Abstract:
A portable air cooling system having a housing having an air inlet, an air outlet, an exterior surface and an interior cavity. A fan is axially disposed within the interior cavity for generating an air flow drawn from the air inlet, through the interior cavity and discharged through the air outlet. A photovoltaic panel is electrically coupled to the fan and provides sufficient electrical generating capacity to at least power the fan during daylight hours. A hydrating element is disposed intermediate the air inlet and air outlet for providing evaporative cooling. A cooling element is disposed intermediate the air inlet and air outlet and provides convective cooling by thermal transfer with a cold active cooling media such as water ice, dry ice or Gel Pack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable 
       RELEVANT FIELD 
       [0002]    This application is directed generally toward an evaporative cooling system and more specifically toward a portable solar powered evaporative cooling system. 
       BACKGROUND 
       [0003]    Numerous types of evaporative cooling systems are known in the relevant art. For example, “swamp coolers” are commonly used to evaporative cooling of homes and businesses located in arid regions. The swamp coolers are effective when used in the low humidity environments encountered in arid regions but are bulky, non-portable, and require constant water and energy supplies in order to operate. In many common situations, a need arises to provide air cooling for comfort and/or electronic equipment operation in locations lacking supplies or water or electrical power. For example, military troops dispatched to remote desert locations, persons camping in remote wilderness areas and/or disaster relief in locations affected by natural or man-made disasters. 
       SUMMARY 
       [0004]    In view of the foregoing, various exemplary embodiments of a portable cooling system are disclosed herein. The exemplary embodiments described herein provides an inexpensive portable cooling system which is not dependent on electrical grid infrastructures. In an exemplary embodiment, a portable air cooling system is comprised of a housing having an air inlet, an air outlet, an exterior surface and an interior cavity. A fan is axially disposed within the interior cavity for generating an air flow by drawing from the air inlet, through the interior cavity and discharging the air through the air outlet. In various exemplary embodiments, a flexible exhaust duct may be coupled to the air outlet. Alternately, a rotatable register may be utilized to direct the air flow from the air outlet. 
         [0005]    A photovoltaic panel is electrically coupled to the fan for powering the fan at least during daylight hours. The photovoltaic panel is sized to provide sufficient electrical generating capacity to power the fan. Photovoltaic panel may be coupled to the housing with a adjustable and/or pivoting geometric mount for positioning of the photovoltaic panel to obtain maximum electrical output therefrom. 
         [0006]    A cooling element is disposed within the interior cavity between the air inlet and air outlet and aligned such that its predominate face intersects the air flow broadside relative to its predominate face. The cooling element is configured to allow air to flow therethrough allowing heat to be transferred from the air to the cooling element. In one exemplary embodiment, the housing includes thermal insulation between its inner and outer walls. In this exemplary embodiment, the insulation generally surrounds the cooling element to maintain the cooling element below ambient temperatures. 
         [0007]    In various exemplary embodiments, the active cooling media may be water ice, dry ice, refrigerant gel, or any combination thereof. The refrigerant gel may comprised of hydroxyethyl cellulose, vinyl coated silica gel or any other media having a sufficient latent heat capacity. The various active cooling media may be suspended in a mesh having sufficient porosity to allow air flow therethrough. In other exemplary embodiments, one or more commercially available GelPacks may be used as the active cooling media. 
         [0008]    In one exemplary embodiment, the portable cooling system may include a hydrating element which is disposed intermediate the air inlet and air outlet. As with the cooling element, the hydrating element is aligned such that a predominate face of the hydrating element intersects the air flow broadside with its predominate face. The hydrating and cooling elements may be combined into a single element. For example, water ice may serve to provide both humidity to accomplish evaporative cooling as well as removing heat from the air flow. In various exemplary embodiments, the active hydrating media may be water or water ice absorbed into a cellulose, wood fiber, sponge, cloth, cloth-paper and/or clay media. 
         [0009]    In one exemplary embodiment, the cooling element may be disposed in a spaced series relationship with the hydrating element. 
         [0010]    In one exemplary embodiment, a desiccating element may be disposed intermediate the air inlet and the hydrating element. The desiccating element is intended to be used in locations where high humidity conditions exists. The desiccating element is optional in most circumstances. 
         [0011]    In one exemplary embodiment, a particulate filter element may be disposed intermediate the air inlet and the hydrating element. The particulate filter is intended to be used in dusty or sandy environments where particulates are of concern. Likewise, the particulate filter is optional in most circumstances. 
         [0012]    In various exemplary embodiments, the hydrating element and/or cooling elements may be disposed in separate compartments within the interior cavity of the housing. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]    The features and advantages of the various exemplary embodiments will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. Where possible, the same reference numerals and characters are used to denote like features, elements, components or portions of the inventive embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the inventive embodiments described herein and as is defined by the claims. 
           [0014]    FIG.  1 —depicts an isometric view of a portable air cooling system in accordance with an exemplary embodiment. 
           [0015]    FIG.  2 —depicts a transparent isometric view of a portable air cooling system in accordance with an exemplary embodiment. 
           [0016]    FIG.  3 —depicts a top view of a portable air cooling system in accordance with an exemplary embodiment. 
           [0017]    FIG.  4 —depicts a block diagram of an electrical system in accordance with an exemplary embodiment. 
           [0018]    FIG.  5 A—depicts a perspective view of an active cooling media in accordance with an exemplary embodiment. 
           [0019]    FIG.  5 B—depicts a perspective view of another active cooling media in accordance with an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Various exemplary embodiments of a portable air cooling system are disclosed herein. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present inventive embodiments. It will be apparent, however, to one skilled in the art that the present inventive embodiments may be practiced without these specific details. In other instances, well-known structures, devices or components may be shown in block diagram form in order to avoid unnecessarily obscuring the present inventive embodiments. 
         [0021]    Referring to  FIG. 1 , an isometric view of a portable air cooling system  100  in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the portable air cooling system  100  includes a housing  5  constructed of a generally rigid and non-corroding material. In a preferred embodiment, the housing  5  is constructed from a lightweight polymeric material. Suitable polymers for construction of the housing  5  include but are not limited to acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), neoprene, ethylene propylene-diene monomer (EPDM) and/or other thermoplastics. The selected polymeric material may preferably include ultraviolet light protective additives to prevent solar degradation of the housing  5 . Alternately, the housing  5  may also be constructed from lightweight metals such as aluminum alloys or galvanized sheet metal. The shape and dimensions of the housing  5  is not critical. One skilled in the art will appreciate that the shape and dimensions may be varied to accomplish a particular design objective. 
         [0022]    The housing  5  includes one or more air intake  10 ,  10 ′ ports from which ambient air is drawn into an interior cavity  5 A,  5 B ( FIG. 3 ) of the housing  5 . The housing further includes one or more discharge ports  15  for releasing water vapor used in evaporative cooling of the air drawn into the interior cavity  5 A,  5 B ( FIG. 3 ) of the housing  5 . The top of the housing  5  may include a lid  20  pivotally attached to the housing with hinges  25 ,  25 ′ for allowing access into the interior cavity  5 A,  5 B ( FIG. 3 ) of the housing  5 . 
         [0023]    Power for the portable air cooling system  100  may be generated by a photovoltaic panel  30 . The photovoltaic panel  30  may be coupled to the housing  5  typically with a multi-axis mount  35 . The mount  35  allows azimuth and/or elevation positioning  35 ′ of the photovoltaic panel  30 . The use of the multi-axis mount  35  is optional as the lightweight construction of the portable air cooling system  100  allows positioning of the photovoltaic panel  30  by simply reorienting the alignment of the housing  5  in a direction which provides the maximum solar exposure incident on the photovoltaic panel  30 . The photovoltaic panel  30  may be attached either to the lid  20  or a side of the housing  5  via the mount  35 . Typical electrical power generation by the photovoltaic panel  30  is in the range of 25-100 watts. One skilled in the art will appreciate that the electrical power generating capacity of the photovoltaic panel  30  is largely dependent on the scaling of the portable air cooling system  100  and internal fan  225  ( FIG. 2 ) electrical current requirements. 
         [0024]    A flexible exhaust duct  40  may be connected at an air outlet end  245  ( FIG. 2 ) of the housing  5 . The flexible exhaust duct  40  is used to routed cooled air flow into a particular location or enclosed structure. The flexible exhaust duct  40  may be constructed of any convenient material, preferably a lightweight and light colored polymeric or polymeric/canvas material. Alternately, a rotatable register may be utilized to direct the air flow from the air outlet (not shown.) 
         [0025]    Referring to  FIG. 2 , a transparent isometric view of a portable air cooling system  100  in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the housing  5  is shown in dotted lines to allow viewing of the major internal components of the portable air cooling system  100 . As mentioned previously, air  200  is drawn into the interior cavity  5 A,  5 B of the housing  5  with an axially mounted fan  225 . The axially mounted fan  225  may be 12 or 24 VDC powered. A high efficiency fan capable of generating air flows in a range of 40-400 CFM should be acceptable for most common configurations. One skilled in the art will appreciate that the flow capacity of the fan may be varied to accomplish a particular design objective. 
         [0026]    In one exemplary embodiment, a particulate filter  205  is mounted immediately downstream of the air intake ports  10  and is used to remove particulate matter such as dust, sand and/or allergens from the air  200  drawn into the housing  5 . The particulate filter  205  may be of any convenient type, for example, foam, fiberglass mesh, paper and/or cloth-paper combinations. The particulate filter  205  is an optional feature and is shown in dotted lines to indicate that its inclusion in the various inventive embodiments is optional. 
         [0027]    In another exemplary embodiment, an optional desiccation element  210  is provided to remove moisture from the air  200  drawn into the housing  5 . The desiccation element  210  is intended to be used in elevated humidity environments which may limit the effectiveness of evaporative cooling by the hydrating element  215 . The desiccation element  210  may include active hydroscopic media such as silica gel, calcium sulfate, calcium chloride, montmorillonite clay, and/or rice to remove humidity from the air  200  drawn into the housing  5 . The desiccation element  210  is likewise an optional feature and is shown in dotted lines to indicate that its inclusion in the various inventive embodiments is optional. 
         [0028]    In an exemplary embodiment, a hydrating element  215  is disposed between the air inlet  10  and air outlet  245  from the interior cavity  5 A,  5 B of the housing  5 . Ambient air  200  drawn into the housing  5  is passed through the hydrating element  215  which causes heat to be transferred from the air to water absorbed in the active hydrating media. The transferred heat causes a portion of the water to be converted in state from liquid to vapor which is released  220  through one or more discharge ports  15 , carrying the heat away from the air flowing through the hydrating element  215 . The air flow is thus evaporatively cooled by the heat carried away by the escaping water vapor  220 . The active hydrating media may be water absorbed onto cellulose, wood fiber, sponge, cloth, water ice, cloth-paper or clay media. 
         [0029]    The axially mounted fan  225  is sized to draw air  200  through the various elements  205 ,  210 ,  215 ,  240  and out through the air outlet  245 . In an exemplary embodiment, the axially mounted fan  225  is installed in a partition  235  which separates the hydrating element  215  from the cooling element  240 . The placement of the partition  235  between the hydrating element  215  and the cooling element  240  is not required but advantageous to minimize ambient heat from reducing the cooling capacity of the cooling element  240 . In an exemplary embodiment, the cooling element  245  is disposed between the partition  235  and the air outlet  245  from the interior cavity  5 A,  5 B of the housing  5 . In this exemplary embodiment, the cooling element  240  is contained in a separate compartment  5 B from the hydrating element  215  in order to provide insulation  325  ( FIG. 3 ) around this portion of the interior cavity  5 B. The air inlet portion of the interior cavity  5 A does not require insulation. 
         [0030]    The cooling element  240  contains an active cooling media which is previously cooled to well below the ambient air temperature of the air  200  being drawn into the interior cavity  5 A,  5 B. The active media may be placed inside the cooling element  240  via a lid  240 ′. The lid  240 ′ allows the interior of the cooling element  240  to be filled with the active cooling media. The active cooling media may be water ice, dry ice, refrigerant gel, or any combination thereof. The refrigerant gel may be comprised of hydroxyethyl cellulose, vinyl coated silica gel or any other media having a sufficient latent heat capacity. In another exemplary embodiment, the various active cooling media may be suspended in a mesh having sufficient porosity to allow air flow through the cooling element  240 . In other exemplary embodiments, one or more commercially available GelPacks may be used as the active cooling media. To the extent reasonably possible, when using solid blocks of ice (either water or dry ice) or GelPacks, the blocks should be arranged to allow air flow through the cooling element  240  to maximize heat transfer between the air flow and the active cooling media. The air  200  flowing through the cooling element  240  exits the interior cavity  5 A,  5 B of the housing  5  through the air outlet  245  and may then discharge into the flexible exhaust duct  40 . The flexible exhaust duct  40  may then be positioned by the user to route the cooled air flow into a particular location or into an enclosed structure, for example a tent. 
         [0031]    Referring to  FIG. 3 , a top view of a portable air cooling system  100  in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the various air treatment elements  205 ,  210 ,  215 ,  240  are shown held in place within the interior cavity  5 A,  5 B of the housing  5  with U-shaped channel members  305 ,  305 ′,  310 ,  310 ′,  315 ,  315 ′  320 ,  320 ′. The U-shaped channel members  305 ,  305 ′,  310 ,  310 ′,  315 ,  315 ′  320 ,  320 ′ are dimensioned to span a width of each element  205 ,  210 ,  215 ,  240  and maintain the various air treatment elements on opposing sides. One skilled in the art will appreciate that other mechanisms to secure the various elements  205 ,  210 ,  215 ,  240  within the interior cavity  5 A,  5 B of the housing  5  may be employed as well. The exemplary nature of the U-shaped channel members  305 ,  305 ′,  310 ,  310 ′,  315 ,  315 ′  320 ,  320 ′ is shown in dotted lines to indicate that this arrangement is optional. In an exemplary embodiment, baffles  330 ,  330 ′ may be provided to direct the air flow into the compartment  5 B containing the cooling element  240 . The baffles  330 ,  330 ′ are likewise optional. The compartment  5 B containing the cooling element  240  may preferably be insulated  320  for extending the life of the active cooling media included with the cooling element  240 . 
         [0032]    Referring to  FIG. 4 , a block diagram of an electrical circuit in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the photovoltaic panel  30  is electrically connected  230  to an optional energy management unit  405 . The energy management unit  405  allows excess power generated by the photovoltaic panel  30  to charge a battery  410 . Alternately, when power output from the photovoltaic panel  30  falls below that required to power the fan  225 , the energy management unit  405  draws power from the battery to power the fan  225 . This arrangement extends the time in which cooling may be provided by the portable air cooling system  100 . In another exemplary embodiment an power switch  425  may be provided to allow the user to turn the portable air cooling system  100  on or off as desired. In another exemplary embodiment, a motor speed control  420  may be provided which controls the speed of the fan  225 . The motor speed control  420  may be used to change the speed of the fan  225  as desired by the user in response to personal preferences and/or changing environmental conditions. One skilled in the art will appreciate that the energy management unit  405 , power switch  425  and/or motor speed control  420  may integrated into a common unit. Other electronic features such as a thermostat may be integrated into one or more of the units as well. 
         [0033]    Referring to  FIG. 5A , a perspective view of an active cooling media in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the lid  240 ′ which allows access into an interior compartment of the cooling element  240  is lifted and water ice  510  is poured from an ice bag  505  into the interior compartment of the cooling element  240 . The water ice  510  may be in any convenient form however, crushed ice or cubes may provide better cooling due to increases in exposed surface areas. Once a sufficient amount of active cooling media has been added to the cooling element  240 , the lid  240 ′ is closed and the cooling element  240  replaced into the housing  5 . 
         [0034]    Referring to  FIG. 5B , another perspective view of an active cooling media in accordance with an exemplary embodiment is depicted. In this exemplary embodiment, the lid  240 ′ which allows access into the interior compartment of the cooling element  240  is lifted and one or more Gel Packs  515  are stacked within the interior compartment of the cooling element  240 . The Gel Packs  515  may be in any convenient form however, cubes or elongated blocks may provide better cooling due to increases in exposed surface areas. As before, once a sufficient amount of active cooling media has been added to the cooling element  240 , the lid  240 ′ is closed and the cooling element  240  replaced into the housing  5 . In another exemplary embodiment, a coarse mesh containing the active media used in the gel blocks may be placed in the position of the cooling element  240  as a type of cooling screen (not shown.) 
         [0035]    The various exemplary inventive embodiments described herein are intended to be merely illustrative of the principles underlying the inventive concept. It is therefore contemplated that various modifications of the disclosed embodiments will without departing from the inventive spirit and scope be apparent to persons of ordinary skill in the art. They are not intended to limit the various exemplary inventive embodiments to any precise form described. In particular, it is contemplated that the portable air cooling system may be constructed from any suitable material with different dimensions and/or cross-sectional profiles. No specific limitation is intended to a particular construction material(s), assembly order, shape or sequence described. Other variations and inventive embodiments are possible in light of the above teachings, and it is not intended that the inventive scope be limited by this specification, but rather by the Claims following herein.