Cooling system for data center rack

A data center can include at least one computing room, and at least one rack system disposed in the computing room. The rack system includes a rack housing that at least substantially encapsulates an interior space, and a plurality of computing devices mounted to the rack in the interior space. The data center can further include a cooling system. The cooling system includes a conduit that is disposed in the interior space of the rack housing and a fluid that flows through the conduit, wherein heat is transferred from air in the interior space to the fluid to produce cooled air in the rack housing.

BACKGROUND

Computing-intensive or data-intensive organizations such as on-line retailers, Internet service providers, search providers, financial institutions, and the like often conduct computer operations from large scale computing facilities, known as data centers. Such computing facilities house and accommodate a large number of server, network, and other computer equipment suitable to process, store, and exchange data as desired to facilitate the organization's operations. Data centers can be located local to the organization or remote from the organization, such that data can be exchanged to and from the data center over a hard wire, over the internet, or a combination of the two. Typically, a computer room of a data center includes many racks that each includes a rack housing that supports a plurality of racks that are spaced from one another so as to define a corresponding plurality of mounting slots, otherwise known as bays. The racks are configured to support a respective plurality of servers that are rack-mounted to the rack housing in the bays so as to define a rack system.

Data centers typically include a number of components that generate a significant amount of waste heat during operation. Such components include printed circuit boards, mass data storage devices, power supplies, and processors. For example, some computers with multiple processors can generate 250 watts of waste heat. For example, a standard 19-inch rack may hold ten to twenty servers of various heights of 1U, 2U, and 3U (wherein “U” designates a rack unit of 1.75 inches). Some conventional rack systems can include up to forty or more such rack-mounted components, and such rack systems can generate as much as 10 kilowatts of waste heat. It is thus recognized that removal of waste heat is a significant challenge in the day-to-day management of data centers.

One conventional attempt to thermally regulate rack systems includes the division of the data center room into hot air aisles and cold air aisles. Cold air is fed through the cold air aisle, such that internal fans of the individual servers draw the cold air from the cold air aisle around various server components, and expel heated air into the hot air aisle. It should thus be appreciated that the racks are open to both the cold air aisles and the warm air aisles. Accordingly, steps are typically taken to filter the air in the data center to remove particulates that could otherwise be drawn into the servers, thereby adding cost and complications to management of the data center.

DETAILED DESCRIPTION

Systems and methods in accordance with various embodiments of the present disclosure provide the ability to remove heat from racks of a data center. For example, in one embodiment, a conduit can extend into the rack housing, through the interior space of the rack housing, and out of the rack housing. A fluid having a fluid temperature less than that of the air temperature of the interior space of the rack housing can flow through the conduit, such that heat is transferred from the interior space to the fluid to produce cooled air in the interior space. The cooled air is drawn into the air-cooled servers that are mounted on the rack in the interior space, to allow for the dissipation of heat from electrical components of the servers. The flow of the fluid in the conduit out of the rack housing causes the transferred heat to be removed from the interior space.

According to one embodiment, because the system does not rely on airflow between the interior space and the computing room of the data center within which the rack resides, the interior space can be at least substantially encapsulated by the rack housing so as to substantially eliminate airflow between the interior space of the rack housing and the computing room. For instance, the interior space can be sealed, and thus air tight, with respect to airflow between the interior space of the rack housing and the computer room.

Further, according to one embodiment, the system can include conventional computing devices that do not require modification in order to facilitate removal of heat from the rack mounted computing devices.

Further still, according to one embodiment, the system does not occupy rack space that can otherwise be reserved for rack mounted computing devices.

As used herein, “data center” includes any facility or portion of a facility in which computer operations are carried out. A data center may include servers dedicated to specific functions or serving multiple functions. Examples of computer operations include information processing, communications, testing, simulations, power distribution and control, and operational control.

As used herein, “computing room” refers to a room in a data center in which at least one rack resides. The room can be fully or partially defined by at least one computing room wall in the data center, or can be defined by an open space in a data center. The computing room wall can be disposed within the data center, or can be defined by an exterior wall of the data center.

As used herein, “rack housing” refers to a housing that at least partially defines an interior space within which at least one rack resides.

As used herein with reference to the rack housing, “interior space” means a space, area, or volume at least partially defined by the rack housing;

As used herein, “rack” means a rack, container, frame, bracket, plurality of brackets, or any other element or combination of elements that can contain or physically support one or more computing devices.

As used herein with reference to a rack housing, the term “substantially encapsulate” can refer to a degree of encapsulation of the interior space of the rack housing that either 1) does not allow airflow between the room and the interior space in sufficient quantity to alone remove a sufficient amount of heat from the computing devices to support the normal operation of the computing devices mounted to the rack in the interior space, 2) does not allow air to flow from the room to the interior space at a rate that would allow air-laden particulates to flow from the room into the interior space in sufficient quantity to adversely affect the normal operation of the computing devices mounted to the rack in the interior space, or 3) both.

As used herein, “computing device” includes any of various devices in which computing operation or data storage can be performed. One example of a computing device is a rack-mounted server. As used herein, the term computing device is not limited to just those integrated circuits referred to in the art as a computer, but broadly refers to a processor, a server, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein. Some examples of computing devices include e-commerce servers, network devices, telecommunications equipment, medical equipment, electrical power management and control devices, and professional audio equipment (digital, analog, or combinations thereof). In the various embodiments, memory may include, but is not limited to, a computer-readable medium, such as a random access memory (RAM). Alternatively or additionally, memory may include a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc (DVD). Also, additional input channels may include computer peripherals associated with an operator interface such as a mouse and a keyboard. Alternatively, other computer peripherals may also be used that may include, for example, a scanner. Further, in some embodiments, additional output channels may include an operator interface monitor and/or a printer.

As used herein, “conduit” means any line, tube, pipe, duct, or other elongate hollow member configured to retain a fluid that flows therein. A conduit can have any size, shape, and cross-section. Further, a conduit can extend along any direction of elongation as desired, such as a substantially straight direction of elongation, a curved direction of elongation, such as a coil, an angled direction of elongation, or any combination thereof.

Referring toFIG. 1, a data center20can include one or more computing rooms, such as a computing room22, and at least one rack system26, such as a plurality of rack systems26a,26b, and26cdisposed in the computing room22. While the data center20illustrates three rack systems26a-26cdisposed in the computing room22, it should be appreciated that the data center20can include any number of rack systems26in the computing room22as desired. Further, it should be appreciated that the data center20can include any number of computing rooms22as desired, including at least one computing room22such as a plurality of computing rooms22.

Referring toFIGS. 1-2B, each rack system26includes a rack housing28that at least partially defines an interior space30, and a rack32supported by the rack housing28in the interior space30. For instance, the rack housing28can encapsulates the interior space30so as to seal the interior space30with respect to airflow in and out of the interior space30. Each rack system26can further include at least one computing device such as a plurality of computing devices34that are configured to be mounted to the rack32in the interior space30. For instance, the rack32can define a plurality of bays36that are each configured to receive a computing device34that is supported by the rack32, though it should be appreciated that the rack32can define any suitable alternative shape and size as desired so as to support the computing devices34in any alternative manner as desired. The rack housing28can further support at least one data bus29in the interior space30, the data bus29configured to be placed in communication with the computing devices34. The rack housing28can further support at least one power distribution unit31in the interior space30, the power distribution unit31configured to carry an output voltage and configured to be placed in electrical communication with the computing devices34so as to supply electrical power to the computing devices. Each rack system26can include one or more brackets27that attaches the rack housing28to the floor of the computing room22, or the rack housings28can be free standing on the floor of the computing room22or any suitable support surface as desired.

The rack housing28can further include an access door44that is movable so as to provide selective access to the interior space30. For example, the access door44is movable to the open position illustrated inFIG. 2A, for instance for a temporary duration, when it is desired to access the rack interior30, for example when it is desired to service the rack system26, e.g., to remove a computing device from the rack32, to connect a computing device to the rack32, to service one of the computing devices, or the like. It is recognized that moving the access door44to the open position causes the interior space30of the rack housing28to be placed in temporary air flow communication with the computing room22. The access door44is movable to the closed position illustrated inFIG. 2Bwhen it is desired to isolate the interior space30from the ambient air in the computing room22, thereby protecting the computing devices34from contaminants in the air of the computing room and potential elevated temperatures of the air in the computing room22. As will be appreciated from the description below, the rack housing28can at least substantially encapsulate the interior space30when the access door44is in the closed position. For instance, the rack housing28can be air tight so as to seal the interior space30with respect to airflow with the computing room22.

The rack system26, and thus the data center20, can further include a cooling system38that includes a conduit40that extends through the rack housing28and into the interior space at least at one interface, such as a first interface28aand a second interface28b. The conduit40can extend into the interior space30at the first interface28a, and out of the interior space30at the second interface28b. The first interface28acan be disposed at a first location of the rack housing28, and the second interface28bcan be disposed at a second location of the rack housing28that is different from the first location of the rack housing28. The rack housing28can be sealed at the first and second interfaces28aand28bso as to prevent air from flowing between the interior space30and the computing room22through the first and second interfaces28aand28b. The cooling system38further includes a fluid42that flows through the conduit40at a fluid flow rate, such that heat is transferred from air in the interior space30to the fluid42so as to produce cooled air in the interior space30of the rack housing28. The fluid42flows through the conduit40from the interior space30to a location out the interior space30, thereby transporting the transferred heat out of the rack housing28. The conduit40can be configured as desired inside the interior space30so as to remove heat from the air in the interior space30.

As will be appreciated from the description below, the cooling system38can be an open system or a closed system. The conduit40can define a fluid intake40a, a fluid outlet40b, and at least one heat exchanger region40cthat extends between the fluid intake40aand the fluid outlet40b. For instance, the at least one heat exchanger region40ccan be disposed at a location adjacent the bays36. At least a portion up to an entirety of the at least one heat exchanger region40cis disposed in the interior space30of the rack housing28, and both the fluid intake40aand the fluid outlet40bcan be disposed external to the rack housing28. In accordance with one embodiment, the heat exchanger region40ccan be configured as heat exchanger coils that are in fluid communication with the fluid intake40aand the fluid outlet40b. For instance, the coils, and thus the heat exchanger region40c, receives the fluid42from the fluid intake40a, causes the fluid42to flow throughout a portion of the interior space, and exhausts the fluid42to the fluid outlet40b. It should be appreciated that the heat exchanger region40ccan define any suitably shaped path as desired, and can be of any size as desired. In accordance with one embodiment, the conduit40can include a pair of heat exchanger regions40cthat are spaced from each other vertically along the rack32and connected between the fluid intake40aand the fluid outlet40b, though it should be appreciated that the conduit40can include any number of heat exchanger regions40cas desired, positioned in the interior space30as desired.

During operation, the fluid42flows from a fluid source, which can be configured as an intake manifold45or any suitable alternatively constructed fluid source, to the fluid intake40a. For instance, as illustrated inFIG. 2A, the conduit40can include a coupling41at the fluid intake40athat is configured to attach to the intake manifold45, so as to place the conduit40in fluid communication with the intake manifold45to receive fluid from the intake manifold45. The conduit40can further include a coupling41at the fluid outlet40bthat is configured to attach to the outlet manifold47, so as to place the conduit40in fluid communication with the outlet manifold47to outlet fluid from the conduit to the outlet manifold47. Each heat exchanger region40ccan receive at least a portion up to an entirety of the fluid42from the fluid intake40a. The fluid42in the heat exchanger region40creceives heat that is transferred from the ambient air in the interior space30to the fluid42. The air in the interior space30thus has a first air temperature before heat is transferred to the fluid42, and second air temperature after heat is transferred from the air to the fluid. Because the second temperature is less than the first temperature, the air that has transferred heat to the fluid42can be referred to as cooled air. The fluid42can then flow from each heat exchanger region40cto the fluid outlet40bso as to transport the transferred heat out of the rack housing28. The fluid42then flows from the fluid outlet40bto an outlet manifold47. The fluid42, which can be water, can be discarded down any suitable drain, or heat can be removed from the fluid42and the fluid42can be recirculated to the intake manifold45as described in more detail below. It should be appreciated that a plurality of heat exchanger regions40ccan be connected between the same fluid intake40aand the same fluid outlet40b. Thus, a portion of the fluid42in the fluid intake40acan be delivered to each of the heat exchanger regions40c. Alternatively, each fluid intake40acan be coupled to a single dedicated heat exchanger region40csuch that each heat exchanger region40creceives all fluid42from the respective fluid intake40a. Each heat exchanger region40ccan outlet its fluid into a dedicated fluid outlet region40bor into a common fluid outlet region40b.

It should thus be appreciated that the heat exchanger region40ccan define a heat transfer region of the conduit40. The conduit40, and in particular the heat exchanger region40cof the conduit40, can be made of any suitable material, and preferably a material that has adequate heat transfer properties to conduct the heat transferred from the ambient air in the interior space30to the fluid42in the conduit40. The fluid42can be any suitable fluid configured to receive a suitable amount of heat from the interior space30as the fluid42travels through the heat exchanger region40c. For instance, the fluid42can be a gas or liquid, such as water or any suitable refrigerant as desired, such as ammonia, sulfur dioxide, or any suitable hydrocarbon, for instance a non-halogenated hydrocarbon. Thus unless otherwise indicated, the fluid is not intended to be limited to any particular fluid.

Referring now toFIGS. 1-3, the computing devices34can each include an outer housing35that contains a plurality of electrical components37of the computing device34. For instance, electrical components37can include one or more hard drives37a, processors37b, and memory modules37c. Each of the electrical components37can produce heat during operation of the computing device34. The computing devices34can further include at least one air intake39athat can be configured as a vent that extends through the housing35, at least one air outlet39bthat can be configured as a vent that extends through the housing35, and at least one fan such as a plurality of fans39cthat draw the cooled air from the interior space30of the rack housing28through the air intake39a. The drawn air travels through the housing35and is exhausted from the housing35through the air outlet39b. Thus, the fans39cof the plurality of computing devices34mounted on the rack32induce a pressure within the housing28that draws the cooled air from the interior space30into the outer housing35, and exhaust air out the housing35through the air outlet39bafter the air has received heat that was transferred to the air from the electrical components37. Alternatively, the fans39ccan be replaced with one or more fans that are disposed in the interior space30, but outside the housings35, that operate so as to direct air into the air intake39a, through the housing35, and out the air outlet39b. Alternatively still, the fans39ccan be disposed in the housing35in addition to fans disposed in the interior space30but outside the housing35.

In accordance with one embodiment, the rack housing28can define a front end30aof the interior30and a rear end30bof the interior30that is spaced from the front end30aalong a longitudinal direction L. The air intake39aand the air outlet39bcan be positioned such that air is drawn from a first end of the interior30, which can be defined by the front end30a, through the air intake39aand into the housing35, and exhausted out the air outlet39binto a second end of the interior30that is opposite the first end. For instance, the second end of the interior30can be defined by the rear end30b. As the air flows over one or more, up to all, of the heat producing electrical components37in the housing35, the heat is transferred to the air and thus dissipated from the electrical components37. In particular, heat is transferred from the electrical components37to the air that flows through the air intake39aand into the housing35. Accordingly, the air is drawn into the air intake39aat a first temperature, and exits the air outlet39bat a second temperature that is greater than the first temperature. Thus, the exited air can be referred to as warm air. As described herein, heat is transferred from the warm air to the fluid42in the heat exchanger region40cof the conduit40so as to produce the cooled air that is preferably at a temperature sufficient to receive an amount of heat from the electrical components37that is suitable for the reliable operation of the computing device34.

The at least one heat exchanger region40ccan be disposed at any location as desired. For instance, in accordance with one embodiment, each of the heat exchanger regions40ccan be disposed in a corresponding one or more of the bays36so as to extend along the longitudinal direction L between the front end30aand the rear end30b. Thus, at least a portion of the air that is exhausted out the air outlets39btravels over the heat exchanger region40calong a direction from the rear end30bto the front end30ato produce cooled air that is again forced into the air intakes39a, either by negative pressure induced by the at least one fan39c, by pressure induced by at least one fan disposed in the interior30but outside the housing35, or both. Accordingly, at least a portion of the conduit40, for instance at the at least one heat exchanger region40c, can be disposed adjacent at least one of the air intakes39aand the air outlets39bof the plurality of the computing devices34. The fans39cof the plurality of computing devices draw air along respective air intake paths through the air intakes39a, and the at least a portion of the conduit40, for instance at the at least one heat exchanger region40c, can be disposed proximate to the air intakes39aso as to be positioned in the respective air intake paths. The fans39cexhaust air out the air outlet39balong respective air exhaust paths, and the at least a portion of the conduit, for instance at the heat exchanger region40c, can be disposed proximate to the air outlets39bso as to be positioned in the respective air exhaust path. The fans39cof the plurality of computing devices34can draw air along respective air intake paths through the air intakes and exhaust air out the air outlet39balong respective air exhaust paths. At least a portion of the conduit40, for instance at the heat exchanger region40c, can define a first region disposed proximate to the air intakes39aso as to be positioned in the respective air intake paths, and a second region disposed proximate to the air outlets39bso as to be positioned in the respective air exhaust path.

A method of constructing the rack system26can include the steps of constructing the rack housing28in an ambient environment, which can be defined by the ambient environment of the computing room22, such that the rack housing28substantially encloses the interior space30. The method can further include the step of supporting the rack32in the rack housing28, such that the rack32is configured to support a plurality of the computing devices34. The method can further include the step of supporting at least one conduit, such as the conduit40, in the rack housing28such that the conduit40enters the interior space30at a first location of the rack housing28, extends in the interior space30, and exits the interior space30at a second location of the rack housing28that is different than the first location. The method can further include the step of placing the conduit40in fluid communication with a fluid source, such that the fluid can flow from the fluid source through the conduit40. The method can further include the step of placing the conduit40in communication with a drain such that fluid that has flown from the fluid source through the conduit40exits the conduit40into the drain.

Referring now toFIGS. 1 and 4, in accordance with another embodiment, the cooling system38can be a closed system whereby the fluid intake40ais in fluid communication with the fluid outlet40b, such that the fluid42travels from the fluid outlet40b, through a heat rejection apparatus49, which can be constructed as desired. For instance, the fluid42can exit the conduit40through the fluid outlet40binto any suitable reservoir51. The heat rejection apparatus49can include a pump52that can, under pressure, deliver the fluid42from the reservoir51into the fluid intake40a. The heat rejection apparatus49can further include a cooled space50, such that the fluid42can flow from the reservoir51and through the cooled space that removes heat from the fluid42. Thus, the fluid42can flow through the fluid intake as cool fluid having a suitable heat absorbing capacity when it flows through the at least one heat exchanger region40cin the manner described above. Alternatively, the cooled space can be defined by the reservoir51, such that heat is removed from the fluid in the reservoir51, and the fluid42is then delivered to the fluid intake40awithout traveling through any additional refrigeration components. It is thus appreciated that heat can be removed from the fluid42in any manner as desired. Alternatively still, the cooling system38can be configured as an open system whereby the fluid42can be expelled from the fluid outlet40bto any suitable receptacle, such as a drain. The intake manifold45can receive the fluid42, configured as water, from a public water utility, irrigation system, well, lake, river, or other water source as desired.

Because the cooling system38, both when configured as an open system and when configured as a closed system, can operate without relying upon airflow between the interior space30of the rack housing28and the room, the rack housing28can at least substantially encapsulate or fully encapsulate the interior space30, in particular when the access door44is in the closed position. Furthermore, rack systems having higher cooling demands do not adversely affect the ability of adjacent rack systems having lower cooling demands to draw cool air, as can be the case in conventional data centers where the rack systems draw cooled air from the same ambient air supply.

With continuing reference toFIG. 1, it is recognized that a greater amount of heat can transfer from the interior space30to the fluid42when the fluid42flows through the heat exchanger region40cat low fluid flow rates than when the fluid42flows through the heat exchanger region40cat high fluid flow rates. Thus, in accordance with one embodiment, the cooling system38can be configured to control the fluid flow rate of the fluid42through the heat exchanger region40c. For instance, the cooling system38can include controller56, a flow regulator such as a valve58in electrical communication with the controller56, a first temperature sensor S1in electrical communication with the controller56, and a second temperature sensor S2in electrical communication with the controller56. The first temperature sensor S1is disposed at a first location of the conduit40and is configured to provide a first output that corresponds to a first fluid temperature of the fluid at a first location of the conduit40. The second temperature sensor S2is disposed at a second location of the conduit40and is configured to provide a second output that corresponds to a second fluid temperature of the fluid at the second location of the conduit40. As described above, the fluid temperature at the fluid intake40ais less than the fluid temperature at the fluid outlet40b. Thus, the first location can be disposed upstream of the interior space30, and the second location can be disposed downstream of the interior space30. The temperature sensors S1and S2can be configured as thermocouples or any suitable alternative apparatus suitable for sending the first and second outputs to the controller56. It should be appreciated that the actual temperatures of the fluid at the first and second locations can be communicated to the controller56or a signal, for instance a voltage differential, indicative of the actual temperatures of the fluid at the first and second locations can be communicated to the controller56.

It should be appreciated that, as used herein, the term “downstream” used with respect to a direction of fluid flow refers to a direction of fluid flow from the fluid intake40ato the fluid outlet40b, and that the term “upstream” used with respect to fluid flow refers to a direction opposite the downstream direction. In both embodiments wherein the cooling system38is an open system and a closed system, it can be said that the fluid outlet40bis disposed downstream from each of the heat exchanger region40cand the fluid intake40awith respect to fluid flow. The heat exchanger region40cis disposed downstream from the fluid intake40aand upstream from the fluid outlet40bwith respect to fluid flow. The fluid intake40ais disposed upstream from each of the heat exchanger region40cand the fluid outlet40bwith respect to fluid flow.

The controller56can receive the first and second outputs and determines a difference between the fluid temperature of the fluid at the first and second locations. The controller56compares the difference to a predetermined threshold, and adjusts the valve58so as to control the fluid flow rate of the fluid42through the conduit40. The predetermined threshold can be input into the controller56and can reflect a desired amount of heat transfer from the air in the interior space30to the fluid42that is sufficient for the normal operation of the computing devices34, but not so large that it causes more heat to be transferred than necessary, as such can decrease the efficiency of the cooling system38and can further unnecessarily heat the fluid42, particularly where the system38is a closed system or where the conduit40extends from the rack housing28into a second rack housing28to remove heat from the second rack housing (seeFIG. 8) before the fluid42travels out the fluid outlet40b. Thus, when the difference between the first and second temperatures is greater than the predetermined threshold, the controller56responds by sending a signal to actuate the valve along an open direction that increases the flow area of the valve58, thereby increasing the fluid flow rate of the fluid42through the heat exchanger region40c. When the difference between the first and second temperatures is less than the predetermined threshold, the controller56responds by sending a signal to actuate the valve58along a closed direction that reduces the flow area through the valve58, thereby decreasing the fluid flow rate of the fluid42through the heat exchanger region40c. Thus, each rack system26can include a controller56and a valve58, or the controller56can be configured to actuate one or more valves58that regulate fluid flow through the respective fluid intakes40aof the rack systems26. Alternatively, the rack systems26can be devoid of the valve58, and the controller can selectively increase and decrease fluid flow through a pump that drives the fluid42from the reservoir51through the conduit40.

With continuing reference toFIGS. 1-3, the rack housing28can define the front end30aof the interior space30and the rear end30bof the interior space30that is opposite the front end30aalong the longitudinal direction L. The rack housing28can further define a pair of side walls55that are spaced apart from each other along a lateral direction A that is substantially perpendicular to the longitudinal direction L. The access door44can define the front end30aof the interior space30, and a rear wall of the rack housing28can define the rear end30bof the interior space30. The computing devices34can be mounted to the rack32such that the air intakes39aare positioned proximate to a first region of the interior space30, which can be defined by the front end30a, and the air outlets39bare positioned proximate to a second region of the interior space30, which can be defined by the rear end30b. Accordingly, during operation, the computing devices34can draw the cooled air from the front end30aand can exhaust the warm air into the rear end30b, though it should be appreciated that the computing devices34can be positioned in any orientation as desired in the interior space30.

As illustrated inFIG. 2A, the at least one heat exchanger region40cof the conduit40can be disposed in a respective one of the bays36so as to be spaced from each other along a transverse direction T that is perpendicular to each of the longitudinal direction L and the lateral direction A. The transverse direction T defines height of the interior space30, and thus of the rack housing28. For instance, the rack housing28can define an upper wall57and a lower wall59that are spaced from each other along the transverse direction T. Thus, one more of the computing devices34can be disposed above the at least one heat exchanger region40calong the transverse direction T. Alternatively or additionally, one or more of the computing devices34can be disposed below the at least one heat exchanger region40calong the transverse direction T.

As described above, the at least one heat exchanger region40ccan be positioned at any location in the interior space30so as to remove heat from the air circulated from the air outlets39bto the air intakes39a. Further, the heat exchanger regions40cof each rack system26can receive fluid42from the same fluid intake40aor from different fluid intakes. For instance, as illustrated inFIGS. 5-6, a first heat exchanger region40ccan be disposed between the computing devices34and a first one of the side walls55, and a second heat exchanger region40ccan be disposed between the computing devices and a second one of the side walls55. Thus, the rack system26can include at least one heat exchanger region40cdisposed between the computing devices34and at least one side wall55along the lateral direction A. As described above, the heat exchanger regions40ccan extend between the front end30aof the interior space30and the rear end30bof the interior space, such that warm exhaust air output by the computing devices34along respective air exhaust paths flows past at least one heat exchanger regions40cexhaust paths, whereby heat is transferred from the warm air to the fluid42to produce cooled air in the interior space30that is ultimately drawn along respective air intake paths and into the air intakes39aof the computing devices34. As illustrated inFIG. 5, the conduit40can be split at a junction41such that each of the heat exchanger regions40ccan receive fluid42from a common intake40aas illustrated inFIG. 5. Alternatively, each of the heat exchanger regions40ccan receive fluid from respective different intakes40aas illustrated inFIG. 6. The different intakes40acan receive fluid42from the same fluid source or from different fluid sources. Alternatively still, as illustrated inFIG. 7, a first heat exchanger region40ccan be disposed between an uppermost one of the computing devices34and the upper wall57along the transverse direction T, and a second heat exchanger region40ccan be disposed between a lowermost one of the computing devices34and the lower wall59. The first and second heat exchanger regions40ccan be in fluid communication with a common fluid intake40aor different fluid intakes40ain the manner described above.

Referring again toFIG. 5, the cooling system38can include the first temperature sensor S1in the fluid intake40ain the manner described above, and the second temperature sensor S2in one of the fluid outlets40bin the manner described above so as to regulate the temperature of the fluid that flows through one of the heat exchanger regions40c. The cooling system38can further include a third temperature sensor S3in a third location of the other of the fluid outlets40bin the manner described above so as to regulate the temperature that flows through the other of the heat exchanger regions40cwhen the heat exchanger regions receive fluid42from the same fluid inlet40a. The controller56(seeFIG. 1) can receive the outputs from the temperature sensors S1and S2and determine a difference between the fluid temperature of the fluid at the first and second locations. The controller56(seeFIG. 1) can receive the outputs from the temperature sensors S1and S3and determine a difference between the fluid temperature of the fluid at the first and third locations. The controller56compares the differences to a predetermined threshold, and adjusts the valve58so as to control the fluid flow rate of the fluid42through the conduit40. When the difference between fluid temperatures at the first and second locations and the difference between fluid temperatures at the first and third locations are each greater than the predetermined threshold, the controller56responds by sending a signal to actuate the valve along an open direction that increases the flow area of the valve58, thereby increasing the fluid flow rate of the fluid42through the heat exchanger region40c. When one of the differences is less than the predetermined threshold, the controller56responds by sending a signal to actuate the valve58along a closed direction that reduces the flow area through the valve58, thereby decreasing the fluid flow rate of the fluid42through the heat exchanger region40c.

Referring toFIG. 6, the cooling system38can further include a third temperature sensor S3in electrical communication with the controller56, and a fourth temperature sensor S4in electrical communication with the controller56(seeFIG. 1). The first and second temperature sensors S1and S2are disposed at a first fluid intake40aand a first fluid outlet40b, respectively, of a first conduit40that is in fluid communication with a first one of the heat exchanger regions40c. A first valve58acan be opened and closed in response to control signals from the controller56to increase and decrease the flow rate of the fluid42through the first conduit40in the manner described above.

The third and fourth temperature sensors S3and S4are disposed at a second fluid intake40aand a second fluid outlet40b, respectively, of a second conduit40that is in fluid communication with a second one of the heat exchanger regions40c. The third temperature sensor S3is configured to provide a third output that corresponds to a third temperature of the fluid42at a first location of the second conduit40, for instance at the fluid intake40a. The fourth temperature sensor S4is disposed at a second location of the second conduit40, for instance at the fluid outlet40b, and is configured to provide a second output that corresponds to a fourth temperature of the fluid at the second location of the second conduit40. A second valve58acan be opened and closed in response to control signals from the controller56to increase and decrease the flow rate of the fluid42through the second first conduit40. When the difference between the third and fourth temperatures is greater than the predetermined threshold, the controller56responds by sending a signal to actuate the second valve58balong an open direction that increases the flow area of the second valve58b, thereby increasing the flow rate of the fluid42through the second heat exchanger region40c. When the difference between the third and fourth temperatures is less than the predetermined threshold, the controller56responds by sending a signal to actuate the second valve58balong a closed direction that reduces the flow area through the second valve58b, thereby decreasing the flow rate of the fluid42through the second heat exchanger region40c. It should be appreciated that the controller56that controls the second valve58bcan be the same controller or a different controller that controls the first valve58a.

It should be appreciated that the cooling system38can include as many heat exchanger regions40cas desired, one or more up to all of which can be defined by separate conduits40that receive their respective fluid42from the a common fluid source or different fluid sources. The heat exchanger regions40ccan be positioned anywhere in the interior space30as desired. The flow rate of the fluid42of one or more up to all of the conduits40can be controlled by one or more respective controllers56as desired. Further, two or more of the conduits40can support fluid flow of the fluid42in opposite directions with respect to each other through the interior space30. Thus, a first heat exchanger region40ccan transport the contained fluid42along a first direction, for instance from a first end to a second end, and a second heat exchanger region40ccan transport the contained fluid42along a second direction that is substantially opposite the first direction, that is from the second end toward the first end. Thus, the first heat exchanger region40cand the second heat exchanger region40csupport fluid flow in opposite directions with respect to each other. The first and second ends can be defined by opposed ends of the interior space, such as the upper and lower ends, respectively. Because the first and second heat exchanger regions40cand40c′ can define respective reverse fluid flows, the fluid of one of the first and second heat exchanger regions40cand40c′ is coolest when disposed adjacent to the computing devices34disposed at one end of the rack32(for instance the lowermost computing devices34), and the fluid of the other of the first and second heat exchanger regions40cand40c′ is coolest when disposed adjacent to the computing devices34at a second end of the rack opposite the first end of the rack (for instance the uppermost computing devices34), thereby providing substantially uniform heat transfer adjacent each of the computing devices34in the interior space30.

As described above, the cooling system38can include at least one conduit40that extends through at least one rack housing28. Referring toFIG. 8, the cooling system38can include at least one conduit40that extends through more than one rack housings28that can be disposed in the same computing room22or in different computing rooms22in the data center20. For instance, the fluid intake40aof the conduit40can receive fluid from the fluid source as described above. The conduit40can include a first at least one heat exchanger region40c, and a second at least one heat exchanger region40c, that is disposed downstream of the first at least one heat exchanger region40c. The first at least one heat exchanger region40ccan extend through the interior space30of the rack housing28, which can be referred to as a first interior space30of a first rack housing28, in any manner described above, and the second at least one heat exchanger region40ccan extend through a second interior space30of a second rack housing28in any manner described above. The fluid outlet40bcan be disposed downstream of the second rack housing28. The first and second locations of the first and second temperature sensors S1and S2can be disposed at a location upstream of the first rack housing28and downstream of the second rack housing28b. The controller56can regulate flow of the fluid42through the interior space30of both the first and second rack housings28.

It should be appreciated that the cooling system38can define reverse flow through the first and second interior spaces30and30′ as desired. For instance, the cooling system38illustrated inFIG. 8can include a second conduit40whose first heat exchanger region is disposed in the second interior space30of the second housing28, and whose second heat exchanger region, which is disposed downstream with respect to the first heat exchanger region, is disposed in the first interior space30of the first housing28. Thus, the fluid of the first conduit40is coolest when disposed in the first interior space30, and the fluid of the second conduit is coolest when disposed in the second interior space30, thereby providing for substantially equal heat transfer capacities in the first and second interior spaces30and30′ It should be further appreciated that the heat exchanger regions of either or both of the first and second conduits can include first and second regions of the type described above.

Referring toFIGS. 1-8generally, a method of managing a rack system26disposed in a computing room22can include the steps of causing the fluid42to flow through the respective at least one conduit40that is at least partially disposed in the interior space30of the rack housing28, the fluid42having a temperature greater that of ambient air in the interior space30of the rack housing28. The method can include the steps of transferring heat from air in the rack housing28to the fluid42so as to produce cooled air, and drawing the cooled air from the interior space30of the rack housing28into the air intakes39aof each of the respective computing devices34. The method can further include the step of exhausting warm air from the air outlet39bof each of the respective computing devices34, the warm air having a temperature greater than that of the cooled air. The method can thus include the step of transferring heat from the warm air to the fluid42.

The drawing step can further include the step of creating an airflow path in the rack housing28from each of the air intakes39athat causing at least some of the air being drawn to flow past the conduit40prior to being drawn into the air intakes39a. The exhausting step can further include the step creating an airflow path in the rack housing28from each of the air outlets39bthat causes at least some of the warm air to flow past the conduit40, for instance the at least one heat exchanging region40c. The drawing step can further include the step of creating an airflow path in the rack housing28from each of the air intakes39athat causes at least some of the air being drawn to flow past the conduit40, for instance the at least one heat exchanging region40c, prior to being drawn into the air intakes39a.

The fluid has a fluid temperature and flows through the conduit40at a fluid flow rate, and the method can further include the steps of measuring a difference in the fluid temperature between a first location of the conduit40and a second location of the conduit40that is disposed downstream of the first location with respect to fluid flow, decreasing the fluid flow rate through the conduit40when the difference is below a threshold value, and increasing the fluid flow rate through the conduit40when the difference is above a threshold value. The decreasing and increasing steps can each further include the step of actuating the valve58in the conduit40.

The fluid can be configured as water, and the causing step can further comprises the steps of receiving the water in the conduit40from the water intake manifold47, and removing the water out the interior space30after heat has transferred from air in the rack housing to the water. The method can further include the step of opening the access door44into the rack housing28so as to access at least one of the computing devices34. The opening step can cause the interior space30of the rack housing28to be placed in temporary air flow communication with the computing room22. The method can further include the step of closing the access door44so as to seal the rack housing28with respect to air flow both from the interior space30into the computing room22and from the computing room22into the interior space30.

It should be noted that the illustrations and discussions of the embodiments shown in the figures are for exemplary purposes only, and should not be construed limiting the disclosure. One skilled in the art will appreciate that the present disclosure contemplates various embodiments. Additionally, it should be understood that the concepts described above with the above-described embodiments may be employed alone or in combination with any of the other embodiments described above. It should further be appreciated that the various alternative embodiments described above with respect to one illustrated embodiment can apply to all embodiments as described herein, unless otherwise indicated.