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Thermally driven adsorption chillers and heat pumps are a very promising approach toward an efficient use of energy as well as an effective climate protection through reduced CO2 emission of conventional heating and cooling devices. With regard to current market entrance of this technology, this paper presents results on the stability of current available materials like silica gels and zeolites, recently developed materials like aluminophosphates (AlPO) and silica-aluminophosphates (SAPO) and novel materials like metal organic frameworks (MOF) under hydrothermal treatment.Seven materials as powders or granules as well as three composite have been analyzed under continuous thermal cycling in a water vapour atmosphere in order to evaluate their suitability for the use in a periodically working heat pump with water as working fluid.The stability of powders has been analyzed in-situ by thermogravimetry in a first stage short-cycle test. In case of the composite, made up of an active sorption material and a support structure, a cycling-test rig has been developed in order to realize a life-cycle stress. The need for a first stage short-cycle test is demonstrated impressively by the dramatic loss of 40% in sorption capacity of a Cu-BTC sample within the first 15 cycles

Heat transformation based on adsorption/desorption of water in microporous adsorbents has been considered for the application as adsorption chiller (ACS), adsorption heat pump (AHP) or thermochemical storage (TCS) since the 1980s. Unfortunately, most of the available adsorbents like zeolites were not optimized for the use in these processes as they originally had been developed for gas separation or catalysis processes. Within the last decade, intensive research on adsorbents yielded in improved and very promising new sorption materials with an enhanced adsorption capacity. This work gives a broad overview on current developments on materials including the new class of metal-organic frameworks for the use in adsorption processes for heat storage and transformation

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