This paper presents the achievements gained in solid sorption refrigeration prototypes since the end of the l970s, when
interest in sorption systems was renewed. The applications included are ice making and air conditioning. The latter
includes not only cooling and heating, but also dehumidification by desiccant systems. The prototypes presented were
designed to use waste heat or solar energy as the main heat source. The waste heat could be from diesel engines or from
power plants, in combined cooling, heating and power systems (CCHP). The current technology of adsorption solarpowered
icemakers allows a daily ice production of between 4 and 7 kgm2 of solar collector, with a solar coefficient of
performance (COP) between 0.10 and 0.16. The silica gel–water chillers studied can be powered by hot water warmer than
55 1C. The COP is usually around 0.2–0.6, and in some commercially produced machines, it can be up to 0.7. The
utilization of such chillers in CCHP systems, hospitals, buildings and grain depots are discussed. Despite their advantages,
solid sorption systems still present some drawbacks such as low specific cooling power (SCP) and COP. Thus, some
techniques to overcome these problems are also contemplated, together with the perspectives for their broad
commercialisation. Among these techniques, a special attention was devoted to innovative adsorbent materials, to
advanced cycles and to heat pipes, which are suitable devices not only to improve the heat transfer but also can help to
avoid corrosion in the adsorbers. Recent experiments performed by the research group of the authors with machines that
employ composite adsorbent material and heat pipes showed that it is possible to achieve a SCP of 770Wkg1 of salt and
COP of 0.39 at evaporation temperatures of 20 1C and generation temperature of 115 1C.
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