other examples RA damper 122 could be opened such that a mixture of OA and RA is conditioned by conditioning system 100.

[0044] In FIG. 2A, system 100 is configured to modulate the conditions in an enclosed space during off-peak conditions, for example when the outdoor air enthalpy is higher than the target/set point indoor air/RA enthalpy. As an example, the ambient conditions in off-peak periods can include relatively low outdoor air temperatures and relatively high humidity levels. In FIG. 2A, OA damper 120 is closed and RA damper 122 is open. In this mode/configuration, the first air stream includes return air from the enclosed space and LAHX3 116 and EC 118 are bypassed and may be completely deactivated. In an another example, both OA damper 120 and RA damper 122 may be opened and LAHX3 116 and EC 118, while not being bypassed and may be deactivated such that the outdoor air flows through the components without being conditioned and mixes with the return air upstream of wet coil 112. [0045] Referring again to FIG. 2 A, in this mode/configuration, the first liquid stream flows between evaporator 140 of chiller 130 and wet coil 112 via liquid branches 148 (cold/supply) and 150 (hot/retum). The second liquid stream flows from condenser 138 of chiller 130 to LAHX1 114 via liquid branch 174 and then from LAHX1 114 to LAHX2 136 via liquid branch 156. The second liquid stream then flows from LAHX2 136 to LAMEE 134 via liquid branch 162 and from LAMEE 134 back to condenser 138 via liquid branch 172. For simplicity and clarity, the multiple liquid junctions and associated control valves depicted in FIG. 1 are not shown in FIG. 2A.

[0046] In operation, return air enters first plenum 110 via RA damper 122 and flows through first plenum 110 as the first air stream through wet coil 112. Wet coil 112 cools the first air stream using the first liquid stream, which is cooled by and delivered from evaporator 140 to wet coil 112 via liquid branch 148. In some cases, wet coil 112 is configured to cool the first air stream to below the dew point temperature, which causes moisture in the air to condense on the coils, which, in turn lowers the humidity of the first air stream. The first liquid stream, which absorbs heat from the first air stream in wet coil 112 is returned to evaporator 140 for cooling via liquid branch 150.

[0047] In some cases, wet coil 112 cools the first air stream to a temperature that is lower than the target/set point temperature for the enclosed space. In such cases, the first air stream flows from wet coil 112 into LAHX1 114. LAHX1 114 heats (i.e. increases the temperature) the first air stream using the second liquid stream, which is heated by and delivered from condenser 138 via liquid branch 174. The first air stream exits LAHX1 114 and is delivered to the enclosed space as supply air via SA outlet 122. The second liquid stream, which is partially precooled by rejecting heat into the first air stream in LAHX1 114 is delivered to LAHX2 136 via liquid branch 156.

[0048] The second liquid stream is sensibly pre-cooled in LAHX2 136 using the second air stream, which is outdoor air that enters second plenum 132 via OA damper 142 and pass through LAMEE 134 before circulating through LAHX2 136. The pre-cooled second liquid stream is delivered from LAHX2 136 to LAMEE 134 via liquid branch 162. LAMEE 134 evaporatively cools the second liquid stream using the second air stream and delivers the fully cooled second liquid stream to condenser 138 of chiller 130.

[0049] FIG. 2B depicts another operational mode/configuration of system 100 during off-peak periods. The mode/configuration of system 100 in FIG. 2B is the same as in FIG. 2A, except that OA damper 142 is closed, bypass damper 144 is opened, and LAMEE 134 is bypassed (and can be deactivated). The mode/configuration of system 100 in FIG. 2B reflects conditions in which it is possible for LAHX2 136 to fully cool the second liquid stream delivered to condenser 138 of chiller 130 without LAMEE 134. The operation of system 100 in FIG. 2B is the same as that described above with reference to FIG. 2A, except that the second liquid stream is sensibly fully cooled in LAHX2 136 using the second air stream, which enters second plenum 132 via bypass damper 144 downstream of LAMEE 134 and upstream of LAHX2 136, and the second liquid stream is delivered to condenser 138 of chiller 130 via liquid branch 162 without circulating through LAMEE 134.

[0050] In FIG. 2C, system 100 is configured to modulate the conditions in an enclosed space during peak conditions, for example when the outdoor air enthalpy is lower than the target/set point indoor air/RA enthalpy. As an example, the ambient conditions in peak periods can include relatively high outdoor air temperatures and relatively low or moderate humidity levels. In FIG. 2C, OA damper 120 and RA damper 122 of first plenum 110 are open. In this mode/configuration, the first air stream includes outdoor air flowing through LAHX3 116 and EC 118 and mixing with return air entering plenum 110 via RA damper 122. The first air stream including a mix of outdoor and return air then flows through wet coil 112 and LAHX1 114 before being delivered to the enclosed space as supply air via SA outlet 122.

[0051] In this mode/configuration, the first liquid stream flows between evaporator 140 of chiller 130 and wet coil 112 via liquid branches 148 (cold/supply) and 150 (hot/retum). The second liquid stream flows from condenser 138 of chiller 130 and from LAHX3 116 to LAHX2136 via liquid branches 174 and 156, respectively, and valve 154. The second liquid stream then flows from LAHX2 136 to LAMEE 134 via liquid branch 162 and from LAMEE 134 back to LAHX3 116 and condenser 138 of chiller 130 via liquid branches 156 and 172, respectively, and valve 168. For simplicity and clarity, the multiple liquid junctions and associated control valves depicted in FIG. 1 are not shown in FIG. 2C.

[0052] In operation, outdoor air enters first plenum 110 via OA damper 120 and flows through first plenum 110 as the first air stream through LAHX3 116. In examples, LAHX3 116 is a dry coil configured to directly and sensibly pre-cool the first air stream using the second cooling liquid delivered to LAHX3 116 from LAMEE 134 via liquid branch 170. The first air stream exits LAHX3 116 and flows through EC 118. Employing LAHX3 116 as a pre-cooling coil upstream EC 118 can have a number of benefits and advantages. For example, employing a precooling coil can allow for use of a greater range of types of evaporative cooling units like the examples including LAMEE 134 to replace or reduce the load on a mechanical liquid chiller, because relatively warm water can be used for precooling. Additionally, employing a pre-cooling coil may significantly reduce water consumption during the evaporative cooling process by EC 118.

[0053] EC 118 is configured to evaporatively cool the first air stream using a cooling/evaporative liquid. EC 118 can use the cooling potential in both the first air stream and the liquid to reject heat. In an example, EC 118 can cool the first air stream to a temperature approaching the wet bulb (WB) temperature of the air leaving LAHX3 116. In examples according to this disclosure, EC 118 is configured to operate adiabatically, which is why EC 118 is not depicted as connected to a source of liquid. In an adiabatic operational mode, EC 118 can be configured to circulate water or another cooling liquid EC 118 in a closed liquid circuit (although, in some examples, a source of make-up water may be required). During adiabatic operation of EC 118, a temperature of the water (or other cooling liquid) can remain generally constant or have minimal temperature fluctuations. In examples, as the first air stream passes through EC 118, it can be cooled adiabatically such that its temperature is reduced, its humidity level increases, and its overall enthalpy remains approximately constant. In such adiabatic operation, the temperature of the liquid circulating through EC 118 can remain relatively constant and can therefore be recirculated through the device in a closed circuit.

[0054] The first air stream (conditioned outdoor air) exits EC 118 and mixes with return air entering first plenum 110 via RA damper 122 between EC 118 and wet coil 112. The mixture of outdoor air and return air flows through first plenum 110 as the first air stream through wet coil 112. Wet coil 112 cools the first air stream using the first liquid stream, which is cooled by and delivered from evaporator 140 to wet coil 112 via liquid branch 148. In some cases, wet coil 112 is configured to cool the first air stream to below the dew point temperature, which causes moisture in the air to condense on the coils, which, in turn lowers the humidity of the first air stream. The first liquid stream, which absorbs heat from the first air stream in wet coil 112 is returned to evaporator 140 for cooling via liquid branch 150.

[0055] In the example of FIG. 2C, wet coil 112 cools the first air stream to the target/set point temperature for the enclosed space (but not below the target/set point temperature). As such, in the example of FIG. 2C, LAHX1 114 is deactivated and does not affect the temperature or humidity of the first air stream that exits wet coil 112. The first air stream therefor flows though deactivated LAHX1 114 and is delivered to the enclosed space as supply air via SA outlet 122. [0056] The second liquid stream is sensibly pre-cooled in LAHX2 136 using the second air stream, which is outdoor air that enters second plenum 132 via OA damper 142 and pass through LAMEE 134 before circulating through LAHX2 136. As noted above, the second liquid stream is delivered to LAHX2 136 from LAHX3 116 AND condenser 138 via liquid branches 156 and 174, respectively, and valve 154. The pre-cooled second liquid stream is delivered from LAHX2 136 to LAMEE 134 via liquid branch 162. LAMEE 134 evaporatively cools the second liquid stream using the second air stream and delivers the fully cooled second liquid stream to LAHX3 116 and condenser 138 of chiller 130 via liquid branches 170 and 172, respectively, and valve 168.

[0057] FIG. 2D depicts another operational mode/ configuration of system 100 during peak periods. The mode/ configuration of system 100 in FIG. 2d is the same as in FIG. 2C, except that OA damper 142 is closed, bypass damper 144 is opened, and LAMEE 134 is bypassed (and can be deactivated). The mode/configuration of system 100 in FIG. 2D reflects conditions in which it is possible for LAHX2 136 to fully cool the second liquid stream delivered to condenser 138 of chiller 130 and LAHX3 116 without LAMEE 134. The operation of system 100 in FIG. 2D is the same as that described above with reference to FIG. 2C, except that the second liquid stream is sensibly fully cooled in LAHX2 136 using the second air stream, which enters second plenum 132 via bypass damper 144 downstream of LAMEE 134 and upstream of LAHX2 136. The second liquid stream is delivered from LAHX2 136 to condenser 138 of chiller 130 via liquid branch 162, liquid branch 172, and valve 168 and from LAHX2 136 to LAHX3 116 via liquid branch 162, liquid branch 170, and valve 168.

[0058] In another example similar to that depicted in FIGS . 2C and 2B, system 100 is configured to modulate the conditions in an enclosed space by conditioning a mixture of OA and RA and delivering the conditioned mixture as supply air to the enclosed space. In such an example with reference to FIG. 2C, both OA damper 120 and RA damper 122 of first plenum 110 are open. In this mode/configuration, the first air stream includes outdoor air flowing through LAHX3 116 and EC 118 and mixing with return air entering plenum 110 via RA damper 122. The first air stream including a mix of outdoor and return air then flows through wet coil 112 and LAHX1 114 before being delivered to the enclosed space as supply air via SA outlet 122.

[0059] In this mode/configuration, the first liquid stream flows between evaporator 140 of chiller 130 and wet coil 112 via liquid branches 148 (cold/supply) and 150 (hot/retum). The second liquid stream flows from condenser 138 of chiller 130 and from LAHX3 116 to LAHX2136 via liquid branches 174 and 156, respectively, and valve 154. The second liquid stream then flows from LAHX2 136 to LAMEE 134 via liquid branch 162 and from LAMEE 134 back to LAHX3 116 and condenser 138 of chiller 130 via liquid branches 156 and 172, respectively, and valve 168. For simplicity and clarity, the multiple liquid junctions and associated control valves depicted in FIG. 1 are not shown in FIG. 2C.

[0060] In operation, outdoor air enters first plenum 110 via OA damper 120 and flows through first plenum 110 as the first air stream through LAHX3 116. In examples, LAHX3 116 is a dry coil configured to directly and sensibly pre-cool the first air stream using the second cooling liquid delivered to LAHX3 116 from LAMEE 134 via liquid branch 170. The first air stream exits LAHX3 116 and flows through EC 118. [0061] EC 118 is configured to evaporatively cool the first air stream using a cooling/evaporative liquid. EC 118 can use the cooling potential in both the first air stream and the liquid to reject heat. In an example, EC 118 can cool the first air stream to a temperature approaching the wet bulb (WB) temperature of the air leaving LAHX3 116. In examples according to this disclosure, EC 118 is configured to operate adiabatically, which is why EC 118 is not depicted as connected to a source of liquid. In an adiabatic operational mode, EC 118 can be configured to circulate water or another cooling liquid EC 118 in a closed liquid circuit (although, in some examples, a source of make-up water may be required). During adiabatic operation of EC 118, a temperature of the water (or other cooling liquid) can remain generally constant or have minimal temperature fluctuations. In examples, as the first air stream passes through EC 118, it can be cooled adiabatically such that its temperature is reduced, its humidity level increases, and its overall enthalpy remains approximately constant. In such adiabatic operation, the temperature of the liquid circulating through EC 118 can remain relatively constant and can therefore be recirculated through the device in a closed circuit.

[0062] The first air stream (conditioned outdoor air) exits EC 118 and mixes with return air entering first plenum 110 via RA damper 122 between EC 118 and wet coil 112. The mixture of outdoor air and return air flows through first plenum 110 as the first air stream through wet coil 112. Wet coil 112 cools the first air stream using the first liquid stream, which is cooled by and delivered from evaporator 140 to wet coil 112 via liquid branch 148. In some cases, wet coil 112 is configured to cool the first air stream to below the dew point temperature, which causes moisture in the air to condense on the coils, which, in turn towers the humidity of the first air stream. The first liquid stream, which absorbs heat from the first air stream in wet coil 112 is returned to evaporator 140 for cooling via liquid branch 150.

[0063] In the example of FIG. 2C, wet coil 112 cools the first air stream to the target/set point temperature for the enclosed space (but not below the target/set point temperature). As such, in the example of FIG. 2C, LAHX1 114 is deactivated and does not affect the temperature or humidity of the first air stream that exits wet coil 112. The first air stream therefor flows though deactivated LAHX1 114 and is delivered to the enclosed space as supply air via SA outlet 122. [0064] The second liquid stream is sensibly pre-cooled in LAHX2 136 using the second air stream, which is outdoor air that enters second plenum 132 via OA damper 142 and pass through LAMEE 134 before circulating through LAHX2 136. As noted above, the second liquid stream is delivered to LAHX2 136 from LAHX3 116 AND condenser 138 via liquid branches 156 and 174, respectively, and valve 154. The pre-cooled second liquid stream is delivered from LAHX2 136 to LAMEE 134 via liquid branch 162. LAMEE 134 evaporatively cools the second liquid stream using the second air stream and delivers the fully cooled second liquid stream to LAHX3 116 and condenser 138 of chiller 130 via liquid branches 170 and 172, respectively, and valve 168.

[0065] Examples according to this disclosure, including all of the above-described variations of system 100 can include a system controller that is configured to control various aspects of the operation/functions of such systems. For example, a system controller can be communicatively connected to and configured to control one or more components of first conditioning system 102, second conditioning system 104, and/or the liquid transport system conveying liquids between the two systems. In an example, a system controller is configured to control OA damper 120, RA damper 122, OA damper 142, bypass damper 144, and one or more fans to change the sources, flow route, and/or flow rate of the first and/or second air streams through first plenum 110 and second plenum 132. Additionally or alternatively, a controller can be configured to control pumps and/or one or more of valves 154, 160, 164, 168, and 176 to change the sources, flow route, and/or flow rate of the first and/or second liquid streams.

[0066] For example, the controller can be configured to control operation of a system in accordance with this disclosure between peak and off-peak conditions based on OA and RA enthalpy. As noted above, OA enthalpy and RA enthalpy can be employed to select the mode(s) of operation of conditioning systems in accordance with this disclosure. OA and RA enthalpy can be calculated or at least estimated in a number of ways. For example, sensors can measure dry bulb and wet bulb temperature, from, at a known elevation, a controller can estimate enthalpy. As another example, dry bulb temperature and relative humidity can be measured from, at a known elevation, a controller can estimate enthalpy. [0067] A system controller can include hardware, software, and combinations thereof to implement the functions attributed to the controller herein. The controller can be an analog, digital, or combination analog and digital controller including a number of components. As examples, the controller can include ICB(s), PCB(s), processor(s), data storage devices, switches, relays, etcetera. Examples of processors can include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry.

[0068] Storage devices, in some examples, are described as a computer-readable storage medium. In some examples, storage devices include a temporary memory, meaning that a primary purpose of one or more storage devices is not long-term storage. Storage devices are, in some examples, described as a volatile memory, meaning that storage devices do not maintain stored contents when the computer is turned off. Examples of volatile memories include random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), and other forms of volatile memories. Storage devices of the controller can also include long-term storage, including, e.g. non-volatile storage. Examples of non-volatile storage elements include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. The data storage devices can be used to store program instructions for execution by processor(s) of the controller. The storage devices, for example, are used by software, applications, algorithms, as examples, running on and/or executed by the controller.

[0069] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0070] All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

[0071] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0072] Method examples included herein can be machine or computer- implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, the code can be tangibly stored on one or more volatile or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.

[0073] Examples, as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules may be hardware, software, or firmware communicatively coupled to one or more processors in order to carry out the operations described herein. Modules may hardware modules, and as such modules may be considered tangible entities capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine-readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations. Accordingly, the term hardware module is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software; the general- purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time. Modules may also be software or firmware modules, which operate to perform the methodologies described herein. [0074] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. [0075] Various aspects ofthe disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A system for modulating the conditions in an enclosed space, the system comprising: a first conditioning system configured to condition a first air stream and direct the conditioned first air stream into the enclosed space, the first conditioning system comprising: a first plenum through which the first air stream is configured to be directed into the enclosed space; a wet coil in the first plenum; and a first liquid-to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; a second conditioning system fluidically connected to the first conditioning system and configured to condition one or more liquid streams, the second conditioning system comprising: a second plenum through which a second air stream is configured to be directed; a liquid-to-air membrane energy exchanger (LAMEE) in the second plenum and comprising a plurality of liquid and air channels, adjacent pairs of which are separated by a permeable membrane; and a second liquid-to-air heat exchanger (LAHX2) downstream of the LAMEE in the second plenum; and a liquid transport system configured to transport the one or more liquid streams in and between the first conditioning system and the second conditioning system.

2. The system of claim 1, wherein the second conditioning system further comprises: a mechanical liquid chiller fluidically connected to one or more of the wet coil, the LAHX1, the LAMEE, and the LAHX2, the mechanical liquid chiller configured to sensibly condition all of the one or more liquid streams.

3. The system of claim 2, wherein: the wet coil is configured to cool and dehumidify the first air stream using a first liquid stream of the one or more liquid streams; the LAHX1 is configured to heat the first air stream using a second liquid stream of the one or more liquid streams.

4. The system of claim 3, wherein: the LAHX2 is configured to sensibly pre-cool the second liquid stream using the second air stream and deliver the pre-cooled second liquid stream to the LAMEE; the LAMEE is configured to evaporatively cool the second liquid stream using the second air stream and deliver the cooled second liquid stream to the mechanical liquid chiller; and the mechanical liquid chiller is configured to cool the first liquid stream and deliver the cooled first liquid stream to the wet coil.

5. The system of claim 4, wherein the mechanical liquid chiller comprises: a compressor; a condenser; an expansion valve; and an evaporator, wherein the chiller is configured to circulate a refrigerant through the compressor, condenser, expansion valve, and evaporator and exchange heat between the refrigerant and the first liquid stream in the evaporator and exchange heat between the refrigerant and the second liquid stream in the condenser.

6. The system of claim 2, wherein the first conditioning system further comprises: a dry coil upstream of the wet coil in the first plenum; and a evaporative cooler (EC) between the wet coil and the dry coil in the first plenum.

7. The system of claim 6, wherein: the wet coil is configured to cool and dehumidify the first air stream using a first liquid stream of the one or more liquid streams; the LAHX1 is configured to heat the first air stream using a second liquid stream of the one or more liquid streams.

8. The system of claim 7, further comprising: a first damper upstream of the LAMEE in the second plenum; and a second damper between the LAMEE and the LAHX2 in the second plenum.

9. The system of claim 8, wherein: the first damper is open and the second damper is closed; the LAHX2 is configured to sensibly pre-cool the second liquid stream using the second air stream and deliver the pre-cooled second liquid stream to the LAMEE; the LAMEE is configured to evaporatively cool the second liquid stream using the second air stream and deliver the cooled second liquid stream to the mechanical liquid chiller; and the mechanical liquid chiller is configured to cool the first liquid stream and deliver the cooled first liquid stream to the wet coil.

10. The system of claim 9, wherein: the first damper is closed and the second damper is open; the LAHX2 is configured to sensibly cool the second liquid stream using the second air stream and deliver the cooled second liquid stream to the mechanical liquid chiller; and the mechanical liquid chiller is configured to cool the first liquid stream and deliver the cooled first liquid stream to the wet coil.

11. The system of claim 10, wherein: the dry coil is configured to sensibly cool the first air stream using the second liquid stream; and the EC is configured to evaporatively cool and humidify the first air stream.

12. The system of claim 11, wherein: the LAMEE is configured to evaporatively cool the second liquid stream using the second air stream and deliver the cooled second liquid stream to the mechanical liquid chiller and the dry coil.

13. The system of claim 12, further comprising: an outdoor air damper upstream of the dry coil in the first plenum; and a return air damper between the EC and the wet coil in the first plenum.

14. The system of claim 13, wherein: the outdoor air damper and the return air damper are open; the first air stream comprises outdoor air that enters the first plenum through the outdoor air damper and flows through the dry coil and the EC and mixes with return air from the enclosed space entering the first plenum through the return air damper and flows through the wet coil and the LAHX1; and the first air stream flows out of the LAHX1 into the enclosed space as supply air.

15. The system of claim 13, wherein: the outdoor air damper is closed and the return air damper is open; the first air stream comprises return air from the enclosed space entering the first plenum through the return air damper and flows through the wet coil and the LAHX1; and the first air stream flows out of the LAHX1 into the enclosed space as supply air.

16. The system of claim 13, wherein: the outdoor air damper is open and the return air damper is closed; the first air stream comprises outdoor air that enters the first plenum through the outdoor air damper and flows through the dry coil, the EC, the wet coil, and the LAHX1; and the first air stream flows out of the LAHX1 into the enclosed space as supply air.

17. The system of claim 6, wherein: the LAHX2 is configured to sensibly pre-cool the second liquid stream using the second air stream and deliver the pre-cooled second liquid stream to the LAMEE; the LAMEE is configured to evaporatively cool the second liquid stream using the second air stream and deliver the cooled second liquid stream to the mechanical liquid chiller and the dry coil; and the mechanical liquid chiller is configured to cool the first liquid stream and deliver the cooled first liquid stream to the wet coil.

18. The system of claim 17, wherein: the dry coil is configured to sensibly cool the first air stream using the second liquid stream; and the EC is configured to evaporatively cool and humidify the first air stream.

19. The system of claim 18, further comprising: an outdoor air damper upstream of dry coil in the first plenum; and a return air damper between the EC and the wet coil in the first plenum.

20. The system of claim 19, wherein: the outdoor air damper and the return air damper are open; the first air stream comprises outdoor air that enters the first plenum through the outdoor air damper and flows through the dry coil and the EC and mixes with return air from the enclosed space entering the first plenum through the return air damper and flows through the wet coil and the LAHX1; and the first air stream flows out of the LAHX1 into the enclosed space as supply air.

21. The system of claim 19, wherein: the outdoor air damper is closed and the return air damper is open; the first air stream comprises return air from the enclosed space entering the first plenum through the return air damper and flows through the wet coil and the LAHX1; and the first air stream flows out of the LAHX1 into the enclosed space as supply air.

22. The system of claim 6, wherein the mechanical liquid chiller comprises: a compressor; a condenser; an expansion valve; and an evaporator, wherein the chiller is configured to circulate a refrigerant through the compressor, condenser, expansion valve, and evaporator and exchange heat between the refrigerant and the first liquid stream in the evaporator and exchange heat between the refrigerant and the second liquid stream in the condenser.

23. A method of modulating the conditions in an enclosed space, the method comprising: cooling and dehumidifying a first air stream using a first liquid stream in a wet coil arranged in a first plenum; heating the first air stream using a second liquid stream in a first liquid-to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; delivering the first air stream from the LAHX1 into the enclosed space as supply air; cooling the first liquid stream using a mechanical liquid chiller; delivering the first liquid stream from the mechanical liquid chiller to the wet coil; sensibly pre-cooling the second liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; evaporatively cooling the second liquid stream using the second air stream in a liquid-to-air membrane energy exchanger (LAMEE) upstream of the LAHX2 in the second plenum; and delivering the cooled second liquid stream from the LAMEE to the mechanical liquid chiller.

24. The method of claim 23, further comprising: sensibly cooling the first air stream using a first liquid stream in a second liquid- to-air heat exchanger (LAHX2) arranged upstream of the wet coil in the first plenum; and evaporatively cooling the first air stream using an evaporative cooler (EC) arranged downstream of the LAHX1 and upstream of the LAHX2 in the first plenum.

25. The method of claim 23 or claim 24, wherein the first air stream is outdoor air.

26. The method of claim 23, wherein the first air stream is return air from the enclosed space.

27. The method of claim 23 or claim 24, wherein the first air stream is a mixture of outdoor air and return air from the enclosed space.

28. The method of claim 23, further comprising: closing an outdoor air damper at an inlet of the first plenum; and opening a return air damper upstream of the wet coil in the first plenum such that the first air stream is return air from the enclosed space.

29. The method of claim 24, further comprising: opening an outdoor air damper at an inlet of and upstream of the LAHX2 in the first plenum; and closing a return air damper between the EC and the wet coil in the first plenum such that the first air stream is outdoor air.

30. The method of claim 24, further comprising: opening an outdoor air damper at an inlet of and upstream of the LAHX2 in the first plenum; and opening a return air damper between the EC and the wet coil in the first plenum such that the first air stream flowing through the LAHX2 and the EC is outdoor air and the first air stream flowing through the wet coil and the LAHX1 is a mixture of outdoor air and return air from the enclosed space.

31. The method of claim 23, further comprising: determining an outdoor air enthalpy based on one or more of a dry bulb temperature of the outdoor air, a wet bulb temperature of the outdoor air, relative humidity of the outdoor air, and an elevation; and comparing the outdoor air enthalpy to a target indoor air enthalpy.

32. The method of claim 31, further comprising: on condition that the determined outdoor air enthalpy is less than the target indoor air enthalpy: sensibly cooling the first air stream using a first liquid stream in a second liquid-to-air heat exchanger (LAHX2) arranged upstream of the wet coil in the first plenum; and evaporatively cooling the first air stream using an evaporative cooler (EC) arranged downstream of the LAHX1 and upstream of the LAHX2 in the first plenum.

33. A method of modulating the conditions in an enclosed space, the method comprising: cooling and dehumidifying a first air stream using a first liquid stream in a wet coil arranged in a first plenum; heating the first air stream using a second liquid stream in a first liquid-to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; delivering the first air stream from the LAHX1 into the enclosed space as supply air; cooling the first liquid stream using a mechanical liquid chiller; delivering the first liquid stream from the mechanical liquid chiller to the wet coil; sensibly cooling the second liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; and delivering the cooled second liquid stream from the LAHX2 to the mechanical liquid chiller.

34. A method of modulating the conditions in an enclosed space, the method comprising: cooling and dehumidifying a first air stream using a first liquid stream in a wet coil arranged in a first plenum; heating the first air stream using a second liquid stream in a first liquid-to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; delivering the first air stream from the LAHX1 into the enclosed space as supply air; sensibly pre-cooling the second liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; evaporatively cooling the second liquid stream using the second air stream in a liquid-to-air membrane energy exchanger (LAMEE) upstream of the LAHX2 in the second plenum; and delivering the cooled second liquid stream from the LAMEE to the wet coil.

35. A method of modulating the conditions in an enclosed space, the method comprising: sensibly cooling a first air stream using a first liquid stream in a first liquid-to-air heat exchanger (LAHX1) arranged in a first plenum; evaporatively cooling the first air stream using an evaporative cooler (EC) arranged downstream of the LAHX1 in the first plenum; cooling and dehumidifying the first air stream using a second liquid stream in a wet coil downstream of the EC in the first plenum; delivering the first air stream from the wet coil into the enclosed space as supply air; cooling the second liquid stream using a mechanical liquid chiller; delivering the second liquid stream from the mechanical liquid chiller to the wet coil; sensibly pre-cooling the first liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; evaporatively cooling the first liquid stream using the second air stream in a liquid-to-air membrane energy exchanger (LAMEE) upstream of the LAHX2 in the second plenum; and delivering the cooled first liquid stream from the LAMEE to the LAHX1.

36. A method of modulating the conditions in an enclosed space, the method comprising: sensibly cooling outdoor air using a first liquid stream in a first liquid-to-air heat exchanger (LAHX1) arranged in a first plenum; evaporatively cooling the outdoor air using an evaporative cooler (EC) arranged downstream of the LAHX1 in the first plenum; mixing the outdoor air with return air from the enclosed space downstream of the EC in the first plenum; cooling and/or dehumidifying the mixture of outdoor air and return air using a second liquid stream in a wet coil downstream of the EC in the first plenum; delivering the mixture of outdoor air and return air from the wet coil into the enclosed space as supply air; cooling the second liquid stream using a mechanical liquid chiller; delivering the second liquid stream from the mechanical liquid chiller to the wet coil; sensibly cooling the first liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; and delivering the cooled first liquid stream from the LAHX2 to the LAHX1.

37. A method of modulating the conditions in an enclosed space, the method comprising: determining an outdoor air enthalpy based on one or more of a dry bulb temperature of the outdoor air, a wet bulb temperature of the outdoor air, relative humidity of the outdoor air, and an elevation; comparing the outdoor air enthalpy to a target indoor air enthalpy; on condition that the determined outdoor air enthalpy is greater than the target indoor air enthalpy: cooling and dehumidifying a first air stream using a first liquid stream in a wet coil arranged in a first plenum; heating the first air stream using a second liquid stream in a first liquid- to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; delivering the first air stream from the LAHX1 into the enclosed space as supply air; cooling the first liquid stream using a mechanical liquid chiller; delivering the first liquid stream from the mechanical liquid chiller to the wet coil; sensibly pre-cooling the second liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; evaporatively cooling the second liquid stream using the second air stream in a liquid-to-air membrane energy exchanger (LAMEE) upstream of the LAHX2 in the second plenum; and delivering the cooled second liquid stream from the LAMEE to the mechanical liquid chiller; on condition that the determined outdoor air enthalpy is greater than the target indoor air enthalpy: cooling and dehumidifying a first air stream using a first liquid stream in a wet coil arranged in a first plenum; heating the first air stream using a second liquid stream in a first liquid- to-air heat exchanger (LAHX1) downstream of the wet coil in the first plenum; delivering the first air stream from the LAHX1 into the enclosed space as supply air; cooling the first liquid stream using a mechanical liquid chiller; delivering the first liquid stream from the mechanical liquid chiller to the wet coil; sensibly pre-cooling the second liquid stream using a second air stream in a second liquid-to-air heat exchanger (LAHX2) in a second plenum; evaporatively cooling the second liquid stream using the second air stream in a liquid-to-air membrane energy exchanger (LAMEE) upstream of the LAHX2 in the second plenum; delivering the cooled second liquid stream from the LAMEE to the mechanical liquid chiller; sensibly cooling the first air stream using a first liquid stream in a second liquid-to-air heat exchanger (LAHX2) arranged upstream of the wet coil in the first plenum; and evaporatively cooling the first air stream using an evaporative cooler

(EC) arranged downstream of the LAHX1 and upstream of the LAHX2 in the first plenum.