Protective suits isolate wearers from chemical and biological weapons. But body heat generated inside the suits can be a problem. Researchers from Pacific Northwest National Laboratory aim to change that.
This is an artist's rendering of a manportable cooling system. The unit, weighing approximately 3 to 4 lb, provides chilled water that flows through a vest (not shown) to keep the wearer comfortable.
They are developing a heat-actuated lightweight and compact cooling unit capable of keeping down temperatures within protective suits for several hours. Chilled water circulates through a vest, and is capable of providing relief up to 6 hr. The chilled-water loop is itself cooled by a heat exchanger in an absorption-cycle cooling system. Here, a thermochemical compressor -- powered by thermal energy from the burning of a fuel such as propane -- circulates refrigerant through the heat exchanger. Such heat-actuated compressors consume much less power than their electromechanical counterparts, making them well suited for portable refrigeration applications.