Abstract:
A modular server cooling unit user standard dimension modules to build a variety of components for use in cooling a server or server farm. One module may be the module in which the server(s) are mounted. Another module may be an exhaust plenum, drawing air through the server module and exhausting the air to the outside. A third module may be a cooling module through which outside air is drawn, filtered and optionally cooled, for example, using an adiabatic, or water-wash, cooler. Exhaust air may be selectively mixed with air from the cooling module to provide finer control of server temperature and humidity.

Description:
BACKGROUND 
     Providing a controlled climate for computer servers and other sensitive equipment is traditionally accomplished by placing the servers in a room with climate controls and may include a raised floor, conditioned power, etc. Each server room has separate power cabling, duct work for conditioned and return air, filters, and airlocks, as required. Size and capacity changes to accommodate increased or reduced space or air conditioning needs are usually costly, if possible at all. 
     SUMMARY 
     One or more servers may be mounted inside a modular cooling environment that provides interchangeable cooling heads to accommodate different requirements. Each module may connect with other modules to provide humidity control, air recirculation, filtering, etc. Assembled modules may be stacked to accommodate additional servers/server racks. In some embodiments, different cooling modes may be exchanged to meet seasonal needs. For example, an adiabatic (swamp) cooler may be used in a desert climate in the most seasons, while a chilled water module may be used in the deep summer when high heat and humidity may require more temperature change than can be met using the adiabatic cooling module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of one embodiment of a modular server cooling system; 
         FIG. 2  is a block diagram of another embodiment of a modular server cooling system; 
         FIG. 3  is a block diagram of yet another embodiment of a modular server cooling system; 
         FIG. 4  is a block diagram of a fourth embodiment of a modular server cooling system; 
         FIG. 5  is a block diagram of a fifth embodiment of a modular server cooling system; 
         FIG. 6  is a top view diagram of a mechanical drawing of a modular server cooling system; 
         FIG. 7  is a side view diagram of the mechanical drawing of  FIG. 6 ; and 
         FIG. 8  is a flow chart of a method of cooling a server using a modular server cooling system. 
     
    
    
     DETAILED DESCRIPTION 
     Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of the description is defined by the words of the claims set forth at the end of this disclosure. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. 
     It should also be understood that, unless a term is expressly defined in this patent using the sentence “As used herein, the term ‘ —————— ’ is hereby defined to mean . . . ” or a similar sentence, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term by limited, by implication or otherwise, to that single meaning. Finally, unless a claim element is defined by reciting the word “means” and a function without the recital of any structure, it is not intended that the scope of any claim element be interpreted based on the application of 35 U.S.C. §112, sixth paragraph. 
     Much of the inventive functionality and many of the inventive principles are best implemented with or in software programs or instructions and integrated circuits (ICs) such as application specific ICs. It is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation. Therefore, in the interest of brevity and minimization of any risk of obscuring the principles and concepts in accordance to the present invention, further discussion of such software and ICs, if any, will be limited to the essentials with respect to the principles and concepts of the preferred embodiments. 
       FIG. 1  illustrates a first embodiment of a modular server cooling unit  100 . A first, server module  102  may be used to hold the servers  104  and may include a intake space  106 , and an exit space  108 . When minimal cooling is required, or if outside air is suitable for primary use, the outside air may be brought in through a filter  110 . The filter  110  may be a simple disposable paper filter. 
     A second, plenum module  112  may be a simple large cavity  114  for drawing air from the exit space  108  of the server module  102 . An exhaust fan  116  may be used to remove the exit air from the plenum module  112 . As can be seen from the illustration, because each module has standard dimensions, they may be attached as needed, as further shown below. 
       FIG. 2  illustrates another modular server cooling unit  200 . In this embodiment, the server module  202  and a heat plenum module  204  may be the same as the corresponding modules from  FIG. 1 . In this embodiment, additional cooling may be required so instead of the simple filter  110  of  FIG. 1 , an entire cooling module  208  may be added. The cooling module  208  may include a filter  210 , and an adiabatic cooler  212 , that is, a porous filter through which water is dripped as air is drawn through the porous filter to cool the air. Such coolers are common in dry climates. The cooling module  208  may also include a mixing box  214  where warmed air may be recirculated, for example, when the inlet air temperature is too low. 
     A heat transfer module  216  may be used to facilitate the recirculation of air from the heat plenum module  204  to the cooling module  208 . A damper  218  may be used to control outside air flow into the cooling module  208  and another damper  220  may be used to mix recirculated air into the mixing box  214 . 
     In operation, outside air may be drawn into the mixing box  214 , may be filtered at filter  210  and cooled and humidified at adiabatic cooler  212 . The heat plenum module  204  may draw air from the server module  202  either by means of the exhaust fan  206  or by drawing air into the heat transfer module  216  and mixing the air into the cooling module  208 . A number of sensors  222 ,  224 ,  226  may sense temperature, humidity and pressure, respectively for use in controlling dampers  218  and  220  and the speed of fans  206  and  228  for managing air flow, temperature and humidity. 
       FIG. 3  illustrates another embodiment of a modular server cooling unit  300 . In this embodiment, the server module  302 , a heat plenum module  304 , a cooling module  308  and a heat transfer module  310  may operate as described above with respect to  FIG. 2 . Cooling coils  308  may be added to the cooling module  306  to provide more aggressive cooling than may be available with the simple adiabatic cooler  212  of  FIG. 2 . For example, the cooling coils  308  may be coupled to an external cooling tower  312 , local water infrastructure  314 , or a natural water source  316  to provide additional cooling, as required. Temperature and humidity sensors may allow a transition from adiabatic cooling to traditional air conditioning as required to meet heat and humidity requirements in the server module  302 . Damper  320  may be used to return air to the cooling module  306 . 
       FIG. 4  illustrates another embodiment of a modular server cooling unit  400 . In this embodiment, the server module  402 , a heat plenum module  404 , a cooling module  408  and a heat transfer module  406  may operate as described above with respect to  FIGS. 2 and 3 . The cooling coils  308  may be supplemented or replaced by cooling coils  412 , providing higher capacity cooling than is available from the chilled or natural water sources  FIG. 3 . A variety of known cooling techniques may be used to provide this additional cooling, for example, a DX evaporative condenser  414 , an air cooled condenser  416 , an air cooled chiller  418 , or a water cooled chiller  420 . Other techniques may also be used to provide cooling in association with the cooling coils  412 . To provide a higher quality server environment, one or more filters  410  may be used to purify the air. Damper  422  may be used to return air to the cooling module  408 . 
       FIG. 5  is another embodiment of a modular server cooling unit  500 . In this embodiment, four server modules  502 ,  504 ,  506 , and  508  are accommodated. Modular power units  510  and  512  may couple power from an outside source (not depicted) to the server modules  502 ,  504 ,  506 ,  508 . Cooling modules  514  and  516  may include adiabatic coolers  518  and  520 , respectively. Heat transfer modules  522  and  524  provide a path for cooled air to travel from the cooling modules  514  and  516  through respective adjustable grates  530 ,  532 ,  534 , and  536  and through each server module. A return exhaust plenum  546  draws air through the server modules  502 ,  504 ,  506  and  508 . An exhaust fan  552  may be used to remove the exhaust air. Return fans  526  and  528  may draw air from the return exhaust plenum  546  through adjustable dampers  548  and  550 . In one embodiment, air from the exhaust plenum  546  may be cooled by cooling coils  525  and  527 . To adjust the mix of input and return air, intake dampers  538  and  540  may be used in combination with the adjustable dampers  548  and  550 . Coolers  542  and  544 , similar to any of the cooling mechanisms described above may be used in conjunction with cooling coils  525  and  527  to provide cooling to the cooling unit  500 . 
       FIG. 6  illustrates a top view of an embodiment of a modular cooling unit  600 , illustrating side-by-side expansion. Each bay  602 ,  604 ,  606 , and  608  may contain one or more server modules  610 , and an adiabatic cooler  612 . Exemplary doors  614  and  618  may be opened to provide access to filters and servers. Access to other areas of the cooling unit  600  may be provided by additional access doors as shown. If each bay is considered to define a plane, bays may be expanded perpendicularly to the plane. 
       FIG. 7  illustrates a side view  700  of the modular cooling unit  600 .  FIG. 7  illustrates the server module  702 , the adiabatic cooler module  704 , and an exhaust fan  706 . An adjustable damper  708  allows controlled mixing of exhaust air with inlet air. A filter  710  may provide a first level of air filtering before the adiabatic cooler module  704 . An exhaust damper  710  may vent at least a portion of the air flowing from the exhaust fan out of the system. 
       FIG. 8  is a flow chart of a method  800  for providing a modular cooling unit, such as the modular cooling unit  400  of  FIG. 4 . At block  802 , a plurality of common-sized modules may be provided. The modules may be uniform in size or may be constructed on a standard grid, such as a one half or a one quarter grid, allowing, for example, doubling the number of units in a module space. Commonly dimensioned mounting points may allow easy mechanical connections both module-to-module and module-to-building/floor. 
     At block  804 , common-sized modules may be adapted to provide a server module  402 , with server mounting hardware (not depicted), such as a standard rack mount or blade mount chassis, a heat plenum module  404  with inlet and exhaust vent points, and a cooling module  410  with one or more filtering and cooling inserts, such as an adiabatic cooler, cooling coil, filter, or all of these. 
     At block  806 , in some embodiments a heat transfer plenum module  406  may be provided to selectively (controllably) return exhaust air to the cooling module to allow adjustment of temperature and humidity. In some embodiments, air to or from the cooling module may be adjusted as part of the exhaust air mixing process. 
     At block  808 , the server  402 , heat plenum  404 , heat transfer  406  (if used) and cooling module  410  may be mechanically and electrically attached to each other as required. The components may be removably attached, e.g., bolted or clipped together, to allow easy maintenance and upgrade. An optional power module, e.g. module  510  of  FIG. 5  may be used to condition and supply power to the server module  402  and other modules as required. Standardized power connection points may be used to accommodate wiring between those modules requiring power connections. When power requirements cannot be determined, or may vary over time, for example, in a server module, channels may be provided to allow different gauge wires or busses to be routed as needed. 
     At block  810 , server computers (not depicted) may be mounted in the server module  402 . 
     At block  812 , the cooling module  410  may be configured as needed and as described above, to include elements from a simple filter to an adiabatic cooler to cooling coils connected to an external condenser or water chilled cooler. 
     At block  814 , the system  400  may be operated, so that outside air may be circulated through the cooling module  410 , through the server module  402  and into the heat plenum  404 . At the heat plenum  404 , the air may exhausted to the outside. 
     At block  816 , air from the heat plenum  404  may be returned to the server module  402  via the heat transfer plenum  406 . 
     Although the foregoing text sets forth a detailed description of numerous different embodiments of the invention, it should be understood that the scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possibly embodiment of the invention because describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention. 
     Thus, many modifications and variations may be made in the techniques and structures described and illustrated herein without departing from the spirit and scope of the present invention. Accordingly, it should be understood that the methods and apparatus described herein are illustrative only and are not limiting upon the scope of the invention.