Development of a man-portable microclimate adsorption cooling device

This paper describes the development of a passive microclimate adsorption cooling device for the Marine. The system is designed to provide cooling to the individual by chilling water that is being pumped through a liquid cooling garment. The entire system is mounted on a portable backpack frame. The system uses the evaporation and subsequent adsorption of water on a desiccant bed to chill the circulating water being pumped through the garment. Extensive screening and testing of numerous desiccants was performed, which resulted in the selection of calcium oxide as the adsorbent for the vaporized water. A bench-top breadboard system was constructed and tested, with demonstrated cooling rates of up to 200 W for periods in excess of six hours. Further development work involved the performance testing of three different demonstration prototype designs that are fixed to a military backpack frame. These three demonstration prototypes were analyzed for maximizing cooling performance at the lowest possible mass. Finally, second-generation prototypes using the optimum designs were fabricated and tested