## 3 Results
### Testing Results for a Pelletized Adsor  
In this section, the results obtained during the tests will be discussed. It is worth noticing that most of them were mainly used afterward for future comparison with the other adsorber, and therefore, new aggregation tables or charts can be found in the following parts of this paper. In Figure 6a, the effect of charge/discharge time is shown. This was the first parameter investigated, in order to find out the optimum value to be used in the evaluation of other operating conditions. Two different boundary conditions were investigated--90/35/15 and 90/30/17 cycles, corresponding to more severe and less severe operating conditions. The cold energy recovered and discharge power are shown in the picture. The trends obtained are: increasing energy recovered for higher charge/discharge times and decreasing power for higher charge/discharge times. The trends are more marked for the less severe condition (90/30/17), where a higher amount of working fluid can be processed. Moreover, the decreasing in the output power is not very high, going from 2700 s to 4500 s, probably because of the saturation of the material: after 2700 s, the uptake exchanged, though still present (as testified by the increasing energy stored) is lower than in the first part of the cycle. In Figure 6b, the effect of evaporation temperature over the discharge power and the energy capacity is shown. As expected, the higher the evaporation temperature, the higher the energy recovered. Moreover, with a 2 nd grade polynomial equation, it is possible to describe the obtained trend, as often happens for such kind of sorption devices. Two curves, parameterized according to condensation temperature, are reported. The highest discharge power is 400 W, obtained for the lower condensation temperature (30 \({}^{\circ}\)C) and an evaporation temperature of 22 \({}^{\circ}\)C. Instead, for a 35 \({}^{\circ}\)C condensation temperature, the obtained discharge powers are very low. The energy recovered arrives at 400 Wh for the higher evaporation temperatures. Figure 6: (**a**) The effect of charge/discharge time, pelletized adsorber; (**b**) the effect of evaporation temperature; (**c**) the effect of condensation temperature. In all these figures, the following nomenclature has been used: HT/MT/LT. When the term XX appears, this means that the specific value (e.g., LT) is variable and must be read on the specific figure (e.g., Figure 6b). Finally, in Figure 6c, the effect of condensation temperature is shown. The curves are parameterized as a function of discharge times. The results are similar to those of the previous graphs: higher condensation temperatures lead to low powers, around 200 W, and low energy capacity (200 Wh for 40 \({}^{\circ}\)C condensation and 2700 s discharge time), whereas more power is available at a lower condensation temperature (300 Wh for 30 \({}^{\circ}\)C condensation and 3600 s discharge time). Testing Results with a Composite Adsorber Based on an Aluminum, Porous Structure and a SAPO-34 Coating  
In this section, the results of the characterization tests are reported, by using the same evaluation parameters previously explained. A direct comparison with the pelletized adsorber will be specifically addressed in a dedicated section. In Figure 7a, tests with two different evaporation temperatures (12 \({}^{\circ}\)C and 15 \({}^{\circ}\)C) and different cycle times are presented. In particular, for the tests here shown, the durations of charge and discharge are the same. The results are presented both in terms of energy (e.g., 85/30/12_E) and power (e.g., 85/30/12_P): as expected, power decreases with increasing cycle time. However, energy, once 900 s of charge/discharge time is reached, has a plateau, indicating that this is the optimal choice. Subsequently, the effect of charging time was evaluated: it is well known that the desorption process is faster than adsorption [14].