Patent Publication Number: US-9854711-B2

Title: Directional grate access floor panel

Description:
RELATED APPLICATION 
     This application is a continuation application of application Ser. No. 14/221,974 filed on Mar. 21, 2014 and entitled “Directional Grate Access Floor Panel,” which in turn is a continuation application of application Ser. No. 12/878,657 filed on Sep. 9, 2010 and entitled “Directional Grate Access Floor Panel.” 
    
    
     BACKGROUND 
     1. Field of the Invention 
     This invention relates to grate panels for access flooring systems. In particular, this invention relates to access floor panels having grates that direct cooling air from the plenum between the sub-floor and the access panel array through the array. 
     2. Background of the Invention 
     A typical data center includes multiple IT racks. Those racks, and the associated peripheral equipment and cables, generate a relatively high amount of heat. Because of that heat, providing adequate cooling to IT racks in the data center is of paramount importance. Moreover, it is desirable that the IT racks be cooled as efficiently as possible, as the energy costs to cool IT racks may approach a large percentage of the energy costs to operate the data center. 
     Data centers typically have a raised floor system, often called an access floor system. An access floor system is usually comprised of a continuous array of floor panels, arranged edge-to-edge, and supported above the sub-floor by support structure. The array of access floor panels usually extends wall-to-wall in the data centers. 
     A plenum is formed between the sub-floor and the access floor panel array. The cables and other equipment run through the plenum, and the plenum is also used as a conduit for cooling air. Often, one or more air conditioning units supply air to the plenum, and some of the access floor panels in the array have grates. The cooling air passes through the grates into the data center. 
     U.S. Pat. No. 6,747,872 discloses a typical cooling system for a data center. In the system of U.S. Pat. No. 6,747,872, cool air from an air conditioner passes through the plenum between the sub-floor and the access panel array to grates in the array. The cool air then passes through those grates to spaces adjacent to the IT racks. However, the perforated panels or grates disclosed in systems such as that in U.S. Pat. No. 6,747,872 merely provide the cool air in a vertical plume between the IT racks. 
     SUMMARY OF THE INVENTION 
     In view of the above, it is desirable to provide a directional grate panel for access floor systems that directs cooling air from the plenum between the sub-floor and the access floor panel array directly and evenly to faces of IT racks in a data center, resulting in more consistent temperature throughout the height of the IT racks and more economic cooling of the racks. 
     A directional grate according to one embodiment may comprise a plurality of spaced vanes provided within a support frame, each of the plurality of vanes having an upstream portion and a downstream portion with respect to a direction of airflow across the plurality of vanes; and a plurality of openings provided in at least some of the plurality of vanes. The downstream portion of at least some of the vanes of the plurality of vanes may be angled with respect to their upstream portions. 
     In another embodiment, the plurality of openings may be circular in shape. Alternatively, the plurality of openings may be any other geometric or non-geometric shape. 
     In a further embodiment, some of the vanes of the plurality of vanes may have at least a portion that is angled at a same angle of inclination with respect to a vertical axis. The angle of inclination may be between 20° and 35°. In yet another embodiment, the plurality of vanes may include two or more groups of vanes that have at least portions that are angled at first and second angles of inclination, respectively. 
     In yet another embodiment, all of the plurality of vanes may have openings that extend through the faces thereof. In one aspect, each of the vanes of the plurality of vanes may have a same pattern of openings. The support frame may have at least one peripheral member that has openings therethrough that align with the openings in at least some of the vanes. Additionally, the openings may be formed as a plurality of partial cutouts along one edge of the plurality of vanes. Further, the openings may be equally spaced in each vane of the plurality of vanes. The openings also may be of equal size in each vane of the plurality of vanes, and a same pattern of openings may be provided in some of the vanes of the plurality of vanes. 
     In another embodiment, the grate access floor panel may comprise a support frame and a plurality of spaced vanes having front and rear faces, wherein at least some of the plurality of spaced vanes may have openings through the faces thereof that permit airflow through the plurality of spaced vanes as well as between adjacent vanes of the plurality of spaced vanes. The airflow through the plurality of spaced vanes results in more even distribution of air through the grate access floor panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a directional grate panel according to one embodiment of this invention. 
         FIG. 2  is a front view of the embodiment of  FIG. 1 . 
         FIG. 3  is a top view of the embodiment of  FIG. 1 . 
         FIG. 4  is a side view of the embodiment of  FIG. 1 . 
         FIG. 5  is a bottom view of the embodiment of  FIG. 1 . 
         FIG. 6  is a bottom perspective view of the embodiment of  FIG. 1 . 
         FIG. 7  is a partial cross-sectional view taken along lines  7 - 7  in  FIG. 3 . 
         FIG. 8  is a partial cross-sectional view of a vane taken along lines  8 - 8  in  FIG. 7 . 
         FIG. 9  is a schematic view illustrating the use of the directional grate of  FIGS. 1-8  in a data center. 
         FIG. 10  is a partial cross sectional view of the vane of another embodiment. 
         FIG. 11  is a partial cross-sectional view of the vane of  FIG. 10  taken along lines  11 - 11  in  FIG. 10 . 
         FIG. 12  is a directional grate panel according to a further embodiment of this invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a top perspective view of the directional grate panel  50 . The directional grate panel  50  can be made of any material that is capable of providing the structural rigidity required for a given application. Preferably the directional grate panel  50  is made of a metal. 
     The directional grate panel  50  includes a frame  130 . In this embodiment, frame  130  includes a square outer frame consisting of members  130   a ,  130   b ,  130   c  and  130   d , and a plurality of cross members  140 ,  150  and  160  that are provided for structural support. The necessity and number of cross members  140 ,  150  and  160  varies depending on the application. 
     The directional grate panel  50  includes a plurality of vanes  80 , which, in this embodiment, are substantially parallel to frame members  130   a ,  130   c  and  140 . The vanes  80  may extend between one of frame members  130   b  and  130   d  and support members  150 , as shown in the figures, or vanes  80  may extend all the way between frame members  130   b  and  130   d . Vanes  80  may form parallel rows. The number of vanes  80  may vary as desired, depending on the application. 
     Vanes  80  have a downstream end  170  and an upstream end  180  (see  FIG. 8 ). “Downstream” and “upstream” are defined relative to the direction of airflow through the directional grate panel  50 . Vanes  80  have opposing faces that extend between the downstream end  170  and the upstream end  180 . 
     Vanes  80  have holes (or openings)  85 . See  FIG. 7 . While holes  85  are shown as a single row of spaced circular openings in  FIG. 7 , the holes  85  can be of any shape and can be arranged in any pattern or randomly. The holes  85  do not have to have the same pattern or size in all the vanes  80 . In fact, the holes in adjacent vanes  80  can be of different sizes and patterns. In addition, some vanes  80  may have a different number of holes  85  than other vanes  80 . For example, one vane  80  may have only four holes  85 , whereas another vane  80  may have five holes. 
     Also, not all of the vanes  80  must have holes  85 . Rather, only selected vanes  80 , or sets of vanes  80 , may have holes  85 . 
     Further, the holes do not have to be “in” the vanes. Rather, the holes or openings can be partially formed by the vanes, as illustrated, for example, in  FIG. 10 , which illustrates partial cross sectional views of the vanes of another embodiment of this invention. In the embodiment illustrated in  FIG. 10 , the openings  85   a  are in the form of partial cutouts along one edge of the vane  80 . In particular,  FIG. 10  illustrates an embodiment in which the openings are in the form of semi-circular cutouts formed in a vane. While the openings  85   a  in  FIG. 10  are semi-circular in shape, the openings  85   a  can be of any shape and spaced as desired along the vane  80 . The shape of the openings  85   a  can vary in a given vane  80 , and the openings  85   a  can be spaced equally, in any pattern or randomly in a given vane  80 .  FIG. 11  is a cross sectional view of the vane illustrated in  FIG. 10 . 
     The holes  85  or openings  85   a  in the vanes  80  have many functions. For instance, they reduce the weight of directional grate panel  50 . They also cause a more turbulent airflow as the air passes along the directional grate panel  50  to be directed through it, which reduces air velocity, helps distribute air across the vanes evenly, and equalizes pressure. 
     In the embodiment illustrated by  FIGS. 1-8 , frame members  130   a  and  130   c  (see the side view of  FIG. 3 ) are provided with through holes  90 , which substantially line up with holes  85  in the end vanes  80 . 
     When the directional grate panel  50  is installed in an access floor panel array, the holes  85  and the through holes  90  are substantially aligned with a direction of the airflow  70 . 
     In the embodiments illustrated in the Figures, the vanes  80  have an angled tip. In particular, an upper portion defining a vane tip  100  is angled with respect to the rest of the vane  80 . The vane tip  100  is on a downstream end  170  of the vane  80  with respect to a direction of airflow through the directional grate panel  50 . In other embodiments, the vanes can be flat, but angled with regard to the airflow direction, as shown in  FIG. 12 . The vanes can have any other shape, such as curved, that directs air as desired. 
     The angle of inclination α of the vane tip  100  of the vane  80  may range between 20° and 35° with respect to the vertical axis. See  FIGS. 8 and 11 . It has been found that tip angles in the range of 20° to 35° provide benefits over other angles because a tip angle range of 20° to 35° directs the optimal airflow to the IT racks, evenly distributing the air to the racks. 
     Some of the vane tips  100  of vanes  80  can have different angles of inclination α than other vane tips  100 . For example, some of the vanes may have vane tips  100  having angles of inclination a of 20°, while other vanes may have vane tips  100  having an angle of inclination α of 35°. Vanes  80  having those differing vane tips may be arranged in sets, i.e., one set of the vanes  80  may have tips having an angle of inclination α of 20°, while another set of the vanes  80  may have tips having an angle of inclination α of 35°. Alternatively, as a further example, the sets of vanes may be arranged in an alternating fashion such that there is a vane having a vane tip at 20°, followed by a vane having a vane tip at 35°, followed by a vane having a vane tip at 20° or the vane tips can alternate randomly, etc., or in any other pattern. An example of another pattern is that the vanes may be arranged with a vane having a tip at 20°, followed by two vanes having a tip ant 35°, followed by a vane having a tip at 20°, followed by a vane having a tip at 35°, etc. Further, all of the vanes  80  may have angled tip portions, or alternatively only some of the vanes  80  may have angled tips with the remaining vanes being vertically oriented or inclined. 
     As stated,  FIG. 9  is a schematic view of a data center, data center  10 , which includes at least one directional grate panel  50 . Data center  10  has one or more air conditioning units  30  that provide cool air via one or more fans  40  to the plenum  110  between the sub-floor  115  and the access floor panel array  125 . An airflow  70  is created by the fan  40  through plenum  110  to the directional grate panel  50 . The directional grate panel  50  is provided in the access floor array  125  adjacent to an IT rack  20 . The directional grate panel  50  directs air toward a face  120  of the IT rack  20 . Warm air exhausted from the IT rack is then exhausted back to the air conditioning unit  30 . 
     The grate panels of this invention evenly distribute the air flow through them. Further, the grate panels of this invention direct a higher percentage of the cooling air toward the adjacent IT racks  20 . This results in less “wasted” air, i.e., air that is circulated through the data center without interacting with the IT racks  20 . Because a higher percentage of the cooling air is directed to the IT rack  20 , less total CFM of the cooling air has to be delivered to each directional grate panel  50 . 
     What has been described and illustrated herein are preferred embodiments of the invention along with some variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.