Patent Publication Number: US-9888614-B1

Title: Modular data center row infrastructure

Description:
This application is a continuation of U.S. patent application Ser. No. 14/285,498, filed May 22, 2014, now U.S. Pat. No. 9,357,681, which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Organizations such as on-line retailers, Internet service providers, search providers, financial institutions, universities, and other computing-intensive organizations often conduct computer operations from large scale computing facilities. Such computing facilities house and accommodate a large amount of server, network, and computer equipment to process, store, and exchange data as needed to carry out an organization&#39;s operations. Typically, a computer room of a computing facility includes many server racks. Each server rack, in turn, includes many servers and associated computer equipment. 
     Because a computing facility may contain a large number of servers, a large amount of electrical power may be required to operate the facility. In addition, the electrical power is distributed to a large number of locations spread throughout the computer room (e.g., many racks spaced from one another, and many servers in each rack). Usually, a facility receives a power feed at a relatively high voltage. This power feed is stepped down to a lower voltage (e.g., 110V). A network of cabling, bus bars, power connectors, and power distribution units, is used to deliver the power at the lower voltage to numerous specific components in the facility. 
     Computer systems typically include a number of components that generate waste heat. Such components include printed circuit boards, mass storage devices, power supplies, and processors. For example, some computers with multiple processors may generate 250 watts of waste heat. Some known computer systems include a plurality of such larger, multiple-processor computers that are configured into rack-mounted components, and then are subsequently positioned within a racking system. Some known racking systems include 40 such rack-mounted components and such racking systems will therefore generate as much as 10 kilowatts of waste heat. Moreover, some known data centers include a plurality of such racking systems. Some known data centers include methods and apparatus that facilitate waste heat removal from a plurality of racking systems, typically by circulating air through one or more of the rack systems. Where a structure includes an enclosure in which waste heat sources are located, the methods and apparatuses may be configured to facilitate waste heat removal from the waste heat sources the enclosure, or some combination thereof. For example, a data center may include methods and apparatuses may be configured to facilitate waste heat removal from a plurality of rack computing systems. 
     Some waste heat removal systems remove waste heat from data centers by transferring waste heat to flows of air (“exhaust air”), which are then used to transport the waste heat to an environment external to the data center. Such an environment can include an ambient environment. 
     The amount of computing capacity needed for any given data center may change rapidly as business needs dictate. Most often, there is a need for increased computing capacity at a location. Initially providing computing capacity in a data center, or expanding the existing capacity of a data center (in the form of additional servers, for example), is resource-intensive and may take many months to implement. Substantial time and resources are typically required to design and build a data center (or expansion thereof), lay cables, install racks, enclosures, and cooling systems to implement waste heat removal therefrom. Additional time and resources are typically needed to conduct inspections and obtain certifications and approvals, such as for electrical and HVAC systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a data center that includes an air handling system and one or more data center row infrastructure modules according to some embodiments. 
         FIG. 2A-B  are schematic diagrams illustrating cross sectional views of one or more data center row infrastructure modules according to some embodiments. 
         FIG. 3  is a cross sectional view of a portion of a data center row infrastructure module according to some embodiments. 
         FIG. 4  is a cross sectional view of a portion of a data center row infrastructure module according to some embodiments. 
         FIG. 5  illustrates a free-standing exhaust plenum structure according to some embodiments. 
         FIG. 6  is a perspective view of a plenum module according to some embodiments. 
         FIG. 7  is a perspective view of a plenum module according to some embodiments. 
         FIG. 8  illustrates providing a data center row infrastructure module in a data center according to some embodiments. 
         FIG. 9  illustrates managing air circulation in a computing enclosure via one or more components of a data center row infrastructure module according to some embodiments. 
         FIG. 10  illustrates managing air circulation in a computing enclosure via one or more components of a data center row infrastructure module according to some embodiments. 
     
    
    
     The various embodiments described herein are susceptible to various modifications and alternative forms. Specific embodiments are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Various embodiments of a modular system for a data center are disclosed. According to one embodiment, a data center includes an enclosure, which itself includes a floor element and an interior space, a data center row infrastructure module positioned in the enclosure interior space. The data center row infrastructure module can direct intake air to at least two rows of server racks and direct exhaust air away from the at least two rows of server racks and into at least a portion of the enclosure interior space. The data center row infrastructure module includes a cold aisle space, two or more free-standing exhaust plenum structures, and a plenum module. The cold aisle space has a long axis and at least two separate rows of rack computing systems. Each of the rows of rack computing systems are positioned on opposite sides of the long axis of the cold aisle, and each rack computing system can receive intake air on a front side facing the long axis of the cold aisle space and discharge exhaust air on a rear side that is opposite the front side and faces away from the long axis of the cold aisle space. Each of the free-standing exhaust plenum structures is mounted on the floor element adjacent to rear sides of separate rows of rack computing systems on opposite sides of the cold aisle space, each extending substantially in parallel with the long axis. Each of the free-standing exhaust plenum structures includes a frame structure, an internal exhaust air plenum, at least one set of wall elements, and at least one support arm structure. The frame structure includes load-bearing frame members and can establish a structural outline and structural support of the free-standing exhaust plenum structure. The internal exhaust air plenum is at least partially bounded by the at least one set of wall elements and the coupled load-bearing frame members, wherein the internal exhaust air plenum is configured to receive the exhaust air from the rear side of the set of rack computer systems and direct the exhaust air into an exhaust air plenum of the enclosure. The set of wall elements are coupled to the frame members and substantially encompass at least a portion of an aisle-facing side of the free-standing exhaust plenum structure that faces the cold aisle space. The set of wall elements can restrict airflow into the internal exhaust air plenum from the cold aisle space to exhaust air discharged from the rear sides of the adjacent row of rack computer systems. The support arm structure extends from the aisle-facing side of the free-standing exhaust plenum structure. The plenum module spans the cold aisle space between the at least two free-standing exhaust plenum structures, and rests upon an upper surface of support arm structures of each of the free-standing exhaust plenum structures, to establish a lower boundary of a cooling air plenum above the plenum module and an upper boundary of the cold aisle space beneath the plenum module and between the at least two free-standing frame structures. The plenum module includes a structural element, that substantially seals the cooling air plenum and the cold aisle space, and an intake air supply vent, extending through the structural element between the cooling air plenum and the cold aisle space, that directs at least a portion of cooling air circulating through the cooling air plenum into the cold aisle space to be supplied to the at least two rows of rack computing systems as intake air. 
     According to one embodiment, a data center row infrastructure module includes at least two free-standing exhaust plenum structures encompassing opposite side ends of an enclosure and a plenum module. Each free-standing exhaust plenum structure includes an internal exhaust air plenum at least partially encompassed by wall elements. The internal exhaust air plenum can receive exhaust air from the enclosure and direct the received exhaust air through an exhaust air outlet on a top end of the free-standing exhaust plenum structure. The plenum module spans a top end of the enclosure between the free-standing exhaust plenum structures, and rests upon at least one support structure of each of the exhaust plenum structures, to establish a bottom end of a cooling air plenum above and separate from the enclosure and between the free-standing exhaust plenum structures. The plenum module includes an intake air supply vent that can supply intake air from the cooling air plenum to the enclosure. 
     According to one embodiment, a method includes mounting free-standing exhaust plenum structures adjacent to opposite ends of a portion of a floor element and mounting a plenum module on separate support structures to establish a top end of an enclosure on a lower surface of the plenum module and to establish a bottom end of a cooling air plenum on an upper surface of the plenum module. Each of the free-standing exhaust plenum structures encompasses a separate internal air plenum and extends substantially in parallel with a long axis of the portion of the floor element, to establish side ends of the enclosure. Each of the separate support structures extend into the enclosure from an enclosure-facing side of a respective one of the free-standing exhaust plenum structures. The plenum module includes at least one intake air supply vent and can direct intake air from the cooling air plenum into the enclosure via the at least one intake air supply vent. Each of the free-standing exhaust plenum structures can receive exhaust air from the enclosure into the internal air plenum and direct the exhaust air out of the internal air plenum and into an external environment via an exhaust air supply vent. 
     As used herein, “air handling module” means a module that provides air to one or more systems or components external to the module. 
     As used herein, an “aisle” means a space next to one or more racks. 
     As used herein, “ambient” refers to a condition of outside air at the location of a system or data center. An ambient temperature may be taken, for example, at or near an intake hood of an air handling system. 
     As used herein, “computing” includes any operations that can be performed by a computer, such as computation, data storage, data retrieval, or communications. 
     As used herein, “computer room” means a room of a building in which computer systems, such as rack-mounted servers, are operated. 
     As used herein, “computer system” includes any of various computer systems or components thereof. One example of a computer system is a rack-mounted server. As used herein, the term computer 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. In the various embodiments, memory may include, but is not limited to, a computer-readable medium, such as a random access memory (RAM). Alternatively, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc (DVD) may also be used. 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. Furthermore, in the some embodiments, additional output channels may include an operator interface monitor and/or a printer. 
     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 and other systems and components dedicated to specific functions (e.g., e-commerce transactions, database management) or serving multiple functions. Examples of computer operations include information processing, communications, simulations, and operational control. 
     As used herein, “mechanical cooling” means cooling of air by a process that involves doing mechanical work on at least one fluid, such as occurs in vapor-compression refrigeration systems. 
     As used herein, “evaporative cooling” means cooling of air by evaporation of liquid. 
     As used herein, “direct evaporative cooling” means cooling of air by evaporation of liquid directly into a stream of air to be cooled. 
     As used herein, “adiabatic system” means a system that cools by evaporation of a liquid. 
     As used herein, “free cooling” includes an operation in which an air handling system pulls air at least partially from an external source (such as air outside a facility) and/or a return from a computer room, and forces the air to electronic equipment without active chilling in the air-handling sub-system (e.g., fluid flow through the chiller coils in the air handling sub-system is shut off by closing a flow control valve). 
     As used herein, a “chimney effect” or “stack effect” refers to a flow of air through a pathway that is induced by an air density difference between the ends of the pathway. Such a difference may be induced by one or more various factors, including temperature differences between the ends of the pathway, ambient pressure differences, humidity differences, and the like. For example, where a building with a warm enclosure is surrounded by a colder ambient environment, the chimney effect may refer to an induced flow of air through a pathway (e.g., a chimney) between the enclosure and the environment that is induced by an air-density difference between the lower-density warmer air of the enclosure passing through the pathway to the environment while being displaced by the higher-density colder air from the environment. 
     As used herein, “room” means a room or a space of a structure. A “computer room” means a room in which computer systems, such as rack-mounted servers, are operated. 
     As used herein, a “damper” includes any device or component that can be moved to control (e.g., increase or decrease) the flow of fluid through a duct, conduit, or other passageway. Examples of dampers include plates, blades, panels, or discs, or any combination thereof. A damper may include multiple elements. For example, a damper may include a series of plates in parallel relation to one another that can be simultaneously rotated to close a duct. As used herein, to “adjust” a damper means to place or leave one or more elements of the damper to achieve desired flow characteristics through the damper, such as open, closed, or partially open. For example, in a system with eighteen passive cooling systems, adjusting the exhaust air dampers may include opening at least some selected exhaust air dampers in eight of the passive cooling systems and keeping at least some exhaust air dampers closed in the other ten passive cooling systems. 
     As used herein, a “space” means a space, area or volume. 
     As used herein, a “module” is a component or a combination of components physically coupled to one another. A module may include functional elements and systems, such as computer systems, racks, blowers, ducts, power distribution units, fire suppression systems, and control systems, as well as structural elements, such a frame, housing, structure, container, etc. In some embodiments, a module is pre-fabricated at a location off-site from a data center. 
       FIG. 1  is a schematic diagram illustrating a data center  100  that includes an air handling system and one or more data center row infrastructure modules according to some embodiments. Planes  150  and  160  represent cross sectional views of various elements included in data center  100 , illustrated and discussed further below with reference to  FIGS. 2A-B . 
     In some embodiments, a data center includes one or more computer rooms including computing systems and one or more cooling systems that remove waste heat energy from the computing systems. For example, in the illustrated embodiment, data center  100  includes a room  102  that encloses an interior enclosure space  106 , also referred to interchangeably hereinafter as an “interior space”, and a floor element  104 . The data center  100  may, in some embodiments, include an exhaust plenum  108  that can receive exhaust air from various heat producing components and direct the exhaust air to at least one external environment, including an ambient environment. 
     Data center  100  includes an air handling system  110 . The air handling system  110  delivers air to one or more portions of the interior enclosure space  106  via one or more outlet conduits  116 . In some embodiments, the air handling system  110  includes one or more air moving devices that supply air as cooling air via one or more conduits  116 . The air handling system may include one or more air cooling systems, including one or more mechanical cooling systems, evaporative cooling systems, etc. that chill at least some of the air supplied as cooling air. In some embodiments, the air handling system supplies at least some of the cooling air via ambient air received from an ambient environment via an intake conduit  112 . The air received via the intake conduit into the air handling system  110  may be chilled and supplied as at least a portion of the cooling air. In some embodiments, ambient air received from an ambient environment is directed to conduit  116  independent of chilling of the ambient air. 
     In some embodiments, air handling system  110  receives at least a portion of exhaust air that is circulating through at least a portion of the exhaust plenum  108  as recirculated air. Recirculated air can be directed to air handling system  110 , from plenum  108 , via one or more conduits  114 . The recirculated air may be mixed, at the air handling system  110 , with at least some chilled air, which can include ambient air received through conduit  112 , to provide a mixed air that is supplied as the cooling air via one or more outlet conduits  116 . One or more of the mixing proportions of ambient air, recirculated exhaust air and chilling of at least some air included in the mixed air may be based at least in part upon one or more target characteristics of the cooling air supplied via conduits  116 . For example, the flow rate of exhaust air through conduit  114  that is mixed with ambient air received via conduit  112  into cooling air supplied via conduit  116  may be controlled, via adjustable controlling of one or more dampers, air moving devices, etc. to maintain one or more characteristics of the cooling air, including temperature, wet bulb temperature, relative humidity, etc. within one or more predetermined ranges of values. 
     Data center  100  includes a data center row infrastructure module  120 . The data center row infrastructure module at least partially encloses an enclosure space  122  in which one or more computer systems of the data center are installed in one or more rows  123  of racks  124 . The enclosure space  122  can include a “cold aisle” space through which intake air is circulated to be provided to the computer systems in separate rows  123  of racks  124  in the enclosure space  122  to remove heat from one or more heat producing components of the computer systems in the racks  124 . 
     In some embodiments, the data center row infrastructure module  120  comprises multiple separate modular elements that are installed in the interior enclosure space  106  of data center  100  to establish and bound at least a portion of enclosure space  122 , and computer systems installed in racks  124  located therein. The modular elements may include free-standing exhaust plenum structural modules (also referred to interchangeably hereinafter as “free-standing exhaust plenum structures”), plenum modules, electrical modules, and air handling modules. Each module or portion of a module may be transported separately, such as on a semi-trailer. In some embodiments, modules, or portions of modules, are pre-fabricated at one location, such as a factory, and transported to a data center site at another location. In certain embodiments, however, all or some portions of the modules may be assembled at the data center  100  site. For example, one or more free-standing exhaust plenum structures  130  and plenum modules  140  may be installed in interior enclosure space  106 , racks  124  may be installed in an enclosure space  122  bounded at least partially by modules  130 ,  140 . Cooling systems, including air moving devices, air cooling systems, etc., may be installed in an air handling system  110 , which may be comprised in one or more modules. In some embodiments, the modules are pre-certified prior to shipment of the modules to the site. 
     The data center row infrastructure module  120  can, in some embodiments, at least partially bound an enclosure space  122  into which racks  124  of computer systems may be installed in one or more rows  123  of racks  124 , where one or more elements of the data center row infrastructure module  120  can circulate intake air into the enclosure space  122  to remove heat from one or more heat producing components of one or more devices, including one or more computer systems, installed in the enclosure space  122 . One or more elements of the data center row infrastructure module  120  can remove air that has removed heat from at least one of the heat producing components, such air referred to hereinafter as “exhaust air”, from the enclosure space  122 . As a result, waste heat can be removed from the computer systems located in the enclosure space  122 . 
     Data center row infrastructure module  120  includes free-standing exhaust plenum structures  130 . Free-standing exhaust plenum structures  130  can include one or more frame members that establish an interior enclosure of the structure  130 , and one or more wall elements can at least partially enclose the interior space of the structure to establish an internal exhaust air plenum  132 . As shown in the illustrated embodiment, free-standing exhaust plenum structures  130  can be positioned in the interior space  106  on one or more sides of the enclosure space  122  to establish one or more side ends of the enclosure space. In some embodiments, a free-standing exhaust plenum structure  130  can be mounted adjacent to a side of the enclosure space  122  so that a rear end of one or more racks of computer systems  124  in the enclosure space  122  abuts a face of the free-standing exhaust plenum structure  130 . The face of the free-standing exhaust plenum structure  130  abutting the rear end of the rack  124  can include a gap  170  through which exhaust air from the rack  124  computer systems can be received into the internal exhaust air plenum  132 . In some embodiments, one or more portions of the gap can be enclosed by a removable panel (not shown in  FIG. 1 ) to at least partially inhibit airflow of exhaust air into the internal exhaust air plenum  132 . Exhaust air received into the plenum  132  can be directed out of the data center row infrastructure module  120  via one or more exhaust vents  134  on one or more sides of the free-standing exhaust plenum structure  130 . 
     In some embodiments, including the illustrated embodiment, the exhaust vents  134  include a top end of the free-standing exhaust plenum structure  130  that is unencompassed by wall elements, such that the top end is open to at least the interior space  106 , the plenum  108 , etc. Exhaust air in the plenum  132  can be directed out of the vent  134  via one or more gradients between the plenum  132  and at least the interior space  106 , including a chimney effect gradient, a pressure gradient, some combination thereof, or the like. In some embodiments, where data center  100  includes an interior space exhaust plenum  108 , exhaust air can be directed out of the plenums  132  into the exhaust plenum  108  via one or more gradients between plenums  132  and plenum  108 . Exhaust air directed out of module  120  and into exhaust plenum  108  can be directed out of the room  102 , recirculated at least partially back to an air handling system  110  via a recirculation conduit  114 , some combination thereof, or the like. 
     Data center row infrastructure module  120  includes one or more plenum modules  140  that are installed to establish a top end of the enclosure space  122  and at least a portion of a cooling air plenum  144  that is separate from the enclosure space  122 . The plenum module  140 , in some embodiments, comprises one or more elements that are mounted on separate support elements of separate free-standing exhaust plenum structures  130 , themselves mounted on opposite sides of an enclosure space  122 , where the plenum module  140  spans at least a portion of the space between the opposite free-standing exhaust plenum structures  130  and establishes at least a top end of the enclosure space  122  and a bottom end of the cooling air plenum  144 . In some embodiments, a plenum module  140  is mounted on support arm structures of the opposite free-standing exhaust plenum structures  130 , where the support arm structures provide structural support to the plenum module. 
     In some embodiments, the cooling air plenum  144  is established based at least in part upon the various modular elements of the data center row infrastructure module  120 . As shown, some embodiments of a cooling air plenum  144  are established based at least in part of one or more free-standing exhaust plenum structures  130  and plenum modules  140 . Side ends of the cooling air plenum  144  may be established based at least in part upon faces of free-standing exhaust plenum structures  130  mounted on opposite sides of the enclosure space  122 , and a bottom end of the cooling air plenum  144  may be established based at least in part upon one or more surfaces of the plenum module  140 , which can include an upper surface of a plenum module  140  element, where the lower surface of the plenum module element establishes the top end of the enclosure space  122  and the plenum module element includes vent  142 . 
     In some embodiments, row infrastructure module  120  includes one or more plenum ducts  146  that can be mounted on free-standing exhaust plenum structures  130 , the structures  130  themselves being mounted on opposite sides of enclosure space  122 , to establish a top end of the cooling air plenum  144  via a lower surface of the plenum duct  146 . The plenum duct  146  can be mounted on support elements of the separate free-standing exhaust plenum structures  130 , where the support elements provide structural support to the plenum duct  146  and transmit the structural load of the plenum duct through at least a portion of the free-standing exhaust plenum structures. A plenum duct, in some embodiments, is mounted to enclose top and side portions of the cooling air plenum  144 . 
     In some embodiments, one or more of the free-standing exhaust plenum structures  130  includes one or more support elements that include one or more support arm structures. A support arm structure may be coupled to one or more frame members of a free-standing exhaust plenum structure. In some embodiments, a support arm structure can structurally support one or more elements mounted on the support arm structure. For example, the support arm structure can transmit a structural load of an element mounted on the support arm structure through at least a portion of the free-standing exhaust plenum structure. In some embodiments, a support arm structure extends away from a face of the free-standing exhaust plenum structure. For example, where one or more free-standing exhaust plenum structures  130  are mounted on a floor element  104  of an interior space  106  on opposite sides of an enclosure space  122 , one or more of the free-standing exhaust plenum structures  130  can include at least one support arm structure that extends away from a face of the free-standing exhaust plenum structure  130  that faces the enclosure space  122  and into at least a portion of the enclosure space  122 . 
     The plenum module  140  includes one or more vents  142  that direct cooling air circulating through at least a portion of the cooling air plenum  144  into the enclosure space  122  as intake air, so that air is provided to computer systems in racks  124  in the enclosure space  122  to remove waste heat from the computer systems. In some embodiments, the plenum module  140  is mounted on separate support arm structures of each of at least two free-standing exhaust plenum structures  130  on opposite sides of an enclosure space  122 , so that the plenum  140  rests upon the support arm structures and transfers structural loads to the free-standing exhaust plenum structures  130  via the support arm structures. 
     In some embodiments, one or more of the modular elements comprised in the data center row infrastructure module  120  is comprised of components that can be utilized for shelving systems. For example, the frame members of a free-standing exhaust plenum structure  130  can be comprised of a free-standing pallet shelving structure. A free-standing pallet shelving rack, as utilized for storing and stacking pallets, may include multiple lateral bracing members through the interior of the structure to provide shelves to support the pallets. The free-standing exhaust plenum structure  130 , in some embodiments, includes a free-standing pallet shelving rack where multiple lateral bracing members are removed to open up the interior of the structure to comprise the internal exhaust air plenum, and one or more wall elements are coupled to one or more faces of the structure to at least partially encompass the internal exhaust air plenum, etc. In another example, one or more support arm structures of a free-standing exhaust plenum structure may comprise support arms of a drive-through pallet shelving system. A drive-through pallet shelving system, as utilized for storing and stacking pallets, may include multiple particularly-spaced vertical posts, which may not comprise free-standing structures, that are bolted to a floor element and each include one or more support arm structures that extend into a space between the posts, where a pallet can be moved into the spaces and lifted to rest upon multiple support arm structures extending from multiple posts into a common space. In a drive-through pallet shelving system, the pallets may be moved and lifted by a forklift vehicle. The free-standing exhaust plenum structure  130 , in some embodiments, includes one or more support arm structures of a drive-through pallet shelving system that are coupled to frame members of the free-standing exhaust plenum structure. In some embodiments, at least a portion of a free-standing exhaust plenum structure  130  can be assembled via coupling of selected elements of the separate shelving systems, including the frame members and support arm structures. 
     In some embodiments, one or more of the free-standing exhaust plenum structures  130 , plenum modules  140 , plenum ducts  146 , etc. can be installed in an interior space  106  to rapidly establish a data center row infrastructure module bounding at least a portion of an enclosure space  122 , also referred to hereinafter as a “bounded enclosure”, for which the modular elements provide air circulation through the bounded enclosure  122  for heat producing components, including rack computer systems, located in the bounded enclosure  122 . The data center row infrastructure module  120  can be increased and decreased in size through addition and removal, respectively, of free-standing exhaust plenum structures  130 , plenum modules  140 , etc. to lengthen or shorten the bounded enclosure  122  for which air circulation is provided via the assembled data center row infrastructure module  120 . 
     In some embodiments, a bounded enclosure  122  includes one or more rows  123  of racks  124  that extend substantially in parallel with one or more faces of one or more free-standing exhaust plenum structures extending along one or more sides of the bounded enclosure  122 . Where free-standing exhaust plenum structures  130  are mounted on opposite sides of an enclosure space  122 , one or more rows of racks  124  may be mounted in the enclosure space  122  to extend along one or more faces of the free-standing exhaust plenum structures that face the enclosure space. 
     In some embodiments, free-standing exhaust plenum structures  130  are mounted on opposite sides of an enclosure space  122  and extend substantially in parallel with an axis of the enclosure space. The axis can include a long axis of the space  122 , a short axis of the space  122 , etc. The rows may be installed in the enclosure space  122  substantially in parallel with free-standing exhaust plenum structures and substantially in parallel with the axis that the structures are also extending in parallel with. In the illustrated embodiment, for example, enclosure space  122  includes a long axis, and free standing structures  130  are extending along opposite sides of the enclosure space  122  substantially in parallel with the long axis of the space  122 . Furthermore, the space  122  includes two separate rows  123  of racks  124 , where each row  123  of racks  124  extends substantially in parallel with the long axis of the room, and each row of racks is installed to abut the rear ends of the racks in a given row against a face of one or more sets of free-standing exhaust plenum structures  130  on a given side of the enclosure space  122 . As a result, the enclosure space  122  (“bounded enclosure”) is bounded on side ends that are substantially parallel to a long axis of the space  122  by opposite-facing sets of free-standing exhaust plenum structures  130  and the space  122  includes two opposite-facing rows  123  of racks  124 , where the front ends of each row  123  of racks  124  faces into the space  122 , towards the long axis and the opposite row  123  of racks  124 , and the rear ends of a given row of racks abuts a face an adjacent set of free-standing exhaust plenum structures  130  that faces into the space  122 . 
     The number of modular elements, including free-standing exhaust plenum structures  130 , plenum modules  140 , etc., deployed in a data center row infrastructure module  120  may be selected based on the requirements of the data center  100 . For example, if a data center in Facility A needs 38 server racks, Facility A may be provided with eight free-standing exhaust plenum structures  130  and four plenum modules  140 , where the eight free-standing exhaust plenum structures can be installed on opposite sides of a space  122 , and the plenum modules  140  can be mounted to span between opposite free-standing exhaust plenum structures  130 , to establish a bounded enclosure  122  that is of sufficient size and air circulation capability to accommodate 38 server racks in Facility A. In addition, over time, modular elements can be added to a data center row infrastructure module  120  at a data center if the computing capacity needed at the facility increases, and modules can be removed from a data center row infrastructure module  120  at a data center and redeployed if the computing capacity needed at the facility decreases. 
       FIG. 2A-B  are schematic diagrams illustrating cross sectional views of one or more data center row infrastructure modules according to some embodiments. 
       FIG. 2A  illustrates a cross-sectional view  150  of data center  100  that includes a cross section of data center row infrastructure module  120  through the enclosure space  122 , as indicated in  FIG. 1 . The illustrated cross-sectional view illustrates the elements included in the enclosure space  122  and cooling air plenum  144  of the row infrastructure module  120 , the one or more rows  123  of racks  124  installed in the enclosure space, and directing of air to the enclosure space  122  to provide intake air to computer systems mounted in the racks  124 . 
     As discussed above with reference to  FIG. 1 , data center  100  can include an air handling system, illustrated in  FIG. 2A  as system  110 , which can direct air to the cooling air plenum  144  of a data center row infrastructure module  120  via one or more outlet conduits  116  extending from an outlet of the air handling system  110 . The air handling system  110  may include an air moving device that supplies the air via the conduit  116 . In some embodiments, the air handling system  110  supplies air that includes air from separate sources. For example, air handling system  110  may receive air from an external environment, including an ambient environment, via one or more supply vents  202 . At least some received air may be cooled via operation of one or more various air cooling systems that may be included in the air handling system  100 , including mechanical cooling systems, evaporative cooling systems, adiabatic cooling systems, free-cooling systems, some combination thereof, or the like. 
     In some embodiments, at least some exhaust air can be received at air handling system  110  and mixed with air from other sources to provide a mixed air that is provided to row infrastructure modules  120  via one or more conduits  116 . For example, at least some exhaust air circulating in an interior space exhaust plenum  108  may be directed to air handling system  110  via one or more vents  204 , recirculation conduits, etc. 
     One or more of the mixing proportions of ambient air, recirculated exhaust air and chilling of at least some air included in the mixed air may be based at least in part upon one or more target characteristics of the cooling air supplied via conduits  116 . For example, the flow rate of exhaust air through conduit  114  that is mixed with ambient air received via at least vent  202  into cooling air supplied via conduit  116  may be controlled, via adjustable controlling of one or more dampers, air moving devices, etc. to maintain one or more characteristics of the cooling air, including temperature, wet bulb temperature, relative humidity, etc. within one or more predetermined ranges of values. 
     As shown in  FIG. 2A , cooling air  210  received into the cooling air plenum  144  of the data center row infrastructure module is directed through at least a portion of the plenum  144 . As shown, the plenum  144  can be established based at least in part upon one or more plenum modules  140 . In the illustrated embodiment, for example, module  120  includes four plenum modules  140  that each establish at least side and bottom ends of the plenum  144 . Each plenum module  140  includes a bottom portion  141  that separates the plenum  144  from the bounded enclosure  122  and establishes at least a bottom end of a portion of the plenum  144 , in addition to establishing a top end of a portion of the bounded enclosure  122 . In some embodiments, one or more of the plenum modules  140  in module  120  includes one or more vents  142  that can direct at least a portion of the cooling air  210  that is being directed through the plenum  144  from the outlet of conduit  116  into at least a portion of the bounded enclosure  122 . Air directed into the bounded enclosure  122  is referred to hereinafter as “intake air”. As shown, portions of cooling air passing through the plenum  144  can be directed, by respective vents  142 , out of the plenum  144  and into the bounded enclosure  122  as intake air  214 . The intake air  214  may be directed into the enclosure via one or more of a pressure gradient from the plenum  144  to at least the bounded enclosure  122  across the vents  142 , an air density gradient, some combination thereof, or the like. In some embodiments, one or more vents  142  include an air moving device that operates to supply air from the plenum  144  into the bounded enclosure  122 . 
     In some embodiments, and as shown in the illustrated embodiment, one or more of the plenum modules  140  may be mounted on one or more support arm structures  212 . The support arm structures may be included in one or more free-standing exhaust plenum structures  130 . In the illustrated embodiment, each free-standing exhaust plenum structure  130  includes two support arm structures  212  extending from the face of the structure  130  that faces the bounded enclosure  122 , and each plenum module  140  is mounted on at least the two support arm structures  212  of a give free-standing exhaust plenum structure, so that the plenum module rests at least in part upon an upper surface of the support arm structures  212  and transmits at least a portion of its structural load to the free-standing exhaust plenum structure  130  via the support arm structures  212  upon which it rests. 
     As shown, intake air  214  may drop from plenum  144  into enclosure space  122  via vents  142 . The enclosure space includes one or more rows  123  of racks  124 , the rear ends of the illustrated row  123  of racks abutting the faces of the illustrated free-standing exhaust plenum structures  130  that face into the space  122 . The intake air  214  may be received into computer systems (not shown) installed in one or more of the racks  124 . The faces of the free-standing exhaust plenum structures  130  facing into the enclosure space  122  include one or more wall elements  220  that substantially enclose one or more interior portions of the free-standing exhaust plenum structures  130 , including one or more internal exhaust air plenums, and partition the interior portions from the enclosure space  122  to preclude air moving from the interior portions of the free-standing exhaust plenum structures  130  directly into the enclosure space  130  via the faces of the structures  130  that face into the enclosure space  130 . For example, the exhaust air plenums in the interior of the free-standing exhaust plenum structures  130  may be at a higher air pressure than the air pressure of the enclosure space, and the wall elements  200  may preclude exhaust air from passing directly back into the enclosure space  122 . In some embodiments, where the rear ends of racks  124  abut the faces of the free-standing exhaust plenum structures  130  facing into the enclosure space  122 , the rear ends of one or more of the racks  124  may abut one or more gaps  230  in the faces of the free-standing exhaust plenum structures  130  facing into the enclosure space  122 , so that exhaust air discharged from computer systems installed in the racks, via the rear ends of the racks  124 , can pass into the interior of one or more of the free-standing exhaust plenum structures. Sealing elements, including one or more gasket components, may be mounted at interfaces between the racks  124  and the wall elements  220  to at least partially mitigate leakage of exhaust air into the enclosure space  122 . 
       FIG. 2B  illustrates a cross-sectional view  160  of data center  100  that includes a cross section of data center row infrastructure module  120  through the exhaust air plenums  132  of at least one set of free-standing exhaust plenum structures  130  mounted on one side of the enclosure space  122 , as indicated in  FIG. 1 . The illustrated cross-sectional view illustrates at least some elements included in the free-standing exhaust plenum structures  130  of the row infrastructure module  120 , the interior exhaust plenum  108  included in the interior space  106  external to the data center row infrastructure module  120 , and the flow of exhaust air through the plenums  132 , out of the module  120 , and through at least a portion of the exhaust plenum  108  of the data center  100 . 
     As shown in  FIG. 2B , exhaust air  240  can be received into the internal exhaust air plenums  132  of one or more free-standing exhaust plenum structures  130 . The exhaust air can be received into the plenums  132  via one or more gaps  230  in the wall elements  220  facing the rear ends of one or more of the racks  124 , as discussed above. Exhaust air  240  received into the plenums  132  may be directed out of the free-standing exhaust plenum structures  130 , and out of the row infrastructure module  120 , via one or more exhaust vents of the free-standing exhaust plenum structures, which can include, as shown in  FIG. 2B , unencompassed top ends of the free-standing exhaust plenum structures. In some embodiments, exhaust vents of a free-standing exhaust plenum structure can include one or more air moving devices that operate to remove exhaust air from the plenum  132  of the structure  130 . 
     Free-standing exhaust plenum structures  130  can include one or more frame members  232 ,  234  that establish an interior enclosure of the structure  130 , and one or more wall elements  220 ,  236  can at least partially enclose the interior space of the structure  130  to establish an internal exhaust air plenum  132 . The one or more frame members  232 ,  234  can be coupled to establish a free-standing frame that collectively encompasses an interior space and define an outline of the free-standing exhaust plenum structure  130 . Where the frame includes multiple frame members, the members may be coupled together via one or more known coupling methods, including bolting, welding, riveting, etc. One or more frame members may include post members  232  that extend vertically through the structure and can transmit at least some of the structural load of the structure to a floor element. One or more frame members may include bracing members  234  that provide at least some lateral structural support to the structure. 
     In some embodiments, a free-standing exhaust plenum structure  130  includes one or more wall elements  220 ,  236  coupled to one or more frame members  232 ,  234  on a portion of one or more faces of the free-standing exhaust plenum structure. For example, wall elements  220 ,  236  may cover a limited portion of a face of the free-standing exhaust plenum structure  130 , so that a gap  230  remains through which exhaust air  240  may be received from one or more waste heat sources into the interior exhaust air plenum  132  of the free-standing exhaust plenum structure  130 . Another gap may be present in a wall element  236  coupled to an upper portion of a face of a free-standing exhaust plenum structure, so that at least some of the exhaust air circulating through the internal exhaust air plenum of the free-standing exhaust plenum structure can be redirected to another external plenum via one or more vents mounted in the gap. In some embodiments, multiple types of wall elements may be coupled to one or more faces of the free-standing exhaust plenum structure. For example, one or more wall elements  236  that include an insulating material may be coupled to an upper portion of a face of a free-standing exhaust plenum structure, so that the wall elements mitigate heat transfer from exhaust air circulating through the internal exhaust air plenum to one or more air plenums  144  external to the free-standing exhaust plenum structure, and one or more wall elements  220  that are substantially free from insulating materials may be coupled to a lower portion of the same face of the free-standing exhaust plenum structure that faces the enclosure space  122 . 
     In some embodiments, exhaust air  240  can be directed out of the plenum  132  of one or more free-standing exhaust plenum structures  130  to exit the row infrastructure module  120 . The exhaust air exiting a module may pass into an exhaust plenum  108  of the data center  108 . In some embodiments, the plenum  108  includes an upper portion of the interior space  106  of the data center. In some embodiments, the plenum  108  is a separate enclosure bounded on a lower end by a ceiling element  109  that separates the interior  106  from the plenum  108 . Exhaust air  240  may pass into the plenum through ceiling element  109  via one or more vents  242 , which may include one or more adjustable dampers that can be controlled to adjust the flow rate of exhaust air into the plenum  108 . 
     In some embodiments, the plenum  108  can include an air handling system  208 , which can include one or more air moving devices, which can move at least some of the exhaust air out of the plenum  108  and to an external environment, including an ambient environment, via one or more vents  206 . In some embodiments, at least some of the exhaust air  270  in plenum  108  can be recirculated, via one or more vents  204 , recirculation conduits  114 , etc. to one or more air handling systems  110  to be mixed with other air, including ambient air, chilled air, etc. to be provided back to one or more row infrastructure modules  120  as cooling air. 
       FIG. 3  is a cross sectional view of a portion of a data center row infrastructure module according to some embodiments. Data center  300  includes an enclosure that comprises an interior enclosure space  302 , a floor element  306 , and an upper portion of the interior enclosure space  302  that includes an interior enclosure space exhaust plenum  304 . The exhaust plenum  304  can receive exhaust air  390  discharged from various components, modules, etc. mounted in the internal enclosure space  302 . 
     Data center  300  includes data center row infrastructure module  301 . The data center row infrastructure module  301  is mounted in the interior enclosure space  302  on at least a portion of floor element  306 . 
     Data center row infrastructure module  301 , also referred to hereinafter as “module  301 ”, includes an enclosure space  312  that is at least partially bounded by various modular elements of module  301 , including at least the illustrated structures  310  and module  330 . The enclosure space  312  may hereinafter be referred to as a “bounded enclosure  312 ”. The bounded enclosure  312 , in some embodiments, includes one or more heat producing components, including racks  314  into which computer systems (not shown) are installed, where the computer systems include one or more heat producing components. The computer systems may require cooling air to remove heat from the heat producing components therein, thereby removing heat from the computer systems and mitigating the risk of damage to sensitive components from overheating. The computer systems may require various infrastructure elements for normal operation, including power distribution infrastructure, communication infrastructure, etc. 
     In some embodiments, module  301  is configured to provide air to the bounded enclosure  312  to remove heat from one or more heat producing components mounted in the bounded enclosure  312 . In some embodiments, a bounded enclosure that receives air for such heat removal is referred to as a “cold aisle”, “cold aisle space”, etc. The bounded enclosure may include a length of floor space (e.g., an “aisle”) on which various components, including racks  314 , are mounted. The racks  314  may be mounted in one or more rows in various portions of the bounded enclosure  312 . As shown, the racks  314  may be mounted on opposite sides of the bounded enclosure  312 . In some embodiments, the racks  314  are mounted to position front ends of the respective racks  314  into the bounded enclosure  312  and the rear ends of the respective racks  314  away from the bounded enclosure  312 . In some embodiments, devices mounted in the racks  314  are configured to receive intake air  342  for heat removal via the front end of the rack and discharge exhaust air that has removed at least some heat from one or more heat producing components of the device via the rear end of the rack. Thus, intake air can be received from the interior of the bounded enclosure  312  into the racks, and exhaust air can be discharged out of the bounded enclosure  312 . 
     In some embodiments, the number of modular elements, including free-standing exhaust plenum structures  310 , plenum modules  330 , etc., deployed in a data center row infrastructure module  301  may be selected based on the requirements of the data center  300 . For example, if a data center in Facility A needs 38 server racks, Facility A may be provided with eight free-standing exhaust plenum structures  310  and four plenum modules  330 , where the eight free-standing exhaust plenum structures can be installed on opposite sides of a space, and the plenum modules can be mounted to span between opposite free-standing exhaust plenum structures, to establish a bounded enclosure  312  that is of sufficient size and air circulation capability to accommodate 38 server racks  314  in Facility A. In addition, over time, modular elements can be added to a data center row infrastructure module  301  at a data center  300  if the computing capacity needed at the facility increases, and modules can be removed from a data center row infrastructure module  301  at a data center  300  and redeployed if the computing capacity needed at the facility decreases. 
     In some embodiments, at least some of the bounded enclosure  312  is established by one or more modular elements of module  301 . For example, as illustrated, where at least two free-standing exhaust plenum structures  310  are mounted in the interior space  302  of data center  300  on floor element  306 , the free-standing exhaust plenum structures  310  can be mounted on the floor  306  to establish side ends of the bounded enclosure. The structures  310  can be mounted in a spaced configuration, where the structures are mounted on opposite sides of a space  303  of the floor element. As illustrated above with reference to  FIG. 1 , module  301  may comprise at least two sets of multiple structures  310  that each extend along opposite sides of a space  303 . Where multiple structures  310  are coupled together on each of the opposite sides of the space  303  to establish respective sets of structures  310 , the two or more sets of structures  310  may extend substantially in parallel with a particular axis  305  of the space  303 . For example, where space  303  includes a substantially rectangular portion of the floor element  306 , where the illustration of space  303  in  FIG. 3  is a width of the space that is less than a perpendicular length of the space (not shown), the axis  305  extending along the length of the space may comprise a long axis of the space, so that the structures  310  mounted on opposite ends of the space extend substantially in parallel with the long axis  305  to establish side ends of the space  303 . In some embodiments, establishing side ends of space  303  includes at least partially establishing side ends of the bounded enclosure  312 . 
     In some embodiments, a top end of the bounded enclosure  312  is at least partially established by a plenum module  330 . As shown, a plenum module  330  is mounted in the interior enclosure space  302  to rest upon at least a portion of separate support arm structures  325  of the separate free-standing exhaust plenum structures  310  mounted on opposite sides of space  303 . The module  330  may comprise a panel element  332 , a vent  333 , etc. The panel element  332  may include a lower surface and an upper surface that restricts airflow between the surfaces beyond the vent  333 . As a result, in some embodiments, a plenum module  330  can be coupled to separate free-standing exhaust plenum structures  310  that are themselves mounted on opposite side ends of space  303  to establish a top end of bounded enclosure  312  and a bottom end of another enclosure that can include a cooling air plenum  340 . Coupling a plenum module  330  to a free-standing exhaust plenum structure  310  can including mounting the plenum module  330  on one or more support art structures  325  of the structure  310 , where the plenum module  300  may rest upon one or more surfaces, including an upper surface, of the support arm structure and transmit at least apportion of the plenum modules  330  structural load to at least a portion of the structure  310  via support arm structure  325 . 
     In some embodiments, module  301  includes various plenums that direct air to bounded enclosure  312  to provide intake air to the bounded enclosure, direct air from the bounded enclosure  312  to remove exhaust air from the bounded enclosure, some combination thereof, or the like. In the illustrated embodiments, a plenum duct  337  can be coupled to the separate free-standing exhaust plenum structures  310  to establish a top end of an enclosure, which can include a cooling air plenum  340 , from which air can be directed into the bounded enclosure  312  as intake air  342 . As shown, at least some ends of the cooling air plenum  340  can be established by the plenum module  330 , free-standing exhaust plenum structures  310 , plenum duct  337 , etc. In some embodiments, where the plenum module  330  includes an enclosure structure that establishes top ends, bottom ends, and side ends of the plenum  340 , a plenum duct  337  may be omitted from module  301 . In the illustrated embodiment, cooling air plenum  340  is established via a lower surface of plenum duct  337 , an upper surface of plenum module  330 , and upper portions of the faces of the free-standing exhaust plenum structures  310  that face into space  303 . Such faces are referred to hereinafter as “enclosure faces” of the respective structures  310 . 
     In some embodiments, cooling air is received into cooling air plenum  340  and circulated through at least a portion of cooling air plenum  340 . The cooling air can be directed from plenum  340  into the bounded enclosure  312  as intake air  342  via one or more vents  333 . In some embodiments, one or more vents  333  include one or more dampers which may be adjustably controllable to adjustably control the flow rate of intake air into at least a portion of the bounded enclosure. In some embodiments, the cooling air is directed through the vents via one or more gradients from the plenum  340  to the enclosure  312 , including a pressure gradient, air density gradient, some combination thereof, or the like. 
     In some embodiments, one or more of the free-standing exhaust plenum structures  310  in module  301  includes a free-standing frame comprised of one or more frame members. As shown in the illustrated embodiment, the free-standing exhaust plenum structures  310  include frame members including vertical frame post members  322  and bracing frame members  324 . The frame members can provide structural support and integrity to a given structure  310  and can establish a structural outline of the structure  310 . In some embodiments, the structure  310  includes an interior space  320  that comprises an internal exhaust air plenum  326 . The plenum  326  can receive exhaust air from rear ends of racks  314  mounted in the bounded enclosure  312  to abut the respective enclosure face of the respective free-standing exhaust plenum structure  310 . Exhaust air  390  can be received from one or more devices that include one or more heat producing components. The exhaust air  390  may comprise intake air that has passed through at least a portion of the rack  314  and removed heat from at least one of the heat producing components included in one or more devices mounted in the rack  314 . 
     In some embodiments, a free-standing exhaust plenum structure  310  includes one or more wall elements that encompass at least a portion of one or more faces of the free-standing exhaust plenum structure. In the illustrated embodiments, at least the enclosure faces of the free-standing exhaust plenum structures  310  include wall elements  327 ,  329  that encompass respective portions of the enclosure faces of the structures  310 . Wall element  327  can include one or more elements that encompass at least a portion of the enclosure face of the free-standing exhaust plenum structure to partition the interior of the free-standing exhaust plenum structure  310  from the bounded enclosure  312 , thereby restricting flow of exhaust air from the internal exhaust air plenum  326  of the structure  310  into the bounded enclosure  312 . In some embodiments, the wall element  327  extends from the portion of the free-standing exhaust plenum structure  310  at which the plenum module  330  is coupled to a portion where one or more racks  314  abut the enclosure face of the free-standing exhaust plenum structure  310 . The enclosure face of the free-standing exhaust plenum structure  310  may include one or more gaps  370 , including one or more gaps  370  where a rack  314  abuts the enclosure face, so that exhaust air  390  can pass from the rear end of the rack  314  into the plenum  326  of the free-standing exhaust plenum structure  310 . One or more sealing elements may be coupled between a rack  314  and a wall element  327  of the proximate structure  310  to seal the interface between the wall element  327  and the structure of the rack  314  and to at least partially mitigate, prevent, etc. leakage of exhaust air from plenum  326  to bounded enclosure  312 . 
     Wall element  329  can include one or more elements that encompass at least a portion of the enclosure face of the free-standing exhaust plenum structure  310  to partition the interior of the free-standing exhaust plenum structure  310  from at least the cooling air plenum  340 , thereby at least partially restricting a flow of exhaust air from the internal exhaust air plenum  326  of the structure  310  into the cooling air plenum, thereby at least partially mitigating, preventing, etc. leakage of exhaust air  390  from plenum  326  to cooling air plenum  340  to mix with cooling air in the plenum  340 . In some embodiments, the wall element  329  extends from the portion of the free-standing exhaust plenum structure  310  at which the plenum module  330  is coupled to a portion where one or more plenum ducts are coupled to the free-standing exhaust plenum structure  310 . The enclosure face of the free-standing exhaust plenum structure  310  may include one or more gaps, so that at least some exhaust air can pass from the plenum  326  to mix with cooling air in plenum  340  to provide mixed air. The gaps may include one or more vents mounted in the enclosure face of the free-standing exhaust plenum structure  310 , where such vents may include one or more sets of adjustably controllable dampers. 
     In some embodiments, a free-standing exhaust plenum structure  310  includes one or more exhaust vents  328  through which exhaust air  390  can be directed from an internal exhaust air plenum of the free-standing exhaust plenum structure  310  to an environment external to module  301 . The external environment can include interior space  302 , interior space exhaust plenum  304 , etc. The exhaust air  390  can be directed through the vents  328  via one or more of a pressure gradient between the plenum  326  and the external environment, an air density gradient, a chimney effect, some combination thereof, or the like. 
     In some embodiments, one or more free-standing exhaust plenum structures  310  in module  301  include multiple enclosure faces. Each of the multiple enclosure faces can include one or more wall elements  327 ,  329 , support arm structures  325 , etc. As a result, a given free-standing exhaust plenum structure  310  can be mounted on a side of multiple spaces  303 , where one face of the structure  310  faces one space  303  and another face, which may be an opposite face, faces another separate space  303 . The plenum  326  of a given structure  310  may receive exhaust air from two or more separate racks  314  that are each mounted in separate bounded enclosures  312 . As a result, module  301  may include multiple bounded enclosures  312  that are each at least partially bounded by one or more structures  310 , modules  330 , etc. 
     In some embodiments, module  301  includes one or more support elements that support one or more infrastructure elements. The support elements can include one or more rails, trays, busways, etc., which may be coupled to one or more various modular elements of module  301 . In the illustrated embodiment, for example, plenum module  330  includes a support tray  335  and a plurality of busways  336  that can support one or more elements of infrastructure, including one or more power busses, power transmission lines, communication lines, lighting elements, sensors, etc. 
     In addition, the illustrated embodiment illustrates support trays  354  that are coupled to support arm structures  352  that are themselves coupled to free-standing exhaust plenum structures  310 . They trays may support one or more one or more elements of infrastructure, including one or more power busses, power transmission lines, communication lines, lighting elements, sensors, etc. One or more of the infrastructure elements supported by one or more of trays  354 , busways  336 , tray  335 , etc. may include elements that are routed through the bounded enclosure to provide at least a portion of infrastructure support to various computer systems installed in racks  314 . For example, trays  354  may route power transmission lines, busses, etc. through bounded enclosure to provide power distribution support to computer systems installed in the racks  314 , and busway  336  may route one or more communication lines, including network communication cables, through the bounded enclosure  312  to communicatively couple one or more computer systems installed in the racks  314  with one or more communication networks. 
       FIG. 4  is a cross sectional view of a portion of a data center row infrastructure module according to some embodiments. In some embodiments, a data center row infrastructure module  401  is mounted on a floor element  406  in an interior enclosure space  402  of a data center  400 . The module  401  includes free-standing exhaust plenum structures  410  and plenum modules  430  that at least partially encompass a bounded enclosure  412  in which one or more racks  414  are mounted. 
     In some embodiments, the plenum module  430  includes a mixing plenum  438  that can mix cooling air received from a cooling air plenum  440  with at least some exhaust air  490  from one or more internal exhaust air plenums  426  of one or more free-standing exhaust plenum structures  410 . The plenum module  430 , which may be coupled to the free-standing exhaust plenum structures  410  via mounting on one or more support arm structures  425 , may include a panel element  432  that establishes at least the bottom end of the mixing plenum  438  and side wall elements that establish side ends of the mixing plenum  438 . The top end of the mixing plenum  438  may be at least partially unencompassed by one or more structural elements of the plenum module  430 , so that the top end of the mixing plenum  438  is at least partially open to an enclosure  440 , which may include the cooling air plenum  440 . The cooling air plenum  440  may be bounded on a top end by plenum duct  437 , one or more portions of plenum module  438 , some combination thereof, or the like. 
     Cooling air received from the cooling air plenum  440  and at least some exhaust air received from one or more plenums  426  of at least one free-standing exhaust plenum structure  410  can result in a mixed air. The mixed air can be directed into the bounded enclosure  412 , via an air vent structure  431 . For example, in the illustrated embodiment, plenum module  430  includes a mixing plenum  438  that is configured to mix cooling air received from a cooling air plenum  440  via the unencompassed top end of the plenum  438 , and at least some recirculated exhaust air  490  from one or more plenums  426  to provide mixed air that can be supplied to a bounded enclosure  412  as intake air  442  through the panel  432  via a vent structure  439  in the panel  432 . The vent structure  439  can include one or more air moving devices that induce airflow from the mixing plenum  438  to the bounded enclosure  412  as intake air  442 . 
     In some embodiments, the exhaust air  490  may be received into the mixing plenum  438  via one or more vents  431  mounted in one or more side walls of the plenum module  430 . The vents  431  can communicatively couple the internal exhaust air plenum  426  of at least one free-standing exhaust plenum structures  410  with the mixing plenum  438  when the plenum module  430  is mounted at least partially on a support arm structure  425  of the free-standing exhaust plenum structure  410 , where exhaust air  490  can be directed through a gap in an enclosure face of the free-standing exhaust plenum structure  410  that faces the bounded enclosure  412 , through the vents  431 , and into the mixing plenum  438  to be mixed with cooling air. The vents  431  may include one or more adjustable dampers that can be adjusted to control the flow of exhaust air into the mixing plenum  438 . 
     In some embodiments, a vent  431  is mounted in the enclosure face of one or more free-standing exhaust plenum structures  410  adjacent to the plenum module  430 . The air directed into the mixing plenum  438  from the cooling air plenum  440 , which can include cooling air, may be mixed with the exhaust air directed into the mixing plenum  438  from one or more plenums  426  to provide mixed air. Adjustable dampers of the vent structures  439  to the mixing plenum  438  from the free-standing exhaust plenum structure may be adjusted to control the flow of exhaust air into the mixing plenum  438  to maintain one or more particular characteristics of the mixed air, including one or more of temperature, relative humidity, wet-bulb temperature, etc. 
       FIG. 5  illustrates a free-standing exhaust plenum structure  500  according to some embodiments. 
     In some embodiments, a free-standing exhaust plenum structure  500  includes a free-standing frame  503 . The free standing frame  503  can include one or more frame members  502 ,  504 ,  505  that collectively encompass an interior space  510  and define an outline of the free-standing exhaust plenum structure  500 . Where the frame  503  includes multiple frame members  502 ,  504 ,  505 , the members  502 ,  504 ,  505  may be coupled together via one or more known coupling methods, including bolting, welding, riveting, etc. One or more frame members may include post members  502  that extend vertically through the structure and can transmit at least some of the structural load of the structure  500  to a floor element  520 . One or more frame members may include one or more lateral bracing members  504 , angular bracing members  505 , some combination thereof, or the like that provide at least some structural support to the structure  500 . 
     In some embodiments, the free-standing exhaust plenum structure  500  includes one or more wall elements  508 ,  509  that are coupled to one or more frame members  502 ,  504 ,  505  of the free-standing frame  503 . In some embodiments, one or more of the wall elements  508 ,  509  include cladding which can restrict airflow between opposite faces of the cladding. In some embodiments, one or more of the wall elements  508 ,  509  includes an insulating material that mitigates heat transfer between separate environments in communication with separate faces of the one or more wall elements  508 ,  509 . In some embodiments, coupling one or more wall elements to frame members  502 ,  504 ,  505  includes encompassing at least a portion of one or more faces of the free-standing exhaust plenum structure  500 , so that an internal space  510  of the free-standing exhaust plenum structure  500  is encompassed to establish an the internal exhaust air plenum that can receive and direct exhaust air through the plenum and out of an exhaust vent  514 , which, as illustrated, may include a top portion of the free-standing exhaust plenum structure  500  that is substantially unencompassed by wall elements  508 ,  509 , a vent structure located on the top portion of the free-standing exhaust plenum structure, etc. 
     In some embodiments, wall elements  508 ,  509  are coupled to one or more frame members  502 ,  504 ,  505  on a portion of one or more faces of the free-standing exhaust plenum structure  500 . For example, as illustrated, wall elements  508 ,  509  may cover a limited portion of a face of the free-standing exhaust plenum structure  500 , so that a gap  512  remains through which exhaust air may be received from one or more waste heat sources into the interior exhaust air plenum  510  of the free-standing exhaust plenum structure  500 . Another gap may be present in a wall element coupled to an upper portion of a face of a free-standing exhaust plenum structure, so that at least some of the exhaust air circulating through the internal exhaust air plenum of the free-standing exhaust plenum structure can be redirected to another external plenum via one or more vents  516  mounted in the gap. 
     In some embodiments, one or more wall panel elements  590  are coupled to one or more portions of the free-standing exhaust plenum structure  500  to enclose at least a portion of the gap  512 . The panel element  590  can partition space  501  from internal plenum  510 , and can generally inhibit unwanted airflow between the spaces in the absence of waste heat sources mounted proximate to the gap. For example, when a rack is mounted to abut a portion of the gap  512 , the interface between the rack and the structure  500  can be sealed via various sealing element so that air does not flow from the plenum  510  to space  501 , or from space  501  to plenum  510 , without passing through the interior of the rack. General inhibition of airflow can by a removable panel can include a panel enclosing a portion of the gap  512  within manufacturing tolerances of construction of one or more of the panel  590 , wall element  508 , frame  503 , etc., where air leakage across the enclosed portion may occur, although airflow is sufficiently inhibited to enable a pressure difference between space  501  and plenum  510  to be maintained. Where a waste heat source is not mounted in space  501  abutting a portion of the gap, a wall panel element  590  can be coupled to the frame structure  503  to enclose that particular portion of the gap  512 , thereby precluding airflow between space  501  and plenum  510  that does not flow through a waste heat source from space  501  into plenum  510 . The wall panel elements  509  can be removably coupled to the structure  503  so that the plenum  510  can be partitioned from space  501  in the absence of waste heat sources to abut the gap, and a gap  512  can be established in a face of the structure  500  when a waste heat source is to be installed in space  501 , so that the waste heat source can be abut the established gap  512  and discharge exhaust air into the plenum  510  via the established gap  512 . 
     In some embodiments, multiple types of wall elements may be coupled to one or more faces of the free-standing exhaust plenum structure. For example, one or more wall elements  509  that include an insulating material may be coupled to an upper portion of a face of a free-standing exhaust plenum structure that faces a cooling air plenum, so that the wall elements mitigate heat transfer from exhaust air circulating through the internal exhaust air plenum  510  to one or more air plenums external to the free-standing exhaust plenum structure  500 , and one or more wall elements  508  that are substantially free from insulating materials may be coupled to a lower portion of the same face of the free-standing exhaust plenum structure that faces a bounded enclosure. 
     In some embodiments, wall elements are coupled on various sides of frame members in the free-standing frame  503 . For example, in the illustrated embodiment, wall elements  508 ,  509  are coupled to outer sides of the free-standing frame  503 , so that at least the vertical members  502  are between the wall elements  508 ,  509  and the internal plenum  510 . In some embodiments, one or more wall elements, including cladding elements, insulating elements, etc. are coupled to inner sides of the free-standing frame  503 , so that the wall elements are positioned between at least some of the frame members  502  and the internal plenum  510 . Separate wall elements may be coupled on inner sides and outer sides of the free-standing frame  503 , so that some wall elements coupled to an outer side of the frame, referred to as “outer wall elements”, and some wall elements coupled to an inner side of the frame, referred to as “inner wall elements”, establish a gap between the two elements. 
     In some embodiments, a free-standing support structure  500  includes one or more support arm structures  518 , also referred to hereinafter as support “arms”, that are coupled to one or more portions of the structure  500 , including one or more frame members  502 ,  504 ,  505 . Each arm  518  may be coupled to one or more of the frame members so that at least a portion of the arm extends outward from a face of the free-standing exhaust plenum structure  500 . For example, in the illustrated embodiment, arms  518  are coupled to post member  502  that each define a portion of a face of the free-standing exhaust plenum structure  500  facing a particular space  501 , the arms  518  may extend away from the post members  502  and the enclosure  510  of the free standing structure  500  in a direction that is substantially perpendicular to at least one face of the free-standing exhaust plenum structure and extends into the space  501 . Each arm  518  can, in some embodiments, support a structural load and transmit at least a portion of the load to at least a portion of the free-standing exhaust plenum structure  500 , so that at least a portion of the free-standing exhaust plenum structure  500  supports the structural load supported by the arm  518 . 
     In some embodiments, including the illustrated embodiment, one or more arms can support one or more trays, which themselves can support one or more infrastructure elements. Various infrastructure elements that can be installed can include power distribution infrastructure, including power busses, power transmission lines, power distribution units, etc. Various infrastructure elements that can be installed can include lighting components, communication components including networking cables, etc. The infrastructure may be installed via mounting on one or more support elements mounted in the bounded enclosure. The support elements may include trays, busways, etc. which may be coupled to one or more free-standing exhaust plenum structures, plenum modules, etc. to route the various infrastructure elements through the bounded enclosure. The support elements may support one or more elements of power and communication infrastructure, including cabling, transmission lines, etc. which are routed to various computer systems installed in various racks that are installed in the bounded enclosure. 
     In some embodiments, one or more support arm structures  518  include one or more sealing elements on one or more surfaces of the arms, including one or more upper surfaces. The sealing elements, which can include one or more foam sealing elements, gasket elements, etc., can seal one or more interfaces between the arm  518  and one or more elements mounted upon the surface of the arm that includes the seal. For example, where an arm  518  includes a sealing element on an upper surface of the arm,  518 , and a plenum module is mounted on the arm  518  so that a lower surface of the plenum module rests upon an upper surface of the arm  518 , the foam seal can seal the interface between the plenum module and the upper surface of the arm  518  to at least partially mitigate, restrict, preclude, etc. airflow, air leakage, and the like through the interface. In some embodiments, a sealing element comprises an L-channel element on one or more ends of a support arm structure extending away from a face of a free-standing exhaust plenum structure, where the L-channel element can receive a portion of a bottom surface and a side surface of a plenum module to seal an interface between the arm  518  and the plenum module. 
     In some embodiments, the free-standing exhaust plenum structure  500  is configured to be mounted in an interior enclosure space. The interior enclosure space may include an encompassed interior space, including a warehouse structure, which includes a floor  520 , ceiling exhaust plenum, air handling system, etc. A free-standing exhaust plenum structure  500  may be coupled to the floor element  520  to establish at least one side of a bounded enclosure within the interior enclosure, including a cold aisle space, which extends substantially parallel to at least one axis of the cold aisle space. 
     In some embodiments, one or more free-standing exhaust plenum structures  500  are shipped to a data center site prior to coupling with other elements, including one or more plenum modules, to establish a data center row infrastructure module at the site. Each free-standing exhaust plenum structure  500  or portion thereof may be transported separately, such as on a semi-trailer. In certain embodiments, however, all or some portions of the free-standing exhaust plenum structure  500  may be assembled at the data center site. For example, free-standing exhaust plenum structures  500  and a plenum module may be coupled together at a site to establish a row infrastructure module, and racks may be installed in the row infrastructure module. 
     In some embodiments, coupling a structure  500  to the floor  520  can include placing the structure  500  on the floor  520  so that the structure  500  rests upon an upper surface of the floor, securing the structure to the floor via one or more coupling elements, bolts, welds, etc., some combination thereof, or the like. 
     In some embodiments, one or more of the components comprised in the free-standing exhaust plenum structure  500  includes components that can be utilized for shelving systems. For example, the frame  503  of free-standing exhaust plenum structure  500  can comprise a free-standing pallet shelving rack. A free-standing pallet shelving rack, as utilized for storing and stacking pallets, may include multiple lateral bracing members  504  and angular bracing members  505  through the interior of the structure to provide shelves to support the pallets. The free-standing exhaust plenum structure  500 , in some embodiments, includes a free-standing pallet shelving rack where multiple lateral bracing members are removed to open up the interior  510  of the structure  500  to comprise the internal exhaust air plenum  510 , and one or more wall elements  508 ,  509  are coupled to one or more faces of the structure  500  to at least partially encompass the internal exhaust air plenum  510 , etc. 
     In another example, one or more support arm structures  518  of a free-standing exhaust plenum structure  500  may comprise support arms of a drive-through pallet shelving system. A drive-through pallet shelving system, as utilized for storing and stacking pallets, may include multiple particularly-spaced vertical posts, which may not comprise free-standing exhaust plenum structures, that are bolted to a floor element and each include one or more support arm structures that extend into a space between the posts, where a pallet can be moved into the spaces and lifted to rest upon multiple support arm structures extending from multiple posts into a common space. In a drive-through pallet shelving system, the pallets may be moved and lifted by a forklift vehicle. The free-standing exhaust plenum structure  500 , in some embodiments, includes one or more support arm structures  518  of a drive-through pallet shelving system that are coupled to one or more frame members  502 ,  504 ,  505  of the free-standing exhaust plenum structure  500 . In some embodiments, at least a portion of a free-standing exhaust plenum structure  500  can be assembled via coupling of selected elements of the separate shelving systems, including the frame members and support arm structures. 
       FIG. 6  is a perspective view of a plenum module according to some embodiments. 
     In some embodiments, a plenum module is configured to be mounted between at least two free-standing exhaust plenum structures on opposite sides of a bounded enclosure, so that the plenum module spans substantially between the two structures and establishes a top end of the bounded enclosure. Where the two structures are located on opposite ends of a cold aisle space, the plenum module can be configured to be mounted between the two structures to establish a top end of the cold aisle space via a lower surface of the plenum module. The plenum module may be configured to establish a bottom end of another enclosure, including a cooling air plenum, via another surface of the plenum module, which may include an upper surface of the plenum module. The plenum module, spanning between two free-standing exhaust plenum structures on opposite sides of a bounded enclosure, may be configured to be mounted on one or more separate support arms of each of the structures, so that a portion of the load of the plenum module is supported by one of the structures and another portion of the load is supported by another one of the structures. 
     In some embodiments, a plenum module comprises a panel element that, when mounted to span between two free-standing exhaust plenum structures, separates a cooling air plenum and a bounded enclosure. In the illustrated embodiment, for example, plenum module  600  includes a panel element  602  that, when the plenum module  600  is mounted on respective support arm structures of separate free-standing exhaust plenum structures, establish a ceiling of a bounded enclosure and establish a floor of a cooling air plenum. The plenum module  600  can include one or more air vents  604  that are configured to direct air, which can include cooling air from a cooling air plenum, through the panel  602  to a bounded enclosure to provide intake air to the bounded enclosure, so that intake air is provided to computer systems in racks in the enclosure space to remove waste heat from the computer systems. The vents  604  may include one or more dampers  606  which can be adjusted to control flow rates of intake air into the bounded enclosure. 
     In some embodiments, a plenum module includes one or more support trays, which themselves can support one or more infrastructure elements. Trays may be coupled to the plenum module, suspended from the plenum module, etc. For example, in the illustrated embodiment, plenum module  600  includes a support tray  610 , comprised of a structural element  612 , which is suspended from the panel  602  of the plenum module  600  via one or more support cabling  614  coupling the element  612  to a load bearing structure  616  of the plenum module  600 . Such an embodiment of a support tray  610  can be configured to hang from the plenum module in a bounded enclosure that is bounded on a top end by the lower surface of panel  602 . Various infrastructure elements that can be supported by the support tray  610  can include power distribution infrastructure, including power busses, power transmission lines, power distribution units, lighting components, communication components including networking cables, etc. One or more elements of the infrastructure elements, including power busses, transmission lines communication components, etc. can be routed to various computer systems installed in various racks that are installed in the bounded enclosure. 
       FIG. 7  is a perspective view of a plenum module according to some embodiments. 
     In some embodiments, a plenum module includes one or more structural elements that establish a mixing plenum that mixes cooling air received from a cooling air plenum and at least some exhaust air received from an internal exhaust air plenum of at least one free-standing exhaust plenum structure to produce a mixed air. The mixed air can be directed into the bounded enclosure, via an air vent. For example, in the illustrated embodiment, plenum module  700  includes a panel element  702  and side walls  706 ,  708  that at least partially enclose an interior space. The interior space, referred to hereinafter as a “mixing plenum”  704 , is configured to mix cooling air received from a cooling air plenum via the unencompassed top end of the plenum, and at least some recirculated exhaust air to provide mixed air that can be supplied to a bounded enclosure through the panel  702  via a vent structure  703  in the panel  702 . The vent structure  703  can include one or more air moving devices  720  that induce airflow from the mixing plenum  704  to the bounded enclosure. In some embodiments, a plenum module includes multiple air moving devices  720 . 
     In some embodiments, the exhaust air may be directed into the mixing plenum  704  via one or more vents  710  mounted in one or more side walls  708  of the plenum module  700 . The vents  710  can communicatively couple the internal exhaust air plenum of at least one free-standing exhaust plenum structure with the mixing plenum  700  when the plenum module  700  is mounted at least partially on a support arm structure of the free-standing exhaust plenum structure, where exhaust air can be directed through a gap in a face of the free-standing exhaust plenum structure that faces the bounded enclosure, through the vents  710 , and into the mixing plenum  704  to be mixed with cooling air. The vents  710  may include one or more adjustable dampers  712  that can be adjusted to control the flow of exhaust air into the mixing plenum  704 . 
     In some embodiments, the vents  710  are mounted in a face of a free-standing exhaust plenum structure adjacent to the plenum module  700 , a sidewall  708  of the mixing plenum  704  that is adjacent to a gap in the face of the free-standing exhaust plenum structure, etc. 
     The air directed into the mixing plenum  704  from the cooling air plenum, which can include cooling air, may be mixed with the exhaust air directed into the mixing plenum  704  to provide mixed air. The adjustable dampers  712  of the vents  710  to the mixing plenum from the free-standing exhaust plenum structure may be adjusted to control the flow of exhaust air into the mixing plenum to maintain one or more particular characteristics of the mixed air, including one or more of temperature, relative humidity, wet-bulb temperature, etc. 
     Mixed air can be directed into one or more bounded enclosures of one or more row infrastructure modules from at least the mixing plenum  704  of the plenum module  700 . Where a bounded enclosure includes an enclosure, including a cold aisle space that is bounded on a bottom end by a floor element, on side ends by free-standing exhaust plenum structures, and a top end by the plenum module  700 , and includes one or more racks that can accommodate one or more computer systems, mixed air can be directed into the bounded enclosure via one or more vent structures  703  in at least a lower surface of the plenum module  700 , where the upper surface of the plenum module may bound a lower end of the mixing plenum, and enables air to flow from the mixing plenum  704  into the bounded enclosure. Air directed into the bounded enclosure from at least the mixing plenum may be referred to as “intake air” with respect to the bounded enclosure. In some embodiments, where the vent  703  of the plenum module includes one or more air moving devices  720 , air is supplied into the bounded enclosure based at least in part upon operation of the one or more air moving devices  720 . The vent structure  703  may include one or more dampers that may be adjustably controlled to manage the flow rate of intake air into the bounded enclosure. 
     In some embodiments, a plenum module includes one or more support trays, which themselves can support one or more infrastructure elements. Trays may be coupled to the plenum module, suspended from the plenum module, etc. For example, in the illustrated embodiment, plenum module  700  includes a support tray  730 , comprised of a structural element  732 , which is suspended from the panel  702  of the plenum module  700  via one or more support cabling  734  coupling the element  732  to a load bearing structure  736  of the plenum module  700 . Such an embodiment of a support tray  730  can be configured to hang from the plenum module in a bounded enclosure that is bounded on a top end by the lower surface of panel  702 . Various infrastructure elements that can be supported by the support tray  730  can include power distribution infrastructure, including power busses, power transmission lines, power distribution units, lighting components, communication components including networking cables, etc. One or more elements of the infrastructure elements, including power busses, transmission lines communication components, etc. can be routed to various computer systems installed in various racks that are installed in the bounded enclosure. 
       FIG. 8  illustrates providing a data center row infrastructure module in a data center according to some embodiments. 
     At  800 , one or more support structures, also referred to hereinafter as support “arms”, are coupled to a free-standing frame. The free standing frame can include one or more frame members that collectively encompass an interior space and define an outline of a free-standing exhaust plenum structure. Where the frame includes multiple frame members, the members may be coupled together via one or more known coupling methods, including bolting, welding, riveting, etc. One or more frame members may include post members that extend vertically through the structure and can transmit at least some of the structural load of the structure to a floor element. One or more frame members may include bracing members that provide at least some lateral structural support to the structure. Each arm may be coupled to one or more of the frame members so that at least a portion of the arm extends outward from a face of the free-standing exhaust plenum structure. For example, where an arm is welded to a post member that defines a corner of the free-standing exhaust plenum structure, the arm may extend away from the post member and the enclosure of the free standing structure in a direction that is substantially perpendicular to at least one face of the free-standing exhaust plenum structure. Each arm can, in some embodiments, support a structural load and transmit at least a portion of the load to at least a portion of the free-standing exhaust plenum structure, so that at least a portion of the free-standing exhaust plenum structure supports the structural load supported by the arm. 
     At  802 , one or more wall elements are coupled to one or more frame members of the free-standing frame. In some embodiments, one or more of the wall elements include cladding which can restrict airflow between opposite faces of the cladding. In some embodiments, one or more of the wall elements includes an insulating material that mitigates heat transfer between separate environments in communication with separate faces of the one or more wall elements. In some embodiments, coupling one or more wall elements to frame members includes encompassing at least a portion of one or more faces of the free-standing exhaust plenum structure, so that an internal space of the free-standing exhaust plenum structure is encompassed to establish an air plenum. The air plenum in the interior of the free-standing exhaust plenum structure, as noted in the previous figures, can include an exhaust air plenum that can receive and direct exhaust air through the plenum and out of an exhaust port, which may include a top portion of the free-standing exhaust plenum structure that is substantially unencompassed by wall elements, a vent structure located on the top portion of the free-standing exhaust plenum structure, etc. 
     In some embodiments, wall elements are coupled to one or more frame members on a portion of one or more faces of the free-standing exhaust plenum structure. For example, as illustrated in at least  FIG. 2B  and  FIGS. 5-6 , wall elements may cover a limited portion of a face of the free-standing exhaust plenum structure, so that a gap remains through which exhaust air may be received from one or more waste heat sources into the interior exhaust air plenum of the free-standing exhaust plenum structure. In some embodiments, one or more wall panel elements are coupled to a limited portion of a face of the free-standing exhaust plenum structure to enclose the gap and generally inhibit airflow between the interior exhaust air plenum and an external environment through the enclosed gap in the face of the free-standing exhaust plenum structure. Another gap may be present in a wall element coupled to an upper portion of a face of a free-standing exhaust plenum structure, so that at least some of the exhaust air circulating through the internal exhaust air plenum of the free-standing exhaust plenum structure can be redirected to another external plenum via one or more vents mounted in the gap. In some embodiments, multiple types of wall elements may be coupled to one or more faces of the free-standing exhaust plenum structure. For example, one or more wall elements that include an insulating material may be coupled to an upper portion of a face of a free-standing exhaust plenum structure, so that the wall elements mitigate heat transfer from exhaust air circulating through the internal exhaust air plenum to one or more air plenums external to the free-standing exhaust plenum structure, and one or more wall elements that are substantially free from insulating materials may be coupled to a lower portion of the same face of the free-standing exhaust plenum structure. 
     At  804 , one or more free-standing exhaust plenum structures are mounted in an interior enclosure. The interior enclosure may include an encompassed interior space, including a warehouse structure, which includes a floor, ceiling exhaust plenum, air handling system, etc. A free-standing exhaust plenum structure may be coupled to the floor element to establish at least one side of a bounded enclosure within the interior enclosure, including a cold aisle space, which extends substantially parallel to at least one axis of the cold aisle space. The axis can include a long axis of the space, a short axis of the space, etc. In some embodiments, two free-standing exhaust plenum structures are coupled to the floor on opposite sides of the cold aisle space. The sides of the cold aisle space may be predetermined, determined based at least in part upon the coupling of one or more free-standing exhaust plenum structures in one or more particular locations on the floor, etc. For example, two free-standing exhaust plenum structures may be coupled to the floor at two particular locations, where the two free-standing exhaust plenum structures extend substantially in parallel and “face” each other across a space between the two structures, so that the space between the two structures is established as the cold aisle space and an axis of the cold aisle space is established as extending substantially in parallel with each of the two structures. In some embodiments, two free-standing exhaust plenum structures are mounted on opposite sides of a bounded enclosure, substantially in parallel, so that support arms of each of the structures extend into the bounded enclosure and towards the opposite respective free-standing exhaust plenum structure. 
     One or more modular elements, including one or more free-standing exhaust plenum structures, plenum modules, etc. can be shipped to a data center site. Each modular element or portion thereof may be transported separately, such as on a semi-trailer. In some embodiments, modular elements, or portions thereof, are pre-fabricated at one location, such as a factory, and transported to a data center site at another location. In certain embodiments, however, all or some portions of the modular elements for a data center row infrastructure module may be assembled at the data center site. For example, free-standing exhaust plenum structures and a plenum module may be coupled together at a site to establish a row infrastructure module, racks may be installed in the row infrastructure module. In some embodiments, the modular elements are pre-certified prior to shipment of the modular elements to the site. 
     In some embodiments, coupling a structure to the floor can include placing the structure on the floor so that the structure rests upon an upper surface of the floor, securing the structure to the floor via one or more coupling elements, bolts, welds, etc., some combination thereof, or the like. 
     At  806 , a plenum module is mounted between at least two free-standing exhaust plenum structures on opposite sides of a bounded enclosure, so that the plenum module spans substantially between the two structures and establishes a top end of the bounded enclosure. Where the two structures are located on opposite ends of a cold aisle space, the plenum module is mounted between the two structures to establish a top end of the cold aisle space via a lower surface of the plenum module. The plenum module may establish a bottom end of another enclosure, including a cooling air plenum, via another surface of the plenum module, which may include an upper surface of the plenum module. The plenum module, spanning between two free-standing exhaust plenum structures on opposite sides of a bounded enclosure, may be mounted on one or more separate support arms of each of the structures, so that a portion of the load of the plenum module is supported by one of the structures and another portion of the load is supported by another one of the structures. 
     In some embodiments, the plenum module includes one or more air vents through which intake air can be directed from at least the cooling air plenum to the bounded enclosure bounded on a top end by the plenum module. The vent may include one or more dampers which can be adjusted to control flow rates of intake air into the bounded enclosure, one or more air moving devices that operate to draw the intake air into the bounded enclosure, etc. 
     In some embodiments, the plenum module includes one or more structural elements that establish a mixing plenum that mixes cooling air received from the cooling air plenum and at least some exhaust air received from an internal exhaust air plenum of at least one free-standing exhaust plenum structure to produce a mixed air. The mixed air can be directed into the bounded enclosure, via the air vent. 
     At  808 , a plenum duct is mounted between at least two free-standing exhaust plenum structures on opposite sides of the bounded enclosure, so that the plenum duct spans substantially between the two structures and establishes a top end of a cooling air plenum that extends above at least one surface of the plenum module. In some embodiments, including embodiments where the plenum module includes an enclosure bounded on a bottom end by a lower surface and on a top end by an upper surface, a plenum duct may be omitted, as the upper surface of the plenum module may establish the top end of the cooling air plenum. 
     At  809 , one or more wall panel elements are removed from a portion of a free-standing exhaust plenum structure that faces the bounded enclosure bounded by the two free-standing exhaust plenum structures and lower surface of the plenum module. The wall panel elements can be removed to establish a “gap” in the enclosure-facing side of the free-standing exhaust plenum structure that enables flow communication with an internal exhaust air plenum of the free-standing exhaust plenum structure. The gap can be established to enable one or more waste heat sources in the bounded enclosure discharge exhaust air into the internal exhaust air plenum of the free-standing exhaust plenum structure via the gap. 
     At  810 , one or more racks are installed in the bounded enclosure bounded by the two free-standing exhaust plenum structures and lower surface of the plenum module. Where the bounded enclosure is a cold aisle space, two or more rows of racks may be installed in the space on opposite sides of the space. The two or more rows may extend substantially in parallel through the cold aisle space and may be installed adjacent to a portion of a respective one of the free-standing exhaust plenum structure. For example, where a portion of a free-standing exhaust plenum structure “facing” the cold aisle space includes a “gap”, which may be at least partially established via the removal of wall panel elements from the portion of the free-standing structure, that enables flow communication with an internal exhaust air plenum of the free-standing exhaust plenum structure, a rack may be placed in the cold aisle space so that a rear end of the rack abuts the gap, and so that exhaust air discharged from one or more heat producing devices installed in the rack is discharged into the internal exhaust air plenum of the free-standing exhaust plenum structure via the gap. One or more computer systems may be installed in the racks, so that the computers may receive intake air that is directed into the bounded enclosure from at least a cooling air plenum via the plenum module and discharge exhaust air that has removed at least some heat from one or more heat producing components of the computer systems into the internal exhaust air plenum of at least one free-standing exhaust plenum structure, where the internal exhaust air plenum directs at least a portion of the exhaust air out of the row infrastructure module via at least one exhaust air vent of the free-standing exhaust plenum structure. 
     At  812 , one or more elements of data center row infrastructure are installed in the bounded enclosure. Various infrastructure elements that can be installed can include power distribution infrastructure, including power busses, power transmission lines, power distribution units, etc. Various infrastructure elements that can be installed can include lighting components, communication components including networking cables, etc. The infrastructure may be installed via mounting on one or more support elements mounted in the bounded enclosure. The support elements may include trays, busways, etc. which may be coupled to one or more free-standing exhaust plenum structures, plenum modules, etc. to route the various infrastructure elements through the bounded enclosure. The support elements may support one or more elements of power and communication infrastructure, including cabling, transmission lines, etc. which are routed to various computer systems installed in various racks that are installed in the bounded enclosure. 
     At  814 , the cooling air plenum at least partially established by the plenum module is coupled to an external air supply. Coupling the cooling air plenum to an external air supply can include coupling one end of the cooling air plenum to an air handling system, which may include one or more air moving devices, air cooling systems, etc., where the cooling air plenum can receive chilled air from the air handling system as cooling air. In some embodiments, coupling the cooling air plenum to an external air supply can include coupling one end of the cooling air plenum to a vent to an ambient environment, where the cooling air plenum can receive ambient air from the ambient environment as cooling air. 
     At  816 , an airflow is induced through the bounded enclosure. Inducing airflow can include supplying intake air into the bounded enclosure, where the intake air can be received by one or more devices installed in the rack, remove heat from one or more heat producing components in the one or more devices, and then be discharged from the one or more devices as exhaust air into one or more internal exhaust air plenums of one or more free-standing exhaust plenum structures. The airflow can, in some embodiments, be induced by an external air handling system, which may include one or more air moving devices, which supplies cooling air to the cooling air plenum to be directed into the bounded enclosure via one or more vents of one or more plenum modules. The external air handling system may mix air that has been chilled via one or more various cooling systems with at least some exhaust air discharged from one or more exhaust vents of one or more free-standing exhaust plenum structures and directed to the external air handling system via at least an exhaust plenum of the interior enclosure that is external to the free-standing exhaust plenum structures to provide the cooling air. The airflow can, in some embodiments, be induced by one or more air moving devices included in one or more plenum modules, where the air moving devices draw air into the cooling air plenum from one or more external sources, which may include an ambient environment, and supply the drawn air into the bounded enclosure. 
       FIG. 9  illustrates managing air circulation in a computing enclosure via one or more components of a data center row infrastructure module according to some embodiments. 
     At  900 , air is received into at least a portion of a cooling air plenum of a data center row infrastructure module in an interior enclosure from an external air source. The external air source, in some embodiments, can include one or more air handling systems that provide cooling air that is at least partially comprised of ambient air that is chilled via operation of one or more various air cooling systems. In some embodiments, the air handling systems mix recirculated exhaust air with chilled ambient air to provide the cooling air. The cooling air may be received from the external air source via one or more conduits, which may include one or more air ducts, which may direct the cooling air between the air handling system and the cooling air plenum. As a result, the air received into the cooling air plenum, in some embodiments, comprises mixed air that is a mixture of chilled air and recirculated exhaust air. The relative proportions of chilled air and exhaust air in mixed air may be controlled, via operation of one or more dampers, air moving devices, etc., based on one or more environmental conditions in one or more bounded enclosures of one or more row infrastructure modules. The relative proportions may be controlled to maintain the one or more environmental conditions within one or more ranges of predetermined values, including ranges of temperature, relative humidity, wet bulb temperature, etc. 
     At  902 , air received into at least a portion of a cooling air plenum of a row infrastructure module is directed through a portion of the cooling air plenum. The air, which may include cooling air, may be directed through the cooling air plenum based at least in part upon one or more gradients in the portion of the cooling air plenum, which may include a pressure gradient, temperature gradient, etc. For example, where air is received into the cooling air plenum from an external air source that includes an air moving device, the air moving device may increase the air pressure upstream of the cooling air plenum relative to various vents through which air can exit the cooling air plenum, including one or more vents that communicatively couple the cooling air plenum and a bounded enclosure of the row infrastructure module, so that air is “pushed” into and through one or more portions of the cooling air plenum toward the various vents. In another example, where air is received into the cooling air plenum from an external air source that includes an ambient environment, one or more air moving devices in flow communication with the cooling air plenum may operate to reduce the air pressure at a point downstream of the cooling air plenum, including at one or more vents that communicatively couple the cooling air plenum and a bounded enclosure of the row infrastructure module, so that air is “pulled” into and through one or more portions of the cooling air plenum toward the various vents. Various portions components that establish one or more boundaries of the cooling air plenum, including portions of one or more plenum ducts, plenum modules, free-standing exhaust plenum structures, etc., may direct air through one or more portions of the cooling air plenum toward one or more vents to a bounded enclosure. 
     At  904 , air is directed into one or more bounded enclosures of one or more row infrastructure modules from at least a cooling air plenum of the respective row infrastructure module. Where a bounded enclosure includes an enclosure, including a cold aisle space that is bounded on a bottom end by a floor element, on side ends by free-standing exhaust plenum structures, and a top end by a plenum module, and includes one or more racks that can accommodate one or more computer systems, air can be directed into the bounded enclosure via one or more vents in at least a lower surface of the plenum module that enables air to flow from the cooling air plenum into the bounded enclosure. Air directed into the bounded enclosure from at least the cooling air plenum may be referred to as “intake air” with respect to the bounded enclosure. In some embodiments, where the vent of the plenum module includes one or more air moving devices, air is supplied into the bounded enclosure based at least in part upon operation of the one or more air moving devices. The vent may include one or more dampers that may be adjustably controlled to manage the flow rate of intake air into the bounded enclosure. 
     At  906 , exhaust air is received into one or more free-standing exhaust plenum structures of one or more row infrastructure modules from one or more bounded enclosures. The exhaust air may be received into one or more internal exhaust air plenums included in an interior of the one or more free-standing exhaust plenum structures. The exhaust air may be received from one or more heat producing components of one or more devices installed in one or more racks that are installed in the bounded enclosure. The exhaust air may be precluded from returning to the bounded enclosure via one or more wall elements bounding one or more faces of the free-standing exhaust plenum structure, one or more seal elements that seal interfaces between the wall elements and racks installed in the bounded enclosure abutting gaps in the free-standing exhaust plenum structure faces, etc. 
     At  908 , exhaust air in one or more internal exhaust air plenums of one or more free-standing exhaust plenum structures in one or more row infrastructure modules is directed to an external location, including one or more exhaust plenums that are external to the row infrastructure module. Exhaust air can be directed to an external location via one or more exhaust vents in the free-standing exhaust plenum structures that enable flow communication between one or more internal exhaust air plenums of the free-standing exhaust plenum structures and an external environment. The external environment can include one or more portions of an interior enclosure in which the row infrastructure module is located, including an exhaust plenum in an upper portion of the interior enclosure. In some embodiments, exhaust air is directed to an external environment, which may include an interior enclosure exhaust plenum, based at least in part upon a chimney effect whereby the exhaust air rises through the internal exhaust plenum and out of one or more exhaust vents located on a top side of the free-standing exhaust plenum structure to rise out of the free-standing exhaust plenum structure and into the external environment. In some embodiments, exhaust air may be directed to the external environment based at least in part upon a pressure gradient between the internal exhaust air plenum and the external environment, which may be induced based at least in part upon one or more air moving devices that may be located in one or more of the external environment, exhaust vents, internal exhaust air plenum, some combination thereof, or the like. 
       FIG. 10  illustrates managing air circulation in a computing enclosure via one or more components of a data center row infrastructure module according to some embodiments. 
     At  1000 , air is received into at least a portion of a cooling air plenum of a row infrastructure module in an interior enclosure from an external air source. The cooling air may be received from the external air source via one or more conduits, which may include one or more air ducts, which may direct the cooling air between the air handling system and the cooling air plenum. In some embodiments, the external air source includes an ambient environment, and the air received into the portion of the cooling air plenum as cooling air includes ambient air received from the ambient environment. 
     At  1002 , air received into at least a portion of a cooling air plenum of a row infrastructure module is directed through a portion of the cooling air plenum. The air, which may include cooling air, may be directed through the cooling air plenum based at least in part upon one or more gradients in the portion of the cooling air plenum, which may include a pressure gradient, temperature gradient, etc. For example, where air is received into the cooling air plenum from an external air source that includes an air moving device, the air moving device may increase the air pressure upstream of the cooling air plenum relative to various vents through which air can exit the cooling air plenum, including one or more vents that communicatively couple the cooling air plenum and a bounded enclosure of the row infrastructure module, so that air is “pushed” into and through one or more portions of the cooling air plenum toward the various vents. In another example, where air is received into the cooling air plenum from an external air source that includes an ambient environment, one or more air moving devices in flow communication with the cooling air plenum may operate to reduce the air pressure at a point downstream of the cooling air plenum, including at one or more vents that communicatively couple the cooling air plenum and a bounded enclosure of the row infrastructure module, so that air is “pulled” into and through one or more portions of the cooling air plenum toward the various vents. Various portions components that establish one or more boundaries of the cooling air plenum, including portions of one or more plenum ducts, plenum modules, free-standing exhaust plenum structures, etc., may direct air through one or more portions of the cooling air plenum toward one or more vents to a bounded enclosure. 
     At  1004 , air that is directed through one or more portions of the cooling air plenum is directed to a mixing plenum and mixed with at least a portion of exhaust air that is directed into the mixing plenum from an internal exhaust air plenum of at least one free-standing exhaust plenum structure. The exhaust air may be directed into the mixing plenum via one or more vents that communicatively couple the internal exhaust air plenum with the mixing plenum. The vents may include one or more adjustable dampers that can be adjusted to control the flow of exhaust air into the mixing plenum, and the vents may be mounted in a face of the free-standing exhaust plenum structure, a face of the mixing plenum that is adjacent to a gap in the face of the free-standing exhaust plenum structure, etc. The air directed into the mixing plenum from the cooling air plenum, which can include cooling air, may be mixed with the exhaust air directed into the mixing plenum to provide mixed air. The adjustable dampers of the vents to the mixing plenum from the free-standing exhaust plenum structure may be adjusted to control the flow of exhaust air into the mixing plenum to maintain one or more particular characteristics of the mixed air, including one or more of temperature, relative humidity, wet-bulb temperature, etc. 
     At  1006 , mixed air is directed into one or more bounded enclosures of one or more row infrastructure modules from at least the mixing plenum of the respective row infrastructure module. Where a bounded enclosure includes an enclosure, including a cold aisle space that is bounded on a bottom end by a floor element, on side ends by free-standing exhaust plenum structures, and a top end by a plenum module, and includes one or more racks that can accommodate one or more computer systems, mixed air can be directed into the bounded enclosure via one or more vents in at least a lower surface of the plenum module, where the lower surface of the plenum module may bound a lower end of the mixing plenum, and enables air to flow from the mixing plenum into the bounded enclosure. Air directed into the bounded enclosure from at least the mixing plenum may be referred to as “intake air” with respect to the bounded enclosure. In some embodiments, where the vent of the plenum module includes one or more air moving devices, air is supplied into the bounded enclosure based at least in part upon operation of the one or more air moving devices. The vent may include one or more dampers that may be adjustably controlled to manage the flow rate of intake air into the bounded enclosure. 
     At  1008 , exhaust air is received into one or more free-standing exhaust plenum structures of one or more row infrastructure modules from one or more bounded enclosures. The exhaust air may be received into one or more internal exhaust air plenums included in an interior of the one or more free-standing exhaust plenum structures. The exhaust air may be received from one or more heat producing components of one or more devices installed in one or more racks that are installed in the bounded enclosure. The exhaust air may be precluded from returning to the bounded enclosure via one or more wall elements bounding one or more faces of the free-standing exhaust plenum structure, one or more seal elements that seal interfaces between the wall elements and racks installed in the bounded enclosure abutting gaps in the free-standing exhaust plenum structure faces, etc. 
     At  1010 , exhaust air in one or more internal exhaust air plenums of one or more free-standing exhaust plenum structures in one or more row infrastructure modules is directed to an external location, including one or more exhaust plenums that are external to the row infrastructure module. Exhaust air can be directed to an external location via one or more exhaust vents in the free-standing exhaust plenum structures that enable flow communication between one or more internal exhaust air plenums of the free-standing exhaust plenum structures and an external environment. The external environment can include one or more portions of an interior enclosure in which the row infrastructure module is located, including an exhaust plenum in an upper portion of the interior enclosure. In some embodiments, exhaust air is directed to an external environment, which may include an interior enclosure exhaust plenum, based at least in part upon a chimney effect whereby the exhaust air rises through the internal exhaust plenum and out of one or more exhaust vents located on a top side of the free-standing exhaust plenum structure to rise out of the free-standing exhaust plenum structure and into the external environment. In some embodiments, exhaust air may be directed to the external environment based at least in part upon a pressure gradient between the internal exhaust air plenum and the external environment, which may be induced based at least in part upon one or more air moving devices that may be located in one or more of the external environment, exhaust vents, internal exhaust air plenum, some combination thereof, or the like. 
     The various methods as illustrated in the Figures and described herein represent example embodiments of methods. The methods may be implemented in software, hardware, or a combination thereof. The order of method may be changed, and various elements may be added, reordered, combined, omitted, modified, etc. 
     Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.