## 4 Results and Discussion
### Comparison with MSC-30/R134a Pair
#### 4.3.3 SHP and Thermal Mass-Dependent COP in Adsorption Heating Application
For example, the excess temperature of the heated adsorber after the regeneration can be used to heat up some parts or deliver the adsorption target temperature of 30 \({}^{\circ}\)C. However, this design is highly local condition-specific and, therefore, only the typical usage is considered in this work. From the results, it is clear that the MSC-30/R134a pair offers better performance in the selected desorption temperature range, especially at higher temperatures. Based on the introduced model, we observed the COP of MSC-30/R134a pair from around 0.05 up to 0.61 through the presented desorption temperatures and thermal mass ratios. Consequently, the model shows the MSC-30/R1234 vf pair's COP from around 0.03 to 0.35 in the simulated condition boundaries. Hence, the difference is similar to the SHP results. The major effect, if not counting the thermal mass, on the COP is the evaporation heat, which in the case of R1234 vf at 90 \({}^{\circ}\)C is 50.53 (kJ/kg) [34], and that of R134a is 82.49 (kJ/kg) [35]. The actual evaporation heat at 90 \({}^{\circ}\)C of R1234 vf is then only around 61% of the R134a. An additional effect is caused by the net uptake (\(w_{max}~{}-~{}w_{min}\)) for the individual adsorption pairs according to the desorption temperature increase, further adding to the gap. Due to these reasons, the COP of the adsorption cycle does not considerably increase according to the desorption temperature increase. Finally, Figure 12 shows the heating cycle COP using the ideal approach model in comparison with [PERSON]'s model. As already mentioned, the adsorption heat calculations based on [PERSON]'s model show higher values. Hence, the predictions using [PERSON]'s model show slightly better performance of the adsorption pairs, even though that the effect on the actual COP can be seen as fractional. It is clear that if isosteric heat of adsorption increases, the COP of a heating application increases as well. However, despite presenting an improved equilibrium model which accounts for the effect of thermal mass and adsorption isotherms, the presented work lacks a detailed study on the adsorption kinetics. Nonetheless, we showed that the kinetics of the MSC-30/R1234 vf system is comparable to the more studied adsorption pairs such as MSC-30/R134a and MSC-30/R32. Furthermore, many actual aspects, such as the heat exchanger design or the packing of adsorbent materials, which strongly affect the kinetics performance, together with the total cost, need to be still considered for commercialization in any case. Since R1234 vf is getting attention as the alternative refrigerant of R134a because of its low GWP, we believe that the experimental data for the uptake of the MSC-30/R1234 vf  
Figure 11: (**a**) Coefficient of performance (COP) for heating application of MSC-30/R134a (Adsorbent mass ratio) with volume correction \(\alpha=1/T\)[K], using the ideal approach of isosteric heat of adsorption. (**b**) COP for heating application of MSC-30/R1234 vf (adsorbent mass ratio) with volume correction \(\alpha=1/T\)[K], using the ideal approach of isosteric heat of adsorption. pair, presented in this work, together with theoretical studies, prove to be indispensable for considering the potential of any R1234 yf/activated carbon system. Currently, refrigerants are evaluated by their energy efficiency, safety, global warming impact, and economic performance. Although R1234 yf gives a trivial GWP below 1, and it belongs to the same safety group with R32 already widely used (ASHRAE34-2013), the economic performance and energy efficiency are comparatively low. Hence, the refrigerant blends with R32, R1123, or CO\({}_{2}\) are currently widely researched and are in the scope of our following work.