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With the aim of standardizing the evaluation of thermal storage systems/tanks, this chapter assesses and compares the different performance indicators that can be found in the literature and tries to recommend those which enable a better comparison.

Analysis of the Ad-HEx dynamic behaviour is of pivotal importance in development of advanced adsorber concepts, enabling reduction of weight and volume of the real adsorption heat pump/chiller unit, as well as its energy density enhancement.

In Chap. 2, the two main methods to study the sorption dynamics for AHT cycles were widely described: (i) the Large Pressure Jump (LPJ) method, in which adsorption is initiated by a jump of pressure over the sample, is the most adequate for pressure-driven AHT cycles; (ii) the Large Temperature Jump (LTJ) method, in which adsorption is enabled by a temperature swing of a heat exchanger wall that is in contact with the adsorbent under an almost isobaric ad/desorption stage, is the proper choice for temperature-driven AHT cycles (see Chaps. 1 and 2). In this chapter, the main factors affecting the sorption dynamics will be highlighted for temperature-driven AHT cycles by the analysis of results achieved by the two versions (namely V-LTJ and G-LTJ) of the LTJ method.

At present, the majority of thermodynamic cycles of heat engines are high-temperature cycles that are realized by internal combustion engines, steam and gas turbines, etc. (Cengel, Boles in Thermodynamics: an engineering approach, 4th edn. McGray-Hill Inc., New York, 2002). Traditional heat engine cycles are mainly based on burning of organic fuel that may result in dramatic increase of CO2 emissions and global warming. The world community has realized the gravity of these problems and taken initiatives to alleviate or reverse this situation. Fulfilment of these initiatives requires, first of all, the replacement of fossil fuels with renewable energy sources (e.g. the sun, wind, ambient heat, natural water basins, soil, air). These new heat sources have significantly lower temperature potential than that achieved by burning of fossil fuels which opens a niche for applying adsorption technologies for heat transformation and storage (Pons et al in Int J Refrig 22:5–17, 1999).

Despite significant progress, the AHT technology as yet remains unfinished and expensive, so that there is still a big room for its improvement [1, 2]. This concerns, first of all, enhancement of the AHT dynamics, like the ad/desorption rate and finally the specific power that is the main figure of merit of the AHT dynamic performance. Therefore, further R&D activity is necessary to realize the potential economic and ecological advantages of the AHT technology [3]. The optimization of the AHT dynamic performance is a multi-purpose task that includes, first of all, the improvement of the “adsorbent–heat exchanger” unit.

Hydrothermal aging of zeolites is an irreversible change of adsorbent surface characteristics due to repeated cyclic adsorption and desorption of water resulting in, among others, reduced adsorption capacity and kinetics of adsorption.

As described in Chap. 1, one of the major adsorber heat exchanger design requirements is the reduction of the ratio between the heat capacity of the adsorber heat exchanger material as well as its heat transfer medium’s holdup and the heat capacity of the applied adsorbent. This results in enhancing the coefficient of performance of the adsorption heat pump and increases the obtainable specific heating or cooling power.

An adsorbent material consolidated in form of coating could present poor mechanical stability if a proper binder and/or an optimized binder content are not adopted in the coating formulation. Mechanical stability of the adsorbent coating may be affected by different typologies of mechanical stresses during its lifetime (vibrations, impacts, etc.). For this reason, a single mechanical test is not sufficient to prove completely the overall mechanical stability of the coated layer.

This book proposes a radically new approach for characterizing thermophysical and mechanical properties of zeolite-based adsorbent coatings for Adsorptive Heat Transformers (AHT). It presents a developed standard protocol for the complete characterization of advanced coated adsorbers. Providing an in-depth analysis of the different procedures necessary for evaluating the performance of adsorbers, it also presents an analysis of their stability under the hydrothermal and mechanical stresses during their entire life cycle. Adsorptive Heat Transformers (AHT), especially adsorption chillers and heat pumps, are considered to be promising technologies to increase thermal energy efficiency. Nevertheless, an overall increase in performance of this apparatus is necessary for them to be considered a mature technology to be used commercially. Development of innovative coated adsorbers can be perceived as a key issue for the enhancement of AHT technology. This procedure relies on the deposition, either by means of a binder or by direct crystallization, of the adsorbent material over a metallic heat exchanger, aiming at the improvement of the heat transfer between the external heat source and the adsorbent itself. This book offers a valuable resource to those working on the development of novel adsorbent materials and advanced adsorbent beds for heating and cooling applications. It is also intended for researchers interested in renewable energy and energy efficiency.

A heat pump process is a thermodynamic process having the main target to pump heat from a heat reservoir at a low temperature (ambient heat source) to a heat sink at a higher temperature (heating net). According to the second law of thermodynamics, this target can only be realized if a driving energy is applied. Contrary to the vapor compression heat pump process, where mechanical work is applied as a driving energy to run the compressor, thermally driven heat pumps (TDHP) make use of heat at a higher temperature (driving heat source), compared to the heat sink temperature, as a driving energy.