Abstract:
A cooling recover system and method are disclosed. A fluid, such as water, is chilled and provided to a cooling coil to cool and dehumidify air passing over the cooling coil. The fluid is output from the cooling coil through an outlet, and at least a portion of the fluid from the outlet of the cooling coil is provided to an inlet of a heat transfer coil to reheat air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil, which warmer temperature serves to reheat the air passing over the heat transfer coil.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 13/854,866 entitled “COOLING RECOVERY SYSTEM AND METHOD,” filed Apr. 1, 2013, which claims priority to U.S. patent application Ser. No. 13/405,019, now U.S. Pat. No. 8,408,015 entitled “COOLING RECOVERY SYSTEM AND METHOD,” and filed Feb. 24, 2012, which claims priority of U.S. patent application Ser. No. 11/852,225, now U.S. Pat. No. 8,151,579 entitled “COOLING RECOVERY SYSTEM AND METHOD,” filed on Sep. 7, 2007, the disclosure of each is incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates generally to air conditioning in a facility, and more particularly to cooling, dehumidification, and heating systems and processes to reduce energy waste and reduce operating costs in facilities. 
         [0003]    The environment of a facility, such as a residential, commercial, industrial or institutional building, is usually tightly controlled, as temperature and humidity must fall within a relatively narrow range to accommodate human comfort, health and safety. Mold, mildew and other biological growth can damage the facility and adversely affect its occupants, and cause extensive damage each year in many facilities. Biological growth particularly thrives in warm, moist areas. To reduce the potential for biological growth, facilities need to reduce the relative humidity of air within the facility. Thus, water is removed from the air in a process called dehumidification. 
         [0004]    Conventional methods for humidity and temperature control in a facility are energy intensive, leading to high costs of operation of its cooling, dehumidification, and heating systems. Economizing either costs or energy often leads to improper use of such systems, defeating their purpose. Worse, misuse of cooling, dehumidification and heating systems permits biological growth. In humid climates, for example cooling systems may be left running twenty-four hours per day, seven days per week to reduce the potential for biological growth, even when the facility is unoccupied. This wastes substantial energy. 
         [0005]      FIG. 1  is a schematic view of a prior art cooling, dehumidification and re-heat system  01 - 0001  that includes one or more air handling units (AHUs)  01 - 0003 , valves  01 - 0055 ,  01 - 0080  and the like. A fluid such as water is typically cooled in a chiller plant  01 - 0040  and conveyed through chilled fluid supply piping  01 - 0045 ,  01 - 0090  towards the one or more AHUs  01 - 0003 , and returned through chilled fluid return piping  01 - 0050 ,  01 - 0085  towards one or more of the chiller plants  01 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller plants  01 - 0040 . 
         [0006]    Fluid is heated in a heating plant  01 - 0035  and conveyed through heated fluid supply piping  01 - 0075 ,  01 - 0105  towards one or more temperature control zones  01 - 0065 , and returned through heated fluid return piping  01 - 0070 ,  01 - 0110  toward one or more heating plants  01 - 0035 . Typically, the heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plants  01 - 0035 . 
         [0007]    The flow of chilled fluid to AHU  01 - 0003  is controlled by selectively modulating a flow control valve  01 - 0055 . The heating source fluid is controlled by selectively modulating a flow control valve,  01 - 0080 . The chilled fluid flow control valves  01 - 0055  are positioned downstream of the AHUs  01 - 0003 , and the heating source fluid flow control valves  01 - 0080  are positioned downstream of heating coils  01 - 0030 . Alternatively, the valves  01 - 0055 ,  01 - 0080  may be situated upstream of the AHU  01 - 0003  or upstream of the heating coils  01 - 0030 , respectively. 
         [0008]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled fluid is distributed through cooling coils  01 - 0015  or other heat exchange units of an AHU  01 - 0003 . Fans  01 - 0060  or blowers receive unconditioned or partially conditioned air from an inlet source consisting of return air  01 - 0002  and fresh air  01 - 0005  mixed in varying proportions to create a mixed air stream  01 - 0010  and deliver it through one or more cooling coils  01 - 0015 . 
         [0009]    The mixed air stream  01 - 0010  is passed through a filter  01 - 0100 , or it can remain unfiltered. As air moves past the cooling coils  01 - 0015 , heat from the unconditioned or partially conditioned air is removed by the chilled fluid therein. When mixed air stream  01 - 0010  or conditioned space conditions  01 - 0171  require it, the conditioned air  01 - 0025  leaving the cooling coils  01 - 0015  is cooled to a point where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. 
         [0010]    Reducing the temperature of the conditioned air  01 - 0025  condenses moisture from the air, drying it. Thus, dry, cold conditioned air  01 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  01 - 0171  through a discharge duct  01 - 0020  or other conveyance system. The dry, cold conditioned air  01 - 0025  is usually too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  01 - 0025  is delivered to temperature control boxes  01 - 0065  that contain a heating coil  01 - 0030 . 
         [0011]    Warm or hot fluid can be used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  01 - 0030  or other heat exchange units of a temperature control box  01 - 0065 . The temperature control box  01 - 0065  may be constant or variable volume. The temperature control box  01 - 0065  includes a control system that controls the control valve  01 - 0080  which controls the volume or pressure of the heated source fluid that is 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 piping  01 - 0075 ,  01 - 0105 , and heating fluid return piping,  01 - 0070 ,  01 - 0110 . The supply air temperature that leaves the heating coil  01 - 0030  and enters the spaces to be conditioned, either directly or through a distribution system  01 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  01 - 0171  by selectively modulating a flow control valve  01 - 0080  to add heat to the cold dry dehumidified air. 
         [0012]    As a result of the heat exchange at the cooling coils  01 - 0015 , the temperature of the air  01 - 0010  passing thereover is decreased to remove moisture, while the temperature of the fluid passing therethrough increases to approximately 55° F. to 60° F., particularly during the summer months when dehumidification loads are typically present. This heated or spent chilled fluid can be collected in a separate spent fluid piping  01 - 0050 ,  01 - 0085  and delivered to the inlet of the chiller system  01 - 0040 . In addition, as a result of the heat transfer from the unconditioned or partially conditioned air to the chilled water occurring at or near the cooling coils  01 - 0015 , the process can also dehumidify the air. 
         [0013]    In general, cooling coils require a chilled fluid supply via the chilled fluid piping from the chiller at a temperature of between 34° F. and 45° F. to meet peak cooling and dehumidification loads. Cooling coils typically provide fluid being returned through chilled fluid piping to a chiller at a temperature of between 55° F. and 60° F. The cooling coils are conventionally designed to provide a discharge air temperature of between 50° F. and 55° F., as required to meet comfort needs of occupants of the facility or the needs of the process cooling loads. 
         [0014]    A maximum discharge air temperature of approximately 55° F. is usually used during dehumidification to reduce the water in the air stream entering the conditioned spaces of the facility. The minimum discharge air temperature may be as low as 40° F. to 45° F., as required by the load being served. The cooling coils are typically sized with a face velocity of 500 to 600 feet per minute, as calculated by dividing the air flow volume in cubic feet per minute (CFM) by the square footage of the face of the coil that air is passing through, although they can have lower and higher face velocities. Finally, the cooling coils are arranged with between four and eight rows of heat transfer tubing, but can have greater or less numbers of heat transfer rows. 
         [0015]    Heating coils in such systems usually require a heated fluid supply temperature of between 150° F. and 200° F., supplied through heated fluid piping from heating plants, and a heated fluid return temperature of between 120° F. and 160° F. returned through heated fluid piping to the heating plants. The heating coils are designed to provide a discharge air temperature of between 60° F. and 110° F. A maximum discharge air temperature of approximately 110° F. is typically 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, the discharge air temperature may be 60° F. to 70° F., as heating of the space or process load might not be required. The heating coils are sized to accommodate a face velocity of 800 to 1,000 feet per minute, which is calculated by dividing the air flow volume in cubic feet per minute (CFM) by the square footage of the face of the coil that air is passing through. The heating coils are usually arranged in one, two, or more rows. 
         [0017]    To reduce energy waste and operating costs, many facility operating engineers deemphasize dehumidification and operate the cooling system with higher air delivery temperatures. While this reduces the amount of re-heat energy that is required, and also reduces the cooling loads, dehumidification is reduced so that the air in the facility is at a higher relative humidity. Higher relative humidity levels can encourage biological growth. 
         [0018]    There is also a compounding energy waste that occurs. Supply air temperature of around 55° F. is far too cold for occupant comfort in most climates during most of the year. Thus, the 55° F. supply air temperature is warmed up or “re-heated” to a temperature that meets the comfort criteria of the occupants or process cooling load. 
         [0019]    The heating source for the re-heat process is usually a new source of energy. Electric heaters, radiant panels, and heating coils that use hot water generated by hot water heaters or boilers are the typical sources of heat for the re-heat process. The fuels for the boiler or hot water heater can be wood chips, natural gas, oil, coal, peat, or some other combustible fuel. The water can also be heated using electricity. Heat recovered from the condenser side of a cooling system may be used to warm up the air, but these systems are less common. Re-heat coils are installed downstream of the cooling coils in a system. They can either be located within the same housing as the cooling coil, or located remotely. 
         [0020]    For most water-based re-heat systems, the re-heat coils require very high water temperatures—typically 150° F. to 200° F. These high water temperatures waste boiler or hot water heater energy, since boiler and hot water heater energy efficiency worsen as the water temperature increases. Re-heat energy adds cooling load to the facility, since most of the heat that is added to the air to meet comfort conditions or process cooling load needs is returned to the AHU system via the return air system. There is another compounding energy waste as heat is continually added to keep facility space comfortable, or to meet the process cooling requirement. But this same heat is removed from the air when dehumidifying the air by reducing the supply air temperature. 
         [0021]    An alternative cooling, dehumidification and re-heat cycle is as follows: air is returned to the AHU where it is mixed with fresh air in varying proportions, now referred to as “mixed air.” In many parts of the country for much of the year, the mixed air is warm and moist, and is reduced to a temperature of around 55° F. by a cooling system to dehumidify it, after which it is known as “supply air.” 
         [0022]    The supply air is re-heated in varying degrees, referred to as “re-heated air,” to provide comfort to the occupants or meet process cooling load needs. The re-heated air is delivered to the occupied spaces or the process cooling loads. Additional heat is added to the air in the occupied spaces or by the process load to produce “warmed-up air.” Once the warmed-up air leaves the conditioned spaces or the process load, it is referred to as “return air.” The return air contains the heat generated in the conditioned spaces or by the process cooling load, as well as the heat imparted to the air during the re-heat process. 
         [0023]    In a typical system, the water from the cooling coils is returned directly to the cooling system source, typically a chiller plant. The return chilled water carries most of the heat from the conditioned spaces, most of the heat from the process loads, the heat from the dehumidification process, the heat associated with cooling the fresh air that is brought into the system, and most of the heat from the re-heat system back to the chiller plant. The heat contained in the air that is exhausted from the facility and not returned to the chiller plant. 
         [0024]    The return chilled water temperature leaving the cooling coils and being returned to the chiller plant is typically 55° F. to 60° F. during the summer months, when most dehumidification is required. The chiller plant takes this 55° F. to 60° F. water and cools it down, typically to 40° F. to 45° F. Once the water is cooled by the chiller plant, it is sent back out to the cooling coils to start the cooling and dehumidification process again. The 55° F. to 60° F. chilled water return temperature common from most cooling systems implementations is too cold to be used effectively as a source of heating. 
         [0025]    With a conventional cooling system, the chillers are typically piped in parallel. Each chiller receives the same return water temperature and each chiller delivers the same supply water temperature. The 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 might be 44° F. The condenser water supply temperature in this example is 85° F. Assuming a constant load on each chiller, efficiency of a chiller is proportional to the temperature difference between the chilled water supply temperature and the condenser water supply temperature. The greater the temperature difference between the chilled water and condenser water temperatures, the poorer the chiller efficiency. Conversely, when the difference between the chilled water and condenser water temperatures is reduced, chiller efficiency is improved. 
         [0026]    Under Floor Air Distribution Systems (UFADS) are a variation of the typical overhead air distribution system for air conditioning systems. A UFADS requires air be supplied to the floor grills at between 62° F. and 65° F. instead of 55° F. to reduce drafts and occupant discomfort. As with a “normal” air conditioning system, air should be cooled to around 55° F. to dehumidify it, then re-heated to the proper temperatures for occupant comfort. To reduce energy use, some operators have resorted to providing 62° F. to 65° F. supply air from the cooling coils, rather than dehumidifying the air down to 55° F. and then re-heating up to 62° F. to 65° F. This reduces the cooling loads, since re-heat is not required, and very little dehumidification is accomplished with these supply air temperatures, and so the dehumidification portion of the cooling load is also reduced. 
         [0027]    Re-heat energy and cooling plant energy are both reduced when these strategies are employed, but many of the facilities eventually suffer from biological growth, and very expensive remediation efforts, whose costs far outweigh the energy savings benefits that results from the lack of dehumidification and re-heat, is sought. 
       SUMMARY 
       [0028]    This document discloses systems and methods for using facility cooling, dehumidification and heaters to reduce the relative humidity in the facility, and to reduce the potential for biological growth in facilities that causes vast amounts of damage each year. The cooling recovery system design improves chiller plant efficiency, as well as reducing the loads that is served and the amount of re-heat energy that is expended. 
         [0029]    In one aspect, an air conditioning system includes a cooling coil having an inlet to receive a fluid from a fluid chiller to cool and dehumidify air that passes over the cooling coil, and having an outlet to output the fluid. The air conditioning system further includes a fluid recovery conduit to receive the fluid from the outlet of the cooling coil, and a heat transfer coil having an inlet to receive the fluid to reheat air from the cooling coil that passes over the heat transfer coil. 
         [0030]    In another aspect, a method for conditioning air includes the steps of chilling a fluid, providing the fluid to a cooling coil to cool air passing over the cooling coil, outputting the fluid from the cooling coil through an outlet, and providing at least a portion of the fluid from the outlet of the cooling coil to an inlet of a heat transfer coil to reheat air passing over the heat transfer coil. The fluid is warmed as it passes through the cooling coil, which warmer temperature serves to reheat the air passing over the heat transfer coil. 
         [0031]    In another aspect, a method for conditioning air includes the steps of receiving, through a fluid recovery conduit connected to an outlet of a cooling coil, a fluid at a heat transfer coil, the fluid being warmed as it flows through the cooling coil. The method further includes the step of reheating, with the heat transfer coil, air that has been cooled and dehumidified by the cooling coil. 
         [0032]    In yet another aspect, an air conditioning system includes a heat transfer coil having an inlet to receive a warmed fluid via a fluid recovery conduit connected to an outlet of a cooling coil. The heat transfer coil is adapted to reheat, with the warmed fluid, air that has been cooled and dehumidified by the cooling coil. 
         [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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    These and other aspects will now be described in detail with reference to the following drawings. 
           [0035]      FIG. 1  is a schematic illustration of a prior art cooling, dehumidification and re-heat system. 
           [0036]      FIG. 2  is a schematic illustration of a cooling, dehumidification and re-heat system in accordance with an implementation. 
           [0037]      FIG. 3  is a schematic illustration of a cooling, dehumidification and re-heat system in accordance with an alternative implementation. 
           [0038]      FIG. 4  is a schematic illustration of an alternative prior art cooling, dehumidification and re-heat system. 
           [0039]      FIG. 5  is a schematic illustration of a cooling, dehumidification and re-heat system in accordance with an alternative implementation. 
           [0040]      FIG. 6  is a schematic illustration of a cooling, dehumidification and re-heat system in accordance with an alternative implementation. 
           [0041]      FIG. 7  is a schematic illustration of a cooling recovery coil system in accordance with an implementation. 
           [0042]      FIG. 8  is a schematic illustration of a cooling recovery coil system with downstream heating or reheating system diverting valve. 
           [0043]      FIG. 9  is a schematic illustration of a cooling recovery coil system in accordance with another implementation. 
           [0044]      FIG. 10  is a schematic illustration of a cooling recovery coil system with an alternative valve configuration. 
           [0045]      FIG. 11  is a schematic illustration of a cooling recovery coil system with another alternative valve configuration. 
           [0046]      FIG. 12  is a schematic illustration of a cooling recovery coil system in accordance with another implementation. 
           [0047]      FIG. 13  is a schematic illustration of a cooling recovery coil system in accordance with yet another implementation. 
           [0048]      FIGS. 14-20  depict alternative layouts of equipment for a cooling system. 
       
    
    
       [0049]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0050]    This document describes systems and methods to substantially reduce the amount of energy required for the cooling and re-heating process of a facility&#39;s air conditioning system, through the use of a cooling recovery coil to re-heat air being delivered to a space of the facility or other process of the air conditioning system. 
         [0051]    When dehumidification is required, but the dehumidified air is too cool for its intended end use, re-heating of the air is required. In some implementations, a cooling recovery coil system is used, rather than a heat recovery coil as is typical, to reduce the cooling loads by reducing the water temperature that is being returned to the cooling plant. The cooling recovery coil system also reduces the amount of re-heat that is used to maintain occupant comfort or process cooling conditions, by increasing the air temperature so that heating loads are reduced. During the cooling process, when a chilled water-based cooling system is used to provide the cooling source to the AHUs, cold water is supplied to cooling coils inside the AHUs to cool the air being circulated by an AHU for dehumidification and comfort cooling, or to meet process cooling loads. 
         [0052]    Warm mixed air passes over these cooling coils, transferring the heat contained in the mixed air into the cold water being circulated through the cooling coils. During this process, the water temperature in the cooling coils increases, as the temperature of the air passing over the cooling coils is decreased. Heat is transferred from the air to the water indirectly through the cooling coil tubing. Some return air is exhausted from the facility, so the heat contained in the exhausted air is not transferred to the cooling coil system or the chiller plant. 
         [0053]    In accordance with some implementations, the AHU cooling coil systems provide a higher than conventional return water temperature, typically 65° F. to 75° F. or higher during summer operation instead of the typical 55° F. to 60° F. temperature. The cooling coils are operated to provide approximately 55° F. supply air temperature, so that dehumidification still occurs. 
         [0054]    The re-heat coil systems utilize a much lower supply water temperature, typically 65° F. to 75° F. to match the temperature of the chilled water leaving the cooling coils and being returned to the chiller plant in one or more coils referred to herein as a “cooling recovery coil.” The cold, dehumidified air leaving the cooling coil at around 55° F. enters the cooling recovery coil. The cooling recovery coil contains chilled water entering the coil at 65° F. to 75° F. or higher. The warm water entering the cooling recovery coil provides heat to the cold, dehumidified air, warming it up. 
         [0055]    The cold air entering the cooling recovery coil system draws heat from the water in the cooling recovery coil, reducing the temperature of the water being returned to the chiller plant. This reduces the cooling load that is served by the chiller plant in direct proportion to the percentage of the water temperature reduction, when compared with the temperature differential of the water without the cooling recovery coil. For example, 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), and the cooling recovery coil drawing enough heat from the chilled water return to reduce the water temperature to 62° F., reduces the chiller plant load by approximately 32%: (70° F.-62° F./70° F.-45° F.)=8° F./25° F. The airstream is heated, and the chilled water return temperature is reduced. New energy required for the re-heat process or cooling energy required for the cooling process is less than conventional systems. 
         [0056]    Piping and control systems are configured to reduce the energy consumption of the cooling, re-heat and heating processes over and above the savings offered by the cooling recovery process by itself. 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 coils 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 systems as described below. 
         [0057]    When peak comfort periods or process cooling loads exist (i.e. maximum cooling required), there is a reduced need for re-heat to raise the supply air temperature above 55° F. for many portions of a facility. In exemplary implementations, the cooling coil and cooling recovery coil are arranged and controlled in such a manner that the entire heat transfer surface area of the two coil systems—the cooling coil system and the cooling recovery coil system—can be used as a very large cooling coil. The added cooling coil heat transfer surface area allows a temperature of chilled water that is supplied to the AHU from the cooling plant to be increased. Increasing the chilled water supply temperature from a chiller increases the efficiency of the chiller system by 1% to 3% or more per degree the chilled water supply temperature is raised. 
         [0058]    When peak comfort heating loads exist (i.e. maximum heating required), there is a reduced need for cooling to reduce the supply air temperature for cooling or dehumidification of many portions of a facility. During days in which heating is necessary, the need for dehumidification is typically very low. In some implementations, the cooling coil and cooling recovery coil are arranged and controlled such that the entire heat transfer surface area of the two coil systems—the cooling coil system and the cooling recovery coil system—can be used as one very large heating coil. This added heating coil heat transfer surface area allows the temperature of heating water supplied to the AHU from the heating plant to be decreased. The efficiency of the heater is increased by 1% or more for every five degrees the heating water supply temperature is reduced. 
         [0059]    A cooling system of a conventional air conditioning arrangement can also be used as a cooling recovery coil system. With a cooling recovery coil, return water temperature is higher than with a conventional system. This allows the chillers to be arranged in series, as will be explained further below, with one chiller being upstream of the other chiller(s). The first chiller receives return chilled water at a temperature of 65° F. to 75° F., instead of 60° F. for conventional systems. This chiller then cools the water to 55° F. to 60° F., which is then supplied to the downstream chiller, which in turn delivers water of 44° F. to 45° F. The downstream chiller will have approximately the same efficiency as the chillers that were piped in parallel, since it is delivering chilled water at approximately the same temperature. However, the upstream chiller will have much better efficiency, since it is delivering much warmer chilled water (55° F. to 60° F.) versus 45° F. of conventional systems. 
         [0060]    A cooling recovery coil is also used as an efficient heating coil when additional heat is required. The sizing of the cooling recovery coil allows comparatively low hot water temperatures to be used for heating, improving heater efficiency. Waste heat of very low quality can be effectively used to meet the re-heat or heating needs of a facility. In particular implementations, heating water temperatures of between 96° F. and 100° F. can provide heating air temperatures in excess of 95° F., where conventional heating and re-heat system designs require 150° F. to 200° F. hot water temperatures to produce 95° F. heating air temperatures. 
         [0061]    If there is no source of 100° F. waste heat available, a new heating source is used. Typical hot water heating equipment is between 80% and 85% efficient when water temperatures of 150° F. to 200° F. are used. In accordance with some implementations, the sizing and design of the cooling recovery coil can allow 100° F. heating water to be used. At these comparatively low water temperatures, new condensing type hot water heaters are between 92% and 95% efficient, depending upon the load on the heaters. During non-peak heating load conditions, the efficiency of these boilers climbs to 96% to 98%. 
         [0062]      FIG. 2  is a schematic illustration of a cooling, dehumidification and re-heat system  02 - 0001  in which the cooling recovery coils are located remotely from the AHU or fan coils, and cooling recovery is the main source of re-heat energy. In accordance with 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 cooling plants  02 - 0040  and conveyed through chilled fluid supply piping  02 - 0045 ,  02 - 0090  towards the one or more AHUs  02 - 0003 , and returned through chilled fluid return piping  02 - 0050 ,  02 - 0085  towards one or more chillers  02 - 0040 . 
         [0063]    Cooled fluid is conveyed through chilled fluid piping by one or more pumps contained in the cooling plants  02 - 0040 . Fluid is heated in cooling coil  02 - 0015  and conveyed through a heated fluid return piping  02 - 0050 ,  02 - 0085  towards cooling plants  02 - 0040 . This heated fluid is returned to one or more cooling plants  02 - 0040 . Prior to entering a cooling plant  02 - 0040 , heated fluid is withdrawn in the amount required to reheat discharge air  02 - 0025 . Pumping system  02 - 0120  and piping system  02 - 0115  are used to convey heated water from the cooling coil systems  02 - 0015  to heated fluid supply piping systems  02 - 0075 ,  02 - 0105  towards one or more temperature control zones  02 - 0065 , and returned through heated fluid return piping  02 - 0070 ,  02 - 0110  towards one or more cooling plants  02 - 0040  through piping system  02 - 0125 . The fluid being transported to and from the reheat coil system has heat removed from it during the reheat process, reducing the load on the cooling plant and heating system simultaneously. 
         [0064]    The flow of chilled fluid to an AHU  02 - 0003  is controlled by selectively modulating flow control valve  02 - 0055 . The heating source fluid is controlled by selectively modulating flow control valve  02 - 0080 . As illustrated in  FIG. 2 , the chilled fluid flow control valve  02 - 0055  is positioned downstream of the AHUs  02 - 0003 , and may include one or more valves. Each heating source fluid flow control valves  02 - 0080  is positioned downstream of the heating coils (i.e. cooling recovery coils)  02 - 0030 . Alternatively, the valves  02 - 0055  and  02 - 0080  may be situated upstream of an AHU  02 - 0003  and/or upstream of the heating coils (cooling recovery coils)  02 - 0030 . 
         [0065]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water is distributed through cooling coils  02 - 0015  or other heat exchange units of AHU  02 - 0003 . Fans  02 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source of return air  02 - 0002  mixed in varying proportions with fresh air  02 - 0005  to create a mixed air stream  02 - 0010 , to be delivered through one or more cooling coils  02 - 0015 . The air stream can either be passed through a filtration system  02 - 0100  or it can be unfiltered. 
         [0066]    Chilled fluid conveyed through cooling coils  02 - 0015  removes heat from the unconditioned or partially conditioned air passing over the cooling coils  02 - 0015 . When mixed air  02 - 0010  or conditioned space conditions  02 - 0171  require, the conditioned air  02 - 0025  leaving the cooling coils  02 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained 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, cold conditioned air  02 - 0025  is delivered to individual offices, rooms or other locations within a facility  02 - 0171  through a discharge duct  02 - 0020  or other conveyance system. The dry, cold conditioned air  02 - 0025  will typically be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  02 - 0025  is delivered to temperature control boxes  02 - 0065  that contain a heating coil (cooling recovery coil)  02 - 0030 . 
         [0067]    Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  02 - 0030  or other heat exchange units of temperature control box  02 - 0065 , which may be constant or variable volume. The temperature control box  02 - 0065  includes a controller that controls the control valve  02 - 0080 , which in turn controls the volume or pressure of the heated source fluid being passed through the heating coil  02 - 0030 . Heated fluid is generated in one or more heating plants  02 - 0035  or the cooling coils in a cooling recovery coil system, and distributed to temperature control zones  02 - 0065  via heating fluid supply piping  02 - 0075 ,  02 - 0105  and heating fluid return piping,  02 - 0070 ,  02 - 0110 . The supply air temperature leaving the heating coil (cooling recovery coil)  02 - 0030  enters the spaces to be conditioned directly, or through a distribution system  02 - 0170  that is continuously varied to maintain the needs of occupants or process cooling loads  02 - 0171  by selectively modulating a flow control valve  02 - 0080  to add heat to the cold, dry dehumidified air. 
         [0068]    As a result of the heat exchange at the cooling coils  02 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher when dehumidification loads are present. This heated or spent chilled fluid is collected in separate spent fluid piping  02 - 0050 ,  02 - 0085  and delivered to the inlet of the chiller  02 - 0040 . Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, the spent chilled fluid is drawn into the cooling recovery coil chilled water piping  02 - 0115  by operating chilled water cooling recovery pumping system  02 - 0120 , and discharging the warm chilled water return into the cooling recovery coil heating water supply lines  02 - 0075 ,  02 - 0105  for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0069]    The main components within the chiller plant systems  02 - 0040  are as follows:  02 - 0140  is the chilled fluid return piping inside the chiller plant systems, and is the piping where all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the cooling loads imposed by the AHUs or process cooling loads  02 - 0003  through the chilled fluid piping  02 - 0085 ,  02 - 0050 , and mixed with the fluid returning from the cooling recovery coil systems through piping system  02 - 0125  and with the fluid from the bypass piping  02 - 0130 . The mixed fluid is then drawn into the chilled fluid pumping systems  02 - 0145 . 
         [0070]    The chilled fluid pumping systems are provided in a draw-through or push-through configuration with the chillers  02 - 0155 . The warm mixed fluid is then passed through the chiller systems  02 - 0155  where the fluid temperature is reduced. The chiller isolation valves  02 - 0160  are controlled to allow flow through the chillers. The chilled fluid then enters a common discharge piping  02 - 0165  where it is either delivered to the cooling loads through the supply piping  02 - 0090 ,  02 - 0045 , or is returned to the chilled fluid return piping  02 - 0140  by passing through the chilled fluid bypass piping  02 - 0130  and bypass piping control valve  02 - 0135 .  FIG. 2  shows the chillers piped in one arrangement. Those having ordinary skill in the art can appreciate that alternative piping configurations can be used, as will be described further. 
         [0071]      FIG. 3  is similar to  FIG. 2 , but includes a positive shutoff isolation valve  03 - 0175 , to ensure that the cooling system and heater fluids do not mix when they are both in operation and the cooling recovery coil systems is not being used. A cooling, dehumidification and re-heat system  03 - 0001  includes one or more AHUs  03 - 0003 , valves  03 - 0055 ,  03 - 0080  and the like. Fluid is cooled in a chiller system  03 - 0040  and conveyed through a chilled fluid supply piping  03 - 0045 ,  03 - 0090  towards one or more AHUs  03 - 0003 , and returned through the chilled fluid return piping  03 - 0050 ,  03 - 0085  towards one or more chiller systems  03 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  03 - 0040 . Fluid is heated in a heater  03 - 0035  and conveyed through a heated fluid supply piping  03 - 0075 ,  03 - 0105  towards one or more temperature control zones  03 - 0065 , and returned through the heated fluid return piping  03 - 0070 ,  03 - 0110  towards one or more heaters  03 - 0035 . The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heaters  03 - 0035 . 
         [0072]    The flow of chilled fluid to an AHU  03 - 0003  is controlled by selectively modulating a flow control valve  03 - 0055 . The heating source fluid is controlled by selectively modulating a flow control valve,  03 - 0080 . As shown in  FIG. 3 , chilled fluid flow control valves  03 - 0055  are positioned downstream of respective AHUs  03 - 0003 . The heating source fluid flow control valves  03 - 0080  are positioned downstream of respective heating coils (cooling recovery coils)  03 - 0030 . Alternatively, the valves  03 - 0055 ,  03 - 0080  may be situated upstream of an AHU  03 - 0003  or upstream of respective heating coils (cooling recovery coils)  03 - 0030 . 
         [0073]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  03 - 0015  or other heat exchange units of an AHU  03 - 0003 . Fans  03 - 0060  or blowers receive unconditioned or partially conditioned air from an inlet source consisting of return air  03 - 0002  and fresh air  03 - 0005  mixed in varying proportions, to create a mixed air stream  03 - 0010  and deliver it through one or more cooling coils  03 - 0015 . The air stream can either be passed through a filtration system  03 - 0100  or it can be unfiltered. 
         [0074]    As air moves past the cooling coils  03 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  03 - 0010 , or conditioned space conditions  03 - 0171  require, the conditioned air  03 - 0025  leaving the cooling coils  03 - 0015  is cooled to the point that water is removed from the air, and the relative humidity in the conditioned spaces is maintained 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, cold conditioned air  03 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  03 - 0171  through a discharge duct  03 - 0020 , or other conveyance system. 
         [0075]    The dry, cold conditioned air  03 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  03 - 0025  is delivered to temperature control boxes  03 - 0065  that contain a heating coil  03 - 0030 . Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils (cooling recovery coils)  03 - 0030  or other heat exchange units of a temperature control box  03 - 0065 . The temperature control box  03 - 0065  includes a controller that controls the control valve  03 - 0080 , which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  03 - 0030 . 
         [0076]    Heated fluid is generated in a heating plant or plants  03 - 0035  and distributed to the temperature control zones  03 - 0065  through heating fluid supply piping  03 - 0075 ,  03 - 0105 , and heating fluid return piping,  03 - 0070 ,  03 - 0110 . The supply air temperature that leaves the heating coil  03 - 0030  enters the spaces to be conditioned, either directly or through a distribution system  03 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  03 - 0171  by selectively modulating a flow control valve  03 - 0080  to add heat to the cold dry dehumidified air. 
         [0077]    As a result of the heat exchange occurring at the cooling coils  03 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months when dehumidification loads are usually present. As illustrated in  FIG. 3 , this heated or spent chilled fluid is collected in a separate spent fluid piping  03 - 0050 ,  03 - 0085  and delivered to the inlet of the chiller system  03 - 0040 . If there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping  03 - 0050 ,  03 - 0085  is drawn into the cooling recovery coil chilled water piping  03 - 0115  by operating the chilled water cooling recovery pumping system  03 - 0120 , and discharging the warm chilled water return into the cooling recovery coil heating water supply lines  03 - 0075 ,  03 - 0105  for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0078]    The main components within the chiller plant systems  03 - 0040  are as follows:  03 - 0140  is the chilled fluid return piping inside the chiller plant systems, and is the piping where all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the cooling loads imposed by the AHUs or process cooling loads  03 - 0003 , through the chilled fluid piping  03 - 0085 ,  03 - 0050 , and mixed with the fluid returning from the cooling recovery coil systems and the fluid from the bypass piping  03 - 0130 . The mixed fluid is then drawn into the chilled fluid pumping systems  03 - 0145 . 
         [0079]    The chilled fluid pumping systems is provided in a draw-through or push-through configuration with the chillers  03 - 0155 . The warm mixed fluid is then passed through the chiller systems  03 - 0155  where the fluid temperature is reduced. The chiller isolation valves  03 - 0160  are controlled to allow flow through the chillers that are operational. The chilled fluid then enters a common discharge piping  03 - 0165 , where it is either delivered to the cooling loads through the supply piping  03 - 0090 ,  03 - 0045 , or is returned to the chilled fluid return piping by passing through the chilled fluid bypass piping  03 - 0130  and bypass piping control valve  03 - 0135 .  FIG. 3  shows the chillers piped in one arrangement, although other arrangements are possible. 
         [0080]      FIG. 4  shows a cooling, dehumidification and re-heat system  04 - 0001  that includes one or more AHUs  04 - 0003 , valves  04 - 0055 ,  04 - 0080  and the like. Fluid is cooled in a chiller system  04 - 0040  and conveyed through a chilled fluid supply piping  04 - 0045 ,  04 - 0090  towards one or more AHUs  04 - 0003 , and returned through the chilled fluid return piping  04 - 0050 ,  04 - 0085  towards one or more chiller systems  04 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  04 - 0040 . In some embodiments, fluid is heated in a heating plant  04 - 0035  and conveyed through a heated fluid supply piping  04 - 0075 ,  04 - 0105  towards one or more heating coil systems  04 - 0030 , and returned through the heated fluid return piping  04 - 0070 ,  04 - 0110  towards one or more heating plants  04 - 0035 . The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plants  04 - 0035 . 
         [0081]    The flow of chilled fluid to a cooling coil  04 - 0015  in an AHU  04 - 0003  is controlled by selectively modulating a flow control valve  04 - 0055 . The heating source fluid is controlled by selectively modulating a flow control valve,  04 - 0080 . As shown in  FIG. 4 , the chilled fluid flow control valves  04 - 0055  are positioned downstream of respective cooling coil  04 - 0015 . The heating source fluid flow control valves  04 - 0080  are positioned downstream of the heating coils,  04 - 0030  respectively. Alternatively, however, the valves  04 - 0055 ,  04 - 0080  may be situated upstream of the cooling coil  04 - 0015  or upstream of the heating coils,  04 - 0030  respectively. 
         [0082]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  04 - 0015  or other heat exchange units of an AHU  04 - 0003 . Fans  04 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source of return air  04 - 0002  and fresh air  04 - 0005  mixed in varying proportions to create a mixed air stream  04 - 0010 , and deliver the mixed air stream  04 - 0010  through one or more cooling coils  04 - 0015 . The mixed air stream  04 - 0010  can either be passed through a filtration system  04 - 0100  or it can be unfiltered. 
         [0083]    As air moves past the cooling coils  04 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When the mixed air stream  04 - 0010  or conditioned space conditions  04 - 0171  require it, the conditioned air  04 - 0025  leaving the cooling coils  04 - 0015  is cooled to a point where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  04 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  04 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  04 - 0171  through a discharge duct  04 - 1070 , or other conveyance system. The dry, cold conditioned air  04 - 0025  will typically be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  04 - 0025  is passed through a heating coil  04 - 0030 . 
         [0084]    Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  04 - 0030  or other heat exchange units of AHU  04 - 0003 . The AHU  04 - 0030  may be constant or variable volume. The AHU  04 - 0003  includes a control system that controls the control valve  04 - 0080 , which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  04 - 0030 . Heated fluid is generated in one or more heating plants  04 - 0035  and distributed to the AHU heating coil  04 - 0030  through heating fluid supply piping  04 - 0075 ,  04 - 0105  and heating fluid return piping  04 - 0070 ,  04 - 0110 . The supply air temperature that leaves the heating coil  04 - 0030  enters the spaces to be conditioned, either directly or through distribution system  04 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  04 - 0171  by selectively modulating a flow control valve  04 - 0080  to add heat to the cold dry dehumidified air. 
         [0085]    As a result of the heat exchange occurring at the cooling coils  04 - 0015  the temperature of the air  01 - 0010  passing thereover is decreased to remove moisture, while the temperature of the fluid passing therethrough increases to approximately 55° F. to 60° F. during the summer months. As illustrated in  FIG. 4 , this heated or spent chilled fluid is collected in a separate spent fluid piping  04 - 0050 ,  04 - 0085  and delivered to the inlet of the chiller system  04 - 0040 . As a result of the heat transfer from the unconditioned or partially conditioned air to the chilled water at or near the cooling coils  04 - 0015 , the process can also dehumidify the air. 
         [0086]    The cooling coils  04 - 0015  provide fluid of between 34° F. and 45° F. being supplied through the chilled fluid piping  04 - 0045 ,  04 - 0090  from the chiller systems  04 - 0040  to meet peak cooling and dehumidification loads. The cooling coils  04 - 0015  provide a chilled fluid return temperature of between 55° F. and 60° F., being returned through the chilled fluid piping  04 - 0050 ,  04 - 0085  to the chiller systems  04 - 0040 . Chilled fluid supply temperature of less than 34° F. and greater than 45° F. can be used in different implementations, and as cooling and dehumidification needs dictate. 
         [0087]    The cooling coils  04 - 0015  provide a discharge air temperature  04 - 0025  of between 50° F. and 55° F., as required to meet comfort needs or the needs of the process cooling loads. A maximum discharge air temperature of approximately 55° F. is typically used when dehumidification is required to reduce the amount of water contained in the air stream that enters the conditioned spaces. The minimum discharge air temperature may be as low as 40° F. to 45° F., as required by the load being served. 
         [0088]    The cooling coils  04 - 0015  are sized with a face velocity of 500 to 600 feet per minute, although lower or higher face velocities can be used. The cooling coils  04 - 0015  are sized for between 4 and 8 rows of heat transfer tubing, although higher or lower row counts can be used. The heating coils  04 - 0030  typically require a heated fluid supply temperature of between 150° F. and 200° F. being supplied through the heated fluid piping  04 - 0075 ,  04 - 0105  from the heating plants  04 - 0035 . The heating coils  04 - 0030  provide a heated fluid return temperature of between 120° F. and 160° F., being returned through the heated fluid piping  04 - 0070 ,  04 - 0110  to the heating plant  04 - 0035 . 
         [0089]    The heating coils  04 - 0030  provide a discharge air temperature of between 60° F. and 110° F., as required to meet comfort needs or the needs of the process heating loads. A maximum discharge air temperature of approximately 110° F. is used to reduce the amount of hot air stratification that occurs when the heated air enters the conditioned space or process load. During dehumidification operation, the discharge air temperature may be 60° F. to 70° F., as heating of the space or process load might not be required. The heating coils  04 - 0030  are sized with a face velocity of 800 to 1,000 feet per minute although in this implementation the heating and cooling coils may have the same face velocity. The heating coils  04 - 0030  are sized for one to two rows of heat transfer tubing, although other numbers of rows of heat transfer tubing can be used. 
         [0090]      FIG. 5  is a schematic view of a cooling, dehumidification and re-heat system in accordance with a cooling recovery system design where the cooling recovery coils are located in close proximity to the cooling coils, and may be within the AHU or fan coil system. Recaptured energy from the cooling recovery coil system would be the primary re-heat source, and there may or not be additional heating coils located remotely from the AHU or fan coil to further temper the air.  FIG. 5  does not include the details associated with a re-heat coil system located downstream of the cooling recovery coils, as those details are shown in other figures. 
         [0091]    A cooling, dehumidification and re-heat system  05 - 0001  includes one or more AHUs  05 - 0003 , valves  05 - 0055 ,  05 - 0080 ,  05 - 0081  and the like. In some embodiments, fluid is cooled in a chiller system  05 - 0040  and conveyed through a chilled fluid supply piping  05 - 0045 ,  05 - 0090  towards one or more AHUs  05 - 0003 , and returned through the chilled fluid return piping  05 - 0050 ,  05 - 0085  towards one or more chiller systems  05 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  05 - 0040 . In this embodiment, the cooling recovery coil system  05 - 0030  is located in close proximity to the cooling coil  05 - 0015 , and may be installed within the AHU  05 - 0003 . In some embodiments, there may be an additional heating coil system located either within the AHU  05 - 0003  or remotely in the air stream downstream of the cooling recovery coil. 
         [0092]    The flow of chilled fluid to an AHU  05 - 0003  is controlled by selectively modulating a flow control valve  05 - 0055 . The cooling recovery source fluid is controlled by selectively modulating flow control valves,  05 - 0080 ,  05 - 0081 . The chilled fluid flow control valves  05 - 0055  are positioned downstream of respective AHUs  05 - 0003 . The cooling recovery source fluid flow control valves  05 - 0080 ,  05 - 0081  are positioned downstream of respective cooling recovery coils  05 - 0030 . Alternatively, the valves  05 - 0055 ,  05 - 0080 ,  05 - 0081  may be situated upstream of an AHU  05 - 0003  or upstream of the cooling recovery coils  05 - 0030 , respectively. 
         [0093]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  05 - 0015  or other heat exchange units of an AHU  05 - 0003 . Fans  05 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source, consisting of return air  05 - 0002 , and fresh air  05 - 0005  mixed in varying proportions, to create a mixed air stream  05 - 0010 , and deliver the mixed air stream  05 - 0010  through one or more cooling coils  05 - 0015 . The air stream can either be passed through a filtration system  05 - 0100 , or it can be unfiltered. 
         [0094]    As air moves past the cooling coils  05 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  05 - 0010 , or conditioned space conditions  05 - 0171  require it, the conditioned air  05 - 0025  leaving the cooling coils  05 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  05 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  05 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  05 - 0171  through a discharge duct  05 - 0020 , or other conveyance system. 
         [0095]    The dry, cold conditioned air  05 - 0025  will typically be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  05 - 0025  is passed through a cooling recovery coil system  05 - 0030 . Warm fluid from the chilled water return piping  05 - 0051  and leaving the cooling coil system  05 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to entirely meet re-heat needs. The supply air temperature that leaves the cooling recovery coil  05 - 0030 , and which enters the spaces to be conditioned either directly or through a distribution system  05 - 0020 , is continuously varied to maintain the needs of the occupant or process cooling loads  05 - 0171  by selectively modulating flow control valves  05 - 0080 ,  05 - 0081  to add heat to the cold dry dehumidified air. As stated previously, there may be addition heating coils located downstream of the cooling recovery coil system that are not shown  FIG. 5 . 
         [0096]    As a result of the heat exchange occurring at the cooling coils  05 - 0015 , the temperature of over-passing air  05 - 0010  is decreased to remove moisture, while the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  05 - 0051 , and delivered to the inlet piping  05 - 0106  for the cooling recovery coil system  05 - 0030  or returned to the chiller system  05 - 0040 . If there is a need for re-heating some or all of cooled and dehumidified air  05 - 0025 , some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping  05 - 0051  is forced into the cooling recovery coil chilled water piping  05 - 0106  by operating control valves  05 - 0080 ,  05 - 0081 , forcing the warm chilled water return into the cooling recovery coil heating water supply lines  05 - 0106  for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0097]    The system shown in  FIG. 6  functions substantially as the system shown in  FIG. 5 , except that the cooling recovery system re-heat coil is connected to an auxiliary heating source to provide heating to an area being served when the need for heating exceeds that which is otherwise available from the fluid leaving the cooling coil. 
         [0098]    A cooling, dehumidification and re-heat system  06 - 0001  includes one or more AHUs  06 - 0003 , valves  06 - 0055 ,  06 - 0080 ,  06 - 0082  and the like. Fluid is cooled in a chiller system  06 - 0040  and conveyed through a chilled fluid supply piping  06 - 0045 ,  06 - 0090  towards one or more AHUs  06 - 0003 , and returned through the chilled fluid return piping  06 - 0050 ,  06 - 0085  towards one or more chiller systems  06 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  06 - 0040 . Fluid is heated in a heating plant  06 - 0035  and conveyed through a heated fluid supply piping  06 - 0075 ,  06 - 0105 ,  06 - 0106  towards one or more heating, reheat or cooling recovery coils  06 - 0030 , and returned through the heated fluid return piping  06 - 0070 ,  06 - 0110 ,  06 - 0111  towards one or more heating plant  06 - 0035 . The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant  06 - 0035 . 
         [0099]    The flow of chilled fluid to an AHU  06 - 0003  is controlled by selectively modulating a flow control valve  06 - 0055 . The heating source fluid is controlled by selectively modulating flow control valves,  06 - 0080 ,  06 - 0082 . The chilled fluid flow control valves  06 - 0055  are positioned downstream of respective AHUs  06 - 0003 . The heating source fluid flow control valves  06 - 0080 ,  06 - 0082  are positioned downstream of respective heating coils (cooling recovery coils)  06 - 0030 . Alternatively, however, the valves  06 - 0055 ,  06 - 0080 ,  06 - 0082  may be situated upstream of an AHU  06 - 0003  or upstream of the heating coils (cooling recovery coils)  06 - 0030  respectively. 
         [0100]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  06 - 0015  or other heat exchange units of an AHU  06 - 0003 . Fans  06 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  06 - 0002  and fresh air  06 - 0005  mixed in varying proportions to create a mixed air stream  06 - 0010 , and deliver the mixed air stream  06 - 0010  through one or more cooling coils  06 - 0015 . The mixed air stream  06 - 0010  can either be passed through a filtration system  06 - 0100  or it can be unfiltered. 
         [0101]    As air moves past the cooling coils  06 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  06 - 0010 , or conditioned space conditions  06 - 0171  require it, the conditioned air  06 - 0025  leaving the cooling coils  06 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  06 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  06 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  06 - 0171  through a discharge duct  06 - 0020 , or other conveyance system. 
         [0102]    The dry, cold conditioned air  06 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  06 - 0025  is passed through a cooling recovery coil system  06 - 0030 . Warm fluid from the chilled water return piping  06 - 0051  leaving the cooling coil system  06 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. 
         [0103]    To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source can be introduced. For example, heated water can be distributed through heating coils (cooling recovery coils)  06 - 0030  or other heat exchange units of an AHU  06 - 0003 . 
         [0104]    The AHU  06 - 0003  includes a control system that controls the control valves  06 - 0080 ,  06 - 0082 , which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating (cooling recovery) coil  06 - 0030 . Heated fluid is generated in a heating plant or plants  06 - 0035  and distributed to the AHU&#39;s  06 - 0003  through heating fluid supply piping  06 - 0075 ,  06 - 0105 ,  06 - 0106  and heating fluid return piping,  06 - 0070 ,  06 - 0110 ,  06 - 0111 . The supply air temperature that leaves the heating coil  06 - 0030 , and enters the spaces to be conditioned either directly or through a distribution system  06 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  06 - 0171  by selectively modulating a flow control valve  06 - 0080  to add heat to the cold dry dehumidified air. 
         [0105]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  06 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  06 - 0050 ,  06 - 0051 ,  06 - 0085  and delivered to the inlet of the chiller system  06 - 0040 . Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping  06 - 0051  is forced into the cooling recovery coil chilled water piping  06 - 0106 ,  06 - 0107  by operating the control valves  06 - 0080 ,  06 - 0082  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  06 - 0106 ,  06 - 0107  for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0106]      FIG. 7  depicts an implementation in which the cooling coil system and the cooling recovery coil system can both be used as cooling coils to meet peak day cooling loads, while chiller plant efficiency is improved by using warmer chilled water temperatures due to the increased heat transfer surface area. Additionally, the cooling coil system and cooling recovery coil system can both be used as heating coils to meet peak heating loads while improving hot water plant efficiency by allowing the use of cooler heating water temperatures due to the increased heat transfer surface area. The cooling recovery system re-heat coil is connected to an auxiliary heating source to provide heating to the area being served when the need for heating exceeds that which is otherwise available from the fluid leaving the cooling coil. 
         [0107]    As shown in  FIG. 7  a cooling, dehumidification and re-heat system  07 - 0001  includes one or more heat transfer systems  07 - 0015 ,  07 - 0030 , valves  07 - 0055 ,  07 - 0082  and the like. Fluid is cooled in a chiller system  07 - 0040  and conveyed through a chilled fluid supply piping  07 - 0045 ,  07 - 0090  towards the cooling, dehumidification and re-heat system  07 - 0001  and returned through the chilled fluid return piping  07 - 0050 ,  07 - 0085  towards one or more chiller systems  07 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  07 - 0040 . Fluid is heated in a heating plant  07 - 0035  and conveyed through a heated fluid supply piping  07 - 0075 ,  07 - 0105 ,  07 - 0106 ,  07 - 0200  towards one or more heating, reheat or cooling recovery coils  07 - 0030 , and returned through the heated fluid return piping  07 - 0070 ,  07 - 0111 ,  07 - 0205  towards one or more heating plants  07 - 0035 . The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plants  07 - 0035 . 
         [0108]    The flow of chilled fluid to cooling coils  07 - 0015 , for heat transfer, is controlled by selectively modulating a flow control valve  07 - 0055 . The heating source fluid is controlled by selectively modulating flow control valve,  07 - 0082 . The chilled fluid flow control valves  07 - 0055  are positioned downstream of respective cooling coils  07 - 0015 . The heating source fluid flow control valves  07 - 0082  are positioned downstream of respective heating coils (cooling recovery coils)  07 - 0030 . Alternatively, however, the valves  07 - 0055 ,  07 - 0082  may be situated upstream of cooling coils  07 - 0015  or upstream of the heating coils (cooling recovery coils)  07 - 0030  respectively. 
         [0109]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  07 - 0015  or other heat exchange units of an AHU. Fans or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  07 - 0002  and fresh air  07 - 0005  mixed in varying proportions to create a mixed air stream and deliver the mixed air stream through one or more cooling coils  07 - 0015 . 
         [0110]    As air moves past the cooling coils  07 - 0015  in cooling recovery coil system, chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air or conditioned space conditions require it, the conditioned air  07 - 0025  leaving the cooling coils  07 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  07 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  07 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior through a discharge duct or other conveyance system. 
         [0111]    The dry, cold conditioned air  07 - 0025  will typically be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  07 - 0025  is passed through a cooling recovery coil system  07 - 0030 . Warm fluid that is being sourced from the chilled water return piping  07 - 0051  that leaves the cooling coils  07 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in its entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. 
         [0112]    To augment the heating capacity available from the warm water leaving the cooling coils  07 - 0015 , a higher temperature heating source is introduced. For example, heated fluid can be distributed through heating coils (cooling recovery coils)  07 - 0030  or other heat exchange units of an AHU. The AHU includes a control system that controls the control valves  07 - 0082 , which in turn control the source, volume or pressure of the heated source fluid that is passed through the cooling recovery coil  07 - 0030 . 
         [0113]    Heated fluid is generated in a heating plant or plants  07 - 0035  and distributed to the AHU&#39;s through heating fluid supply piping  07 - 0075 ,  07 - 0105 ,  07 - 0106 ,  07 - 0210  and heating fluid return piping,  07 - 0070 ,  07 - 0111 ,  07 - 0205 . The supply air temperature that leaves the heating coil (cooling recovery coil)  07 - 0030  and enters the spaces to be conditioned, either directly or through a distribution system is continuously varied to maintain the needs of the occupant or process cooling loads by selectively modulating a flow control valve  07 - 0082  to add heat to the cold dry dehumidified air. 
         [0114]    As a result of the heat exchange occurring at the cooling coils  07 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months when dehumidification loads are typically present. This heated or spent chilled fluid is collected in a separate spent fluid piping  07 - 0050 ,  07 - 0051 ,  07 - 0085  and delivered to the inlet of the chiller system  07 - 0040 . Or, if there is a need for re-heating some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping  07 - 0051  is forced into the cooling recovery coils  07 - 0106 ,  07 - 0107  by operating the control valves  07 - 0082 , and forcing the warm chilled water return into the cooling recovery coils  07 - 0106 ,  07 - 0107  for delivery as the heating source. 
         [0115]    The main components within the chiller plant systems  07 - 0040  are as follows:  07 - 0140  is the chilled fluid return piping inside the chiller plant systems, and is the piping in which all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the cooling loads imposed by the AHU&#39;s or process cooling loads through the chilled fluid piping  07 - 0085 ,  07 - 0050 , mixed with the fluid returning from the cooling recovery coil systems, and the fluid from the bypass piping  07 - 0130 . The mixed fluid is then drawn into the chilled fluid pumping systems  07 - 0145 . 
         [0116]    The chilled fluid pumping systems is provided in a draw-through or push-through configuration with the chillers  07 - 0155 . The warm mixed fluid is then passed through the chiller systems  07 - 0155  where the fluid temperature is reduced. The chiller isolation valves  07 - 0160  are controlled to allow flow through the chillers that are operational. The chilled fluid then enters a common discharge piping  07 - 0165 , where it is either delivered to the cooling loads through the supply piping  07 - 0090 ,  07 - 0045 , or is returned to the chilled fluid return piping by passing through the chilled fluid bypass piping  07 - 0130  and bypass piping control valve  07 - 0135 . While  FIG. 7  illustrates one piping arrangement, and other piping configurations can be used. 
         [0117]    The main components within the heating plant systems  07 - 0035  are as follows:  07 - 0265  is the heated fluid return piping inside the heating plant systems, and is the piping where all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the heating loads imposed by the AHU&#39;s or process loads through heated fluid piping  07 - 0020 ,  07 - 0215 ,  07 - 0205  mixed with the fluid returning from the cooling recovery coil systems,  07 - 0111 , the fluid from heating/cooling crossover piping,  07 - 0225 ,  07 - 0230  and the fluid from the bypass piping  07 - 0250 . The mixed fluid is then drawn into the heated fluid pumping systems  07 - 0260 . 
         [0118]    The heated fluid pumping systems are provided in a draw-through or push-through configuration with heaters  07 - 0275 . The warm mixed fluid is then passed through the heater systems  07 - 0275  where the fluid temperature is increased. The heater isolation valves  07 - 0280  are controlled to allow flow through operational heaters. The heated fluid then enters a common discharge piping  07 - 0270  where it is either delivered to the heating loads through the supply piping  07 - 0075 ,  07 - 0105 , or is returned to the heated fluid return piping by passing through the heated fluid bypass piping  07 - 0250  and bypass piping control valve  07 - 0245 ,  07 - 0255 .  FIG. 7  shows the heaters piped in one arrangement, although different arrangements are possible. 
         [0119]    The system shown in  FIG. 8  functions substantially as the system shown in  FIG. 6 , except that the cooling recovery system cooling recovery coil is directly connected to the cooling coil via pipes and valves  08 - 111 ,  08 - 106 ,  08 - 0081 ,  08 - 0055 ,  08 - 0050 , and there is an auxiliary reheat coil system  08 - 0065 ,  08 - 0031  that is connected to a heating source to provide heating to an area being served when the need for heating exceeds that which is otherwise available from the fluid leaving the cooling coil and cooling recovery coil systems. 
         [0120]    In some implementations, a cooling, dehumidification and re-heat system  08 - 0001  includes one or more AHUs  08 - 0003 , valves  08 - 0055 ,  08 - 0081 , and the like. Fluid is cooled in a chiller system not shown in this figure and conveyed through a chilled fluid supply piping  08 - 0045 , towards one or more AHUs  08 - 0003 , and returned through the chilled fluid return piping  08 - 0050 ,  08 - 0085  towards one or more chiller systems. The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems. Fluid is heated in a heating plant and conveyed through a heated fluid supply piping towards one or more heating, or reheat coils  08 - 0031 , and returned through the heated fluid return piping towards one or more heating plants. The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant. 
         [0121]    The flow of chilled fluid to an AHU  08 - 0003  is controlled by selectively modulating a flow control valve  08 - 0055 . The cooling recovery coil source fluid is controlled by selectively modulating flow control valves,  08 - 0081 ,  08 - 0055 . The heating source fluid is controlled by selectively modulating flow control valves, not shown in this figure. The chilled fluid flow control valves  08 - 0055 ,  08 - 0081  are positioned downstream of respective AHUs  08 - 0003 . Alternatively, however, the valves  08 - 0055 ,  08 - 0081  may be situated upstream of an AHU  08 - 0003  or upstream of the cooling recovery coils  08 - 0030  respectively. 
         [0122]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  08 - 0015  or other heat exchange units of an AHU  08 - 0003 . Fans  08 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  08 - 0002  and fresh air  08 - 0005  mixed in varying proportions to create a mixed air stream  08 - 0010 , and deliver the mixed air stream  08 - 0010  through one or more cooling coils  08 - 0015 . The mixed air stream  08 - 0010  can either be passed through a filtration system  08 - 0100  or it can be unfiltered. 
         [0123]    As air moves past the cooling coils  08 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  08 - 0010 , or conditioned space conditions  08 - 0171  require it, the conditioned air  08 - 0025  leaving the cooling coils  08 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  08 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  08 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  08 - 0171  through a discharge duct  08 - 0020 , or other conveyance system. 
         [0124]    The dry, cold conditioned air  08 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  08 - 0025  is passed through a cooling recovery coil system  08 - 0030 . Warm fluid from the chilled water return piping  08 - 0051  leaving the cooling coil system  08 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety; If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources by sending this warm fluid through a reheat coil system  08 - 0031 . 
         [0125]    To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source is introduced and used to add heat to the air entering the reheat coil system  08 - 0031 . For example, heated water can be distributed through heating coils  08 - 0031  or other heat exchange units of a temperature control zone,  08 - 0065 . The temperature control zone,  08 - 0065  includes a control system that controls the control valves not shown in this figure, which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating coil  08 - 0031 . Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones,  08 - 0065  through heating fluid supply and return piping. The supply air temperature that leaves the heating coil  08 - 0031 , and enters the spaces to be conditioned either directly or through a distribution system  08 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  08 - 0171  by selectively modulating a flow control valve to add heat to the cold dry dehumidified air. 
         [0126]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  08 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  08 - 0050 , and delivered to the inlet of the chiller system. Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping is forced into the cooling recovery coil chilled water piping  08 - 0106 , by operating the control valves  08 - 0081  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  08 - 0106 , for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0127]    Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones  08 - 0065  through heating fluid supply and return piping, not shown in  FIG. 8 . The supply air temperature that leaves the heating coil  08 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  08 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  08 - 0171  by selectively modulating a flow control valve to add additional heat to the cold dry dehumidified air. 
         [0128]    The dry, cold conditioned air  03 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  08 - 0025  is passed through the cooling recovery coil  08 - 0030  to add heat to the air and warm it up. The air is then delivered to temperature control boxes  08 - 0065  that contain a heating coil  08 - 0031 . If the space conditions or process cooling loads  08 - 0171  require air that is warmer than that which is provided after leaving the cooling recovery coil  08 - 0030 , the reheat coil  08 - 0031  is activated. Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  08 - 0031  or other heat exchange units of a temperature control box  08 - 0065 . The temperature control box  08 - 0065  includes a controller that controls a control valve, which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  08 - 0031 . 
         [0129]    Heated fluid is generated in a heating plant or plants not shown in this figure and distributed to the temperature control zones  08 - 0065  through heating fluid supply and return piping (not shown). The supply air temperature that leaves the heating coil  08 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  08 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  08 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the cold dry dehumidified air. 
         [0130]    The system shown in  FIG. 9  functions substantially as the system shown in  FIG. 8 , except that the cooling recovery system cooling recovery re-heat coil are provided with heating water sourced either directly from the cooling coil, or from any auxiliary heating source, and there is an auxiliary reheat coil  09 - 0065  that is connected to a heating source to provide heating to an area being served when the need for heating exceeds that which is otherwise available from the fluid leaving the cooling coil. 
         [0131]    Cooling, dehumidification and re-heat system  09 - 0001  includes one or more AHUs  09 - 0003 , valves  09 - 0055 ,  09 - 0081 , and the like. Fluid is cooled in a chiller system and conveyed through a chilled fluid supply piping  09 - 0045  towards one or more AHUs  09 - 0003 , and returned through the chilled fluid return piping  09 - 0050 ,  09 - 0085  towards one or more chiller systems. The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems. Fluid is heated in a heating plant and conveyed through a heated fluid supply piping  09 - 0075 ,  09 - 0105  towards one or more heating, reheat or cooling recovery coils  09 - 0030 ,  09 - 0031  and returned through the heated fluid return piping  09 - 0070 ,  09 - 0110 , towards one or more heating plants. The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant. 
         [0132]    The flow of chilled fluid to an AHU  09 - 0003  is controlled by selectively modulating a flow control valve  09 - 0055 . The cooling recovery coil heating source fluid is controlled by selectively modulating flow control valve  09 - 0081 . The chilled fluid flow control valves  09 - 0055  are positioned downstream of respective AHUs  09 - 0003 . The cooling recovery coil heating source fluid flow control valve,  09 - 0081  is positioned upstream of respective cooling recovery coils  09 - 0030 . Alternatively, however, the valves  09 - 0055 ,  09 - 0081 , may be situated upstream of an AHU  09 - 0003  or downstream of the cooling recovery coils  09 - 0030  respectively. 
         [0133]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water is distributed through cooling coils  09 - 0015  or other heat exchange units of an AHU  09 - 0003 . Fans  09 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of a mixture of return air  09 - 0002  and fresh air  09 - 0005  to create a stream of mixed air  09 - 0010  for delivery to one or more cooling coils  09 - 0015 . The mixed air  09 - 0010  can either be passed through a filtration system  09 - 0100  or it can be unfiltered. 
         [0134]    As air moves past the cooling coils  09 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  09 - 0010 , or conditioned space conditions  09 - 0171  require it, the conditioned air  09 - 0025  leaving the cooling coils  09 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  09 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  09 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  09 - 0171  through a discharge duct  09 - 0020 , or other conveyance system. 
         [0135]    The dry, cold conditioned air  09 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  09 - 0025  is passed through a cooling recovery coil system  09 - 0030 . Warm fluid from the chilled water return piping  09 - 0111  leaving the cooling coil system  09 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source is introduced. For example, heated water can be distributed through heating coils (cooling recovery coils)  09 - 0030  or other heat exchange units of an AHU  09 - 0003 . 
         [0136]    The AHU  09 - 0003  includes a control system that controls the control valves  09 - 0081 ,  09 - 0082 , which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating cooling recovery coil  09 - 0030 . Heated fluid is generated in a heating plant or plants and distributed to the AHU&#39;s  09 - 0003  through heating fluid supply piping  09 - 0075 ,  09 - 0105 , and heating fluid return piping,  09 - 0070 ,  09 - 0110 . If further heating of the air is required, a heating coil  09 - 0031  located in a temperature control box  09 - 0065  is operated as required to increase the temperature of the air as required. The supply air temperature that leaves the heating coil  09 - 0031 , and enters the spaces to be conditioned either directly or through a distribution system  09 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  09 - 0171  by selectively modulating a flow control valve to add heat to the dehumidified air. 
         [0137]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  09 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  09 - 0050 ,  09 - 0085  and delivered to the inlet of the chiller system. Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping is forced into the cooling recovery coil chilled water piping  09 - 0106 , and check valve system  09 - 0108  by operating the control valves  09 - 0081  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  09 - 0106 , for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0138]    Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones  09 - 0065  through heating fluid supply and return piping, not shown in this figure. The supply air temperature that leaves the heating coil  09 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  09 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  09 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the air. 
         [0139]    The dry, cold conditioned air  08 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  08 - 0025  is passed through the cooling recovery coil  09 - 0030  to add heat to the air and warm it up. The air is then delivered to temperature control boxes  09 - 0065  that contain a heating coil  09 - 0031 . If the space conditions or process cooling loads  09 - 0171  require air that is warmer than that which is provided after leaving the cooling recovery coil  09 - 0030 , the reheat coil  09 - 0031  is activated. Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  09 - 0031  or other heat exchange units of a temperature control box  09 - 0065 . The temperature control box  09 - 0065  includes a controller that controls the control valve not shown in this figure, which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  09 - 0031 . 
         [0140]    Heated fluid is generated in a heating plant or plants not shown in this figure and distributed to the temperature control zones  09 - 0065  through heating fluid supply and return piping not shown in this figure. The supply air temperature that leaves the heating coil  09 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  09 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  09 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the cold dry dehumidified air. 
         [0141]    The system shown in  FIG. 10  functions substantially as the system shown in  FIG. 8 , although a different piping and valve system arrangement is used to convey the warm spent chilled water return fluid to the cooling recovery coil inlet. Cooling, dehumidification and re-heat system  10 - 0001  includes one or more AHUs  10 - 0003 , valves  10 - 0055 ,  10 - 0081 ,  10 - 0082 , and the like. Fluid is cooled in a chiller system not shown in this figure and conveyed through a chilled fluid supply piping  10 - 0045 , towards one or more AHUs  10 - 0003 , and returned through chilled fluid return piping  10 - 0050 ,  10 - 0085  towards one or more chiller systems. The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems. Fluid is heated in a heating plant and conveyed through a heated fluid supply piping towards one or more heating, or reheat coils  10 - 0031 , and returned through the heated fluid return piping towards one or more heating plants. The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant. 
         [0142]    The flow of chilled fluid to an AHU  10 - 0003  is controlled by selectively modulating a flow control valve  10 - 0055 . The cooling recovery coil source fluid is controlled by selectively modulating flow control valves  10 - 0081 ,  10 - 0082 , and  10 - 0055 . The heating source fluid is controlled by selectively modulating flow control valves, not shown in this figure. The chilled fluid flow control valves  10 - 0055 ,  10 - 0081 ,  10 - 0082  are positioned downstream of respective AHUs  10 - 0003 . Alternatively, however, the valves  10 - 0055 ,  10 - 0081 ,  10 - 0082  may be situated upstream of an AHU  10 - 0003  or upstream of the cooling recovery coils  10 - 0030  respectively. 
         [0143]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  10 - 0015  or other heat exchange units of an AHU  10 - 0003 . Fans  10 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  10 - 0002  and fresh air  10 - 0005  mixed in varying proportions to create a mixed air stream  10 - 0010 , and deliver the mixed air stream  10 - 0010  through one or more cooling coils  10 - 0015 . The mixed air stream  10 - 0010  can either be passed through a filtration system  10 - 0100  or it can be unfiltered. 
         [0144]    As air moves past the cooling coils  10 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  10 - 0010 , or conditioned space conditions  10 - 0171  require it, the conditioned air  10 - 0025  leaving the cooling coils  10 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  10 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  10 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  10 - 0171  through a discharge duct  10 - 0020 , or other conveyance system. 
         [0145]    The dry, cold conditioned air  10 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  10 - 0025  is passed through a cooling recovery coil system  10 - 0030 . Warm fluid from the chilled water return piping  10 - 0051  leaving the cooling coil system  10 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources by sending this warm fluid through a reheat coil system  10 - 0031 . 
         [0146]    To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source is introduced and used to add heat to the air entering the reheat coil system via heating coils  10 - 0031 . For example, heated water can be distributed through heating coils  10 - 0031  or other heat exchange units of a temperature control zone,  10 - 0065 . The temperature control zone,  10 - 0065  includes a control system that controls the control valves not shown in this figure, which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating coil  10 - 0031 . Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones,  10 - 0065  through heating fluid supply and return piping. The supply air temperature that leaves the heating coil  10 - 0031 , and enters the spaces to be conditioned either directly or through a distribution system  10 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  10 - 0171  by selectively modulating a flow control valve to add heat to the cold dry dehumidified air. 
         [0147]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  10 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  10 - 0050 , and delivered to the inlet of the chiller system. Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping is forced into the cooling recovery coil chilled water piping  10 - 0106 , by operating the control valves  10 - 0081 ,  10 - 0082  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  10 - 0106 , for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0148]    Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones  10 - 0065  through heating fluid supply and return piping, not shown in this figure. The supply air temperature that leaves the heating coil  10 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  10 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  10 - 0171  by selectively modulating a flow control valve not shown in this figure to add additional heat to the cold dry dehumidified air. 
         [0149]    The dry, cold conditioned air  10 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  10 - 0025  is passed through the cooling recovery coil  10 - 0030  to add heat to the air and warm it up. The air is then delivered to temperature control boxes  10 - 0065  that contain a heating coil  10 - 0031 . If the space conditions or process cooling loads  10 - 0171  require air that is warmer than that which is provided after leaving the cooling recovery coil  10 - 0030 , the heating coil  10 - 0031  is activated. Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water is distributed through heating coil  10 - 0031  or other heat exchange units of a temperature control box  10 - 0065 . The temperature control box  10 - 0065  includes a controller that controls the control valve not shown in this figure, which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  10 - 0031 . 
         [0150]    Heated fluid is generated in a heating plant or plants not shown in this figure and distributed to the temperature control zones  10 - 0065  through heating fluid supply and return piping (not shown). The supply air temperature that leaves the heating coil  10 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  10 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  10 - 0171  by selectively modulating a flow control valve to add heat to the cold dry dehumidified air. 
         [0151]    The system shown in  FIG. 11  functions substantially as the system shown in  FIG. 9 , although a different piping and valve system arrangement is used to convey the warm spent chilled water return fluid to the cooling recovery coil inlet. Cooling, dehumidification and re-heat system  11 - 0001  includes one or more AHUs  11 - 0003 , valves  11 - 0055 ,  11 - 0081 , and the like. Fluid is cooled in a chiller system and conveyed through a chilled fluid supply piping  11 - 0045  towards one or more AHUs  11 - 0003 , and returned through the chilled fluid return piping  11 - 0050 ,  11 - 0085  towards one or more chiller systems. The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems. Fluid is heated in a heating plant and conveyed through a heated fluid supply piping  11 - 0075 ,  11 - 0105  towards one or more heating, reheat or cooling recovery coils  11 - 0030 ,  11 - 0031  and returned through the heated fluid return piping  11 - 0070 ,  11 - 0110 , towards one or more heating plants. The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant. 
         [0152]    The flow of chilled fluid to an AHU  11 - 0003  is controlled by selectively modulating a flow control valve  11 - 0055 . The cooling recovery coil heating source fluid is controlled by selectively modulating flow control valve  11 - 0081 . The chilled fluid flow control valves  11 - 0055  are positioned downstream of respective AHUs  11 - 0003 . The cooling recovery coil heating source fluid flow control valve,  11 - 0081  is positioned upstream of respective cooling recovery coils  11 - 0030 . Alternatively, however, the valves  11 - 0055 ,  11 - 0081 , may be situated upstream of an AHU  11 - 0003  or downstream of the cooling recovery coils  11 - 0030  respectively. 
         [0153]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  11 - 0015  or other heat exchange units of an AHU  11 - 0003 . Fans  11 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  11 - 0002  and fresh air  11 - 0005  mixed in varying proportions to create a mixed, air stream  11 - 0010 , and deliver the mixed air stream  11 - 0010  through one or more cooling coils  11 - 0015 . The mixed air stream  11 - 0010  can either be passed through a filtration system  11 - 0100  or it can be unfiltered. 
         [0154]    As air moves past the cooling coils  11 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  11 - 0010 , or conditioned space conditions  11 - 0171  require it, the conditioned air  11 - 0025  leaving the cooling coils  11 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained 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, cold conditioned air  11 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  11 - 0171  through a discharge duct  11 - 0020 , or other conveyance system. 
         [0155]    The dry, cold conditioned air  11 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  11 - 0025  is passed through a cooling recovery coil system  11 - 0030 . Warm fluid from the chilled water return piping  11 - 0111  leaving the cooling coil system  11 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. 
         [0156]    To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source is introduced. For example, heated water can be distributed through heating coils (cooling recovery coils)  11 - 0030  or other heat exchange units of an AHU  11 - 0003 . 
         [0157]    The AHU  11 - 0003  includes a control system that controls the control valves  11 - 0081 ,  11 - 0082 , which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating cooling recovery coil  11 - 0030 . Heated fluid is generated in a heating plant or plants and distributed to the AHU&#39;s  11 - 0003  through heating fluid supply piping  11 - 0075 ,  11 - 0105 , and heating fluid return piping,  11 - 0070 ,  11 - 0110 . If further heating of the air is required, a heating coil  11 - 0031  located in a temperature control box  11 - 0065  is operated as required to increase the temperature of the air as required. The supply air temperature that leaves the heating coil  11 - 0031 , and enters the spaces to be conditioned either directly or through a distribution system  11 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  11 - 0171  by selectively modulating a flow control valve to add heat to the dehumidified air. 
         [0158]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  11 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  11 - 0050 ,  11 - 0085  and delivered to the inlet of the chiller system. Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping is forced into the cooling recovery coil chilled water piping  11 - 0106 , and check valve system  11 - 0108  by operating the control valves  11 - 0081  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  11 - 0106 , for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0159]    Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones  11 - 0065  through heating fluid supply and return piping, not shown in this figure. The supply air temperature that leaves the heating coil  11 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  11 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  11 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the air. 
         [0160]    The dry, cold conditioned air  08 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  08 - 0025  is passed through the cooling recovery coil  11 - 0030  to add heat to the air and warm it up. The air is then delivered to temperature control boxes  11 - 0065  that contain a heating coil  11 - 0031 . If the space conditions or process cooling loads  11 - 0171  require air that is warmer than that which is provided after leaving the cooling recovery coil  11 - 0030 , the heating coil  11 - 0031  is activated as a reheat coil. Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  11 - 0031  or other heat exchange units of a temperature control box  11 - 0065 . The temperature control box  11 - 0065  includes a controller that controls the control valve not shown in this figure, which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  11 - 0031 . 
         [0161]    Heated fluid is generated in a heating plant or plants not shown in this figure and distributed to the temperature control zones  11 - 0065  through heating fluid supply and return piping not shown in this figure. The supply air temperature that leaves the heating coil  11 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  11 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  11 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the cold dry dehumidified air. 
         [0162]    The system shown in  FIG. 12  functions substantially as the system shown in  FIG. 8 , except that there is an additional cooling coil and heat recovery system applied to the cooling recovery coil system. Cooling, dehumidification and re-heat system  12 - 0001  includes one or more AHUs  12 - 0003 , valves  12 - 0055 ,  12 - 0081 , and the like. Fluid is cooled in a chiller system not shown in this figure and conveyed through a chilled fluid supply piping  12 - 0045 , towards one or more AHUs  12 - 0003 , and returned through the chilled fluid return piping  12 - 0050 ,  12 - 0085  towards one or more chiller systems. The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems. Fluid is heated in a heating plant and conveyed through a heated fluid supply piping towards one or more heating, or reheat coils  12 - 0031 , and returned through the heated fluid return piping towards one or more heating plants. The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plant. 
         [0163]    A direct expansion (DX) refrigerant cooling coil  12 - 0024  and system is added to the cooling recovery coil system to provide air that has been dehumidified to a greater extent. This DX system is equipped with heat rejection systems  12 - 0330 ,  12 - 0340  that will reject the heat to atmosphere, or alternately the heat is rejected into the chilled water return system through pipes  12 - 0300 ,  12 - 0310 , by use of a pumping system  12 - 0320 , or a heat recovery system through pipes  12 - 0360 ,  12 - 0370 , by use of a pumping and control valve system  12 - 0350 ,  12 - 0355 . The compressor system  12 - 0380  discharges refrigerant into the heat rejection system or systems  12 - 0330 ,  12 - 0340 . The condensed refrigerant is carried through refrigerant piping systems  12 - 0332 ,  12 - 0335  to and from the refrigeration coil  12 - 0024 . 
         [0164]    The rejected heat is used to heat water, or some other heat transfer fluid, that is utilized in a radiant heating system, a pool heating system, a domestic water heating system or any other system that requires heat of the quality level that is provided by the compressor/heat recovery system. The capacity of the compressor system  12 - 0380  is varied as required to provide the proper temperature and dehumidification level of the discharge air  12 - 0025 . Once the air  12 - 0025  leaves the DX cooling coil  12 - 0024 , the remainder of the process can occur as described in the following paragraphs. 
         [0165]    The flow of chilled fluid to an AHU  12 - 0003  is controlled by selectively modulating a flow control valve  12 - 0055 . The cooling recovery coil source fluid is controlled by selectively modulating flow control valves,  12 - 0081 ,  12 - 0055 . The heating source fluid is controlled by selectively modulating flow control valves, not shown in this figure. The chilled fluid flow control valves  12 - 0055 ,  12 - 0081  are positioned downstream of respective AHUs  12 - 0003 . Alternatively, however, the valves  12 - 0055 ,  12 - 0081  may be situated upstream of an AHU  12 - 0003  or upstream of the cooling recovery coils  12 - 0030  respectively. 
         [0166]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water is distributed through cooling coils  12 - 0015  or other heat exchange units of an AHU  12 - 0003 . Fans  12 - 0060  or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  12 - 0002  and fresh air  12 - 0005  mixed in varying proportions to create a mixed air stream  12 - 0010 , and deliver the mixed air stream  12 - 0010  through one or more cooling coils  12 - 0015 . The mixed air stream  12 - 0010  can either be passed through a filtration system  12 - 0100  or it can be unfiltered. 
         [0167]    As air moves past the cooling coils  12 - 0015 , chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air  12 - 0010 , or conditioned space conditions  12 - 0171  require it, the conditioned air  12 - 0025  leaving the cooling ‘coils  12 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  12 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  12 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior  12 - 0171  through a discharge duct  12 - 0020 , or other conveyance system. 
         [0168]    The dry, cold conditioned air  12 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  12 - 0025  is passed through a cooling recovery coil system  12 - 0030 . Warm fluid from the chilled water return piping  12 - 0051  leaving the cooling coil system  12 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in it&#39;s entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources by sending this warm fluid through a reheat coil system  12 - 0031 . 
         [0169]    To recapture the cooling from the cooling coil using the cooling recovery coil, a higher temperature heating source is introduced and used to add heat to the air entering the reheat coil system  12 - 0031 . For example, heated water can be distributed through heating coils  12 - 0031  or other heat exchange units of a temperature control zone,  12 - 0065 . The temperature control zone,  12 - 0065  includes a control system that controls the control valves not shown in this figure, which in turn which controls the source, volume or pressure of the heated source fluid that is passed through the heating coil  12 - 0031 . Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones,  12 - 0065  through heating fluid supply and return piping. The supply air temperature that leaves the heating coil  12 - 0031 , and enters the spaces to be conditioned either directly or through a distribution system  12 - 0170 , is continuously varied to maintain the needs of the occupant or process cooling loads  12 - 0171  by selectively modulating a flow control valve to add heat to the cold dry dehumidified air. 
         [0170]    As a result of the heat exchange occurring at the cooling coils in a cooling recovery coil system  12 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months. This heated or spent chilled fluid is collected in a separate spent fluid piping  12 - 0050 , and delivered to the inlet of the chiller system. Or, if there is a need for re-heating of some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping is forced into the cooling recovery coil chilled water piping  12 - 0106 , by operating the control valves  12 - 0081  and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  12 - 0106 , for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0171]    Heated fluid is generated in a heating plant or plants and distributed to the temperature control zones  12 - 0065  through heating fluid supply and return piping, not shown in this figure. The supply air temperature that leaves the heating coil  12 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  12 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  12 - 0171  by selectively modulating a flow control valve not shown in this figure to add additional heat to the cold dry dehumidified air. 
         [0172]    The dry, cold conditioned air  03 - 0025  may be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  12 - 0025  is passed through the cooling recovery coil  12 - 0030  to add heat to the air and warm it up. The air is then delivered to temperature control boxes  12 - 0065  that contain a heating coil  12 - 0031 . If the space conditions or process cooling loads  12 - 0171  require air that is warmer than that which is provided after leaving the cooling recovery coil  12 - 0030 , the reheat coil  12 - 0031  is activated. Warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. For example, heated water can be distributed through heating coils  12 - 0031  or other heat exchange units of a temperature control box  12 - 0065 . The temperature control box  12 - 0065  includes a controller that controls the control valve not shown in this figure, which in turn controls the volume or pressure of the heated source fluid that is passed through the heating coil  12 - 0031 . 
         [0173]    Heated fluid is generated in a heating plant or plants not shown in this figure and distributed to the temperature control zones  12 - 0065  through heating fluid supply and return piping not shown in this figure. The supply air temperature that leaves the heating coil  12 - 0031  enters the spaces to be conditioned, either directly or through a distribution system  12 - 0170 . The supply air temperature is continuously varied to maintain the needs of the occupant or process cooling loads  12 - 0171  by selectively modulating a flow control valve not shown in this figure to add heat to the cold dry dehumidified air. 
         [0174]      FIG. 13  depicts an implementation in which the cooling coil system and the cooling recovery coil system can both be used as cooling coils to meet peak day cooling loads, while chiller plant efficiency is improved by using warmer chilled water temperatures due to the increased heat transfer surface area. Additionally, the cooling coil system and cooling recovery coil system can both be used as heating coils to meet peak heating loads while improving hot water plant efficiency by allowing the use of cooler heating water temperatures due to the increased heat transfer surface area. The cooling recovery system re-heat coil is connected to an auxiliary heating source to provide heating to the area being served when the need for heating exceeds that which is otherwise available from the fluid leaving the cooling coil. This implementation is very similar to  FIG. 7 , and includes the addition of a radiant heating and cooling system. 
         [0175]    As shown in  FIG. 13  a cooling, dehumidification and re-heat system  13 - 0001  includes one or more heat transfer systems  13 - 0015 ,  13 - 0030 , valves  13 - 0055 ,  13 - 0082  and the like. Fluid is cooled in a chiller system  13 - 0040  and conveyed through a chilled fluid supply piping  13 - 0045 ,  13 - 0090  towards one or more AHUs  13 - 0003 , and returned through the chilled fluid return piping  13 - 0050 ,  13 - 0085  towards one or more chiller systems  13 - 0040 . The cooled fluid is conveyed through the chilled fluid piping via one or more pumping units contained in the chiller systems  13 - 0040 . Fluid is heated in a heating plant  13 - 0035  and conveyed through a heated fluid supply piping  13 - 0075 ,  13 - 0105 ,  13 - 0106 ,  13 - 0200  towards one or more heating, reheat or cooling recovery coils  13 - 0030 , and returned through the heated fluid return piping  13 - 0070 ,  13 - 0111 ,  13 - 0205  towards one or more heating plants  13 - 0035 . The heated fluid is conveyed through the heated fluid piping via one or more pumping units contained in the heating plants  13 - 0035 . 
         [0176]    The flow of chilled fluid to cooling coils  13 - 0015  for heat transfer is controlled by selectively modulating a flow control valve  13 - 0055 . The heating source fluid is controlled by selectively modulating flow control valve,  13 - 0082 . The chilled fluid flow control valves  13 - 0055  are positioned downstream of cooling coils  13 - 0015 . The heating source fluid flow control valves  13 - 0082  are positioned downstream of respective heating coils (cooling recovery coils)  13 - 0030 . Alternatively, however, the valves  13 - 0055 ,  13 - 0082  may be situated upstream of cooling coils  13 - 0015  or upstream of the heating coils (cooling recovery coils)  13 - 0030  respectively. 
         [0177]    Chilled fluid is used to condition air or to remove heat from one or more other sources. For example, chilled water can be distributed through cooling coils  13 - 0015  or other heat exchange units of an AHU. Fans or blowers can receive unconditioned or partially conditioned air from an inlet source consisting of return air  13 - 0002  and fresh air  13 - 0005  mixed in varying proportions to create a mixed air stream and deliver the mixed air stream through one or more of the cooling coils  13 - 0015 . 
         [0178]    As air moves past the cooling coils  13 - 0015  in cooling recovery coil system, chilled fluid therein removes heat from the unconditioned or partially conditioned air. When mixed air or conditioned space conditions require it, the conditioned air  13 - 0025  leaving the cooling coils  13 - 0015  is cooled to where water is removed from the air and the relative humidity in the conditioned spaces is maintained low enough to reduce the potential for biological growth. Reducing the temperature of the conditioned air  13 - 0025  will condense moisture from the air, drying it out. Thus, dry, cold conditioned air  13 - 0025  is delivered to individual offices, rooms or other locations within a facility&#39;s interior through a discharge duct or other conveyance system. 
         [0179]    The dry, cold conditioned air  13 - 0025  will typically be too cold to meet comfort needs or process cooling loads for many of the spaces that require cooling and dehumidification, so the conditioned air  13 - 0025  is passed through a cooling recovery coil system  13 - 0030 . Warm fluid that is being sourced from the chilled water return piping  13 - 0051  that leaves the cooling coils  13 - 0015  is used to add heat to the air to reduce the need for heat from other heating sources, or to meet the need for re-heat in its entirety. If the leaving air temperature is not raised adequately to meet the needs of the area or process load, warm or hot fluid is used to condition air or to add heat to the air from one or more heating sources. 
         [0180]    To augment the heating capacity available from the warm water leaving the cooling coils  13 - 0015 , a higher temperature heating source is introduced. For example, heated fluid can be distributed through heating coils (cooling recovery coils)  13 - 0030  or other heat exchange units of an AHU. The AHU includes a control system that controls the control valves  13 - 0082 , which in turn control the source, volume or pressure of the heated source fluid that is passed through the cooling recovery coil  13 - 0030 . 
         [0181]    Heated fluid is generated in a heating plant or plants  13 - 0035  and distributed to the AHU&#39;s through heating fluid supply piping  13 - 0075 ,  13 - 0105 ,  13 - 0106 ,  13 - 0210  and heating fluid return piping,  13 - 0070 ,  13 - 0111 ,  13 - 0205 . The supply air temperature that leaves the heating coil (cooling recovery coil)  13 - 0030  and enters the spaces to be conditioned, either directly or through a distribution system is continuously varied to maintain the needs of the occupant or process cooling loads by selectively modulating a flow control valve  13 - 0082  to add heat to the cold dry dehumidified air. 
         [0182]    As a result of the heat exchange occurring at the cooling coils  13 - 0015 , the temperature of the fluid passing therethrough increases to approximately 65° F. to 75° F. or higher during the summer months when dehumidification loads are typically present. This heated or spent chilled fluid is collected in a separate spent fluid piping  13 - 0050 ,  13 - 0051 ,  13 - 0085  and delivered to the inlet of the chiller system  13 - 0040 . Or, if there is a need for re-heating some or all of the air that has been cooled and dehumidified, some or all of the heated or spent chilled fluid that has been collected in the separate spent fluid piping  13 - 0051  is forced into the cooling recovery coil chilled water piping  13 - 0106 ,  13 - 0107  by operating the control valves  13 - 0082 , and forcing the warm chilled water return into the cooling recovery coil heating water supply lines  13 - 0106 ,  13 - 0107  for delivery to the cooling recovery coils as the heating source for the cooling recovery coils. 
         [0183]    The main components within the chiller plant systems  13 - 0040  are as follows:  13 - 0140  is the chilled fluid return piping inside the chiller plant systems, and is the piping in which all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the cooling loads imposed by the AHU&#39;s or process cooling loads through the chilled fluid piping  13 - 0085 ,  13 - 0050 , mixed with the fluid returning from the cooling recovery coil systems, and the fluid from the bypass piping  13 - 0130 . The mixed fluid is then drawn into the chilled fluid pumping systems  13 - 0145 . 
         [0184]    The chilled fluid pumping systems is provided in a draw-through or push-through configuration with the chillers  13 - 0155 . The warm mixed fluid is then passed through the chiller systems  13 - 0155  where the fluid temperature is reduced. The chiller isolation valves  13 - 0160  are controlled to allow flow through the chillers that are operational. The chilled fluid then enters a common discharge piping  13 - 0165 , where it is either delivered to the cooling loads through the supply piping  13 - 0090 ,  13 - 0045 , or is returned to the chilled fluid return piping by passing through the chilled fluid bypass piping  13 - 0130  and bypass piping control valve  13 - 0135 . While  FIG. 13  illustrates one piping arrangement, other piping configurations can be used. 
         [0185]    The main components within the heating plant systems  13 - 0035  are as follows:  13 - 0265  is the heated fluid return piping inside the heating plant systems, and is the piping where all of the various fluid streams mix and become one common fluid stream. The fluid is returned from the heating loads imposed by the AHU&#39;s or process loads through heated fluid piping  13 - 0020 ,  13 - 0215 ,  13 - 0205  mixed with the fluid returning from the cooling recovery coil systems,  13 - 0111 , the fluid from heating/cooling crossover piping,  13 - 0225 ,  13 - 0230  and the fluid from the bypass piping  13 - 0250 . The mixed fluid is then drawn into the heated fluid pumping systems  13 - 0260 . 
         [0186]    The heated fluid pumping systems is provided in a draw-through or push-through configuration with heaters  13 - 0275 . The warm mixed fluid is then passed through the heater systems  13 - 0275  where the fluid temperature is increased. The heater isolation valves  13 - 0280  are controlled to allow flow through operational heaters. The heated fluid then enters a common discharge piping  13 - 0270  where it is either delivered to the heating loads through the supply piping  13 - 0075 ,  13 - 0105 , or is returned to the heated fluid return piping by passing through the heated fluid bypass piping  13 - 0250  and bypass piping control valve  13 - 0245 ,  13 - 0255 .  FIG. 13  shows the heaters piped in one arrangement, although different arrangements are possible. 
         [0187]      FIG. 13  shows one arrangement that includes the addition of a radiant heating and cooling system. The radiant heating and cooling system  13 - 0500 , draws its source water through supply water piping  13 - 0520 ,  13 - 0720 ,  13 - 0610 , and discharges the return water through return water piping  13 - 0530 ,  13 - 0710 ,  13 - 0730 . Control valves  13 - 0700 ,  13 - 0600 ,  13 - 0800 ,  13 - 0810  are used to direct flow to and from either the cooling source or the heating source. Pumping system  13 - 0510  is used to provide flow to and from the radiant heating and cooling system from the cooling and heating sources. 
         [0188]      FIG. 14  depicts an alternative layout of a cooling system, including a filtration system,  14 - 0100 , a fan or blower system,  14 - 0060 , a pre-heat coil,  14 - 0012 , a cooling coil,  14 - 0015 , and a cooling recovery coil  14 - 0030 . The cooling recover coil  14 - 0030  can also be used as a reheat coil in alternative implementations. 
         [0189]      FIG. 15  depicts another alternative layout of a cooling system, including a filtration system,  15 - 0100 , a fan or blower system,  15 - 0060 , a pre-heat coil,  15 - 0012 , a cooling coil,  15 - 0015 , a cooling recovery coil  15 - 0030 , and a reheat coil  15 - 0031 . 
         [0190]      FIG. 16  depicts another alternative layout of a cooling system, including a filtration system,  16 - 0100 , a fan or blower system,  16 - 0060 , a cooling coil,  16 - 0015 , a cooling recovery coil  16 - 0030 , and a reheat coil  16 - 0031 . 
         [0191]      FIG. 17  depicts another alternative layout of a cooling system, including a filtration system,  17 - 0100 , a fan or blower system,  17 - 0060 , a pre-heat coil that can also be used as a cooling coil in some embodiments,  17 - 0018 , and a cooling recovery coil  17 - 0030 . 
         [0192]      FIG. 18  depicts another alternative layout of a cooling system, including a filtration system,  18 - 0100 , a fan or blower system,  18 - 0060 , a pre-heat coil that can also be used as a cooling coil in some embodiments,  18 - 0018 , a cooling recovery coil  18 - 0030 , and a reheat coil  18 - 0031 . 
         [0193]      FIG. 19  depicts another alternative layout of a cooling system, including a filtration system,  19 - 0100 , a fan or blower system,  19 - 0060 , a pre-heat coil  19 - 0012 , a cooling coil,  19 - 0015 , a direct expansion cooling coil,  19 - 0028 , and a cooling recovery coil  19 - 0030 . The cooling recover coil  19 - 0030  can also be used as a reheat coil in alternative implementations. 
         [0194]      FIG. 20  depicts another alternative layout of a cooling system, including a filtration system,  20 - 0100 , a fan or blower system,  20 - 0060 , a pre-heat coil  20 - 0012 , a cooling coil,  20 - 0015 , a direct expansion cooling coil,  20 - 0028 , a cooling recovery coil that can also be used as a reheat coil in some embodiments  20 - 0030 , and a reheat coil  20 - 0031 . 
         [0195]    Spent (warm) chilled water return that is not required by the cooling recovery coils is delivered to the inlet of a chiller to be cooled and sent back out into the cooling system. As a result of the heat transfer from the unconditioned or partially conditioned air to the chilled water at or near the cooling coils, humidity is also removed from the air. The warm chilled water used in the cooling recovery coil system can re-heat the air, reducing the amount of new re-heat energy that is required. This also reduces the amount of cooling energy that is required, since the cold air draws heat from the water being returned to the chiller. 
         [0196]    The cooling coils described with respect to some implementations above require a chilled fluid supply temperature of between 45° F. and 50° F. to meet peak cooling and dehumidification loads being supplied through chilled fluid piping from the chiller system. This is a higher temperature for the chilled water supply than typical designs, and helps to reduce chiller plant energy consumption by allowing increased chiller efficiencies. The chillers can be piped in series, rather than in parallel, further improving chiller efficiency. Chilled fluid supply temperature of less than 45° F. and greater than 50° F. can be used as cooling and dehumidification needs dictate. 
         [0197]    The cooling coils described above can provide a chilled fluid return temperature of between 65° F. and 75° F. or higher, being returned to the chiller systems or being used as heating source water for the cooling recovery coil by moving the water through cooling recovery coil piping. The higher chilled fluid return temperature that leaves the cooling coils in a cooling recovery coil system allows this warm fluid as a heating source for the cooling recovery coils. 
         [0198]    Except where noted, in the implementations described above the cooling coils provide a discharge air temperature of between 50° F. and 55° F., as required to meet comfort needs or the needs of the process cooling loads. A maximum discharge air temperature of approximately 55° F. is used when dehumidification is required to reduce the amount of water contained in the air stream that enters the conditioned spaces. Discharge air temperature of less than 50° F. and greater than 55° F. can be used in different system embodiments, and as cooling and dehumidification needs dictate. 
         [0199]    The cooling coils described above are preferably sized with a face velocity of 200 to 600 feet per minute, and preferably 250 to 450 feet per minute, although lower or higher face velocities can be used. The cooling coils are sized with between six and ten rows, but a greater or lower number of rows can also be used. The heating coils described above are preferably sized with a face velocity of 200 to 500 feet per minute, but may have higher or lower coil face velocities. The heating coils include between two and six rows of heat transfer tubing, but higher or lower row counts can also be used. 
         [0200]    During the heating season for a facility, the heating coils (cooling recovery coils) require a heated fluid supply temperature of approximately 80° F. and 120° F. supplied through the heated fluid piping from the heating plants. This is a lower heating water supply temperature than typical designs and helps to reduce heating plant energy consumption by allowing increased hot water heater or boiler efficiencies. 
         [0201]    Also during the heating season, the heating coils (cooling recovery coils) provide a heated fluid return temperature of between 60° F. and 90° F., being returned through the heated fluid piping to the heating plants. The heating coils (cooling recovery coils) provide a discharge air temperature of between 70° F. and 110° F., as required to meet comfort needs or the needs of the process heating loads. A maximum discharge air temperature of approximately 110° F. is used to reduce the amount of hot air stratification that occurs when the heated air enters the conditioned space or process load, but higher or lower temperatures can be used as dictated by the application. 
         [0202]    During the cooling season for the facility, when the cooling recovery process is optimally used, the heating coils (cooling recovery coils) require a heated fluid supply temperature of approximately 62° F. and 75° F. supplied through the heated fluid piping from the cooling recovery piping. The heating coils (cooling recovery coils) provide a discharge air temperature of between 58° F. and 72° F., as required to meet comfort needs or the needs of the process heating loads. During the cooling season, there is usually a low need for heating, so the supply air temperature can be lower, allowing the use of the cooling recovery coil as the heating source. 
         [0203]    Also during the cooling season, the heating coils (cooling recovery coils) provide a heated fluid return temperature of between 58° F. and 65° F., being returned through the heated fluid piping and the cooling recovery piping to the chiller plant systems. The cooling recovery coil system removes cooling load from the chiller plant by reducing the water temperature that is returned to the chiller, and reduces the need for new source energy for the re-heat system by warming the air up. 
         [0204]    Although a few embodiments have been described in detail above, other modifications are possible. Other arrangements, implementations and alternatives may be within the scope of the following claims.