Abstract:
A mobile communications shelter comprising a personnel accessible chamber containing racks of stacked electronic communications equipment positioned along or adjacent to interior walls of the chamber, and a refrigeration apparatus mounted outside of the chamber and configured to supply cooled air to the chamber, is characterized by an air distribution assembly having a plurality of air ducts configured for directing cooled air supplied by the refrigeration apparatus to a plurality of selected vertical levels of the equipment.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Mobile communications shelters are designed to house electronic communications equipment for many different agencies such as Army, field and combat communications centers, police and intelligence agency surveillance, and the like. The electronics equipment is typically stacked in the interior space of vans, combat vehicles such as Hummvees, communications shelters or similar mobile facilities or tents with standing racks of the equipment placed against the interior vertical walls of the space. It is important to maintain the interior of the space or at least the directed air flow in the space at a temperature necessary to maintain the equipment at desired operating temperatures and to prevent equipment shutdown or failure due to excessive interior temperature resulting in equipment temperatures leading to unreliable operation or shut-down. For this purpose, such mobile communications shelters are equipped with air conditioning equipment often mounted exterior to the equipment chamber to provide cool air which is typically directed to the chamber interior from a single or duel air outlet in the back wall. Often, it is found that the electronic communications equipment is pushed against the chamber wall, in front of, if not against, the cool air distribution vent, and otherwise stacked vertically in the chamber with one or more stacks at least partially, if not substantially, obstructing cool air from being directed to other stacks of equipment, thereby impeding and preventing proper cooling and ventilation. 
       SUMMARY OF THE DISCLOSURE 
       [0002]    The mobile communications shelter described herein is characterized by an air distribution assembly cooperating with the air outlet of a mounted refrigeration apparatus or including an air outlet assembly cooperating with the evaporator of a mounted refrigeration apparatus. The assembly comprises a plurality of air ducts configured for directing cooled air supplied by the refrigeration apparatus to the racks of stacked electronic communications equipment positioned in the shelter interior and with the air distribution being adjustable to direct cool air to a plurality of selected vertical levels of the stacked equipment and to selected locations or positions within the equipment chamber. The air distribution assembly comprises one or more primary air ducts for directing air from the air outlet of the mobile shelter mounted refrigeration system and a plurality of secondary air ducts communicating with the primary air ducts. In a preferred embodiment, the secondary air ducts include one or more air vents or outlet ports configured to selectively direct and/or adjust cold air flow to selected components and heat loads. Specific details and description of the air distribution assembly are presented in the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a perspective view of a mobile communications shelter with the top and two side walls removed to show the interior chamber and illustrate the components of the air distribution assembly and examples of racks and equipment layout; 
           [0004]      FIG. 2  illustrates a portion of a secondary air duct showing connected segments and illustrating examples of air distribution outlet ports; and 
           [0005]      FIG. 3  shows a supplemental cooling coil and fan components used with the assembly. 
       
    
    
     DETAILED DESCRIPTION  
       [0006]    In  FIG. 1 , two side walls and the ceiling of mobile communications shelter  10  are removed to show the interior chamber  11  in which are positioned a plurality of vertical racks  26  on which electronic communication components are stacked. The location and layout of the vertical racks is for the purpose of illustration only. In the embodiment illustrated, three sets or rows of racks are shown, with only a portion of the electronic equipment used stacked in the racks. Each of the rows of stacked equipment are adjacent to an interior wall. In the embodiment, the racks of equipment are spaced apart from the respective walls along which they are positioned, thereby providing a space between the equipment and the walls for air distribution ducts and air flow. 
         [0007]    Although the shelter provided air conditioner is not shown, the air conditioner inlet  15  is located at end wall  13  of the shelter. Communicating with the cool air inlet  15  are primary air ducts  20  and  22  which extend generally horizontally along the interior walls. In an alternative embodiment, one or more primary air ducts may extend into the center area of the chamber, in addition to or instead of, along the interior walls. The length of a primary air duct is not critical so long as it provides adequate air supply to the secondary air ducts which communicate with and extend from the primary air duct or ducts. 
         [0008]    Secondary air ducts are provided with vents for directing air to the interior chamber, at selected vertical and horizontal positions for maintaining the interior chamber at the desired temperature. In the embodiment shown, secondary air duct  24  extends vertically, downwardly from primary air duct  22  between an interior wall (not shown) and stack of equipment  25 . Another secondary air duct  28  extends horizontally from primary air duct  20  to the front of a stack of electronic equipment, and downwardly therefrom to provide the cooling air. Any number of secondary air ducts may be used, and their respective lengths, as well as positions of air vents for directing air therefrom selected to meet the configuration and layout of the electronic equipment within the shelter. For this purpose, the secondary air ducts may comprise a plurality of connected and disengagable duct segments. 
         [0009]    Also observing  FIG. 2 , a section of a secondary air duct is illustrated, with segments  17  and  19  connected. The secondary air duct may be shortened or lengthened by increasing or reducing the number of segments. Any number of segments of the same or different lengths may be used to accomplish the purpose of distributing the air at different vertical levels, thereby providing cooling to the equipment along the vertical racks as needed. As shown, air distribution vents  14  and  16  are on different surfaces or faces of the segments. The secondary air duct segments are preferably shaped so that the air distribution vents can be directed by simply rotating a segment to allow the air to be directed as desired. For this purpose, it may be preferred to use cylindrical air ducts and air duct segments or square or rectangular air duct segments. Moreover, the primary air ducts may also be segmented to accommodate length modifications as desired. The secondary air duct segments may be provided with a single air vent, multiple air vents, or no air vents. The air vents are preferably configured to allow adjustment of the direction and/or amount of cold air to selected equipment components and heat loads. Moreover, an air duct segment  17  may also be opened or vented at a lower end  21  to direct air downwardly, or the end of a duct may be closed, or capped, as desired. 
         [0010]    The ends of the segments may be connected using a force-fit connection, threadedly engaging, or otherwise detachably secured to the ends of the adjacent segments using clamps, screws, clips, brackets, etc. as well. Moreover, the ducting itself may be of any suitable material such as sheet metal, plastic, or the like commonly used for air handling or air conditioning ducts. 
         [0011]    In another embodiment of the invention, the air distribution assembly may include one or more fans positioned at the juncture of the primary air duct or ducts and the vehicular air conditioning or refrigeration cool air outlet. The use of such fans will aid in the distribution of desired amounts of cool air to the various positions in the shelter chamber where cool air is to be vented. For this purpose, a shroud, manifold or other air handling equipment component may be mounted, connected to, or added on to the described air distribution assembly. Such an added component may house the supplemental fan or fans to meet the desired air distribution demands. 
         [0012]    In yet another embodiment, where high ambient environmental temperatures and/or equipment temperature needs dictate, a supplemental cooling system may be used, either as a stand alone heat exchange apparatus cooperating with the above described air distribution assembly to cool the shelter interior, or added as an additional component to the previously described air distribution assembly. A standalone system will have its own cooling coil or evaporator and one or more fans for providing additional cooling to the shelter chamber. Alternatively, the supplemental cooling may comprise a cooling coil or evaporator as a component of an air handler integrated into the previously described air distribution assembly for further reducing the temperature of the air from the vehicular air conditioner. The fan may be placed upstream or downstream from the cooling coil or evaporator for directing cool air into the air ducts. Chilled water, heat exchange fluid or refrigerant may be supplied to the coil or evaporator using a supplemental condenser or refrigeration system such as a vapor compression refrigeration apparatus, or a complex compound solid-gas absorption system such as described in U.S. Pat. Nos. 5,598,721, 6,224,842 and 6,736,194, the descriptions of which are incorporated herein by reference. Other supplemental cooling or refrigeration systems known to those skilled in the art may also be used.  FIG. 3  illustrates such a supplemental cooling and air handling assembly attached to a shelter wall at the shelter AC cool air vent  15 . The supplemental assembly incorporates a fan  27  and a cooling coil  29  to provide further cooling to the air supplied to primary air ducts  20  and  22 .