Patent Publication Number: US-2023141044-A1

Title: Server holder with flow restraining device

Description:
TECHNICAL FIELD 
     The application relates generally to air distribution and, more particularly, to air distribution in large conditioned air plenum environments such as data centers. 
     BACKGROUND 
     In data centers, it is generally desirable to maximize the number of servers per unit area of floor space. It is also necessary to cool the servers to prevent them from overheating. 
     SUMMARY 
     In one aspect, there is provided a data center, comprising: a room; at least one fan operable to convey air through the room; server holders in the room, at least one of the server holders including: a holder defining a holder volume and having server supports spaced apart in the holder volume, the holder defining a holder opening to permit fluid communication between the holder volume and the air in the room; a plurality of servers supported by the server supports to be in fluid communication with the air in the room via the holder opening; and at least one baffle mounted to the holder adjacent to one or more servers of the plurality of servers, the at least one baffle extending outwardly from the holder into a volume of the room, the at least one baffle shaped and sized to locally restrain the air being conveyed through the volume of the room around the one or more servers. 
     In an embodiment according to any of the previous embodiments, the at least one baffle extends outwardly from the holder at an angle defined with respect to the holder, the angle being greater than 0 degrees and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is greater than 45 degrees and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is 60 degrees. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a length defined between a root of the at least one baffle adjacent to the holder and a tip of the at least one baffle, the length being less than 10 inches. 
     In an embodiment according to any of the previous embodiments, the length is less than 5 inches. 
     In an embodiment according to any of the previous embodiments, the length is between 2.5 inches and 3.5 inches. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a horizontal orientation. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a vertical orientation. 
     In an embodiment according to any of the previous embodiments, wherein the at least one baffle includes a plurality of baffles. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a horizontal orientation, and the at least one baffle is adjacent to a number of servers less than all of the servers. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a vertical orientation, and the at least one baffle is adjacent to all of the servers. 
     In an embodiment according to any of the previous embodiments, the room includes a floor defining an underfloor and includes at least one floor panel positioned on the floor in front of the holder of the at least one of the server holders, the at least one fan operable to convey the air through the underfloor and into the room via the at least one floor panel: the holder being upright and the servers supported by the server supports being vertically spaced apart, the servers including one or more lower servers positioned closer to the at least one floor panel than a remainder of the servers; and the at least one baffle having a horizontal orientation and mounted to the holder adjacent to one or more of the one or more lower servers. 
     In an embodiment according to any of the previous embodiments, the at least one baffle includes a plurality of baffles, the plurality of baffles including a first baffle mounted to the holder in front of a first server of the one or more of lower servers, and a second baffle mounted to the holder in front of a second server of the one or more of lower servers, the first baffle being above the second baffle. 
     In an embodiment according to any of the previous embodiments, the at least one fan is operable to convey the air through the room from a wall of the room, the server holders arranged in a row of server holders, one or more leading server holders of the row of server holders positioned closer to the wall than a remainder of the server holders of the row of server holders, one or more of the one or more leading server holders including: the holder being upright and the servers supported by the server supports being vertically spaced apart; and the at least one baffle having a vertical orientation and extending across a majority of the vertically-spaced apart server supports. 
     In an embodiment according to any of the previous embodiments, the at least one baffle includes two or more baffles horizontally spaced apart from each other. 
     In another aspect, there is provided a server holder, comprising: a holder defining a holder volume and having server supports spaced apart in the holder volume to support servers, the holder defining a holder opening to permit fluid communication between the server supports in the holder volume and air flowing outside the holder; and at least one baffle mounted to the holder adjacent to one or more of the server supports, the at least one baffle extending outwardly from the holder, the at least one baffle shaped and sized to locally restrain the air flowing outside the holder around the one or more server supports. 
     In an embodiment according to any of the previous embodiments, the at least one baffle extends outwardly from the holder at an angle defined with respect to the holder, the angle being greater than 1 degree and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is greater than 45 degrees and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is 60 degrees. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a length defined between a root of the at least one baffle adjacent to the holder and a tip of the at least one baffle, the length being less than 10 inches. 
     In an embodiment according to any of the previous embodiments, the length is less than 5 inches. 
     In an embodiment according to any of the previous embodiments, the length is between 2.5 inches and 3.5 inches. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a horizontal orientation. 
     In an embodiment according to any of the previous embodiments, the at least one baffle has a vertical orientation. 
     In an embodiment according to any of the previous embodiments, the at least one baffle includes a plurality of baffles. 
     In an embodiment according to any of the previous embodiments, the holder is upright and the server supports are vertically spaced apart, the server supports including one or more lower server supports positioned closer to a bottom of the holder than a remainder of the server supports, the at least one baffle having a horizontal orientation and mounted to the holder adjacent to one or more of the one or more lower server supports. 
     In an embodiment according to any of the previous embodiments, the at least one baffle includes a plurality of baffles, the plurality of baffles including a first baffle mounted to the holder in front of a first server support of the one or more of lower server supports, and a second baffle mounted to the holder in front of a second server support of the one or more of lower server supports, the first baffle being above the second baffle. 
     In an embodiment according to any of the previous embodiments, the holder is upright and the server supports are vertically spaced apart, the at least one baffle having a vertical orientation and extending across a majority of the vertically-spaced apart server supports. 
     In an embodiment according to any of the previous embodiments, the at least one baffle includes two or more baffles horizontally spaced apart from each other. 
     In an embodiment according to any of the previous embodiments, the server holder is one of a server cabinet and a server rack. 
     In a further aspect, there is provided a server cabinet/rack baffle mountable to a server cabinet/rack to face one or more of server supports of the server cabinet/rack, and to extend outwardly from the server cabinet/rack, the baffle shaped and sized to locally restrain the air flowing outside the server cabinet/rack around the one or more server supports. 
     In an embodiment according to any of the previous embodiments, the baffle is mountable to extend outwardly from the server cabinet/rack at an angle defined with respect to the server cabinet/rack, the angle being greater than 1 degree and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is greater than 45 degrees and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, the angle is 60 degrees. 
     In an embodiment according to any of the previous embodiments, the baffle has a length defined between a root of the baffle and a tip of the baffle, the length being less than 10 inches. 
     In an embodiment according to any of the previous embodiments, the length is less than 5 inches. 
     In an embodiment according to any of the previous embodiments, the length is between 2.5 inches and 3.5 inches. 
     In an embodiment according to any of the previous embodiments, the baffle is mountable to have a horizontal orientation. 
     In an embodiment according to any of the previous embodiments, the baffle is mountable to have a vertical orientation. 
     In a further aspect, there is provided a method of restraining a flow of air around part of a server cabinet/rack, the method comprising: mounting at least one baffle to an exterior of the server cabinet/rack adjacent to one or more server supports of the server cabinet/rack, such that the at least one baffle extends outwardly from the server cabinet/rack to restrain the flow of air outside the server cabinet/rack around the one or more server supports. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting the at least one baffle at an angle defined with respect to the exterior of the server cabinet/rack, the angle being greater than 0 degrees and less than 90 degrees. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting the at least one baffle to have a horizontal orientation. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting the at least one baffle to have a vertical orientation. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting a plurality of baffles. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting the at least one baffle to have a horizontal orientation, and mounting the at least one baffle adjacent to a number of server supports less than all of the server supports. 
     In an embodiment according to any of the previous embodiments, mounting the at least one baffle includes mounting the at least one baffle to have a vertical orientation, and mounting the at least one baffle adjacent to all of the server supports. 
     In a further aspect, there is provided a method of increasing a capacity of a server cabinet/rack, the method comprising: mounting at least one baffle to an exterior of the server cabinet/rack adjacent to one or more server supports of the server cabinet/rack, such that the at least one baffle extends outwardly from the server cabinet/rack to restrain the flow of air outside the server cabinet/rack around the one or more server supports. 
     In an embodiment according to any of the previous embodiments, the method further includes adjusting an ability of the at least one baffle to restrain the flow of air by adjusting an angle defined between the at least one baffle and the exterior of the server cabinet/rack, the angle being greater than 0 degrees and less than 90 degrees. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Reference is now made to the accompanying figures in which: 
         FIG.  1 A  is a perspective view of a room of a data center; 
         FIG.  1 B  is a front view of the room of  FIG.  1 A ; 
         FIG.  2 A  is an enlarged perspective view of the portion IIA-IIA in  FIG.  1 A ; 
         FIG.  2 B  is an enlarged side section view of the portion IIA-IIA in  FIG.  1 A ; 
         FIG.  2 C  is an enlarged perspective view of part of  FIG.  1 A ; 
         FIG.  2 D  is an enlarged perspective view of part of  FIG.  2 C ; 
         FIG.  3 A  is another perspective view of part of a room of a data center; 
         FIG.  3 B  is an enlarged perspective view of the portion IIIB-IIB in  FIG.  3 A ; 
         FIG.  4    is a pressure map showing pressure profiles for a part of a room of a data center; 
         FIG.  5    is another pressure map showing pressure profiles for the part of the room of  FIG.  1 A ; 
         FIG.  6    is another perspective view of part of a room of a data center; 
         FIG.  7 A  is a perspective view of a server holder of a data center; and 
         FIG.  7 B  is a top view of the server holder of  FIG.  7 A . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  1 A and  1 B  show a room  12  of a data center  10 . The room  12  may be part of a building of the data center  10 , and may be of any suitable size or shape. The room  12  has one or more walls  12 A and a floor  12 B which define and delimit some or all of an inner volume  12 C of the room  12 . The building of the data center  10  may have one large room  12  that occupies all of the interior of the building, multiple rooms  12 , or any combination of these. For the purposes of explanation and clarity,  FIGS.  1 A and  1 B  only show a part of the room  12  of the data center  10 . More particularly,  FIGS.  1 A and  1 B  show the part of the room  12  that is occupied by a single row of server holders  20  housed within the building and forming part of the data center  10 . The server holders  20  are located in the inner volume  12 C of the room  12  and are capable of supporting one or more servers  22 . It is understood that the room  12  of the data center  10  may include multiple rows of server holders  20  similar to, or different from, the row of server holders  20  shown in  FIGS.  1 A and  1 B . Parts of the present disclosure relate to data centers  10 , and it is appreciated that the present disclosure is applicable to other centers and systems, whether they are electrical or electric-mechanical. 
     Referring to  FIGS.  1 A and  1 B , each server holder  20  (also referred to as server cabinet/rack) includes a holder  24 . The holder  24  is a structure for supporting the servers  22 , and can take any suitable form. For example, and referring to  FIGS.  1 A and  1 B , the holder  24  is a cabinet  24 A (i.e. a “server cabinet”). The holder  24  has multiple walls which are interconnected to define an inner holder volume  24 C. The holder  24  has multiple server supports  24 B, each of which supports one or more servers  22  thereon. The server supports  24 B are spaced apart from each other within the holder volume  24 C. The server supports  24 B may take any suitable form or shape to achieve their purpose. For example, in a configuration, the server supports  24 B are rails attached to the walls of the holder  24  which allow for the servers  22  to be slid along the rails to be installed in the server holder  20 . For example, in another configuration, the server supports  24 B are shelves which support the servers  22  and on which the servers  22  rest. For example, in another configuration, the server supports  24 B are racks. Other configurations for the server supports  24 B are possible. Referring to  FIGS.  1 A and  1 B , the holder  24  has an upright orientation, and the server supports  24 B are oriented horizontally and are vertically spaced apart from each other by equal distances. In an alternate embodiment, the server supports  24 B are oriented vertically, and thus may take the form of holder dividers that are horizontally spaced-apart from each other. The server supports  24 B may also have any other suitable orientation and inter-support spacing. The holder volume  24 C is separate from the inner volume  12 C of the room  12 , and is able to fluidly communicate with the inner volume  12 C so that the air of the inner volume  12 C penetrates into the holder volume  24 C to cool the servers  22  supported by the server supports  24 B. This fluid communication between the inside and outside of the holder  24  may take different forms. For example, and referring to  FIGS.  1 A and  1 B , the holder  24  includes a door  24 D having a door frame pivotably mounted to a wall of the holder  24 . The door  24 D includes or defines a holder opening  24 E through which cooling air enters the holder volume  24 C from the inner volume  12 C of the room  12 . The holder opening  24 E may be uncovered, or may include an air-permeable mesh, screen, or grate to prevent the ingress of physical objects into the holder volume  24 C. The holder opening  24 E thus permits fluid communication between the holder volume  24 C and the air in the room  12  in order to cool the servers  22  in the holder  24 . The holder opening  24 E is located along a portion of the holder  24  that is designated herein as the “front” of the holder  24 . The holder  24  may take other forms. For example, in an alternate embodiment, the holder  24  is a rack support (i.e. a “server rack”), in which the server supports  24 B are racks, and which may be free of a door. Additional forms for the holder  24  are also possible. 
     Referring to  FIGS.  1 A and  1 B , each of the servers  22  is resting on one of the server supports  24 B which are shelves, and is positioned between two vertically-adjacent shelves  24 B. The servers  22  may be positioned on the shelves  24 B such that they are recessed from the front of the holder  24 . For example, the servers  22  may be recessed about four inches from the surface of the door  24 D, or up to six inches. In the embodiment where the holder  24  has no door  24 D, or is a server rack, the servers  22  may not be recessed and may be positioned right up to the edge of the holder  24 . 
     Referring to  FIGS.  1 A and  1 B , the data center  10  has one or more fans  14 . The one or more fans  14  function to convey a flow of air F through the room  12  in order to cool the servers  22  which are supported on/by the server holders  20 . The fans  14  and their associated components and machinery thus form one or more cooling units of the data center  10 , and are part of an air distribution system of the data center  10  which may include vents, ducting, valves, and any other component of an air distribution system. The capacity of the fans  14  is selected based on the anticipated cooling requirements of the servers  22 , and there may be one or more fans  14  in each room  12 , or one or more fans  14  used to cool multiple rooms  12  housing servers  22 . Referring to  FIGS.  1 A and  1 B , the fan  14  is located within the room  12 , and within the inner volume  12 C of the room  12 , in order to convey the flow of air F through the inner volume  12 C. In an alternate embodiment, one or more fans  14  are positioned outside the room  12  and operate to convey the cooling flow of air F from outside the inner volume  12 C to the inner volume  12 C of the room  12 . Referring to  FIGS.  1 A and  1 B , the flow of air F conveyed by the fan  14  is drawn from outside the room  12 , such as from the environment outside of the building of the data center  10 . In an alternate embodiment, the flow of air F is internal air from the inner volume  12 C that is cooled in a suitable heat exchanger before being conveyed by the fan  14 . In addition to conveying the flow of air F, the fan  14  may circulate the flow of air F through the inner volume  12 C, such that air from the inner volume  12 C is drawn into the fan  14  and subsequently pressurized by the fan  14  to be conveyed back to the inner volume  12 C. The flow of air F circulated by the fan  14  may be cooled by any suitable heat exchange medium, such as glycol, water or salt water, prior to being conveyed by the fan  14 . 
     Referring to  FIGS.  1 A and  1 B , the room  12  has an underfloor UF through which the flow of air F can travel so as to allow for underfloor cooling of the inner volume  12 C. The floor  12 B defines the underfloor UF, and the floor  12 B is installed on a slab  12 D of the building of the data center  10 . Below a walking surface  12 E of the floor  12 B and vertically spaced apart from it is a conductor support floor  12 F. The conductor support floor  12 F is substantially co-extensive in area with the walking surface  12 E. The volume between the underside of the walking surface  12 E and the upper surface of the conductor support floor  12 F includes a wire way level  12 H. Electrical conductors and other electrical or mechanical components may be housed in the wire way level  12 H and lying on the conductor support floor  12 F. Beneath the conductor support floor  12 F is and isolated conditioned air plenum  12 G. The air plenum  12 G is substantially co-extensive in area with walking surface  12 E and the conductor support floor  12 F. The air plenum  12 G and/or conductor support floor  12 F may have portions at different vertical positions or levels, and reference is made in this regard to U.S. Pat. No. 10,927,555 B2, the entire contents of which are incorporated by reference herein. 
     Referring to  FIGS.  1 A and  1 B , the room  12  is cooled via an “underfloor cooling” system. The cooling flow of air F is conveyed by the fan  14  into the air plenum  12 G of the underfloor UF. From the plenum  12 G, the cooling flow of air F enters the inner volume  12 C of the room via one or more floor panels  16 . Each floor panel  16  covers an opening in the floor  12 B, and is a perforated and air-permeable grate or mesh, thereby forming a floor vent through which the flow of air F is introduced into the inner volume  12 C. Referring to  FIGS.  1 A and  1 B , the floor panels  16  are positioned on the floor  12 B in front of every second holder  24  of the row of server holders  20 . In an alternate embodiment, the floor panels  16  are positioned in front of every holder  24 , or in front of every third, fourth, fifth, etc. holder  24 . For example, for lower-capacity server holders  20  (e.g. those in which the collective wattage of the servers  22  is 9 kW), the cooling requirements of the servers  22  may only require that the floor panels  16  be positioned at every second holder  24 . For higher-capacity server holders  20  (e.g. those in which the collective wattage of the servers  22  is 18 kW or 30 kW and which may have higher heat loads), the cooling requirements may require that a floor panel  16  be positioned in front of every server holder  20  in order to adequately cool its servers  22 . The floor panels  16  may be positioned away from the server holders  20  as well, such as adjacent to the walls  12 A of the room  12 , in order to improve the flow of air F through the inner volume  12 C or to ensure adequate cooling of the servers  22  in the server holder  22  at the end of the row. The inner volume  12 C of the room  12  is separated from the volume of the air plenum  12 G of the underfloor UF, and the inner volume  12 C is in fluid communication with the air plenum  12 G only via the floor panels  16 . 
       FIGS.  1 A and  1 B  show a configuration of the room  12  that has “underfloor cooling” over two floor levels (i.e. the floor  12 B and the conductor support floor  12 F). Other designs for the room  12  and for the fan  14  are possible. For example, in another possible configuration of the room  12  with “underfloor cooling”, there may be a single floor level which is the floor  12 B. The floor  12 B in such a configuration is spaced apart from the slab  12 D to define the air plenum  12 G, and the electrical conductors and other electrical or mechanical components are located in the air plenum  12 G along the slab  12 D or in cable trays. Other designs for the room  12  and for the fan  14  are possible, such as a “flooded room” design described in greater detail below, or a combination of underfloor cooling and flooded room designs. 
     The inventor has observed that the relatively high-velocity cooling flow of air F emanating from the floor panels  16  creates a Venturi effect above the floor panels  16  near the bottom of the server holders  22 . One or more of the servers  22  located along the lower reaches of the server cabinet  20  adjacent the floor panels  16  may thus experience lower inlet pressure. This is more clearly shown in  FIG.  4   , which shows a pressure map for the server holders  20  of  FIGS.  1 A and  1 B . The pressure map shows that the inlet pressure for all the server holders  20  shown in  FIG.  4    is lowest in the region immediately above the floor panels  16 , and thus in the same region where some of the servers  22  are positioned closest to the floor panels  16 . The lower inlet pressure in the region of these servers  22  causes the fans of these servers  22  to work harder (and thus consume more energy) against a higher pressure drop, and deliver less cooling flow to the hot internal components of the servers  22 . This means that these servers  22  located near the bottom of the sever holder  20  and adjacent the floor panels  16  may be getting less air than the other servers  22  (a phenomenon caused by the Venturi effect, which is sometimes referred to in industry as “blow-by air”), resulting in higher equipment operating temperatures and/or higher power consumption. The higher power consumption of these servers  22  is expensive energy that increases the operating costs of the data center  10 . 
     In order to address the higher power consumption of these servers  22 , one or more of the server holders  20  and one or more of the rows of server holders  20  may include a flow-restraining or flow-guiding device. 
     Referring to  FIGS.  2 A to  2 D , one or more of the server holders  20  includes one or more baffles  30 . The baffles  30  are physical objects which have a physical extent, and engage with the flow of air F so that more of the air is received by the servers  22  to cool the servers  22 . The baffles  30  may thus be any device or object that functions to restrain the flow of the air F locally around the servers  22  in order to increase the pressure of the air, such as by interfering with the flow of air F. The baffles  30  may therefore be any suitable guide vane, blade, fluid damper, louver, flow restrictor, turning vane, or other such flow-restraining device which achieves the above-described function. 
     Referring to  FIGS.  2 A to  2 D , the baffles  30  are mounted to the holder  24  adjacent to one or more of the servers  22 . In the depicted embodiment, the baffles  30  are mounted to the holder  24  adjacent to the servers  22  that are closest to the floor panels  16 . Referring to  FIGS.  2 A to  2 D , each baffle  30  is mounted adjacent to one of the servers  22 . The baffles  30  are mounted to the holder  24  to face the servers  22  and the server supports  24 B they are supported by. The baffles  30  extend outwardly from the holder  24  into the inner volume  12 C of the room  12 , so as to engage the cooling flow of air F of the room  12  flowing past the holder  24 . The baffles  30  may be attached to the door  24 D or another part of the holder  24  using any suitable mechanical fastener or adhesive, so as to extend into the room  12 . In the embodiment where the holder  24  has a door  24 D and the baffles  30  are mounted thereto, the baffles  30  displace with the door  24 D. In an alternate embodiment, one or more of the baffles  30  extends inwardly into the holder  24  and into the holder volume  24 C, such that the baffles  30  are present on the inside of the holder  24 . By “mounted”, it is understood that the baffles  30  may be added or attached to an existing holder  24 , for instance as a retrofit. Additionally or alternatively, “mounted” baffles  30  (or the step of mounting the baffles  30 ) may include incorporating (for instance as add-on components or integral members of the holder  24 ) the baffles  30  during the manufacturing of a holder  24 . Other arrangements for the mounting of the baffles  30  may be contemplated. 
     The one or more baffles  30  are shaped and sized to locally restrain the flow of air F that is being conveyed through the inner volume  12 C of the room  12  in the vicinity of the servers  22  adjacent to which the baffles  30  are mounted. The baffles  30  function to interfere with the flow of air F in the immediate vicinity of the baffles  30  and adjacent to the servers  22  that the baffles  30  are intended to assist, so that the baffles  30  can slow the flow of air F and/or increase the static pressure of the air and/or guide the flow of air F in the vicinity of the servers  22  served by the baffles  30 . By locally restraining the flow of air F around the servers  22  in this manner, the baffles  30  allow the fans of the servers  22  to more efficiently draw cooling air into the servers  22  to cool their internal components. In this way, the baffles  30  contribute to countering or reducing the Venturi effect described above which causes the fans of these servers  22  to work harder (and thus consume more energy) against a higher pressure drop, and deliver less cooling flow to the hot internal components of the servers  22 . With the baffles  30 , the fans of these servers  22  may therefore be able to consume less energy to adequately cool their components compared to a configuration where the baffles  30  are not present, thereby contributing to lowering the total energy consumption of the data center  10 . For example, in the configuration of the room  12  shown in  FIGS.  2 A and  2 B  with underfloor cooling, the baffles  30  function to interfere with the flow of air F coming from the floor panels  16  that is in the immediate vicinity of the baffles  30 . The baffles  30  disrupt the flow of air F adjacent to the servers  22  that the baffles  30  are intended to assist, thereby slowing the flow of air F and/or increasing the static pressure of the air in the vicinity of the servers  22  served by the baffles  30 . 
     The baffles  30  disclosed herein thus help to reduce the consequences of the Venturi effect described above. While the beneficial effect of the baffles  30  on the power consumption of individual servers  22  may be small, some data centers  10  contain thousands or tens-of-thousands of servers  22  experiencing the Venturi effect, such that the cumulative beneficial effect of the baffles  30  over all these servers  22  over long durations of time may provide an important contribution to reducing the overall energy consumption of the data center  10  over that period of time. 
     The baffles  30  contribute to enhancing the air distribution and air delivery effectiveness, aka, “ventilation effectiveness,” of large conditioned air plenum environments for installation in building structures including, but not limited to, data centers and similar rooms that have high heat loads requiring dedicated cooling systems. By enhancing the ventilation effectiveness in the data center  10 , it may be possible to increase the number of server holders  20 , and thereby increase the number of servers  22 , in the data center  10 , all while occupying the same white space in the data center  10 . This may allow for reducing both the capital expenditure for constructing a data center  10 , as well as the operating expenditures associated with running a data center  10 . 
     By enhancing the ventilation effectiveness in the data center  10 , it may be possible to increase the capacity of the server holders  20  of the data center  10 . Some server holders  20  are rated by their power consumption (e.g. 9 kW, 18 kW, 30 kW, etc.), and air ventilation systems for data centers  10  are often designed based on the expected power consumption of the server holders  20 . By helping to improve the cooling of some of the servers  22  in the data center  10 , the baffles  30  may allow for higher capacity server holders  20  (e.g. 18 kW instead of 9 kW, or 30 kW instead of 18 kW) with higher heat loads to be used in the data center  10 . The ability of the baffles  30  to locally restrain the flow of air F may be adjusted by “opening” or “closing” them, as described below. The capacity of the server holders  20 , assessed in kW of power consumption, may thus be adjusted (increased or decreased) by simply adjusting the baffle  30  open or closed. 
     The baffles  30  may have various orientations and be arranged in different numbers, in order to achieve the functionalities ascribed to the baffles  30  herein. 
     For example, and referring to  FIGS.  2 A to  2 D , the baffles  30  extend horizontally across the holder opening  24 E in a direction that is substantially parallel to the floor  12 B. The baffles  30  have a width defined along their horizontal extent. Each of the baffles  30  is a continuous or uninterrupted body. Referring to  FIGS.  2 A to  2 D , the baffles  30  extend across the holder opening  24 E of only one of the holders  24 . In an alternate embodiment, the baffles  30  extend across the holder openings  24 E of multiple holders  24 . In an embodiment, the baffles  30  extend across only some of the holder opening  24 E that is in fluid communication with the holder volume  24 C. The baffles  30  may extend at any angle defined relative to the floor  12 B that is greater than 0 degrees and less than 90 degrees. The baffles  30  have a horizontal orientation in that they are oriented parallel to the floor  12 B. Referring to  FIGS.  2 A to  2 D , the number of baffles  30  mounted to the holder  24  is less than the number of servers  22  in the holder  24 . Referring to  FIGS.  2 A to  2 D , the number of baffles  30  corresponds to the number of servers  22  they are intended to assist. Referring to  FIGS.  2 A to  2 D , the number of baffles  30  is two, and they are mounted to the holder  24  adjacent to two of the servers  22 . Referring to  FIGS.  2 A to  2 D , the baffles  30  are positioned adjacent to a number of servers  22  in the holder  24  that is less than all of the servers  22  in the holder  24 . 
     In the configuration of the room  12  that has underfloor cooling shown in  FIGS.  2 A and  2 B , the holders  24  have upright orientations, and the servers  22  are on vertically-spaced apart server supports  24 B to form a vertical stack of servers  22 . The servers  22  including one or more lower servers  22 L. The lower servers  22 L are the first servers  22  in the holder  24  when counting from the floor  12 B in an upward direction. The lower servers  22 L are the servers  22  in the lower server holder  20  that are closest to the floor  12 B, and thus closest to the floor panel  16 . Referring to  FIG.  2 B , there are two lower servers  22 L and a “dual baffle” configuration. A first baffle  30 A is mounted to the holder  20  in front of a first lower server  22 L 1 , and a second baffle  30 B is mounted to the holder  24  in front of a second server  22 L 2  of the lower servers  22 L. The first baffle  30 A is located vertically above the second baffle  30 B. The lower servers  22 L are mounted on lower racks or server supports  24 BL, which are positioned with respect to the other server supports  24 B similarly to the lower servers  22 L. 
     Referring to  FIG.  2 B , the lower servers  22 L are the lowermost servers  22 L of all the servers  22  in the same holder  24 . In other configurations, there may be only one lower server  22 L, or between two and five lower servers  22 L, depending on the Venturi effect caused by the flow of air F from the nearest floor panel  16 . The number of lower servers  22 L in a holder  24  is less than the total number of servers  22  in the same holder  24 . The number of lower servers  22 L in a holder  24  is less than half of the total number of servers  22  in the same holder  24 . In this configuration of the server holders  20 , and referring to  FIG.  2 B , the horizontal baffles  30  extending outwardly from the holders  24  and over the floor panels  16  function to interfere with the flow of air F from the floor panels  16  in the immediate vicinity the lower servers  22 L, so that the baffles  30  can slow the flow of air F and/or increase the static pressure of the air and/or guide the flow of air F in the vicinity of the lower servers  22 L. The baffles  30  in  FIGS.  2 A and  2 B  thus contribute to countering or reducing the impact of the Venturi effect described above on the lower servers  22 L, which are the servers  22  in the holder  24  which may be most negatively impacted by the Venturi effect. 
     The baffles  30  may have various shapes and sizes, in addition to their various possible orientations and arrangements in different numbers, in order to achieve the functionalities ascribed to the baffles  30  herein. 
     For example, and referring to  FIG.  2 B , the baffles  30  extend outwardly from the holder  24  at an angle α that is defined with respect to part of the holder  24 , for example the door  24 D of the holder  24 . The angle α may also be defined with respect to the direction D of the flow of air F from the floor panels  16 , where the direction D is substantially perpendicular to the floor  12 B. The baffles  30  are inclined toward the floor panel  16 , and thus into the direction of the flow of air F, such that the angle α is greater than 0 degrees and less than 90 degrees. In an embodiment, the angle α is greater than 45 degrees and less than 90 degrees. In an embodiment, the angle α is about 60 degrees. In an embodiment, the angle α is greater than 0 degrees and less than 45 degrees. The angle α may be adjusted to “open” or “close” each baffle  30  with respect to the oncoming flow of air F. “Opening” the baffle  30  involves increasing the angle α toward 90 degrees, such that more of the flow of air F is restrained by the baffle  30  in the vicinity of the server  22 . “Closing” the baffle  30  involves decreasing the angle α towards 0 degrees, such that less of the flow of air F is restrained by the baffle  30  in the vicinity of the server  22 . Referring to  FIG.  2 B , the angle α for the first and second baffles  30 A, 30 B is the same at 60 degrees. In an alternate embodiment, one or more of the baffles  30  form different angles α relative to the holder  24 . 
     Some possible shapes and sizes of the baffles  30  are now described with reference to  FIGS.  2 A and  2 B . Each baffle  30  has a length L that is measured or defined between a root  30 R of the baffle  30  that is adjacent to the holder  20 , and a tip  30 T of the baffle  30  that is located in the inner volume  12 C of the room  21 . The length L can vary or be selected to adjust the ability of the baffles  30  to locally restrain the flow of air F. In an embodiment, the length L of one or more of the baffles  30  is greater than 0 inches and less than 10 inches. In an embodiment, the length L of one or more of the baffles  30  is greater than 0 inches and less than 5 inches. In an embodiment, the length L of one or more of the baffles  30  is between 2.5 inches and 3.5 inches. Other values for the length L are possible, and may be determined based on the spacing or aisle width between adjacent rows of server holders  20 , and/or on the angle α. The length L of the baffles  30  in one row of server holders  20  may be longer than the length L of the baffles  30  in another row of server holders  20 , demonstrating that the length L of the baffles  30  may be selected for the specific airflow conditions in an aisle. The length L of adjacent baffles  30  in the same server holder  20  may vary. For example, and referring to  FIGS.  2 A and  2 B , the first baffle  30 A has a length L of 3.5 inches, and the second baffle  30 B has a length of 2.5 inches such that the second baffle  30 B is shorter than the first baffle  30 A. These sizes for the first and second baffles  30 A, 30 B may allow the lower, second baffle  30 B to adequately restrain the flow of air F in front of the second lower server  22 L 2 , while still allowing adequate cooling flow to reach the higher, first baffle  30 A. Referring to  FIGS.  2 A and  2 B , the baffles  30  are straight or planar bodies. In an alternate embodiment, one or more of the baffles  30  may be curved, or some or all of the baffle  30  may be curved or have a curvature greater than zero. 
     The baffles  30  may have other shapes as well. For example, and referring to  FIGS.  3 A and  3 B , the baffles  30  include side walls  32  that have an upright orientation. Each of the side walls  32  is located at one of the horizontal extremities of the baffles  30 , and extends between and vertically past the baffles  30  to close off the horizontal ends of the baffles  30 . The side walls  32  may function to guide some of the flow of air F from the floor panels  16  toward the baffles  30 . 
     The beneficial effect of the baffles  30  on the flow of air F may be better appreciated by considering the pressure profiles in  FIG.  5   . As the flow of air F enters the inner volume  12 C of the room  12  from the floor panels  16 , it is locally restrained by the first and second baffles  30 A, 30 B. The static pressure of the air in the vicinity of the baffles  30  is increased, as shown in region  34 A, and is even greater in region  34 B which is immediately adjacent to the holder opening  24 E and to the servers  22 . By locally restraining the flow of air F in regions  34 A, 34 B around the servers  22  in this manner, the baffles  30  allow the fans of these targeted servers  22  to more efficiently draw cooling air into the servers  22  to cool their internal components. The flow of air F further away from the baffles  30  in region  34 C is unrestrained by the baffles  30 , and thus has a lower static pressure than the air in regions  34 A,  34 B. 
     Yet another possible arrangement and orientation of the baffles  30  which achieve the functionalities described herein is now described. Referring to  FIG.  6   , the baffles  30  have a vertical configuration. The baffles  30  extend vertically across the holder opening  24 E in a direction that is substantially perpendicular to the floor  12 B. Each of the baffles  30  is a continuous or uninterrupted body. Each of the vertical baffles  30  extends over, and in front of, a majority of the servers  22  in the server holder  20 . Referring to  FIG.  6   , each of the vertical baffles  30  extends over, and in front of, all of the servers  22  in the server holder  20 . In an embodiment, the baffles  30  extend across only some of the holder opening  24 E that is in fluid communication with the holder volume  24 C. The baffles  30  have a vertical orientation in that they are oriented perpendicular to the floor  12 B. Referring to  FIG.  6   , the number of baffles  30  mounted to the holder  24  is less than the number of servers  22  in the holder  24 . Referring to  FIG.  6   , the number of baffles  30  is four per server holder  20 , and they are mounted to the holder  24  to extend across all of the servers  22 . Each of the vertical baffles  30  is spaced apart horizontally from an adjacent vertical baffle  30  on the same server holder  20 . 
     In the configuration of the room  12  shown in  FIG.  6   , the fan  14  is adjacent to one of the walls  12 A of the room  12 , and provides cooling air by “flooding” the room  12  with the flow of air F. In such “flooded room” designs, a high velocity flow of air F enters a cold aisle along a horizontal direction between rows of server holders  20  from the perimeter of the room  12 . The Venturi effect described above is also present in flooded room designs, and may affect a large number of servers  22  because most or all of the servers  22  in a single server holder  20  may be negatively impacted by the Venturi effect caused by the high velocity air coming from the fan  14  adjacent to one of the walls  12 A of the room  12 . In fact, in the “flooded room” approach, the problem presented by the high velocity air may be even greater than it is in the underfloor cooling room configuration because far more servers  22  may be negatively impacted by its effects in the flooded room approach. 
     Referring to  FIG.  6   , the server holders  20  have upright orientations, and the servers  22  are on vertically-spaced apart server supports  24 B to form a vertical stack of servers  22 . The server holders  20  include one or more leading server holders  20 L. The leading server holders  20 L are the first one or more server holders  20 L in the row of server holders  20  when counting from the fan  14  in the direction of the flow of air F. The leading server holders  20 L are the server holders  20  in the row of server holders  20  that are positioned closest to the fan  14 , and thus closest to the wall  12 A. The one or more leading server holders  20 L include the server holder  20  that is closest to the fan  14  compared to the other server holders  20  in the row of server holders  20 . In configurations where the velocity of the flow of air F is high, the servers  22  in the leading server holders  20 L may not be adequately cooled, or their fans may have to work harder to draw sufficient cooling air into the servers  22 . Referring to  FIG.  6   , there are four or more leading server holders  20 L. Each of the leading server holders  20 L has multiple vertical baffles  30  (four are shown, but fewer or more baffles  30  are possible) and horizontally-extending side walls  32 . 
     In some embodiments, there may be only one leading server holder  20 L with vertical baffles  30 , or between two and six leading server holders  20 L with vertical baffles  30 , depending on the Venturi effect caused by the flow of air F from the fan  14 . The number of leading server holders  20 L in a row of server holders  20  may be less than the total number of server holders  20  in the same row of server holders  20 . In this configuration of the server holders  20 , and referring to  FIG.  6   , the vertical baffles  30  extend outwardly from the holders  24  and into the inner volume  12 C of the room  12 . The baffles  30  function to interfere with the flow of air F from the fan  14  so that the baffles  30  can slow the flow of air F and/or increase the static pressure of the air and/or guide the flow of air F in the vicinity of the servers  22  of the leading server holders  20 L. The baffles  30  in  FIG.  6    thus contribute to countering or reducing the impact of the Venturi effect described above on the servers  22  of the leading server holders  20 L, which are the servers  22  in the row of server holders  22  which may be most negatively impacted by the Venturi effect. 
     Referring to  FIG.  6   , the baffles  30  extend outwardly from the holder  24  at an angle α that is defined with respect to part of the holder  24 , for example the door  24 D of the holder  24 . The angle α may also be defined with respect to the direction D of the flow of air F from the fan  14 , this direction D being substantially parallel to the floor  12 B. The baffles  30  are inclined toward the fan  14 , and thus into the direction of the flow of air F, such that the angle α is greater than 0 degrees and less than 90 degrees. In an embodiment, the angle α is greater than 45 degrees and less than 90 degrees. In an embodiment, the angle α is about 60 degrees. In an embodiment, the angle α is greater than 0 degrees and less than 45 degrees. The angle α may be adjusted to “open” or “close” each baffle  30  with respect to the oncoming flow of air F. “Opening” the baffle  30  involves increasing the angle α toward 90 degrees, such that more of the flow of air F is restrained by the baffle  30  in the vicinity of the servers  22 . “Closing” the baffle  30  involves decreasing the angle α towards 0 degrees, such that less of the flow of air F is restrained by the baffle  30  in the vicinity of the servers  22 . Referring to  6 , the angle α for each baffle  30  on a given one of the leading server holders  20 L is the same. In an alternate embodiment, one or more of the baffles  30  on a given one of the leading server holders  20 L form different angles α. 
     Yet another possible arrangement and orientation of the baffles  30  which achieve the functionalities described herein is now described. Referring to  FIGS.  7 A and  7 B , the baffles  30  have a vertical configuration. The description of the baffles  30  provided above with respect to  FIG.  6    applies mutatis mutandis to the baffles  30  shown in  FIGS.  7 A and  7 B . The baffles  30  extend vertically across the holder opening  24 E in a direction that is substantially perpendicular to the floor  12 B. Each of the baffles  30  is a continuous or uninterrupted body. Each of the vertical baffles  30  extends over, and in front of, a majority of the servers  22  in the server holder  20 . Referring to  FIGS.  7 A to  7 B , each of the vertical baffles  30  extends over, and in front of, all of the servers  22  in the server holder  20 . In an embodiment, the baffles  30  extend across only some of the holder opening  24 E that is in fluid communication with the holder volume  24 C. The baffles  30  have a vertical orientation in that they are oriented perpendicular to the floor  12 B. Referring to  FIGS.  7 A and  7 B , the number of baffles  30  mounted to the holder  24  is less than the number of servers  22  in the holder  24 . Referring to  FIGS.  7 A to  7 B , the number of baffles  30  is four per server holder  20 , and they are mounted to the holder  24  to extend across all of the servers  22 . Each of the vertical baffles  30  is spaced apart horizontally from an adjacent vertical baffle  30  on the same server holder  20 . 
     Referring to  FIGS.  7 A to  7 B , the vertical baffles  30  extend outwardly from the holders  24  and into the inner volume  12 C of the room  12 . The baffles  30  function to interfere with the flow of air F from the fan  14  so that the baffles  30  can slow the flow of air F and/or increase the static pressure of the air and/or guide the flow of air F in the vicinity of the servers  22  of the leading server holders  20 L. The baffles  30  in  FIGS.  7 A to  7 B  thus contribute to countering or reducing the impact of the Venturi effect on the servers  22  of the server holders  20 L which are closest to the fan  14 , and which are the servers  22  in the row of server holders  22  which may be most negatively impacted by the Venturi effect. 
     Referring to  FIGS.  7 A to  7 B , the baffles  30  extend outwardly from the holder  24  at an angle α that is defined with respect to part of the holder  24 , for example the door  24 D of the holder  24 . The angle α may also be defined with respect to the direction D of the flow of air F from the fan  14 , this direction D being substantially parallel to the floor  12 B. The baffles  30  are inclined toward the fan  14 , and thus into the direction of the flow of air F, such that the angle α is greater than 0 degrees and less than 90 degrees. In an embodiment, the angle α is greater than 45 degrees and less than 90 degrees. In an embodiment, the angle α is about 60 degrees. In an embodiment, the angle α is greater than 0 degrees and less than 45 degrees. The angle α may be adjusted to “open” or “close” each baffle  30  with respect to the oncoming flow of air F. “Opening” the baffle  30  involves increasing the angle α toward 90 degrees, such that more of the flow of air F is restrained by the baffle  30  in the vicinity of the servers  22 . “Closing” the baffle  30  involves decreasing the angle α towards 0 degrees, such that less of the flow of air F is restrained by the baffle  30  in the vicinity of the servers  22 . Referring to  6 , the angle α for each baffle  30  on a given one of the leading server holders  20 L is the same. In an alternate embodiment, one or more of the baffles  30  on a given one of the server holders  20  closest to the fan  14  form different angles α. 
     Referring to  FIG.  7 B , each baffle  30  has a length L that is measured or defined between a root  30 R of the baffle  30  that is adjacent to the holder  20 , and a tip  30 T of the baffle  30  that is located in the inner volume  12 C of the room  21 . The length L can vary or be selected to adjust the ability of the baffles  30  to locally restrain the flow of air F. For example, and referring to  FIG.  7 B , all of the vertical baffles  30  of the server holder  20  have different lengths L. Referring to  FIG.  7 B , the length L of the baffle  30  that is closest to the fan  14  and to the oncoming flow of air F is less than the length L of the baffle  30  that is furthest from the fan  14 . Referring to  FIG.  7 B , the length L of the baffle  30  that is furthest from the fan  14  is greater than the lengths L of all the other baffles  30  of the server holder  20 . Referring to  FIG.  7 B , the length L of the baffle  30  that is closest to the fan  14  is less than the lengths L of all the other baffles  30  of the server holder  20 . Referring to  FIG.  7 B , the length L of the baffles  30  increases with each baffle  30 , in the direction starting from the baffle  30  closest to the fan  14  (which is the shortest length L) to the baffle  30  furthest from the fan  14  (which has the greatest length L). In an embodiment, the length L of one or more of the baffles  30  is greater than 0 inches and less than 10 inches. 
     Referring to  FIGS.  2 B and  6   , there is disclosed a method of restraining the flow of air F around part of the server cabinet/rack (i.e. the server holder  20 ). This method may also be referred to as a method of slowing or restraining the flow of air F in the data center  10 . The method includes mounting one or more baffles  30  to an exterior of the server holder  20  adjacent to one or more of the server supports  24 B (and the one or more servers  22  supported thereby), such that the at least one baffle  30  extends outwardly from the server holder  20  to restrain the flow of air F outside the server holder  20  around the one or more server supports  24 B. 
     Referring to  FIGS.  2 B and  6   , there is disclosed a method of increasing the capacity of the server holder  20 . The “capacity” may refer to the power consumption of the server holder  20 , in Watts for example. The method includes mounting one or more baffles  30  to an exterior of the server holder  20  adjacent to one or more of the server supports  24 B (and the one or more servers  22  supported thereby), such that the at least one baffle  30  extends outwardly from the server holder  20  to restrain the flow of air F outside the server holder  20  around the one or more server supports  24 B. By helping to improve the efficiency at which the fans of the servers  22  draw cooling air into the servers  22 , the baffles  30  may allow for higher capacity server holders  20  which may have higher heat loads to be used (e.g. use 18 kW server holders  20  instead of 9 kW ones, or use 30 kW server holders  20  instead of 18 kW ones), thereby helping to increase the capacity of the server holder  20 . The method also includes “opening” or “closing” the baffles  30 , as described above, to increase or decrease the capacity of the server holder  20 . 
     The embodiments described in this document provide non-limiting examples of possible implementations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. For example, although the expressions “server” and “server holder” are used herein, the baffles  30  are not limited to being used only with these devices, and may also be used with other types of cabinets, racks, etc. which house or support other electrical or electro-mechanical equipment or objects. Similarly, the baffles  30  are not limited to being used only in data centers  10 , and may also be used with any other type of electro-mechanical distribution system. Yet further modifications could be implemented by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.