Abstract:
A wearable personal cooling apparatus includes an outer layer, wherein the outer layer comprises fabric proportioned and configured to closely envelop a human torso, a primary air plenum proximate the outer layer, an inner layer proximate the outer layer and in communication with the primary air plenum, wherein the inner layer is configured to distribute air from the primary air plenum throughout an inner surface of the inner layer, and a secondary air plenum arranged within the inner layer and in communication with the primary air plenum, wherein the secondary air plenum comprises a first end proximate the primary air plenum and a second end, and wherein the secondary air plenum is configured to direct air from the first end to the second end.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Generally, the present invention is directed to a personal cooling apparatus, and more particularly, example embodiments of the present invention are directed to a personal cooling vest configured to enhance sensible and latent heat transfer from a user wearing the vest. 
         [0002]    Heat stress is a symptom of excessive heat exposure which may lead to loss of the ability to function effectively (e.g., disruption of cognitive thought), to unconsciousness, and to critical or full body failure. There are numerous occupations where an excessively hot environment or particularly strenuous task affects the ability for persons to perform effectively. Military personnel in particular are affected in hot environments due to additional clothing and personal protection which are generally employed. Conventional systems for personal cooling involve complex liquid circulation systems which typically aim to exchange heat with a wearer through complex tubing. Other systems employ ice-packs or other pre-cooled means. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0003]    According to an example embodiment of the present invention, a wearable personal cooling apparatus includes an outer layer, wherein the outer layer comprises fabric proportioned and configured to envelop a human torso, a primary air plenum proximate the outer layer, an inner layer proximate the outer layer and in communication with the primary air plenum. The inner layer is configured to distribute air from the primary air plenum throughout an inner surface of the inner layer, and a secondary air plenum is arranged within the inner layer and in communication with the primary air plenum. The secondary air plenum includes a first end proximate the primary air plenum and a second end. The secondary air plenum is configured to direct air from the first end to the second end. 
         [0004]    According to an additional example embodiment of the present invention, a wearable personal cooling apparatus includes an outer layer, wherein the outer layer includes fabric proportioned and configured to envelop a human torso. The outer layer further includes a neck cutout proximate a neck portion of the human torso, wherein the outer layer further includes first and second arm cutouts proximate first and second arm portions of the human torso. The outer layer further includes a neck exit vent arranged within the neck cutout, and the outer layer further includes first and second arm exit vents arranged within the first and second arm cutouts. The apparatus further includes a primary air plenum proximate the outer layer and arranged proximate a waist portion of the human torso, an inner layer proximate the outer layer and in communication with the primary air plenum. The inner layer is configured to distribute air from the primary air plenum throughout an inner surface of the inner layer. The inner surface of the inner layer is proximate an outer surface of the human torso, and a secondary air plenum is arranged within the inner layer and in communication with the primary air plenum. The secondary air plenum includes a first end proximate the primary air plenum and a second end proximate a chest area of the human torso, and the secondary air plenum is configured to direct air from the first end to the second end. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0006]      FIG. 1  depicts a personal cooling vest, according to an example embodiment; 
           [0007]      FIG. 2  depicts a personal cooling vest, according to an example embodiment; 
           [0008]      FIG. 3  depicts a personal cooling vest, according to an example embodiment; 
           [0009]      FIG. 4  depicts a personal cooling vest, according to an example embodiment; 
           [0010]      FIG. 5A  depicts a cut-away of fabric forming a portion of a personal cooling vest, according to an example embodiment; 
           [0011]      FIG. 5B  depicts a cut-away of fabric forming a portion of a personal cooling vest, according to an example embodiment; 
           [0012]      FIG. 6  depicts a primary air plenum of a personal cooling vest, according to an example embodiment; 
           [0013]      FIG. 7  depicts a fan apparatus for use with a personal cooling vest, according to an example embodiment; 
           [0014]      FIG. 8  depicts a personal cooling vest, according to an example embodiment; and 
           [0015]      FIG. 9  depicts a personal cooling vest, according to an example embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Example embodiments of the present invention provide a personal cooling vest which greatly enhances the transfer of heat from a user to effectively reduce the user&#39;s core temperature. In this manner, the user benefits through increased ability to withstand hot environments. Further benefits include a more distributed pattern of pressure impinging upon a user when wearing addition material, armor, backpacks, etc upon the vest. According to example embodiments, the personal cooling vest augments sensible and latent heat transfer for better personal cooling. Sensible heat transfer occurs if supply air is below the user&#39;s skin surface temperature. Latent heat transfer occurs by evaporating perspiration from the user&#39;s body. 
         [0017]    Turning to  FIG. 1 , the personal cooling vest  100  is designed to receive ambient air supplied by a fan, or to receive conditioned air supplied by an external cooling device through a supply opening near the waistline  101 . The ambient or conditioned air enters a primary plenum at the waistline  101  and flows upwards across the torso. The primary plenum consists of a number of vent holes distributing the air at an optimal velocity. The air flow then enters a matrix material that surrounds the torso. The air moves through two different mediums to cool the user. The stretchable outer vest material  201  holds the matrix close to the users body so that the air may not channel, but rather be forced to travel through the intended plenums. Most of the air will travel up through the matrix, causing the air to be turbulent and direct it to the user&#39;s body with added turbulence. The resultant turbulent air flow increases sensible heat transfer from the body due to the higher coefficient of thermal convection and introduces dry air to the user&#39;s body providing greater latent heat transfer. The process air warms as it moves up a user&#39;s body resulting in an increase of its dew point. As the dew point increases, so does the air&#39;s potential water content. For example, increasing from 20° C. to 30° C. increases the potential water content from 17.148 g/m 3  to 30.078 g/m 3  equivalent to a 75% increase in water content. This expanded capability allows the cooling apparatus to govern itself. For example, even if the surrounding air is at 100% relative humidity, or fully saturated with water, as it warms it is enabled to accept vaporized perspiration from the user. The air exits past the user&#39;s body at a neck portion  103  and under the user&#39;s arms at portions  102 ,  104 . This exit air is directed to increase the cooling area, thus further enhancing cooling. All of these components reside within the stretchable vest that holds the aforementioned matrix against the user&#39;s body, not allowing the air to channel to the exit without proper cooling flow. 
         [0018]      FIG. 2  depicts an alternate configuration of the personal cooling vest  100 , according to an example embodiment. As depicted, waste heat is recycled in a closed fashion. Thus, the closed system shares all of the above components, further including a seal configured to prohibit air from leaving the vest at the underarm portions  102 ,  104 . Although not illustrated in  FIGS. 1-2 , it should be appreciated that additional sealing functionality may be provided by a waist-band draw-string or other means to prohibit leakage in the waist area of the vest  100 . The exit air is collected at the user&#39;s neck through portion  103  and recycled through supporting cooling systems. Capturing this air allows some cooling systems to achieve higher efficiency. Furthermore, the vest may be worn beneath sealed garments configured to protect a user from the external environment, such as a HAZMAT suit. Thus, capturing and re-circulating this air facilitates cooling while limiting or prohibiting external air from entering the vest  100 . Thus, the personal cooling vest  100  may provide enhanced cooling thereby allowing a user to survive hostile environments (e.g., nuclear-biological-contamination areas) where completely closed systems should be employed. 
         [0019]    As described above, example embodiments provide personal cooling vests which are configured to enhance both latent and sensible heat transfer through use of a matrix configured to promote turbulent air flow proximate a user&#39;s skin/torso. It should be noted, however, that warm air, as well as ambient temperature air, may be circulated to provide personal heating in some applications, for example, applications where a user is in a cold environment. 
         [0020]    Hereinafter a more detailed description of the componentry and construction of the vest  100  is provided. 
         [0021]      FIG. 3  depicts the personal cooling vest  100 , according to an example embodiment. As illustrated, the vest  100  includes the primary air plenum  204  arranged within a primary chamber  203 . The primary chamber  203  may be a sewn or bonded chamber comprised primarily of a flexible, stretchable outer vest material  201 , proximate a matrix material  202 . The vest  100  further includes exit vents  205 ,  206 ,  207  arranged within the underarm and neck portions. 
         [0022]    Turning to  FIG. 4 , a view of the interior portion of the vest  100 , which would be proximate a user&#39;s torso when wearing the vest, is provided. As illustrated, the vest  100  includes first, second, and third secondary air plenums  210 ,  211 ,  212  arranged within the matrix  202 . For example, studies have shown that for a given core temperature, the back and chest have higher sweating rates as compared to other portions of a user&#39;s torso. Therefore, the secondary air plenums  210 - 212  are configured to deliver air more readily to these portions of a user&#39;s body. Thus, the effectiveness of the cooling/evaporative air flow is greatly enhanced due impingement heat transfer, which generates high convection coefficients, because the bodies fluid boundary is disrupted by the perpendicular impinging jets The secondary air plenums  210 ,  211 , and  212  are fed air from the primary plenum  204 . Each secondary air plenum  210 ,  211 , and  212  comprises a plurality of plenum-portions  505 . The plenum portions  505  are configured to transmit air more readily than the surrounding matrix  202 . For example, the plenum portions  505  may comprise fabric less dense than the surrounding matrix, tubes, tube-like pockets, or any suitable means to increase airflow relative to the surrounding fabric of the matrix  202 . 
         [0023]    With regards to supply air, ports  208  and  209  are arranged on the primary plenum  204 , and configured to receive supply air from an external source. 
         [0024]    With regards to maintaining air flow from the supply air throughout the matrix  202  to the exit vents  205 ,  206 , and  207 , flap  213  comprising sealing zipper  214  arranged on the vest  100 . The sealing zipper  214  may be a zipper configured to limit and/or reduce the flow of air there-through. Further, the flap  213  provides further closure/sealing to reduce the loss of internal air and promote internal circulation of the air. An alternate design may include a fully closed vest with expansion folds, allowing the user to pull the garment over their head and avoid zipping. 
         [0025]    Turning to  FIGS. 5A-5B , the particular arrangement of layers within the vest  100  are illustrated. As shown the primary plenum  204  comprises a plurality of apertures  507  configured to distribute air supplied to the plenum  204  relatively evenly throughout the matrix  202 . These apertures  507  may be arranged equidistant or relatively equidistant. Further, the matrix  202  includes a plurality of layers configured to distribute the supplied air to a torso of a user. 
         [0026]    Generally, a first layer  502  is arranged to be proximate a user&#39;s skin. The layer  502  may comprise any fabric allowing air to flow and pass there-through. The first layer  502  is configured to disrupt localized air-flow in such a manner that any laminar flow is converted to more turbulent airflow. This turbulent flow is transmitted to the user such that localized turbulence is impingent on a user&#39;s torso. The secondary air plenums&#39; portions  505  are arranged within the matrix  202  proximate the first layer  502 . Air plenums&#39; portions  505  are configured at a substantially optimal distance from the users body to enhance impingment heat transfer and user comfort. Finally, the outer, stretchable layer  201  is arranged proximate the matrix  202 . The layer  201  is arranged at a waistline  101  of the vest to surround the primary plenum  204 , and affixed to the matrix  202  within the interior of the vest  100 . Furthermore, a waist-band and/or waist-tie  509  may further facilitate positioning of the matrix  202  against a user&#39;s torso. As the layer  201  is generally or substantially impermeable with regards to air, air supplied from the primary plenum  204  is directed upwards through the matrix  202  and secondary plenums. 
         [0027]      FIG. 6  depicts the primary air plenum  204  of the personal cooling vest  100 , according to an example embodiment. As shown the plenum  204  may be tubular and may be arranged to wrap around a user&#39;s waist when arranged within the vest  100 . Upon vest closure, a first end  601  is configured to mate and/or seal with a second end  602 . This may be facilitated through interlocking means, sliding means, or any other suitable means to secure the first end  601  to the second end  602  and maintain airflow therein. If the apparel is designed as a pull over, this interlocking means may be a sliding mechanism as well to enable donning the garment. 
         [0028]      FIG. 7  depicts a fan apparatus for use with the personal cooling vest, according to an example embodiment. The fan apparatus  700  is configured to provide airflow to the primary plenum  204  through ports  708 - 709 . The fan apparatus  700  includes a housing  701  defining a fan assembly  702  and the ports  708 - 709 . The fan apparatus  700  may further include heat exchangers  703  and thermo-electric modules  704 . Thus, the fan apparatus  700  may reduce of temperature of air entering the fan assembly  702  before exiting the ports  708 - 709 . Alternatively, the fan apparatus  700  may supply ambient air without conditioning. In other alternatives, conditioned air may be provided to the primary plenum  204  from entirely external means, for example, from an umbilical line or piping providing conditioned or heated air from a vehicle, air-conditioning/filtration system, or any other suitable means. 
         [0029]    To better understand the form-fitting nature of exemplary personal cooling vests,  FIGS. 8-9  provide stylized views of the same. It is noted that according to some example embodiments, an adjustment means  901 ,  902  may be provided to reduce the proximity of the matrix  202  and a user&#39;s torso. The adjustment means  901 ,  902  may comprise pleats and/or additional zippers. Furthermore, a drawstring, elastic band, or waistline adjustment means  509  may be provided within or proximate chamber  203  to further enhance the form-fitting nature of the vest  100 . Moreover, additional cushioning or positioning material  903  may be arranged within a lumbar or back portion of the vest  100  to position the matrix  202  proximate a user&#39;s skin to reduce uninterrupted air flow and further reduce process air channeling 
         [0030]    Although particularly described above as encompassing a personal cooling vest, it is readily appreciated that the matrix and plenum combinations described above are applicable to any number of garments. For example, short trousers may be arranged with a turbulence matrix and plenum to facilitate cooling/heating of lower extremities of a user. Furthermore, a cap or hood may be arranged with a turbulence matrix and plenum to facilitate cooling/heating of a user&#39;s cranial areas. Moreover, any combination of hood, vest, short trousers may be combined as a complete personal cooling/heating temperature regulation system. In such combinations a primary plenum may be provided for each portion, or a main plenum may supply air for all portions, for example, through mating of respective turbulence matrices of each portion. Therefore, example embodiments should not be limited to personal cooling vests alone, but are extensible to any suitable personal garment. 
         [0031]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.