## 3 Results and Discussion  
### Mediterranean System (Low Temperature)  
For the MED system, the number of potential PCM candidates found in the literature review having a phase change temperature in the range between 0 \({}^{\circ}\)C and 7 \({}^{\circ}\)C was around 60. After applying some excluding criteria as explained in the methodology, this number was further reduced by half. Finally, the decision matrix was only applied to PCM with phase change temperature within the core temperature interval between 2 \({}^{\circ}\)C and 4 \({}^{\circ}\)C shown in Table 3.  
Figure 1 shows the results obtained by applying the decision matrix based on the scoring criteria shown in Table 1 and using the weights that correspond to Scenario 1 in Table 2. The best score was obtained by savE OM 03, a commercial product manufactured by the Indian company PLUSS(r) [23]. The second-best score was obtained by another commercial PCM, RT4, manufactured by the German company Rubitherm [19]. Three other commercial PCM, RT3 HC_1 [19], A3 [20], and PureTemp 4 [25], share the third place of the ranking with very similar scores. Furthermore, three of the pre-selected PCM candidates among those that obtained the highest score were characterized in the laboratory. Figure 2 shows the results of the DSC analysis of savE OM 03, RT4, and RT3 HC_1 pre-selected PCM candidates. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{
\begin{tabular}{c} **Commercial** \\ **Name/Composition** \\ \end{tabular} } & \multirow{2}{*}{**Type**} & **Melting** & **Phase Change** & **Thermal** & \multirow{2}{*}{**Density** **(kg/m\({}^{3}\))**} & \multirow{2}{*}{**Reference**} \\  & & **Temperature** & **Enthalpy** & **Conductivity** & & \\  & & **(°C)** & **(0/J/kg)** & **(W/m-K)** & & \\ \hline RT3 HC\_1 & Organic (paraffin) & 1–3 & 190 & 0.20 (s) & 770 (t) & \\ A3 & Organic (n.a.) & 3 & 200 & 0.20 (s) & 880 (s) & [19] \\
0200- Q2 BioPCM & Organic (bioPCM) & 2 & 200–230 & 0.2–0.7 (b) & 850–1300 (t) & [21] \\ PCM-PDR03P & Organic (n.a.) & 3.5 & 185 & n.a. & 570 & [22] \\ savE OM 03 & Organic (n.a.) & 3.5 & 229 & 0.224 (l) & 835 (l) & [23] \\ Caprylic acid + lauric acid (9:1 by mol) & Organic eutectic (fatty acid) & 3.8 & 151.5 & n.a. & n.a. & [24] \\ RT4 & Organic (paraffin) & 2–4 & 175 & 0.20 (s) & 770 (l) & \\  & & & 0.20 (s) & 880 (s) & [19] \\
0200- Q4 BioPCM & Organic (bioPCM) & 4 & 200–230 & 0.25–2.5 (s) & 900–1250 (s) & [21] \\ PureTemp 4 & Organic (bio-based) & 4 & 195 & n.a. & n.a. & [25] \\ Tetrahydrofuran & Inorganic (clathrate & 4.4 & 255 & n.a. & n.a. & [26] \\ clathrate hydrate & hydrate) & & n.a.—not available. & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Pre-selected available phase change material (PCM) for the Mediterranean system and some of their thermophysical properties as reported in the literature. On the one hand, it can be seen that both PCM from Rubitherm have an acceptable behavior in both heating and cooling processes, with the temperature difference between the heating and cooling peaks being around 0.5 \({}^{\circ}\)C. Moreover, RT3 HC_1 shows a sharper curve profile around the phase change temperature and a slightly higher phase change enthalpy than RT4. On the other hand, savE OM 03 has a heating curve more similar to the one for RT3 HC_1, while the cooling curve is by far much sharper than the ones for the two PCM from Rubitherm. However, the difference between the heating and cooling peaks corresponding to melting and solidification curves for savE OM 03 is about 8 \({}^{\circ}\)C, which is a serious drawback for the implementation of this PCM in practical applications. Figure 1: Score obtained by each of the pre-selected PCM candidates in Scenario 1 for the Mediterranean concept (MED) system. Figure 2: DSC analysis of three of the most promising pre-selected PCM for the MED system. (**a**) savE OM 03; (**b**) RT4; (**c**) RT3 HC_1.