Patent Publication Number: US-2010108272-A1

Title: Air barrier for datacenter usage which automatically retracts when fire sprinklers are activated

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an air barrier structure located in an air flow passageway for datacenter usage, which is automatically retractable upon activation of fire sprinklers in the event of a conflagration. 
     In the present state of the data processing technology, large datacenters are employed, which require the consumption of huge amounts of electricity, and thereby frequently necessitate that extensive amounts of air be conveyed across computer racks of such datacenters in order to conduct heat that is generated by the electronic components in the computer racks to computer room air conditioner units (CRAC), or to other suitable air cooling arrangements. 
     2. Discussion of the Prior Art 
     A problem which is frequently encountered in such datacenter installations is an undesirable mixing of flows of air of widely divergent temperatures emanating from hot-air aisles and from cold-air aisles between the computer racks, and wherein even the direct recirculation of hot air, which is exhausted proximate the top of a rack or racks, passes over the upper surface or top of the racks or adjoining racks and is resultingly sucked into the front of a rack normally employed for cooling. However, the cooling efficiency of the datacenter can be significantly increased in the instance in which the respective hot-aisle and the cold-aisle can be partitioned from each other so as to minimize or inhibit any exchange of air flows therebetween. 
     At this time, there are systems in existence which fully enclose the hot-aisle structure, however, these systems are expensive to manufacture and require extensive installations and the use of specific in-row coolers. Many datacenters would improve upon their cooling by simply blocking recirculation of an air flow across the tops of the racks, which can be implemented with inexpensive materials installed downstream of the racks. Nevertheless, in many locales, the promulgation of fire-safety codes do not allow for the positioning of any flow-restricting barricades between the tops of the racks and the level of the ceiling or sprinkler levels of the datacenter installation, in order to ensure that water emanating from fire sprinklers can adequately reach all areas of the datacenter when the sprinklers are triggered by a conflagration. Therefore, the technology is in need of an inexpensive, easy-to-install system of barricades that can be installed in a variable height space above any computer rack, but which would not interfere with the function of activated fire sprinklers. 
     SUMMARY OF THE INVENTION 
     Accordingly, pursuant to the present invention, in order to obtain the desired functions in separating the air flows between the hot-air and cold-air aisles, of the computer racks, there are provided suitable barriers which will permit fire sprinklers to operate efficiently in quenching fires or conflagrations which may be encountered in the datacenters without such barriers creating obstructions. 
     The invention provides for self-retracting barriers to airflows that are held in their extended (airflow-blocking) orientations by incorporating water-soluble retaining members. Hereby, upon water from a fire sprinkler striking either side of the barrier, the water-soluble retainers will rapidly dissolve and the barrier will automatically retract, permitting the fire sprinklers to function as if no barrier was ever present. Although this concept may require some certifications and/or fire-code modification in some geographic locales, from an engineering standpoint, it represents a fail-safe solution in that the barrier will retract when the fire sprinklers are activated, even in the absence of any electrical power or initiation of an external control signal. 
     In essence, the foregoing provides for suitable airflow barrier structures, which, while serving the function of inhibiting any unwanted mixing hot-airflows and cold-airflows, between the computer racks, will concurrently facilitate the unhindered operation of fire sprinklers, and which can functionally satisfy local fire ordinances and regulations. 
     Although different concepts can be applied in the forming of retractable and/or collapsible barriers, pursuant to the invention, a generally simple and flexible structure resides in a so-called “window-shade” style device with a spring-loaded cylinder about which there is wrapped a barrier material. This design allows the extension of the shade-like barrier to be easily varied so that any available space can be blocked, up to the maximum length of the extended barrier. However, a typical roll-up window shade normally incorporates a clutch mechanism that prevents the shade from retracting once it has been pulled down. Typically the shade is manually retracted by extending it slightly and then quickly releasing it to thereby unlatch the clutch mechanism. Such a manual approach is obviously unacceptable in a datacenter, where automatic retraction of the barrier must be triggered by activation of the fire sprinklers. 
     Accordingly, in order to obviate the limitations which are currently encountered in providing air flow barriers for datacenter installations, the present invention provides for a shade-type roll up barrier, which in the absence of any complex mechanical structure, will automatically retract upon the activation of a fire sprinkler, and whereby the barrier incorporates water-soluble structural aspects which will facilitate such automatic retraction upon being impinged by a flow of water emanating from an activated fire sprinkler. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference may now be made to the following detailed description of a preferred embodiment of the invention, taken in conjunction with the accompanying drawings in which: 
         FIG. 1  illustrates, in a generally diagrammatic perspective representation, an air barrier for datacenter usage which is automatically retractable responsive to activation of a fire sprinkler; and 
         FIG. 2  illustrates, on an enlarged scale, a fragmentary segment of the air barrier of  FIG. 1 , as represented by encircled portion A thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring, in particularity to the drawings,  FIG. 1  illustrates a barrier structure  10  which is generally in the shape of a curtain-like roll-up shade. The barrier structure has the shade portion  12  constituted of an airflow-resistant or impervious material, which may be of a fabric or other flexible consistency. The shade portion  12  may be opaque, translucent or transparent in nature. 
     At the upper end  14  of the barrier structure, there is a spring-loaded roller  16 , which has the upper end of shade portion  12  attached thereto, and wherein the roller  16  is adapted to be fastened to a suspended ceiling of a datacenter (not shown), or to any other ceiling structure located above the upper end or end surfaces of computer racks (not shown) in a spaced relationship with the ceiling. The roller  16  is fastened to the ceiling so as to be freely rotatably about its longitudinal axis, and normally imparts a roll-up winding force to the shade portion  12  about the roller for retracting the shade portion  16 . 
     At its lower end  18 , the shade portion  12  is fastened to a termination rod member  22  extending along the bottom edge  20  of the shade portion. 
     Arranged in a closely spaced, parallel relationship with the termination rod member  22 , is a hold-down structure  24 , which may comprise a rod member  26  similar in shape to the termination rod member  22 . The rod member  26  may have attachment devices  28  fastened thereto, preferably proximate the ends thereof, for attaching the hold-down structure  24  to the upper surface or surface of computer racks. These attachment devices may consist of magnets, adhesives, clips, screws, clamps, as may be applicable or practical for their physical installation. 
     In order to maintain the shade portion  12  in its downward extended barrier-forming position, in which it obstructs the unwanted flow of air between hot-air and cold-air aisles, during normal usage thereof in the datacenter, there are provided connections  32 . As illustrated more closely in  FIG. 2  of the drawings, this shows one of the connections  30  between rod members  22  and  26 , as enlarged from “A” in  FIG. 1 , whereby these connections  30  are located at preferably the opposite ends of the rod members. 
     Each of the connections  30  may consist of a loop-shaped retention strap constituted of a water-soluble material, such as a film or strip, which can be heat-welded into flexible loops, lengths or other suitable shapes. The water-soluble material is adapted to rapidly (i.e., within a few seconds) dissolve upon being contacted by water. 
     Thus, by attaching each end of the extended barrier or shade portion  12  to the hold-down structure  34  with a separate loop  30  (or length) of the water soluble film material connecting rod members  22  and  26 , it is assured that the barrier  10  will be released and the shade portion  12  spring-retracted about a roller  16  when either (or both) of the hold-down loops  30  is contacted by water from a sprinkler and resultingly dissolved. Furthermore, by attaching a preferably V-shaped plastic gutter-tray  32  at the bottom end of the extended barrier above rod member  22 , it is possible to channel any water running off from either side of the shade portion  12  to at least one of the water-soluble retention loops  30 . Through this type of structure, the activation of any sprinkler that sprays water onto either side of the extended shade portion  12  will quickly wet at least one of the loops  30 , dissolving the latter and quickly result in the force of the spring-loaded roller  16  causing upward retraction of the barrier  10  upon being released from the hold-down structure  24 . Long or contiguous sections constituted of barriers  10  can be created simply by mounting several of these in end-to-end relationships above the computer racks (with or without some material overlap). 
     While it is apparent that the invention herein disclosed is well calculated to fulfill the objects stated above, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.