Cooling recovery system and method

Abstract

To provide a novel cooling recovery system and method.SOLUTION: A cooling recovery system and method are disclosed. A fluid, such as water, is cooled and supplied to the cooling coils to cool and dehumidify the air passing over the cooling coils. Fluid is discharged from the cooling coil through the outlet, and at least a portion of the fluid from the outlet of the cooling coil is supplied to the inlet of the heat transfer coil to reheat air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil and its warmer temperature serves to reheat the air passing over the heat transfer coil.SELECTED DRAWING: Figure 2

Description

Related Applications

[0001]

[0001] This application claims priority to U.S. patent application Ser. No. 11 / 852,225, filed Sep. 7, 2007, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002]

[0002] This disclosure relates generally to air conditioning in facilities, and more particularly to cooling, dehumidifying, and heating systems and processes for reducing energy waste and lowering operating costs in facilities. [Background technology]

[0003]

[0003] The environment of a facility, such as a residential, commercial, industrial, or institutional building, is always tightly controlled, as temperature and humidity must fall within relatively narrow ranges to accommodate human comfort, hygiene, and safety. Every year, mold, mildew, and other biological growth in many facilities can damage the facility and adversely affect its occupants, causing widespread damage. Biological growth is particularly prevalent in warm, humid areas. To reduce the likelihood of biological growth, the relative humidity of the air within the facility must be reduced. Therefore, moisture is removed from the air in a process known as dehumidification.

[0004]

[0004] Traditional approaches to controlling humidity and temperature within facilities are energy intensive, resulting in high costs of operating their cooling, dehumidifying, and heating systems. Saving either cost or energy often leads to improper use of such systems, defeating the purpose of the systems. Worse yet, misuse of cooling, dehumidifying, and heating systems allows for biological growth. For example, in humid climates, cooling systems may be left running 24 hours a day, 7 days a week, even when the facility is unoccupied, to reduce the likelihood of biological growth. This wastes a great deal of energy.

[0005] 1 is a schematic diagram of a prior art cooling, dehumidification, and reheat system 01-0001 including one or more air handling units (AHUs) 01-0003, valves 01-0055, 01-0080, etc. A fluid, such as water, is typically cooled in a cooling plant 01-0040, conveyed through cooling fluid supply piping 01-0045, 01-0090 to one or more AHUs 01-0003, and returned to the one or more cooling plants 01-0040 through cooling fluid return piping 01-0050, 01-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units contained within the cooling plants 01-0040.

[0006] Fluid is heated in the heating plant 01-0035 and conveyed through heating fluid supply piping 01-0075, 01-0105 to one or more temperature control zones 01-0065 and returned to the one or more heating plants 01-0035 through heating fluid return piping 01-0070, 01-0110. Typically, the heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant 01-0035.

[0007]

[0007] The flow of cooling fluid to the AHU 01-0003 is controlled by selectively adjusting the flow control valve 01-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valve 01-0080. The cooling fluid flow control valve 01-0055 is located downstream of the AHU 01-0003, and the heat source fluid flow control valve 01-0080 is located downstream of the heating coil 01-0030. Alternatively, the valves 01-0055 and 01-0080 may be located upstream of the AHU 01-0003 or upstream of the heating coil 01-0030, respectively.

[0008]

[0008] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, the cooling fluid is distributed through cooling coils 01-0015 or other heat exchange units of the AHU 01-0003. A fan 01-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 01-0002 and fresh air 01-0005 mixed in varying proportions, generates a mixed air flow 01-0010, and delivers it through one or more cooling coils 01-0015.

[0009] The mixed air stream 01-0010 may be passed through a filter 01-0100 or may remain unfiltered. As the air moves through the cooling coil 01-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When the mixed air stream 01-0010 or the conditions in the conditioned space 01-0171 require, the conditioned air 01-0025 exiting the cooling coil 01-0015 is cooled to the point where moisture is removed from the air and the relative humidity of the conditioned space is kept low enough to reduce the possibility of biological growth.

[0010]

[0010] Reducing the temperature of the conditioned air 01-0025 condenses moisture from the air, drying it out. Thus, the dry, cool conditioned air 01-0025 is delivered to individual offices, rooms, or other locations within facility 01-0171 through discharge line 01-0020 or other delivery system. The dry, cool conditioned air 01-0025 is typically too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 01-0025 is delivered to a temperature control box 01-0065 that contains a heating coil 01-0030.

[0011]

[0011] Warm or hot fluid can be used to condition air or add heat to air from one or more heat sources. For example, hot water can be distributed through a heating coil 01-0030 or other heat exchange unit in a temperature control box 01-0065. The temperature control box 01-0065 can be constant volume or variable volume. The temperature control box 01-0065 includes a control system that controls a control valve 01-0080, which controls the volume or pressure of the heating source fluid passed through the heating coil 01-0030. Heated fluid is generated in one or more heating plants 01-0035 and distributed to the temperature control zones 01-0065 through heating fluid supply lines 01-0075, 01-0105 and heating fluid return lines 01-0070, 01-0110. The temperature of the supply air exiting the heating coil 01-0030 and entering the space to be conditioned, either directly or through a distribution system 01-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 01-0080 to maintain occupant needs or the needs of the process cooling load 01-0171.

[0012]

[0012] As a result of heat exchange in the cooling coil 01-0015, particularly during the summer months when dehumidification loads are typically present, the temperature of the air 01-0010 passing over (i.e., along) the coil drops, removing moisture, while the temperature of the fluid passing through the coil rises to approximately 55°F to 60°F. This heated, or spent, cooling fluid may be collected in separate spent fluid lines 01-0050, 01-0085 and delivered to the inlet of the cooling system 01-0040. Furthermore, this process may also dehumidify the air as a result of heat transfer from the unconditioned or partially conditioned air to the chilled water at or near the cooling coil 01-0015.

[0013] Typically, to handle maximum cooling and dehumidification loads, the cooling coil requires a supply of cooling fluid from the chiller through the cooling fluid piping at a temperature between 34°F and 45°F. Typically, the cooling coil provides fluid that is returned to the chiller through the cooling fluid piping at a temperature between 55°F and 60°F. Cooling coils are conventionally designed to provide a discharge air temperature between 50°F and 55°F needed to meet the facility's occupant comfort needs or process cooling load needs.

[0014] A maximum discharge air temperature of about 55°F is typically used during dehumidification to reduce moisture in the airstream entering the facility's conditioned space. The minimum discharge air temperature required by the operating load may be on the order of 40°F to 45°F. Cooling coils are typically sized for a face velocity of 500 to 600 ft / min, calculated by dividing the volume of airflow in cubic feet per minute (CFM) by the number of square feet of coil surface through which the air passes, but can have lower and higher face velocities. Finally, cooling coils are configured with between four and eight rows of heat transfer piping, but may have more or fewer rows of heat transfer.

[0015] The heating coils in such systems typically require a heating fluid supply temperature of between 150°F and 200°F, supplied through the heating fluid piping from the heating plant, and a heating fluid return temperature of between 120°F and 160°F, returned through the heating fluid piping to the heating plant. The heating coils are designed to provide a discharge air temperature of between 60°F and 110°F. A maximum discharge air temperature of about 110°F is generally used to reduce the amount of hot air stratification that occurs when the heated air enters the conditioned space or process load, although higher temperatures can be used.

[0016] During dehumidification operation, no heating of the space or process load should be required, so the discharge air temperature may be 60°F to 70°F. The heating coils are sized to accommodate a face velocity of 800 ft / min to 1,000 ft / min, calculated by dividing the amount of airflow in cubic feet per minute (CFM) by the number of square feet of coil surface through which the air passes. The heating coils are typically configured in one or more rows.

[0017] To reduce energy waste and operating costs, many facility operators deemphasize dehumidification and operate cooling systems at higher air discharge temperatures. This reduces the amount of reheat energy required and the cooling load, but reduces dehumidification and results in higher relative humidity levels in the facility. Higher relative humidity levels can encourage biological growth.

[0018] Compounding energy waste also occurs. A supply air temperature of approximately 55°F is too cold for occupant comfort in most climates for most of the year. Therefore, the 55°F supply air temperature is preheated or "reheated" to a temperature that meets occupant comfort standards or handles process cooling loads.

[0019]

[0019] The heat source for the reheat process is usually a new energy source. Electric heaters, radiant panels, and heating coils using hot water generated by a hot water heater or boiler are common sources of heat for the reheat process. The fuel for the boiler or hot water heater can be wood chips, natural gas, oil, coal, peat, or any other combustible fuel. Electricity can also be used to heat the water. Heat recovered from the condenser side of a cooling system can be used to preheat the air, but these systems are less common. The reheat coil is installed downstream of the cooling coil in the system. The reheat coil can be located in the same vessel as the cooling coil or remotely.

[0020]

[0020] For most water-based reheat systems, the reheat coil requires very high water temperatures, typically 150°F to 200°F. These high water temperatures waste energy in the boiler or hot water heater because their energy efficiency decreases as water temperature increases. The reheat energy adds a cooling load to the facility because much of the heat added to the air to meet comfort requirements or process cooling load needs is returned to the AHU system via the return air system. Another compounding energy waste occurs because heat is constantly being added to keep facility spaces comfortable or to meet process cooling requirements. However, this same heat is removed from the air when dehumidifying it by lowering the supply air temperature.

[0021] An alternative cooling, dehumidification and reheat cycle is as follows: Air is returned to the AHU where it is mixed with fresh air in varying proportions and is now called "mixed air." In many parts of the United States, the mixed air is warm and humid for most of the year, and is cooled by the cooling system to a temperature of about 55°F to dehumidify it, after which it is called "supply air."

[0022]

[0022] Supply air is reheated to varying degrees to provide occupant comfort or to meet the needs of a process cooling load and is referred to as "reheated air." The reheated air is delivered to the occupied space or process cooling load. Additional heat is added to the occupied space air or air by the process load to create "preheated air." Once the preheated air leaves the conditioned space or process load, it is referred to as "return air." Return air contains the heat generated by the conditioned space or process cooling load as well as the heat given to the air during the reheating process.

[0023] In a typical system, the water from the cooling coil is returned directly to the source of the cooling system, which is typically a chiller plant. The return chilled water carries most of the heat from the conditioned space, most of the heat from the process load, heat from the dehumidification process, heat associated with cooling the fresh air brought into the system, and most of the heat from the reheat system returning to the chiller plant. This heat is contained in the air exhausted from the facility that does not return to the chiller plant.

[0024] The temperature of the return chilled water leaving the cooling coil and returning to the chiller plant is typically 55°F to 60°F during the summer months when maximum dehumidification is required. The chiller plant takes this 55°F to 60°F water and cools it, typically to 40°F to 45°F. Once the water has been cooled by the chiller plant, it is sent back to the cooling coil to begin the cooling and dehumidification process again. The 55°F to 60°F chilled water return temperature, common in most chiller system implementations, is too cold to be used effectively as a heating source.

[0025] In conventional cooling systems, chillers are typically piped in parallel. Each chiller receives the same return water temperature, and each chiller delivers the same supply water temperature. These chillers also receive the same condenser water temperature. As an example, when there are two chillers, the return water temperature to each chiller may be 60°F, and the supply water temperature from each chiller may be 44°F. In this example, the condenser supply water temperature is 85°F. Assuming a constant load on each chiller, the efficiency of the chiller is proportional to the temperature difference between the chilled water supply temperature and the condenser supply water temperature. The greater the temperature difference between the chilled water and the condenser water temperature, the worse the chiller's efficiency. Conversely, the smaller the difference between the chilled water and the condenser water temperature, the better the chiller's efficiency.

[0026]

[0026] Underfloor air distribution systems (UFADS) are a variation of the typical overhead air distribution system for air conditioning systems. UFADS require air to be supplied to floor grills between 62°F and 65°F instead of 55°F to reduce drafts and occupant discomfort. As with "normal" air conditioning systems, the air should be cooled to approximately 55°F to dehumidify it and then reheated to a temperature appropriate for occupant comfort. To reduce energy consumption, some operators have resorted to supplying supply air from a cooling coil at 62°F to 65°F, rather than lowering the air temperature to 55°F, dehumidifying it, and then reheating it to 62°F to 65°F. This reduces the cooling load because no reheating is required, and also reduces the dehumidification portion of the cooling load, since little dehumidification occurs at these supply air temperatures.

[0027]

[0027] While these measures reduce both reheat energy and cooling plant energy, many facilities end up suffering from biological growth and very expensive remediation efforts, the costs of which far outweigh the energy savings gained from eliminating dehumidification and reheat. Summary of the Invention [Means for solving the problem]

[0028] This specification discloses a system and method for using facility air conditioners, dehumidifiers, and heaters to reduce the relative humidity in a facility and reduce the potential for biological growth in a facility, which causes significant damage each year. This cooling recovery system design improves the efficiency of the cooling plant and also reduces the load it handles and the amount of reheat energy it consumes.

[0029] In one aspect, an air conditioning system includes a cooling coil having an inlet for receiving fluid from a fluid cooler to cool and dehumidify air passing over the cooling coil (i.e., flowing along a surface of the cooling coil), and an outlet for discharging the fluid. The air conditioning system further includes a fluid return line for receiving fluid from the outlet of the cooling coil, and a heat transfer coil having an inlet for receiving fluid to reheat air from the cooling coil passing over the heat transfer coil (i.e., flowing along a surface of the heat transfer coil).

[0030] In another aspect, a method of air conditioning includes the steps of cooling a fluid, supplying the fluid to a cooling coil to cool air passing over the cooling coil, discharging the fluid from the cooling coil through an outlet, and supplying at least a portion of the fluid from the outlet of the cooling coil to the inlet of the heat transfer coil to reheat the air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil, and its warmer temperature serves to reheat the air passing over the heat transfer coil.

[0031] In another aspect, a method of air conditioning includes receiving a fluid at a heat transfer coil through a fluid return line connected to an outlet of the cooling coil, the fluid being warmed as it flows through the cooling coil, and further including reheating the air cooled and dehumidified by the cooling coil with the heat transfer coil.

[0032] In yet another aspect, the air conditioning system includes a heat transfer coil having an inlet for receiving a heated fluid via a fluid return line connected to an outlet of the cooling coil, the heat transfer coil adapted to reheat air cooled and dehumidified by the cooling coil with the heated fluid.

[0033]

[0033] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description and drawings, and from the claims.

[0034]

[0034] These and other aspects will now be described in detail with reference to the following figures: [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a schematic diagram of a prior art cooling, dehumidification and reheat system. [Figure 2] 1 is a schematic diagram of a cooling, dehumidification and reheating system according to one implementation. [Figure 3] FIG. 1 is a schematic diagram of a cooling, dehumidifying and reheating system according to an alternative implementation. [Figure 4] FIG. 1 is a schematic diagram of an alternative prior art cooling, dehumidification and reheat system. [Figure 5] FIG. 1 is a schematic diagram of a cooling, dehumidifying and reheating system according to an alternative implementation. [Figure 6] FIG. 1 is a schematic diagram of a cooling, dehumidifying and reheating system according to an alternative implementation. [Figure 7] FIG. 1 is a schematic diagram of a cooling recovery coil system according to one implementation. [Figure 8] FIG. 1 is a schematic diagram of a cooling recovery coil system with a downstream heating or reheat system diverter valve. [Figure 9] FIG. 1 is a schematic diagram of a cooling recovery coil system according to another implementation. [Figure 10] FIG. 10 is a schematic diagram of a cooling recovery coil system with an alternative valve configuration. [Figure 11] FIG. 10 is a schematic diagram of a cooling recovery coil system having another alternative valve configuration. [Figure 12] FIG. 1 is a schematic diagram of a cooling recovery coil system according to another implementation. [Figure 13] FIG. 10 is a schematic diagram of a cooling recovery coil system according to yet another implementation. [Figure 14] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 15] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 16] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 17] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 18] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 19] 1 illustrates an alternative layout of equipment for a cooling system. FIG. [Figure 20] 1 illustrates an alternative layout of equipment for a cooling system. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0036]

[0049] Like reference numbers in the various drawings indicate like elements.

[0037]

[0050] Described herein are systems and methods that substantially reduce the amount of energy required for the cooling and reheating processes of a facility's air conditioning system by using cooling recovery coils to reheat air that is delivered to the facility's spaces or other processes in the air conditioning system.

[0038]

[0051] When dehumidification is required, but the dehumidified air is too cold for its intended end use, air reheating is necessary. In some implementations, a cooling recovery coil system is used rather than a typical heat recovery coil to reduce the cooling load by lowering the water temperature returned to the cooling plant. A cooling recovery coil system also reduces the amount of reheat used to maintain occupant comfort or process cooling conditions by raising the air temperature so that the heating load is reduced. During the cooling process, when a chilled water-based cooling system is used to provide the cooling source to the AHU, chilled water is supplied to a cooling coil inside the AHU to cool the air being circulated by the AHU for dehumidification and comfort cooling, or to address the process cooling load.

[0039]

[0052] Warm mixed air passing over (i.e., along the surface of) these cooling coils transfers heat contained in the mixed air into the chilled water circulating through the cooling coil. Through this process, the temperature of the air passing over the cooling coil decreases, and the temperature of the water in the cooling coil increases. Heat is transferred indirectly from the air to the water through the cooling coil piping. Some return air is exhausted from the facility, so the heat contained in the exhaust air is not transferred to the cooling coil system or chiller.

[0040]

[0053] According to some implementations, the AHU cooling coil system provides water temperatures of 65°F to 75°F or higher, typically higher than conventional return water temperatures, during summer operation instead of the typical 55°F to 60°F temperatures. The cooling coil is operated to provide a supply air temperature of approximately 55°F, so that dehumidification still occurs.

[0041]

[0054] Reheat coil systems utilize a much lower supply water temperature, typically 65°F to 75°F, to correspond to the temperature of the chilled water leaving the cooling coil and returning to the cooling plant in one or more coils referred to herein as "cooling recovery coils." Chilled, dehumidified air leaving the cooling coil at approximately 55°F enters the cooling recovery coil. The cooling recovery coil contains chilled water that enters the coil at 65°F to 75°F or higher. The hot water entering the cooling recovery coil supplies heat to preheat the chilled, dehumidified air.

[0042]

[0055] The chilled air entering a cooling recovery coil system draws heat from the water in the cooling recovery coil, lowering the temperature of the water returned to the cooling plant. This reduces the cooling load the cooling plant can accommodate in direct proportion to the percentage of the water temperature reduction, compared to the water temperature differential without the cooling recovery coil. For example, in a cooling recovery coil-based system operating with a 25°F chilled water system temperature differential (assuming a 45°F chilled water supply temperature and a 70°F chilled water return temperature), if the cooling recovery coil draws enough heat from the return chilled water to lower the water temperature to 62°F, the cooling plant load will be reduced by approximately 32%, as follows: (70°F - 62°F / 70°F - 45°F) = 8°F / 25°F. The airflow is heated, lowering the chilled water return temperature. The new energy required for the reheating process or the refrigeration energy required for the cooling process is less than with conventional systems.

[0043]

[0056] The piping and control system is configured to reduce the energy consumption of the cooling, reheat, and heating processes beyond the savings provided by the cooling recovery process alone. For example, when maximum heating or cooling loads are experienced, the system can use the entire heat transfer surface area of ​​the cooling coil and cooling recovery coil as either a large heating coil or a large cooling coil. The greater heat transfer surface area improves the efficiency of the heating and cooling system, as described below.

[0044]

[0057] During peak comfort periods, i.e., when process cooling loads are at their highest (i.e., maximum cooling is required), there is little need to reheat supply air temperatures above 55°F for many parts of the facility. In an exemplary implementation, the cooling coil and cooling recovery coil are configured and controlled to utilize the entire heat transfer surface area of ​​the two coil systems—the cooling coil system and the cooling recovery coil system—as a very large cooling coil. The added cooling coil heat transfer surface area allows for an increase in the temperature of the chilled water supplied to the AHUs from the cooling plant. Increasing the chilled water supply temperature from the chiller can improve the efficiency of the cooling system by 1% to 3% or more for every 1°F increase in chilled water supply temperature.

[0045]

[0058] When the comfort heating load is at its highest (i.e., when maximum heating is required), there is little need for cooling to lower the supply air temperature in order to cool or dehumidify many parts of the facility. Throughout the days when heating is required, the need for dehumidification is generally very low. In some implementations, the cooling coil and cooling recovery coil are configured and controlled to use the entire heat transfer surface area of ​​the two coil systems—the cooling coil system and the cooling recovery coil system—as one very large heating coil. This additional heating coil heat transfer surface area allows for a lower temperature of the heated water supplied to the AHU from the heating plant. Heater efficiency improves by more than 1% for every 5°F reduction in the heated water supply temperature.

[0046]

[0059] A conventional air conditioning cooling system can also be used as a cooling recovery coil system. Using a cooling recovery coil results in a higher return water temperature than using a conventional system. This allows for chillers to be arranged in series, with one chiller upstream of the other chillers, as described further below. The first chiller receives return chilled water at a temperature of 65°F to 75°F, rather than the 60°F of a conventional system. This chiller then chills the water to 55°F to 60°F, which is then fed to the downstream chiller, which then delivers water at 44°F to 45°F. The downstream chiller will have approximately the same efficiency as the chillers piped in parallel, since it delivers chilled water at approximately the same temperature. However, the upstream chiller will have much greater efficiency, since it delivers chilled water that is much warmer (55°F to 60°F) compared to the 45°F of a conventional system.

[0047]

[0060] When additional heat is needed, cooling recovery coils are also used as efficient heating coils. Sizing of the cooling recovery coil allows relatively low hot water temperatures to be used for heating, improving heater efficiency. Very low-quality waste heat can be effectively used to meet reheat or facility heating needs. In certain implementations, heated water temperatures between 96°F and 100°F can produce heated air temperatures above 95°F, whereas conventional heating and reheat system designs require hot water temperatures of 150°F to 200°F to produce a heated air temperature of 95°F.

[0048]

[0061] If there is no available source of 100°F waste heat, a new heat source is used. Typical hot water heating equipment efficiencies are between 80% and 85% when using water temperatures between 150°F and 200°F. According to some implementations, sizing and cooling recovery coil design can allow for the use of 100°F heated water. At these relatively low water temperatures, the efficiency of new condensing-type hot water heaters is between 92% and 95%, depending on the load on the heater. Through non-peak heating load conditions, the efficiency of these boilers rises to 96% to 98%.

[0049]

[0062] 2 is a schematic diagram of a cooling, dehumidification, and reheat system 02-0001 in which the cooling recovery coils are located remotely from the AHUs or fan coils, and the cooling recovery is the primary source of reheat energy. According to this implementation, the system 02-0001 includes one or more AHUs 02-0003 and one or more valves 02-0055, 02-0080. Fluid is cooled in a cooling plant 02-0040, conveyed through cooling fluid supply piping 02-0045, 02-0090 to one or more AHUs 02-0003, and returned to the one or more chillers 02-0040 through cooling fluid return piping 02-0050, 02-0085.

[0050]

[0063] The cooling fluid is conveyed through the cooling fluid piping by one or more pumps contained within the cooling unit 02-0040. The fluid is heated in the cooling coil 02-0015 and conveyed towards the cooling unit 02-0040 through the heated fluid return piping 02-0050, 02-0085. This heated fluid is returned to the one or more cooling units 02-0040. Before entering the cooling unit 02-0040, the heated fluid has the amount of heat extracted from it required to reheat the discharge air 02-0025. A pump system 02-0120 and piping system 02-0115 are used to convey heated water from the cooling coil system 02-0015 to the heated fluid supply piping system 02-0075, 02-0105 towards one or more temperature control zones 02-0065 and back via piping system 02-0125 through the heated fluid return piping 02-0070, 02-0110 towards one or more cooling plants 02-0040. Fluid passing to and from the reheat coil system carries heat removed from the reheat coil system during the reheat process, simultaneously reducing the load on the cooling plant and heating system.

[0051]

[0064] The flow of cooling fluid to the AHU 02-0003 is controlled by selectively adjusting the flow control valve 02-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valve 02-0080. As shown in FIG. 2, the cooling fluid flow control valve 02-0055 is disposed downstream of the AHU 02-0003 and may include one or more valves. Each heat source fluid flow control valve 02-0080 is disposed downstream of the heating coil (i.e., cooling recovery coil) 02-0030. Alternatively, the valves 02-0055 and 02-0080 may be located upstream of the AHU 02-0003 and / or upstream of the heating coil (cooling recovery coil) 02-0030.

[0052]

[0065] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water is distributed through cooling coils 02-0015 or other heat exchange units of the AHU 02-0003. A fan 02-0060 or blower may receive unconditioned or partially conditioned air from the return air 02-0002 intake source, mixed in varying proportions with fresh air 02-0005, to generate a mixed air flow 02-0010, which is delivered through one or more cooling coils 02-0015. The air flow may or may not be passed through a filtration system 02-0100.

[0053]

[0066] The cooling fluid conveyed through the cooling coil 02-0015 removes heat from the unconditioned or partially conditioned air passing over it. When required by the mixed air 02-0010 or the conditions in the conditioned space 02-0171, the conditioned air 02-0025 exiting the cooling coil 02-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space is kept low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 02-0025 condenses moisture from the air, drying it out. Thus, dry, cool conditioned air 02-0025 is delivered to individual offices, rooms, or other locations within the facility 02-0171 through exhaust line 02-0020 or other delivery system. The dry, cold conditioned air 02-0025 will generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 02-0025 is delivered to a temperature control box 02-0065 which contains a heating coil (cooling recovery coil) 02-0030.

[0054]

[0067] Warm or hot fluid is used to condition air or add heat to air from one or more heat sources. For example, hot water can be distributed through heating coils 02-0030 or other heat exchange units in the temperature control box 02-0065, which can have a fixed or variable volume. The temperature control box 02-0065 includes a controller that controls a control valve 02-0080, which controls the volume or pressure of the heating source fluid passed through the heating coil 02-0030. Heated fluid is generated in one or more heating plants 02-0035 or cooling coils in a cooling recovery coil system and distributed to the temperature control zones 02-0065 through heated fluid supply lines 02-0075, 02-0105 and heated fluid return lines 02-0070, 02-0110. The temperature of the supply air exiting the heating coil (cooling recovery coil) 02-0030 and entering the space to be conditioned, either directly or through the distribution system 02-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 02-0080 to maintain occupant needs or the needs of the process cooling load 02-0171.

[0055]

[0068] When a dehumidification load is present, the temperature of the fluid passing through the cooling coil 02-0015 rises to approximately 65°F to 75°F or higher as a result of heat exchange in the cooling coil 02-0015. This heated, or spent, cooling fluid is collected in separate spent fluid lines 02-0050, 02-0085 and delivered to the inlet of the chiller 02-0040. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, the spent cooling fluid is drawn into the cooling recovery coil's chilled water line 02-0115 by operating the chilled water cooling recovery pump system 02-0120 and discharging the warmed chilled water back into the cooling recovery coil's heated water supply line 02-0075, 02-0105 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0056]

[0069] As a major component within the chiller system 02-0040, 02-0140 is the chilled fluid return line within the chiller system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the cooling loads imposed by the AHUs or process cooling loads 02-0003 through chilled fluid piping 02-0085, 02-0050 and mixed with fluid returning from the cooling recovery coil system through piping system 02-0125 and fluid from bypass piping 02-0130. The combined fluid is then drawn into the chilled fluid pump system 02-0145.

[0057]

[0070] A refrigerant fluid pumping system is provided to the chiller 02-0155 in either a suction or push configuration. The warm mixed fluid then passes through the cooling system 02-0155, where the fluid temperature is reduced. The chiller isolation valve 02-0160 is controlled to allow flow through the chiller. The refrigerant fluid then enters a common discharge line 02-0165, where it is delivered to the cooling load through supply lines 02-0090, 02-0045, or returned to the refrigerant fluid return line 02-0140 through the refrigerant fluid bypass line 02-0130 and bypass piping control valve 02-0135. Figure 2 shows the chillers piped in one arrangement. Those skilled in the art will recognize that alternative piping arrangements can be used, which will be described further.

[0058]

[0071] Figure 3 is similar to Figure 2, but includes a positive shutoff isolation valve 03-0175 to ensure that the fluids of the cooling system and heater do not mix when both are operating and the cooling recovery coil system is not in use. The cooling, dehumidification, and reheat system 03-0001 includes one or more AHUs 03-0003, valves 03-0055, 03-0080, etc. Fluid is cooled in the cooling system 03-0040, transported through cooling fluid supply piping 03-0045, 03-0090 to one or more AHUs 03-0003, and returned to one or more cooling systems 03-0040 through cooling fluid return piping 03-0050, 03-0085. The cooling fluid is transported through the cooling fluid piping by one or more pump units contained within the cooling system 03-0040. Fluid is heated in the heater 03-0035 and conveyed through heated fluid supply piping 03-0075, 03-0105 to one or more temperature control zones 03-0065 and returned to the one or more heaters 03-0035 through heated fluid return piping 03-0070, 03-0110. The heated fluid is conveyed through the heated fluid piping by one or more pump units contained within the heater 03-0035.

[0059]

[0072] The flow of cooling fluid to the AHUs 03-0003 is controlled by selectively adjusting the flow control valves 03-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valves 03-0080. As shown in FIG. 3, the cooling fluid flow control valves 03-0055 are located downstream of each AHU 03-0003. The heat source fluid flow control valves 03-0080 are located downstream of each heating coil (cooling recovery coil) 03-0030. Alternatively, the valves 03-0055 and 03-0080 may be located upstream of the AHUs 03-0003 or upstream of each heating coil (cooling recovery coil) 03-0030.

[0060]

[0073] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 03-0015 or other heat exchange units of the AHU 03-0003. The fan 03-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 03-0002 and fresh air 03-0005 mixed in varying proportions, creates a mixed air stream 03-0010, and delivers it through one or more cooling coils 03-0015. The air stream may or may not be passed through a filtration system 03-0100.

[0061]

[0074] As the air moves through the cooling coil 03-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 03-0010 or the conditions in the conditioned space 03-0171, the conditioned air 03-0025 exiting the cooling coil 03-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 03-0025 condenses moisture from the air, drying it out. Thus, dry, cool conditioned air 03-0025 is delivered to individual offices, rooms, or other locations within the facility 03-0171 through exhaust line 03-0020 or other delivery system.

[0062]

[0075] The dry, cool conditioned air 03-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 03-0025 is delivered to a temperature control box 03-0065 that contains a heating coil 03-0030. Warm or hot fluids are used to condition the air or add heat to the air from one or more heat sources. For example, hot water can be distributed through the heating coil (cooling recovery coil) 03-0030 or other heat exchange unit in the temperature control box 03-0065. The temperature control box 03-0065 contains a controller that controls the control valve 03-0080, which controls the volume or pressure of the heat source fluid passed through the heating coil 03-0030.

[0063]

[0076] Heated fluid is generated in one or more heating plants 03-0035 and distributed to the temperature controlled zones 03-0065 through heated fluid supply lines 03-0075, 03-0105 and heated fluid return lines 03-0070, 03-0110. The supply air temperature leaving the heating coils 03-0030 enters the space to be conditioned either directly or through a distribution system 03-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valves 03-0080 to maintain the needs of the occupants or process cooling loads 03-0171.

[0064]

[0077] Throughout the summer months, when dehumidification loads are typically present, the temperature of the fluid passing through the cooling coil 03-0015 increases to approximately 65° F. to above 75° F. as a result of the heat exchange that occurs in the cooling coil 03-0015. As shown in Figure 3, this heated or spent cooling fluid is collected in separate spent fluid lines 03-0050, 03-0085 and delivered to the inlet of the cooling system 03-0040. If there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated or spent cooling fluid collected in the separate spent fluid lines 03-0050, 03-0085 is drawn into the cooling recovery coil chilled water line 03-0115 by operating the chilled water cooling recovery pump system 03-0120 and discharging the warmed chilled water back into the cooling recovery coil heated water supply line 03-0075, 03-0105 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0065]

[0078] As a major component within the chiller system 03-0040, 03-0140 is the chilled fluid return line within the chiller system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the cooling load imposed by the AHU or process cooling load 03-0003 through chilled fluid lines 03-0085, 03-0050 and mixed with the fluid returning from the cooling recovery coil system and fluid from bypass line 03-0130. The combined fluid is then drawn into the chilled fluid pump system 03-0145.

[0066]

[0079] A refrigerated fluid pumping system is provided to the chiller 03-0155 in either a suction or push configuration. The warm mixed fluid then passes through the cooling system 03-0155 where the fluid temperature is reduced. The chiller isolation valves 03-0160 are controlled to allow flow through the chillers in operation. The refrigerated fluid then enters a common discharge line 03-0165 where it is delivered to the cooling load through supply lines 03-0090, 03-0045 or returned to the refrigerated fluid return line through the refrigerated fluid bypass line 03-0130 and bypass piping control valve 03-0135. While FIG. 3 shows the chillers piped in one configuration, other configurations are possible.

[0067]

[0080] 4 shows a cooling, dehumidification and reheat system 04-0001 including one or more AHUs 04-0003, valves 04-0055, 04-0080, etc. Fluid is cooled in the cooling system 04-0040 and conveyed through cooling fluid supply piping 04-0045, 04-0090 to one or more AHUs 04-0003 and returned to the one or more cooling systems 04-0040 through cooling fluid return piping 04-0050, 04-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units contained within the cooling system 04-0040. In some embodiments, fluid is heated in the heating plant 04-0035 and conveyed through heating fluid supply piping 04-0075, 04-0105 to one or more heating coil systems 04-0030 and returned through heating fluid return piping 04-0070, 04-0110 to the one or more heating plants 04-0035. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant 04-0035.

[0068]

[0081] The flow of cooling fluid to the cooling coils 04-0015 of the AHU 04-0003 is controlled by selectively adjusting the flow control valve 04-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valve 04-0080. As shown in FIG. 4, the cooling fluid flow control valves 04-0055 are disposed downstream of the respective cooling coils 04-0015. The heat source fluid flow control valves 04-0080 are disposed downstream of the respective heating coils 04-0030. Alternatively, however, the valves 04-0055, 04-0080 may be located upstream of the cooling coils 04-0015 or upstream of the heating coils 04-0030, respectively.

[0069]

[0082] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 04-0015 or other heat exchange units of the AHU 04-0003. The fan 04-0060 or blower receives unconditioned or partially conditioned air from the intake air source, a varying mixture of return air 04-0002 and fresh air 04-0005, to generate a mixed air stream 04-0010 and delivers the mixed air stream 04-0010 through one or more cooling coils 04-0015. The mixed air stream 04-0010 may or may not be passed through a filtration system 04-0100.

[0070]

[0083] As the air moves through the cooling coil 04-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air flow 04-0010 or the conditions in the conditioned space 04-0171, the conditioned air 04-0025 exiting the cooling coil 04-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 04-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 04-0025 is delivered to individual offices, rooms, or other locations within the facility 04-0171 through exhaust line 04-1070 or other delivery system. The dry, cool conditioned air 04-0025 will generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 04-0025 is passed through a heating coil 04-0030.

[0071]

[0084] Warm or hot fluid is used to condition air or add heat to air from one or more heat sources. For example, hot water can be distributed through a heating coil 04-0030 or other heat exchange unit in the AHU 04-0003. The AHU 04-0030 can be constant volume or variable volume. The AHU 04-0003 includes a control system that controls a control valve 04-0080, which controls the volume or pressure of the heating source fluid passed through the heating coil 04-0030. Heated fluid is generated in one or more heating plants 04-0035 and distributed to the AHU's heating coil 04-0030 through heating fluid supply lines 04-0075, 04-0105 and heating fluid return lines 04-0070, 04-0110. The temperature of the supply air exiting the heating coil 04-0030 and entering the space to be conditioned, either directly or through a distribution system 04-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 04-0080 to maintain occupant needs or the needs of the process cooling load 04-0171.

[0072]

[0085] Throughout the summer months, the heat exchange that occurs in the cooling coil 04-0015 reduces the temperature of the air 01-0010 passing over the coil, removing moisture, while the temperature of the fluid passing through the coil increases to approximately 55°F to 60°F. As shown in Figure 4, this heated, or spent, cooling fluid is collected in separate spent fluid lines 04-0050, 04-0085 and delivered to the inlet of the cooling system 04-0040. This process can also dehumidify the air as a result of heat transfer from the unconditioned or partially conditioned air to the chilled water at or near the cooling coil 04-0015.

[0073]

[0086] The cooling coil 04-0015 provides a fluid between 34°F and 45°F that is supplied from the cooling system 04-0040 via cooling fluid lines 04-0045, 04-0090 to handle maximum cooling and dehumidification loads. The cooling coil 04-0015 provides a return temperature of the cooling fluid between 55°F and 60°F that is returned to the cooling system 04-0040 via cooling fluid lines 04-0050, 04-0085. Cooling fluid supply temperatures below 34°F and above 45°F can be used in different implementations as required by the cooling and dehumidification needs.

[0074]

[0087] The cooling coil 04-0015 provides a discharge air temperature 04-0025 between 50°F and 55°F as needed to meet comfort or process cooling load needs. A maximum discharge air temperature of about 55°F is generally used when dehumidification is required to reduce the moisture content in the airstream entering the conditioned space. The minimum discharge air temperature can be as low as 40°F to 45°F, as required by the load in operation.

[0075]

[0088] The cooling coil 04-0015 is sized for a face velocity of 500 to 600 feet per minute, although lower or higher face velocities can be used. The cooling coil 04-0015 is sized for a heat transfer piping size of 4 to 8 rows, although higher or lower row counts can be used. The heating coil 04-0030 typically requires a supply temperature of the heating fluid between 150°F and 200°F, which is supplied from the heating plant 04-0035 via heating fluid piping 04-0075, 04-0105. The heating coil 04-0030 provides a return temperature of the heating fluid between 120°F and 160°F, which is returned to the heating plant 04-0035 via heating fluid piping 04-0070, 04-0110.

[0076]

[0089] The heating coil 04-0030 provides a discharge air temperature between 60°F and 110°F as needed to meet comfort or process heating load needs. A maximum discharge air temperature of approximately 110°F is used to reduce the amount of hot air stratification that occurs when heated air enters the conditioned space or process load. During dehumidification operation, no heating of the space or process load should be required, so the discharge air temperature may be 60°F to 70°F. The heating coil 04-0030 is sized for a face velocity of 800 ft / min to 1,000 ft / min, although in this implementation, the heating and cooling coils may have the same face velocity. The heating coil 04-0030 is sized for one or two rows of heat transfer piping, although other numbers of rows of heat transfer piping can be used.

[0077]

[0090] Figure 5 is a schematic diagram of a cooling, dehumidification, and reheat system with a cooling recovery system design in which the cooling recovery coil is located in close proximity to the cooling coil and may be located within the AHU or fan coil system. The energy recovered from the cooling recovery coil system becomes the primary reheat supply, and there may or may not be an additional heating coil located remotely from the AHU or fan coil to further condition the air. Details regarding the reheat coil system located downstream of the cooling recovery coil are not included in Figure 5, as they are shown in other figures.

[0078]

[0091] The cooling, dehumidification, and reheat system 05-0001 includes one or more AHUs 05-0003, valves 05-0055, 05-0080, 05-0081, etc. In some embodiments, fluid is cooled in the cooling system 05-0040, conveyed through cooling fluid supply piping 05-0045, 05-0090 to one or more AHUs 05-0003, and returned to the one or more cooling systems 05-0040 through cooling fluid return piping 05-0050, 05-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units included within the cooling system 05-0040. In this embodiment, the cooling recovery coil system 05-0030 is located proximate to the cooling coil 05-0015 and may also be installed within the AHU 05-0003. In some embodiments, there may be an additional heating coil system located within the AHU 05-0003 or farther into the air stream downstream of the cooling recovery coil.

[0079]

[0092] The flow of cooling fluid to the AHU 05-0003 is controlled by selectively adjusting the flow control valve 05-0055. The cooling recovery source fluid is controlled by selectively adjusting the flow control valves 05-0080, 05-0081. The cooling fluid flow control valve 05-0055 is located downstream of each AHU 05-0003. The cooling recovery source fluid flow control valves 05-0080, 05-0081 are located downstream of each cooling recovery coil 05-0030. Alternatively, the valves 05-0055, 05-0080, 05-0081 may be located upstream of the AHU 05-0003 or upstream of the cooling recovery coil 05-0030, respectively.

[0080]

[0093] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 05-0015 or other heat exchange units of the AHU 05-0003. The fan 05-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 05-0002 and fresh air 05-0005 mixed in varying proportions, generates a mixed air stream 05-0010, and delivers the mixed air stream 05-0010 through one or more cooling coils 05-0015. The air stream may or may not be passed through a filtration system 05-0100.

[0081]

[0094] As the air moves through the cooling coil 05-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 05-0010 or the conditions in the conditioned space 05-0171, the conditioned air 05-0025 exiting the cooling coil 05-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 05-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 05-0025 is delivered to individual offices, rooms, or other locations within the facility 05-0171 through exhaust line 05-0020 or other delivery system.

[0082]

[0095] The dry, cool conditioned air 05-0025 will generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 05-0025 is passed through a cooling recovery coil system 05-0030. Warm fluid exiting the cooling coil system 05-0015 from the chilled water return line 05-0051 is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. The temperature of the supply air leaving the cooling recovery coil 05-0030 and entering the space to be conditioned, either directly or through the distribution system 05-0020, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valves 05-0080, 05-0081 to maintain occupant needs or the process cooling load 05-0171. As previously mentioned, additional heating coils may be located downstream of the cooling recovery coil system, which are not shown in FIG.

[0083]

[0096] Throughout the summer months, the heat exchange that occurs in the cooling coil 05-0015 reduces the temperature of the air 05-0010 passing over the coil, removing moisture, while increasing the temperature of the fluid passing through the coil to approximately 65° F. to over 75° F. This heated, or spent, cooling fluid is collected in a separate spent fluid line 05-0051 and delivered to the inlet line 05-0106 for the cooling recovery coil system 05-0030 or returned to the air conditioning system 05-0040. If there is a need to reheat some or all of the cooled and dehumidified air 05-0025, some or all of the heated, i.e., spent, cooling fluid collected in separate spent fluid line 05-0051 is forced into the cooling recovery coil's chilled water line 05-0106 by operating control valves 05-0080, 05-0081 to force the warmed chilled water back into the cooling recovery coil's heated water supply line 05-0106 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0084]

[0097] The system shown in Figure 6 functions substantially like the system shown in Figure 5, except that the reheat coil of the cooling recovery system is connected to a supplemental heat source to supply heat to the corresponding zone when heating needs exceed the heat that would otherwise be available from the fluid exiting the cooling coil.

[0085]

[0098] The cooling, dehumidification and reheat system 06-0001 includes one or more AHUs 06-0003, valves 06-0055, 06-0080, 06-0082, etc. Fluid is cooled in the cooling system 06-0040 and conveyed through chilled fluid supply piping 06-0045, 06-0090 to one or more AHUs 06-0003 and returned to the one or more cooling systems 06-0040 through chilled fluid return piping 06-0050, 06-0085. The chilled fluid is conveyed through the chilled fluid piping by one or more pump units included within the cooling system 06-0040. Fluid is heated in the heating plant 06-0035 and conveyed through heating fluid supply piping 06-0075, 06-0105, 06-0106 to one or more heating, reheat or cooling recovery coils 06-0030 and returned to the one or more heating plants 06-0035 through heating fluid return piping 06-0070, 06-0110, 06-0111. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant 06-0035.

[0086]

[0099] The flow of cooling fluid to the AHU 06-0003 is controlled by selectively adjusting the flow control valve 06-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valves 06-0080, 06-0082. The cooling fluid flow control valve 06-0055 is located downstream of each AHU 06-0003. The heat source fluid flow control valves 06-0080, 06-0082 are located downstream of each heating coil (cooling recovery coil) 06-0030. Alternatively, however, the valves 06-0055, 06-0080, 06-0082 may be located upstream of the AHU 06-0003 or upstream of the heating coil (cooling recovery coil) 06-0030, respectively.

[0087]

[0100] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 06-0015 or other heat exchange units of the AHU 06-0003. The fan 06-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 06-0002 and fresh air 06-0005 mixed in varying proportions, generates a mixed air stream 06-0010, and delivers the mixed air stream 06-0010 through one or more cooling coils 06-0015. The mixed air stream 06-0010 may or may not be passed through a filtration system 06-0100.

[0088]

[0101] As the air moves through the cooling coil 06-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 06-0010 or the conditions in the conditioned space 06-0171, the conditioned air 06-0025 exiting the cooling coil 06-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 06-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 06-0025 is delivered to individual offices, rooms, or other locations within the facility 06-0171 through exhaust line 06-0020 or other delivery system.

[0089]

[0102] The dry, cool conditioned air 06-0025 may generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 06-0025 is passed through a cooling recovery coil system 06-0030. Warm fluid exiting the cooling coil system 06-0015 from the chilled water return line 06-0051 is used to add heat to the air to alleviate heat needs from other sources or to completely meet reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources.

[0090]

[0103] A higher temperature heat source can be introduced to recover cooling from the cooling coil using a cooling recovery coil. For example, hot water can be distributed through a heating coil (cooling recovery coil) 06-0030 or other heat exchange unit in AHU 06-0003.

[0091]

[0104] The AHU 06-0003 includes a control system that controls control valves 06-0080, 06-0082, which in turn control the source, volume, or pressure of the heated source fluid passed through the heating coil (cooling recovery coil) 06-0030. Heated fluid is generated in one or more heating plants 06-0035 and distributed to the AHU 06-0003 through heated fluid supply lines 06-0075, 06-0105, 06-0106 and heated fluid return lines 06-0070, 06-0110, 06-0111. The temperature of the supply air exiting the heating coil 06-0030 and entering the space to be conditioned, either directly or through a distribution system 06-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 06-0080 to maintain occupant needs or the needs of the process cooling load 06-0171.

[0092]

[0105] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 06-0015, the temperature of the fluid passing through the cooling coils increases to approximately 65° F. to above 75° F. This heated, or spent, cooling fluid is collected in separate spent fluid lines 06-0050, 06-0051, 06-0085 and delivered to the inlet of the cooling system 06-0040. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, i.e., spent, cooling fluid collected in separate spent fluid lines 06-0051 is forced into the cooling recovery coil's chilled water lines 06-0106, 06-0107 by operating control valves 06-0080, 06-0082 to force the warmed chilled water back into the cooling recovery coil's heated water supply lines 06-0106, 06-0107 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0093]

[0106] Figure 7 shows an implementation in which both the cooling coil system and the cooling recovery coil system can be used as cooling coils to handle the highest cooling load days, while the increased heat transfer surface area allows for warmer chilled water temperatures, improving the efficiency of the cooling plant. Additionally, to handle the highest heating loads, both the cooling coil system and the cooling recovery coil system can be used as heating coils, while the increased heat transfer surface area allows for cooler heated water temperatures, improving the efficiency of the hot water plant. The reheat coil of the cooling recovery system is connected to an auxiliary heat source to provide heat to the corresponding area when heating needs exceed the heat otherwise available from the fluid exiting the cooling coils.

[0094]

[0107] As shown in Figure 7, the cooling, dehumidifying and reheating system 07-0001 includes one or more heat transfer systems 07-0015, 07-0030, valves 07-0055, 07-0082, etc. Fluid is cooled in the cooling system 07-0040 and conveyed to the cooling, dehumidifying and reheating system 07-0001 through cooling fluid supply piping 07-0045, 07-0090 and returned to the one or more cooling systems 07-0040 through cooling fluid return piping 07-0050, 07-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units included within the cooling system 07-0040. Fluid is heated in the heating plant 07-0035 and conveyed through heating fluid supply piping 07-0075, 07-0105, 07-0106, 07-0200 to one or more heating, reheat or cooling recovery coils 07-0030 and returned to the one or more heating plants 07-0035 through heating fluid return piping 07-0070, 07-0111, 07-0205. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant 07-0035.

[0095]

[0108] The flow of cooling fluid for heat transfer to the cooling coils 07-0015 is controlled by selectively adjusting the flow control valve 07-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valve 07-0082. The cooling fluid flow control valve 07-0055 is located downstream of each cooling coil 07-0015. The heat source fluid flow control valve 07-0082 is located downstream of each heating coil (cooling recovery coil) 07-0030. Alternatively, however, the valves 07-0055, 07-0082 may be located upstream of the cooling coil 07-0015 or upstream of the heating coil (cooling recovery coil) 07-0030, respectively.

[0096]

[0109] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 07-0015 or other heat exchange units in the AHU. A fan or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 07-0002 and fresh air 07-0005 mixed in varying proportions, creates a mixed air flow, and delivers the mixed air flow through one or more cooling coils 07-0015.

[0097]

[0110] As air moves through the cooling coils 07-0015 in the cooling recovery coil system, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When the conditions in the mixed air or conditioned space require, the conditioned air 07-0025 exiting the cooling coils 07-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 07-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 07-0025 is delivered to individual offices, rooms, or other locations within the facility through exhaust ductwork or other delivery systems.

[0098]

[0111] The dry, cool conditioned air 07-0025 will generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 07-0025 is passed through a cooling recovery coil system 07-0030. The warm fluid exiting the cooling coils 07-0015, supplied by the chilled water return line 07-0051, is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, the warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources.

[0099]

[0112] To increase the heating capacity available from the hot water exiting the cooling coil 07-0015, a higher temperature heat source is introduced. For example, the heated fluid can be distributed through a heating coil (cooling recovery coil) 07-0030 or other heat exchange unit in the AHU. The AHU includes a control system that controls the control valve 07-0082, which controls the source, volume, or pressure of the heated source fluid passed through the cooling recovery coil 07-0030.

[0100]

[0113] Heated fluid is generated in one or more heating plants 07-0035 and distributed to the AHUs through heated fluid supply lines 07-0075, 07-0105, 07-0106, 07-0210 and heated fluid return lines 07-0070, 07-0111, 07-0205. The temperature of the supply air leaving the heating coil (cooling recovery coil) 07-0030 and entering the space to be conditioned, either directly or through a distribution system, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 07-0082 to maintain occupant needs or process cooling load needs.

[0101]

[0114] Throughout the summer months, when dehumidification loads are typically present, the temperature of the fluid passing through cooling coil 07-0015 rises to approximately 65°F to 75°F or higher as a result of the heat exchange that occurs in cooling coil 07-0015. This heated, or spent, cooling fluid is collected in separate spent fluid lines 07-0050, 07-0051, 07-0085 and delivered to the inlet of cooling system 07-0040. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in separate spent fluid line 07-0051 is forced into cooling recovery coils 07-0106, 07-0107 by activating control valve 07-0082, forcing the warmed chilled water back into the cooling recovery coils 07-0106, 07-0107 for delivery as a heat source.

[0102]

[0115] As a major component within the chiller system 07-0040, 07-0140 is the chilled fluid return line within the chiller system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the cooling load imposed by the AHU or process cooling load through chilled fluid lines 07-0085, 07-0050 and mixed with fluid returning from the cooling recovery coil system and fluid from bypass line 07-0130. The combined fluid is then drawn into the chilled fluid pump system 07-0145.

[0103]

[0116] A refrigerated fluid pumping system is provided to the chiller 07-0155 in either a suction or push configuration. The warm mixed fluid then passes through the cooling system 07-0155 where the fluid temperature is reduced. The chiller isolation valves 07-0160 are controlled to allow flow through the operating chillers. The refrigerated fluid then enters a common discharge line 07-0165 where it is delivered to the cooling load through supply lines 07-0090, 07-0045 or returned to the refrigerated fluid return line through the refrigerated fluid bypass line 07-0130 and bypass line control valve 07-0135. While FIG. 7 shows one piping scheme, other piping configurations can be used.

[0104]

[0117] As a major component within heating plant system 07-0035, 07-0265 is the heating fluid return line within the heating plant system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the heating loads imposed by the AHUs or process loads through heating fluid lines 07-0020, 07-0215, and 07-0205 and mixed with fluid returning from the cooling recovery coil system 07-0111, fluid from the heating / cooling crossover lines 07-0225 and 07-0230, and fluid from bypass line 07-0250. The combined fluid is then drawn into heating fluid pump system 07-0260.

[0105]

[0118] A heating fluid pump system is provided to the heater 07-0275 in either a suction or push configuration. The warm mixed fluid then passes through the heating system 07-0275, where the fluid temperature is increased. The heater shut-off valves 07-0280 are controlled to allow flow through the heaters that are in operation. The heated fluid then enters the common discharge line 07-0270, where it is delivered to the heating load through supply lines 07-0075, 07-0105, or returned to the heating fluid return line through heating fluid bypass line 07-0250 and bypass line control valves 07-0245, 07-0255. While FIG. 7 shows the heaters piped in one configuration, other configurations are possible.

[0106]

[0119] The system shown in Figure 8 functions substantially like the system shown in Figure 6, except that the cooling recovery coils of the cooling recovery system are connected directly to the cooling coils via piping and valves 08-111, 08-106, 08-0081, 08-0055, 08-0050, and an auxiliary reheat coil system 08-0065, 08-0031 connected to a heat source supplies heat to the corresponding zones when heating needs exceed the heat that would otherwise be available from the fluid exiting the cooling coils and cooling recovery coil system.

[0107]

[0120] In some implementations, the cooling, dehumidification, and reheat system 08-0001 includes one or more AHUs 08-0003, valves 08-0055, 08-0081, etc. Fluid is cooled in a cooling system (not shown in this figure), transported through a cooling fluid supply line 08-0045 to one or more AHUs 08-0003, and returned to one or more cooling systems through a cooling fluid return line 08-0050, 08-0085. The cooling fluid is transported through the cooling fluid piping by one or more pump units included in the cooling system. Fluid is heated in a heating plant, transported through a heating fluid supply line to one or more heating or reheat coils 08-0031, and returned to one or more heating plants through a heating fluid return line. The heating fluid is transported through the heating fluid piping by one or more pump units included in the heating plant.

[0108]

[0121] The flow of cooling fluid to the AHU 08-0003 is controlled by selectively adjusting the flow control valve 08-0055. The heat source fluid for the cooling recovery coil is controlled by selectively adjusting the flow control valves 08-0081, 08-0055. The heat source fluid is controlled by selectively adjusting a flow control valve not shown in this figure. The cooling fluid flow control valves 08-0055, 08-0081 are located downstream of the respective AHU 08-0003. Alternatively, however, the valves 08-0055, 08-0081 may be located upstream of the AHU 08-0003 or upstream of the cooling recovery coil 08-0030, respectively.

[0109]

[0122] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 08-0015 or other heat exchange units of the AHU 08-0003. The fan 08-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 08-0002 and fresh air 08-0005 mixed in varying proportions, generates a mixed air stream 08-0010, and delivers the mixed air stream 08-0010 through one or more cooling coils 08-0015. The mixed air stream 08-0010 may or may not be passed through a filtration system 08-0100.

[0110]

[0123] As the air moves through the cooling coil 08-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 08-0010 or the conditions in the conditioned space 08-0171, the conditioned air 08-0025 exiting the cooling coil 08-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 08-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 08-0025 is delivered to individual offices, rooms, or other locations within the facility 08-0171 through exhaust line 08-0020 or other delivery system.

[0111]

[0124] The dry, cool conditioned air 08-0025 may generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 08-0025 is passed through a cooling recovery coil system 08-0030. Warm fluid exiting the cooling coil system 08-0015 from the chilled water return line 08-0051 is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources by sending the hot fluid through a reheat coil system 08-0031.

[0112]

[0125] To recover cooling from the cooling coils using a cooling recovery coil, a higher temperature heat source is introduced and used to add heat to the air entering the reheat coil system 08-0031. For example, hot water can be distributed through the heating coil 08-0031 or other heat exchange unit of the temperature control zone 08-0065. The temperature control zone 08-0065 includes a control system that controls control valves, not shown in this figure, that control the source, volume, or pressure of the heated source fluid passed through the heating coil 08-0031. Heated fluid is generated in one or more heating plants and distributed to the temperature control zone 08-0065 through heated fluid supply and return piping. The temperature of the supply air exiting the heating coil 08-0031 and entering the space to be conditioned, either directly or through the distribution system 08-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves to maintain occupant needs or the needs of the process cooling load 08-0171.

[0113]

[0126] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 08-0015, the temperature of the fluid passing through the cooling coils rises to approximately 65°F to 75°F or higher. This heated, or spent, cooling fluid is collected in a separate spent fluid line 08-0050 and delivered to the cooling system inlet. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in the separate spent fluid line is forced into the cooling recovery coil's chilled water line 08-0106 by operating control valve 08-0081, forcing the warmed chilled water back into the cooling recovery coil's heated water supply line 08-0106, for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0114]

[0127] Heated fluid is generated in one or more heating plants and distributed to the temperature control zones 08-0065 through heated fluid supply and return piping, not shown in Figure 8. The supply air temperature exiting the heating coils 08-0031 enters the space to be conditioned either directly or through a distribution system 08-0170. The supply air temperature is continuously varied to add additional heat to the cool, dry, dehumidified air by selectively adjusting flow control valves to maintain the needs of the occupants or process cooling loads 08-0171.

[0115]

[0128] Because the dry, cool conditioned air 03-0025 is generally too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, the conditioned air 08-0025 passes through a cooling recovery coil 08-0030, which adds heat to the air to preheat it. The air is then delivered to a temperature control box 08-0065 containing a heating coil 08-0031. If space conditions or the process cooling load 08-0171 require warmer air than is supplied after leaving the cooling recovery coil 08-0030, the reheat coil 08-0031 is activated. Warm or hot fluids are used to condition the air or add heat to the air from one or more heat sources. For example, hot water can be distributed through the heating coil 08-0031 or other heat exchange unit in the temperature control box 08-0065. The temperature control box 08-0065 contains a controller that controls a control valve, which controls the volume or pressure of the heat source fluid that is passed through the heating coil 08-0031.

[0116]

[0129] Heated fluid is generated in one or more heating plants, not shown in this view, and distributed to the temperature control zones 08-0065 through heated fluid supply and return piping (not shown). The supply air temperature exiting the heating coils 08-0031 enters the space to be conditioned either directly or through a distribution system 08-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 08-0171.

[0117]

[0130] The system shown in Figure 9 functions substantially like the system shown in Figure 8, except that the cooling recovery reheat coils of the cooling recovery system are supplied with heated water either directly from the cooling coil or from some auxiliary heat source, and auxiliary reheat coils 09-0065 connected to the heat source supply heat to the corresponding zones when heating needs exceed the heat that would otherwise be available from the fluid exiting the cooling coil.

[0118]

[0131] The cooling, dehumidification, and reheat system 09-0001 includes one or more AHUs 09-0003, valves 09-0055, 09-0081, etc. Fluid is cooled in the cooling system and transported through cooling fluid supply piping 09-0045 to one or more AHUs 09-0003 and returned to one or more cooling systems through cooling fluid return piping 09-0050, 09-0085. The cooling fluid is transported through the cooling fluid piping by one or more pump units included in the cooling system. Fluid is heated in the heating plant and transported through heating fluid supply piping 09-0075, 09-0105 to one or more heating, reheat, or cooling recovery coils 09-0030, 09-0031 and returned to one or more heating plants through heating fluid return piping 09-0070, 09-0110. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating installation.

[0119]

[0132] The flow of cooling fluid to the AHUs 09-0003 is controlled by selectively adjusting the flow control valves 09-0055. The flow of cooling fluid to the cooling recovery coils is controlled by selectively adjusting the flow control valves 09-0081. The cooling fluid flow control valves 09-0055 are located downstream of each AHU 09-0003. The cooling recovery coils' heat source fluid flow control valves 09-0081 are located upstream of each cooling recovery coil 09-0030. Alternatively, however, the valves 09-0055, 09-0081 may be located downstream of the AHUs 09-0003 or upstream of the cooling recovery coils 09-0030, respectively.

[0120]

[0133] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water is distributed through cooling coils 09-0015 or other heat exchange units of the AHU 09-0003. A fan 09-0060 or blower can receive unconditioned or partially conditioned air from the intake air source, consisting of a mixture of return air 09-0002 and fresh air 09-0005, and generate a flow of mixed air 09-0010 for delivery to one or more cooling coils 09-0015. The mixed air 09-0010 may or may not be passed through a filtration system 09-0100.

[0121]

[0134] As the air moves through the cooling coil 09-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 09-0010 or the conditions in the conditioned space 09-0171, the conditioned air 09-0025 exiting the cooling coil 09-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 09-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 09-0025 is delivered to individual offices, rooms, or other locations within the facility 09-0171 through exhaust line 09-0020 or other delivery system.

[0122]

[0135] The dry, cool conditioned air 09-0025 is generally too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification; therefore, the conditioned air 09-0025 is passed through the cooling recovery coil system 09-0030. The warm fluid exiting the cooling coil system 09-0015 from the chilled water return line 09-0111 is used to add heat to the air to alleviate heat needs from other sources or to fully satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources. A higher temperature heat source is introduced to recover cooling from the cooling coil using the cooling recovery coil. For example, hot water can be distributed through the heating coil (cooling recovery coil) 09-0030 or other heat exchange unit of the AHU 09-0003.

[0123]

[0136] The AHU 09-0003 includes a control system that controls control valves 09-0081, 09-0082, which in turn control the source, volume, or pressure of the heating source fluid that is passed through the heating and cooling recovery coil 09-0030. Heated fluid is generated in one or more heating plants and distributed to the AHU 09-0003 through heating fluid supply lines 09-0075, 09-0105 and heating fluid return lines 09-0070, 09-0110. If the air needs to be further heated, the heating coil 09-0031 located in the temperature control box 09-0065 is activated as needed to raise the temperature of the air as needed. The temperature of the supply air exiting the heating coil 09-0031 and entering the space to be conditioned, either directly or through the distribution system 09-0170, is continuously varied to add heat to the dehumidified air by selectively adjusting the flow control valves to maintain occupant needs or the needs of the process cooling load 09-0171.

[0124]

[0137] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 09-0015, the temperature of the fluid passing through the cooling coils rises to approximately 65°F to 75°F or higher. This heated, or spent, cooling fluid is collected in separate spent fluid lines 09-0050, 09-0085 and delivered to the cooling system inlet. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in the separate spent fluid lines is forced into the cooling recovery coil's chilled water line 09-0106 and check valve system 09-0108 by operating control valve 09-0081, forcing the warmed chilled water back into the cooling recovery coil's heated water supply line 09-0106, for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0125]

[0138] Heated fluid is generated in one or more heating plants and distributed to temperature controlled zones 09-0065 through heated fluid supply and return piping, not shown in this view. The supply air temperature leaving the heating coils 09-0031 enters the space to be conditioned either directly or through a distribution system 09-0170. The supply air temperature is continuously varied to add heat to the air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 09-0171.

[0126]

[0139] Because the dry, cool conditioned air 08-0025 is generally too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, the conditioned air 08-0025 passes through a cooling recovery coil 09-0030, which adds heat to the air to preheat it. The air is then delivered to a temperature control box 09-0065 containing a heating coil 09-0031. If space conditions or the process cooling load 09-0171 require warmer air than is supplied after leaving the cooling recovery coil 09-0030, the reheat coil 09-0031 is activated. Warm or hot fluids are used to condition the air or add heat to the air from one or more heat sources. For example, hot water can be distributed through the heating coil 09-0031 or other heat exchange unit in the temperature control box 09-0065. The temperature control box 09-0065 contains a controller that controls a control valve, not shown in this view, which controls the volume or pressure of the heat source fluid passed through the heating coil 09-0031.

[0127]

[0140] Heated fluid is generated in one or more heating plants, not shown in this view, and distributed to temperature controlled zones 09-0065 through heated fluid supply and return piping, also not shown in this view. The supply air temperature exiting the heating coils 09-0031 enters the space to be conditioned either directly or through a distribution system 09-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 09-0171.

[0128]

[0141] The system shown in Figure 10 functions substantially like the system shown in Figure 8, although it uses a different piping and valve system arrangement to convey the warm, used chilled water return fluid to the inlet of the cooling recovery coil. The cooling, dehumidification and reheat system 10-0001 includes one or more AHUs 10-0003, valves 10-0055, 10-0081, 10-0082, etc. The fluid is cooled in a cooling system, not shown in this figure, and conveyed through cooling fluid supply piping 10-0045 to one or more AHUs 10-0003 and back to one or more cooling systems through cooling fluid return piping 10-0050, 10-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units contained within the cooling system. Fluid is heated in the heating plant and conveyed through a heating fluid supply line to one or more heating or reheating coils 10-0031 and returned to the one or more heating plants through a heating fluid return line. The heating fluid is conveyed through the heating fluid lines by one or more pump units contained within the heating plant.

[0129]

[0142] The flow of cooling fluid to AHU 10-0003 is controlled by selectively adjusting flow control valve 10-0055. The cooling recovery coil source fluid is controlled by selectively adjusting flow control valves 10-0081, 10-0082, and 10-0055. The heat source fluid is controlled by selectively adjusting flow control valves not shown in this figure. The cooling fluid flow control valves 10-0055, 10-0081, and 10-0082 are located downstream of the respective AHU 10-0003. Alternatively, however, valves 10-0055, 10-0081, and 10-0082 may be located upstream of the AHU 10-0003 or upstream of the cooling recovery coil 10-0030, respectively.

[0130]

[0143] A cooling fluid is used to condition the air or remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 10-0015 or other heat exchange units of the AHU 10-0003. The fan 10-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 10-0002 and fresh air 10-0005 mixed in varying proportions, generates a mixed air stream 10-0010, and delivers the mixed air stream 10-0010 through one or more cooling coils 10-0015. The mixed air stream 10-0010 may or may not be passed through a filtration system 10-0100.

[0131]

[0144] As the air moves through the cooling coil 10-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When the mixed air 10-0010 or conditioned space conditions 10-0171 require, the conditioned air 10-0025 exiting the cooling coil 10-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space is kept low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 10-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 10-0025 is delivered to individual offices, rooms, or other locations within the facility 10-0171 through exhaust line 10-0020 or other delivery system.

[0132]

[0145] The dry, cool conditioned air 10-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 10-0025 is passed through a cooling recovery coil system 10-0030. Warm fluid exiting the cooling coil system 10-0015 from the chilled water return line 10-0051 is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources by sending the hot fluid through a reheat coil system 10-0031.

[0133]

[0146] To recover cooling from the cooling coils using a cooling recovery coil, a higher temperature heat source is introduced and used to add heat to air entering the reheat coil system through heating coils 10-0031. For example, hot water can be distributed through heating coils 10-0031 or other heat exchange units in temperature control zone 10-0065. Temperature control zone 10-0065 includes a control system that controls control valves, not shown in this figure, that control the source, volume, or pressure of the heated source fluid passed through heating coils 10-0031. Heated fluid is generated in one or more heating plants and distributed to temperature control zone 10-0065 through heated fluid supply and return lines. The temperature of the supply air exiting the heating coil 10-0031 and entering the space to be conditioned, either directly or through the distribution system 10-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valves to maintain occupant needs or the needs of the process cooling load 10-0171.

[0134]

[0147] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 10-0015, the temperature of the fluid passing through the cooling coils rises to approximately 65°F to 75°F or higher. This heated, or spent, cooling fluid is collected in a separate spent fluid line 10-0050 and delivered to the cooling system inlet. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in the separate spent fluid line is forced into the cooling recovery coil's chilled water line 10-0106 by operating control valves 10-0081, 10-0082 to force the warmed chilled water back into the cooling recovery coil's heated water supply line 10-0106 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0135]

[0148] Heated fluid is generated in one or more heating plants and distributed to the temperature controlled zones 10-0065 through heated fluid supply and return piping, not shown in this view. The supply air temperature exiting the heating coils 10-0031 enters the space to be conditioned either directly or through a distribution system 10-0170. The supply air temperature is continuously varied to add additional heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 10-0171.

[0136]

[0149] Dry, cool conditioned air 10-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification; therefore, the conditioned air 10-0025 passes through a cooling recovery coil 10-0030 to add heat to the air to preheat it. The air is then delivered to a temperature control box 10-0065 that contains a heating coil 10-0031. If space conditions or the process cooling load 10-0171 require warmer air than is supplied after leaving the cooling recovery coil 10-0030, the heating coil 10-0031 is activated. Warm or hot fluids are used to condition the air or add heat to the air from one or more heat sources. For example, hot water is distributed through the heating coil 10-0031 or other heat exchange unit in the temperature control box 10-0065. Temperature control box 10-0065 contains a controller that controls a control valve, not shown in this view, which controls the volume or pressure of the heat source fluid passed through heating coil 10-0031.

[0137]

[0150] Heated fluid is generated in one or more heating plants, not shown in this view, and distributed to the temperature controlled zones 10-0065 through heated fluid supply and return piping (not shown). The supply air temperature exiting the heating coils 10-0031 enters the space to be conditioned either directly or through a distribution system 10-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves to maintain the needs of the occupants or process cooling loads 10-0171.

[0138]

[0151] The system shown in Figure 11 functions substantially like the system shown in Figure 9, although it uses a different piping and valve system arrangement to convey warm, used chilled water return fluid to the inlet of the cooling recovery coil. The cooling, dehumidification and reheat system 11-0001 includes one or more AHUs 11-0003, valves 11-0055, 11-0081, etc. Fluid is cooled in the cooling system and conveyed through chilled fluid supply piping 11-0045 to one or more AHUs 11-0003 and returned to one or more cooling systems through chilled fluid return piping 11-0050, 11-0085. The chilled fluid is conveyed through the chilled fluid piping by one or more pump units contained within the cooling system. Fluid is heated in the heating plant and conveyed through heating fluid supply piping 11-0075, 11-0105 to one or more heating, reheat or cooling recovery coils 11-0030, 11-0031 and returned to the one or more heating plants through heating fluid return piping 11-0070, 11-0110. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant.

[0139]

[0152] The flow of cooling fluid to the AHUs 11-0003 is controlled by selectively adjusting flow control valves 11-0055. The flow of cooling recovery coil heat source fluid is controlled by selectively adjusting flow control valves 11-0081. The cooling fluid flow control valves 11-0055 are located downstream of each AHU 11-0003. The cooling recovery coil heat source fluid flow control valves 11-0081 are located upstream of each cooling recovery coil 11-0030. Alternatively, however, valves 11-0055, 11-0081 may be located upstream of the AHUs 11-0003 or downstream of the cooling recovery coils 11-0030, respectively.

[0140]

[0153] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 11-0015 or other heat exchange units of the AHU 11-0003. The fan 11-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 11-0002 and fresh air 11-0005 mixed in varying proportions, generates a mixed air stream 11-0010, and delivers the mixed air stream 11-0010 through one or more cooling coils 11-0015. The mixed air stream 11-0010 may or may not be passed through a filtration system 11-0100.

[0141]

[0154] As the air moves through the cooling coil 11-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 11-0010 or the conditions in the conditioned space 11-0171, the conditioned air 11-0025 exiting the cooling coil 11-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space is kept low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 11-0025 condenses moisture from the air, drying it out. Thus, dry, cool conditioned air 11-0025 is delivered to individual offices, rooms, or other locations within the facility 11-0171 through exhaust line 11-0020 or other delivery system.

[0142]

[0155] The dry, cool conditioned air 11-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 11-0025 is passed through a cooling recovery coil system 11-0030. Warm fluid exiting the cooling coil system 11-0015 from the chilled water return line 11-0111 is used to add heat to the air to alleviate heat needs from other sources or to completely meet reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources.

[0143]

[0156] A higher temperature heat source is introduced to recover cooling from the cooling coil using a cooling recovery coil. For example, hot water can be distributed through a heating coil (cooling recovery coil) 11-0030 or other heat exchange unit in AHU 11-0003.

[0144]

[0157] AHU 11-0003 includes a control system that controls control valves 11-0081, 11-0082, which in turn control the source, volume, or pressure of the heating source fluid passed through heating and cooling recovery coil 11-0030. Heated fluid is generated in one or more heating plants and distributed to AHU 11-0003 through heating fluid supply piping 11-0075, 11-0105 and heating fluid return piping 11-0070, 11-0110. If the air needs to be further heated, heating coil 11-0031, located within temperature control box 11-0065, is activated as needed to raise the temperature of the air as needed. The temperature of the supply air exiting the heating coil 11-0031 and entering the space to be conditioned, either directly or through the distribution system 11-0170, is continuously varied to add heat to the dehumidified air by selectively adjusting the flow control valves to maintain occupant needs or the needs of the process cooling load 11-0171.

[0145]

[0158] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 11-0015, the temperature of the fluid passing through the cooling coils rises to approximately 65°F to 75°F or higher. This heated, or spent, cooling fluid is collected in separate spent fluid lines 11-0050, 11-0085 and delivered to the cooling system inlet. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in the separate spent fluid lines is forced into the cooling recovery coil's chilled water line 11-0106 and check valve system 11-0108 by operating control valve 11-0081, forcing the warmed chilled water back into the cooling recovery coil's heated water supply line 11-0106, for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0146]

[0159] Heated fluid is generated in one or more heating plants and distributed to the temperature control zones 11-0065 through heated fluid supply and return piping, not shown in this view. The supply air temperature leaving the heating coils 11-0031 enters the space to be conditioned either directly or through a distribution system 11-0170. The supply air temperature is continuously varied to add heat to the air to maintain the needs of the occupants or process cooling loads 11-0171 by selectively adjusting flow control valves, not shown in this view.

[0147]

[0160] Dry, cool conditioned air 08-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification; therefore, the conditioned air 08-0025 passes through a cooling recovery coil 11-0030, which adds heat to the air to preheat it. The air is then delivered to a temperature control box 11-0065 containing a heating coil 11-0031. If space conditions or the process cooling load 11-0171 require warmer air than is supplied after leaving the cooling recovery coil 11-0030, the heating coil 11-0031 is activated as a reheat coil. Warm or hot fluids can be used to condition the air or add heat to the air from one or more heat sources. For example, hot water can be distributed through the heating coil 11-0031 or other heat exchange units in the temperature control box 11-0065. The temperature control box 11-0065 contains a controller that controls a control valve, not shown in this view, which controls the volume or pressure of the heat source fluid passed through the heating coil 11-0031.

[0148]

[0161] Heated fluid is generated in one or more heating plants, not shown in this view, and distributed to the temperature control zones 11-0065 through heated fluid supply and return piping, also not shown in this view. The supply air temperature exiting the heating coils 11-0031 enters the space to be conditioned either directly or through a distribution system 11-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 11-0171.

[0149]

[0162] The system shown in FIG. 12 functions substantially like the system shown in FIG. 8, except that there is an additional cooling coil and heat recovery system in addition to the cooling recovery coil system. The cooling, dehumidification, and reheat system 12-0001 includes one or more AHUs 12-0003, valves 12-0055, 12-0081, etc. Fluid is cooled in a cooling system (not shown in this figure), conveyed through cooling fluid supply piping 12-0045 to one or more AHUs 12-0003, and returned to one or more cooling systems through cooling fluid return piping 12-0050, 12-0085. The cooling fluid is conveyed through the cooling fluid piping by one or more pump units included within the cooling system. Fluid is heated in a heating plant, conveyed through heating fluid supply piping to one or more heating or reheat coils 12-0031, and returned to one or more heating plants through heating fluid return piping. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating installation.

[0150]

[0163] A direct expansion (DX) cooling coil 12-0024 and system are added to the cooling recovery coil system to provide more dehumidified air. The DX system is equipped with heat rejection systems 12-0330, 12-0340 that reject heat to the atmosphere, or to a chilled water return system through piping 12-0300, 12-0310 using a pump system 12-0320, or to a heat recovery system through piping 12-0360, 12-0370 using a pump 12-0350 and control valve 12-0355 system. A compressor system 12-0380 discharges refrigerant to one or more of the heat rejection systems 12-0330, 12-0340. The compressed refrigerant is transported to and from the cooling coil 12-0024 through refrigerant piping systems 12-0332, 12-0335.

[0151]

[0164] The removed heat is used to heat water or some other heat transfer fluid for use in a radiant heating system, pool heating system, domestic hot water system, or any other system requiring the quality level of heat provided by the compressor / heat recovery system. The discharge of the compressor system 12-0380 is varied as needed to provide the appropriate temperature and dehumidification level of the discharge air 12-0025. Once the air 12-0025 exits the DX cooling coil 12-0024, the remainder of the process can occur as described in the following paragraphs.

[0152]

[0165] The flow of cooling fluid to the AHU 12-0003 is controlled by selectively adjusting flow control valve 12-0055. The cooling recovery coil source fluid is controlled by selectively adjusting flow control valves 12-0081, 12-0055. The heat source fluid is controlled by selectively adjusting flow control valves not shown in this figure. The cooling fluid flow control valves 12-0055, 12-0081 are located downstream of the respective AHU 12-0003. Alternatively, however, valves 12-0055, 12-0081 may be located upstream of the AHU 12-0003 or upstream of the cooling recovery coil 12-0030, respectively.

[0153]

[0166] A cooling fluid is used to condition the air or remove heat from one or more other heat sources. For example, chilled water is distributed through cooling coils 12-0015 or other heat exchange units of the AHU 12-0003. The fan 12-0060 or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 12-0002 and fresh air 12-0005 mixed in varying proportions, generates a mixed air stream 12-0010, and delivers the mixed air stream 12-0010 through one or more cooling coils 12-0015. The mixed air stream 12-0010 may or may not be passed through a filtration system 12-0100.

[0154]

[0167] As the air moves through the cooling coil 12-0015, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When required by the mixed air 12-0010 or the conditions in the conditioned space 12-0171, the conditioned air 12-0025 exiting the cooling coil 12-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space is kept low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 12-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 12-0025 is delivered to individual offices, rooms, or other locations within the facility 12-0171 through exhaust line 12-0020 or other delivery system.

[0155]

[0168] The dry, cool conditioned air 12-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 12-0025 is passed through a cooling recovery coil system 12-0030. Warm fluid exiting the cooling coil system 12-0015 from the chilled water return line 12-0051 is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources by sending the hot fluid through a reheat coil system 12-0031.

[0156]

[0169] To recover cooling from the cooling coils using a cooling recovery coil, a higher temperature heat source is introduced and used to add heat to the air entering the reheat coil system 12-0031. For example, hot water can be distributed through the heating coils 12-0031 or other heat exchange units in the temperature control zone 12-0065. The temperature control zone 12-0065 includes a control system that controls control valves, not shown in this figure, that control the source, volume, or pressure of the heated source fluid passed through the heating coils 12-0031. Heated fluid is generated in one or more heating plants and distributed to the temperature control zone 12-0065 through heated fluid supply and return piping. The temperature of the supply air exiting the heating coils 12-0031 and entering the space to be conditioned, either directly or through the distribution system 12-0170, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves to maintain occupant needs or the needs of the process cooling load 12-0171.

[0157]

[0170] During the summer months, as a result of the heat exchange that occurs in the cooling coils within the cooling recovery coil system 12-0015, the temperature of the fluid passing through the cooling coils rises to approximately 65°F to 75°F or higher. This heated, or spent, cooling fluid is collected in a separate spent fluid line 12-0050 and delivered to the cooling system inlet. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, or spent, cooling fluid collected in the separate spent fluid line is forced into the cooling recovery coil's chilled water line 12-0106 by operating control valve 12-0081, forcing the warmed chilled water back into the cooling recovery coil's heated water supply line 12-0106, for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0158]

[0171] Heated fluid is generated in one or more heating plants and distributed to the temperature controlled zones 12-0065 through heated fluid supply and return piping, not shown in this view. The supply air temperature leaving the heating coils 12-0031 enters the space to be conditioned either directly or through a distribution system 12-0170. The supply air temperature is continuously varied to add additional heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 12-0171.

[0159]

[0172] Dry, cool conditioned air 03-0025 may be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification; therefore, the conditioned air 12-0025 passes through a cooling recovery coil 12-0030 to add heat to the air to preheat it. The air is then delivered to a temperature control box 12-0065 containing a heating coil 12-0031. If space conditions or the process cooling load 12-0171 require warmer air than is supplied after leaving the cooling recovery coil 12-0030, the reheat coil 12-0031 is activated. Warm or hot fluids are used to condition the air or add heat to the air from one or more heat sources. For example, hot water can be distributed through the heating coil 12-0031 or other heat exchange unit in the temperature control box 12-0065. The temperature control box 12-0065 contains a controller that controls a control valve, not shown in this view, which controls the volume or pressure of the heat source fluid passed through the heating coil 12-0031.

[0160]

[0173] Heated fluid is generated in one or more heating plants, not shown in this view, and distributed to the temperature control zones 12-0065 through heated fluid supply and return piping, also not shown in this view. The supply air temperature exiting the heating coils 12-0031 enters the space to be conditioned either directly or through a distribution system 12-0170. The supply air temperature is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting flow control valves, not shown in this view, to maintain the needs of the occupants or process cooling loads 12-0171.

[0161]

[0174] FIG. 13 shows an implementation in which both the cooling coil system and the cooling recovery coil system can be used as cooling coils to handle the highest cooling load days, while the increased heat transfer surface area allows for warmer chilled water temperatures, improving the efficiency of the cooling plant. Additionally, to handle the highest heating loads, both the cooling coil system and the cooling recovery coil system can be used as heating coils, while the increased heat transfer surface area allows for cooler heated water temperatures, improving the efficiency of the hot water plant. The reheat coil of the cooling recovery system is connected to an auxiliary heat source to provide heat to the corresponding area when heating needs exceed the heat otherwise available from the fluid exiting the cooling coil. This implementation is very similar to FIG. 7 and includes the addition of a radiant heating and cooling system.

[0162]

[0175] As shown in Figure 13, the cooling, dehumidification and reheat system 13-0001 includes one or more heat transfer systems 13-0015, 13-0030, valves 13-0055, 13-0082, etc. Fluid is cooled in the cooling system 13-0040 and transported through cooling fluid supply piping 13-0045, 13-0090 to one or more AHUs 13-0003 and returned to the one or more cooling systems 13-0040 through cooling fluid return piping 13-0050, 13-0085. The cooling fluid is transported through the cooling fluid piping by one or more pump units included within the cooling system 13-0040. Fluid is heated in the heating plant 13-0035 and conveyed through heating fluid supply piping 13-0075, 13-0105, 13-0106, 13-0200 to one or more heating, reheat or cooling recovery coils 13-0030 and returned to the one or more heating plants 13-0035 through heating fluid return piping 13-0070, 13-0111, 13-0205. The heating fluid is conveyed through the heating fluid piping by one or more pump units contained within the heating plant 13-0035.

[0163]

[0176] The flow of cooling fluid for heat transfer to the cooling coils 13-0015 is controlled by selectively adjusting the flow control valve 13-0055. The flow of heat source fluid is controlled by selectively adjusting the flow control valve 13-0082. The cooling fluid flow control valve 13-0055 is located downstream of each cooling coil 13-0015. The heat source fluid flow control valve 13-0082 is located downstream of each heating coil (cooling recovery coil) 13-0030. Alternatively, however, the valves 13-0055, 13-0082 may be located upstream of the cooling coil 13-0015 or upstream of the heating coil (cooling recovery coil) 13-0030, respectively.

[0164]

[0177] A cooling fluid is used to condition the air or to remove heat from one or more other heat sources. For example, chilled water may be distributed through cooling coils 13-0015 or other heat exchange units in the AHU. A fan or blower receives unconditioned or partially conditioned air from the intake air source, consisting of return air 13-0002 and fresh air 13-0005 mixed in varying proportions, creates a mixed air flow, and delivers the mixed air flow through one or more cooling coils 13-0015.

[0165]

[0178] As air moves through the cooling coils 13-0015 in the cooling recovery coil system, heat is removed from the unconditioned or partially conditioned air by the cooling fluid therein. When the conditions in the mixed air or conditioned space require, the conditioned air 13-0025 exiting the cooling coils 13-0015 is cooled to a point where moisture is removed from the air and the relative humidity of the conditioned space remains low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air 13-0025 causes moisture to condense from the air, drying it out. Thus, dry, cool conditioned air 13-0025 is delivered to individual offices, rooms, or other locations within the facility through exhaust ductwork or other delivery system.

[0166]

[0179] The dry, cool conditioned air 13-0025 will generally be too cold to handle the comfort needs or process cooling loads for many spaces requiring cooling and dehumidification, so the conditioned air 13-0025 is passed through a cooling recovery coil system 13-0030. The warm fluid exiting the cooling coils 13-0015, supplied by the chilled water return line 13-0051, is used to add heat to the air to alleviate heat needs from other sources or to completely satisfy reheat needs. If the temperature of the exiting air does not rise adequately to meet the needs of the zone or process load, the warm or hot fluid is used to condition the air or add heat to the air from one or more heat sources.

[0167]

[0180] To increase the heating capacity available from the hot water exiting the cooling coil 13-0015, a higher temperature heat source is introduced. For example, the heated fluid can be distributed through a heating coil (cooling recovery coil) 13-0030 or other heat exchange unit in the AHU. The AHU includes a control system that controls the control valve 13-0082, which controls the source, volume, or pressure of the heated source fluid passed through the cooling recovery coil 13-0030.

[0168]

[0181] Heated fluid is generated in one or more heating plants 13-0035 and distributed to the AHUs through heated fluid supply lines 13-0075, 13-0105, 13-0106, 13-0210 and heated fluid return lines 13-0070, 13-0111, 13-0205. The temperature of the supply air leaving the heating coil (cooling recovery coil) 13-0030 and entering the space to be conditioned, either directly or through a distribution system, is continuously varied to add heat to the cool, dry, dehumidified air by selectively adjusting the flow control valve 13-0082 to maintain occupant needs or process cooling load needs.

[0169]

[0182] Throughout the summer months when dehumidification loads are typically present, the temperature of the fluid passing through cooling coil 13-0015 increases to approximately 65° F. to above 75° F. as a result of the heat exchange that occurs in cooling coil 13-0015. This heated, or spent, cooling fluid is collected in separate spent fluid lines 13-0050, 13-0051, 13-0085 and delivered to the inlet of cooling system 13-0040. Alternatively, if there is a need to reheat some or all of the cooled and dehumidified air, some or all of the heated, i.e., spent, cooling fluid collected in the separate spent fluid line 13-0051 is forced into the cooling recovery coil's cold water line 13-0106, 13-0107 by operating control valve 13-0082 to force the warmed chilled water back into the cooling recovery coil's heated water supply line 13-0106, 13-0107 for delivery to the cooling recovery coil as a heat source for the cooling recovery coil.

[0170]

[0183] As a major component within the chiller system 13-0040, 13-0140 is the chilled fluid return line within the chiller system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the cooling load imposed by the AHU or process cooling load through chilled fluid lines 13-0085, 13-0050 and mixed with fluid returning from the cooling recovery coil system and fluid from bypass line 13-0130. The combined fluid is then drawn into the chilled fluid pump system 13-0145.

[0171]

[0184] A refrigerated fluid pumping system is provided in a suction or push configuration to the chiller 13-0155. The warm mixed fluid then passes through the cooling system 13-0155 where the fluid temperature is reduced. The chiller isolation valves 13-0160 are controlled to allow flow through the chillers in operation. The refrigerated fluid then enters a common discharge line 13-0165 where it is delivered to the cooling load through supply lines 13-0090, 13-0045 or returned to the refrigerated fluid return line through the refrigerated fluid bypass line 13-0130 and bypass piping control valve 13-0135. While FIG. 13 shows one piping scheme, other piping configurations can be used.

[0172]

[0185] As a major component within heating plant system 13-0035, 13-0265 is the heating fluid return line within the heating plant system, where all of the various fluid streams combine into one common fluid stream. This fluid is returned from the heating loads imposed by the AHUs or process loads through heating fluid lines 13-0020, 13-0215, 13-0205 and mixed with fluid returning from the cooling recovery coil system 13-0111, fluid from the heating / cooling crossover lines 13-0225, 13-0230, and fluid from bypass line 13-0250. The combined fluid is then drawn into heating fluid pump system 13-0260.

[0173]

[0186] A heating fluid pump system is provided to the heater 13-0275 in either a suction or push configuration. The warm mixed fluid then passes through the heating system 13-0275 where the fluid temperature increases. The heater shut-off valves 13-0280 are controlled to allow flow through the heaters that are in operation. The heated fluid then enters the common discharge piping 13-0270 where it is delivered to the heating load through supply piping 13-0075, 13-0105 or returned to the heating fluid return piping through the heating fluid bypass piping 13-0250 and bypass piping control valves 13-0245, 13-0255. While FIG. 13 shows the heaters piped in one configuration, other configurations are possible.

[0174]

[0187] Figure 13 shows one arrangement that includes an additional radiant heating and cooling system. The radiant heating and cooling system 13-0500 draws its source water through supply water lines 13-0520, 13-0720, and 13-0610 and discharges return water through return water lines 13-0530, 13-0710, and 13-0730. Control valves 13-0700, 13-0600, 13-0800, and 13-0810 are used to direct flow to and from either the cooling or heat source. A pump system 13-0510 is used to direct flow from the cooling and heat sources to and from the radiant heating and cooling system.

[0175]

[0188] 14 shows an alternative layout of a cooling system including a filtration system 14-0100, a fan or blower system 14-0060, a preheat coil 14-0012, a cooling coil 14-0015, and a cooling recovery coil 14-0030. The cooling recovery coil 14-0030 may also be used as a reheat coil in an alternative implementation.

[0176]

[0189] FIG. 15 shows another alternative layout of a cooling system including a filtration system 15-0100, a fan or blower system 15-0060, a preheat coil 15-0012, a cooling coil 15-0015, a cooling recovery coil 15-0030, and a reheat coil 15-0031.

[0177]

[0190] FIG. 16 shows another alternative layout of a cooling system including a filtration system 16-0100, a fan or blower system 16-0060, cooling coils 16-0015, cooling recovery coils 16-0030, and reheat coils 16-0031.

[0178]

[0191] FIG. 17 shows another alternative layout for a cooling system including a filtration system 17-0100, a fan or blower system 17-0060, a preheat coil 17-0018, which may also be used as a cooling coil in some embodiments, and a cooling recovery coil 17-0030.

[0179]

[0192] FIG. 18 shows another alternative layout of a cooling system including a filtration system 18-0100, a fan or blower system 18-0060, a preheat coil 18-0018 which may also be used as a cooling coil in some embodiments, a cooling recovery coil 18-0030, and a reheat coil 18-0031.

[0180]

[0193] 19 shows another alternative layout of a cooling system including a filtration system 19-0100, a fan or blower system 19-0060, a preheat coil 19-0012, a cooling coil 19-0015, a direct expansion cooling coil 19-0028, and a cooling recovery coil 19-0030. The cooling recovery coil 19-0030 may also be used as a reheat coil in an alternative implementation.

[0181]

[0194] FIG. 20 shows another alternative layout of a cooling system including a filtration system 20-0100, a fan or blower system 20-0060, a preheat coil 20-0012, a cooling coil 20-0015, a direct expansion cooling coil 20-0028, a cooling recovery coil 20-0030, which may also be used as a reheat coil in some embodiments, and a reheat coil 20-0031.

[0182]

[0195] Used (warm) chilled water return not needed for the cooling recovery coil is sent to the chiller inlet to be cooled and sent back to the cooling system. Moisture is also removed from the air as a result of heat transfer from unconditioned or partially conditioned air to the chilled water at or near the cooling coil. The warm chilled water used in the cooling recovery coil system can reheat the air, reducing new reheat energy requirements. This chilled air draws heat from the water returned to the chiller, also reducing cooling energy requirements.

[0183]

[0196] The cooling coils described with respect to some implementations above require a chilled fluid supply temperature of between 45°F and 50°F delivered through the chilled fluid piping from the chiller system to handle maximum cooling and dehumidification loads. This is a higher temperature than typical designs for chilled water supply, allowing for improved chiller efficiency, thereby helping to reduce chiller energy consumption. Chillers can be plumbed in series rather than in parallel, further improving chiller efficiency. Chilled fluid supply temperatures below 45°F and above 50°F can be used as required by cooling and dehumidification needs.

[0184]

[0197] The cooling coils described above can provide a refrigerated fluid return temperature of between 65°F and 75°F or more, which is returned to the cooling system by moving water through the cooling recovery coil piping, i.e., used as heat source water for the cooling recovery coil. The higher return temperature of the refrigerated fluid exiting the cooling coil in a cooling recovery coil system allows this warmer fluid to serve as a heat source for the cooling recovery coil.

[0185]

[0198] In the foregoing implementations, except where noted, the cooling coil provides a discharge air temperature between 50°F and 55°F as needed to address comfort needs or process cooling load needs. A maximum discharge air temperature of approximately 55°F is used when dehumidification is required to reduce the moisture content in the airstream entering the conditioned space. Discharge air temperatures below 50°F and above 55°F can be used in different system embodiments as cooling and dehumidification needs dictate.

[0186]

[0199] The cooling coils are preferably sized for face velocities of 200 to 600 feet / minute, and preferably 250 to 450 feet / minute, although lower or higher face velocities can be used. The cooling coils are sized for six to ten rows, although more or fewer rows can be used. The heating coils are preferably sized for face velocities of 200 to 500 feet / minute, although lower or higher coil face velocities can be used. The heating coils include two to six rows of heat transfer piping, although more or fewer rows can be used.

[0187]

[0200] Throughout the heating season for a facility, the heating coil (cooling recovery coil) requires heating fluid supplied from the heating plant through the heating fluid piping at a supply temperature of between approximately 80° F. and 120° F. This is a lower water supply temperature than typical designs, allowing for increased efficiency of the hot water heater or boiler, thereby helping to reduce the heating plant's energy consumption.

[0188]

[0201] Also, throughout the heating season, the heating coil (cooling recovery coil) provides a heating fluid return temperature of between 60°F and 90°F that is returned to the heating plant through the heating fluid piping. The heating coil (cooling recovery coil) provides a discharge air temperature of between 70°F and 110°F as needed to meet comfort needs or process heating load needs. A maximum discharge air temperature of approximately 110°F is used to reduce the amount of hot air stratification that occurs when heated air enters the conditioned space or process load, although higher or lower temperatures can be used depending on the application requirements.

[0189]

[0202] During the cooling season for a facility, the cooling recovery process is optimally utilized, and the heating coil (cooling recovery coil) requires a heating fluid supply temperature of between approximately 62°F and 75°F, supplied through the heating fluid piping from the cooling recovery piping. The heating coil (cooling recovery coil) provides a discharge air temperature of between 58°F and 72°F as needed to meet comfort needs or process heating load needs. During the cooling season, the need for heating is typically low, allowing the supply air temperature to be lowered, allowing the cooling recovery coil to be used as a heat source.

[0190]

[0203] Additionally, throughout the cooling season, the heating coil (cooling recovery coil) provides a heating fluid return temperature of between 58°F and 65°F that is returned to the chiller system through the heating fluid piping and cooling recovery piping. The cooling recovery coil system removes the cooling load from the chiller by lowering the water temperature returned to the chiller, and by preheating the air, reduces the need for a new energy source for the reheat system.

[0191]

[0204] Although several embodiments have been described in detail above, other variations are possible, and other features, implementations, and alternatives may fall within the scope of the following claims. [Explanation of symbols]

[0192] 02-0001...Cooling, dehumidification and reheating system, 02-0003...Air handling unit (AHU), 02-0015...Cooling coil, 02-0040...Chiller, 02-0045, 02-0090...Supply piping, 02-0050, 02-0085...Refrigerated fluid return piping.

Claims

1. a cooling coil having an inlet for receiving fluid at a first temperature to cool and dehumidify air passing over the cooling coil, and an outlet for discharging spent fluid at a second temperature higher than the first temperature due to heat exchange occurring from the air to the fluid during the cooling and dehumidification of the air; a direct expansion coil having a refrigerant configured to receive the cooled and dehumidified air from the cooling coil and to effect heat exchange with the refrigerant to further dehumidify and cool the air received from the cooling coil; a cooling recovery coil having an inlet for receiving the spent fluid from the cooling coil at the second temperature, the cooling recovery coil configured to effect heat exchange to heat air received from the direct expansion coil, and discharging the spent fluid at a third temperature lower than the second temperature; An air conditioning system equipped with:

2. 10. The air conditioning system of claim 1, further comprising a reheat coil having an inlet for receiving a heated fluid supply, the reheat coil configured to effect heat exchange with air received from the direct expansion coil to provide additional heating of the air, the reheat coil being positioned downstream of the direct expansion coil.

3. the reheat coil is disposed downstream of the cooling recovery coil and further heats the air received from the cooling recovery coil; 3. The air conditioning system of claim 2.

4. 3. The air conditioning system of claim 2, wherein the reheat coil receives the heated fluid supply from the cooling coil.

5. The air conditioning system of claim 2 , wherein the cooling coil, the direct expansion coil, the cooling recovery coil, and the reheat coil are all located within a single filtration system.

6. 2. The air conditioning system of claim 1, further comprising an auxiliary heating source for providing additional heating to the air when the cooling recovery coil is unable to heat the air to a predetermined temperature, the auxiliary heating source receiving air from the cooling recovery coil.

7. 3. The air conditioning system of claim 2, wherein the cooling recovery coil is used as a reheat coil.

8. The air conditioning system of claim 1 , further comprising a preheat coil disposed upstream of the cooling coil, the preheat coil receiving heated fluid from a fluid heater.

9. The air conditioning system of claim 8 , wherein the preheat coil comprises one or more rows of heat transfer tubing.

10. 10. The air conditioning system of claim 1, further comprising at least one first flow control valve for controlling a first amount of fluid from said outlet of said cooling coil.

11. 11. The air conditioning system of claim 10, further comprising at least one second flow control valve for controlling a second amount of fluid to the inlet of the cooling recovery coil.

12. The air conditioning system of claim 1 , further comprising one or more fans for moving the air past the cooling coil, the direct expansion coil, and the cooling recovery coil.

13. cooling and dehumidifying air passing over a cooling coil, said cooling and dehumidification resulting from heat exchange between said air and a fluid received at an inlet of said cooling coil at a first temperature; Discharging at least a portion of the fluid at an outlet, the portion of the fluid being discharged at a second temperature higher than the first temperature; receiving at least a portion of the air from the cooling coil with a direct expansion coil having a refrigerant therein; cooling the portion of the air received from the cooling coil by passing the portion of the air received from the cooling coil over the direct expansion coil, the cooling resulting from heat exchange between the air and the refrigerant; supplying at least a portion of the fluid from the outlet of the cooling coil to a cooling recovery coil at the second temperature and discharging the fluid from a second outlet of the cooling recovery coil at a third temperature lower than the second temperature; heating at least a portion of the air received from the direct expansion coil by passing the portion of the air received from the direct expansion coil over the cooling recovery coil, the heating resulting from heat exchange between the fluid and the air; A method comprising:

14. 14. The method of claim 13, further comprising heating at least a portion of the air received from the direct expansion coil by passing the portion of the air received from the direct expansion coil over a reheat coil positioned downstream of the direct expansion coil.

15. The method of claim 14 further comprising receiving at least a portion of the fluid from the outlet of the cooling coil at an inlet of the reheat coil.

16. The method of claim 14 further comprising heating at least a portion of the air from the cooling recovery coil with a supplemental heating source.

17. 14. The method of claim 13, further comprising preheating the air received from a preheat coil before passing over the cooling coil.

18. 14. The method of claim 13, further comprising controlling a first amount of fluid received from the outlet of the cooling coil, the control comprising at least one first flow control valve.

19. 20. The method of claim 18, further comprising controlling a second amount of fluid to the inlet of the cooling recovery coil, the control comprising at least one second flow control valve.

20. The method of claim 13 further comprising moving air over the cooling coil and the direct expansion coil with one or more fans.

Images