An adsorber unit has an outer shell, a plurality of internal tubes extending through the shell for carrying 
heat transfer fluid, each tube having outwardly projecting fins along its entire length, and a 
solid adsorbent material in the shell surrounding the tubes such that the fins project into the adsorbent material, the fins being of a material (e.g., 
metal) of higher 
thermal conductivity than the adsorbent material. 
Metal wool loosely packed inside the tubes, or internal radial fins swaged into the tubes, increase internal surface area thereby enhancing 
convective heat transfer. 
Metal wool loosely packed between the external fins, or fine wire 
metal coils lightly squeezed between the external fins, further increase external surface area of the 
heat exchanger in contact with the adsorbent thereby enhancing 
contact heat transfer. Performance is enhanced because the external fins and 
wool or wire coils transport heat more efficiently to all regions of the adsorbent, and permit less non-adsorbent 
heat exchanger material (e.g., 
metal) to be used for a given amount of adsorbent. Two or more such units are used in an adsorption 
heat pump. This design utilizes existing components (e.g., shell-&-tube 
heat exchanger, internally and externally finned tubing, and metal wool or wire coils) in a novel manner heretofore untried. In one exemplary embodiment, 
automobile air conditioning, 
exhaust heat is used to power such an air conditioner. The significant additional power used by the mechanical compressor of an automobile (12%-17% during commuting for subcompact to midsize cars) can be nearly eliminated by powering the air conditioner with otherwise wasted 
exhaust heat. The adsorbent is heated and cooled by light oil (called 
Heat Transfer Fluid, HTF) which in turn is heated and cooled by exhaust and 
fresh air. Such indirect heating and cooling achieves the required efficiency, and allows using 
phase change material (e.g., 
wax) to store and therefore fully utilize 
exhaust heat. A 
refrigerant reservoir is included which provides immediate cooling after start-up of a cold engine, while the exhaust 
system and 
heat pump are still heating up in order to start pumping 
refrigerant. Eliminating the mechanical compressor increases fuel mileage by 14-18% for midsize, compact, MS and subcompact cars, or 4.6-6.0% annually, given a four-month cooling season.