## 3 Results and Discussion
### Discussion  
During the solid-phase sensible heat storage stage, a small portion of the PCMs undergo melting, but the primary heat transfer mechanism of the phase change panel remains as thermal conduction. In this stage, the heating rate and heating duration of the unheated side of the phase change panel reflect its insulation performance. As shown in Figure 10, with the start of the heating process, the temperature of the heated side of the phase change panels in experimental groups 3 and 4 rapidly rises until it exceeds 30 \({}^{\circ}\)C. The heat simultaneously transfers from the heated side to the unheated side. The temperature of the unheated side rises slowly, with the rate of increase diminishing over time. Therefore, during the solid-phase sensible heat storage stage, the insulation performance of the phase change panel improves as the heating time increases. The unheated side in experimental group 4 reaches 28 \({}^{\circ}\)C at 80 min, while that in experimental group 5 reaches 28 \({}^{\circ}\)C at 120 min. The heating duration for both groups exceeds one hour, with a temperature difference of only 7 \({}^{\circ}\)C before and after heating. This is because both paraffin and n-butyl sclearate have very low thermal conductivities, resulting in a low thermal conductivity for the composite PCMs. Even though the exterior of the phase change panel has high thermal conductivity due to the aluminum alloy material, the overall thermal conductivity is determined by the internal PCMs, causing the panel to exhibit high thermal resistance. The difference between experimental groups 1 and 4 lies in the heating temperature. The heating temperature for experimental group 1 is 45 \({}^{\circ}\)C, while for experimental group 4, it is 35 \({}^{\circ}\)C. As shown in Figure 8, the temperature on the unheated side of experimental group 1 reaches 28 \({}^{\circ}\)C at 40 min, with a temperature difference of 5 \({}^{\circ}\)C before and after heating. Meanwhile, the temperature on the unheated side of experimental group 4 reaches 28 \({}^{\circ}\)C at 80 min, with a temperature difference of 7 \({}^{\circ}\)C before and after heating. Therefore, during the solid-phase sensible heat storage stage, the heating rate of experimental group 4 is lower than that of experimental group 1. As the heating temperature decreases, the insulation performance of the phase change panel improves. These phenomena demonstrate that in addition to excellent temperature control effects, the phase change panel also has outstanding insulation performance, which can play an important role during hot seasons. In a recent similar study, [PERSON] et al. [30] used COMSOL Multiphysics to optimize the position of the phase change layer, the melting point of PCMs, and different loading conditions. The authors defined the intensity of thermal discomfort as the period during which the temperature is outside the chosen thermal comfort range of 22 \({}^{\circ}\)C to 28 \({}^{\circ}\)C. It was found that the optimal position is obtained for PCMs placed close to the inner layer of the wall, and the selection of the melting point of PCMs is highly dependent on the loading condition. The authors recommend PCMs with a melting point between 26 \({}^{\circ}\)C and 30 \({}^{\circ}\)C for cooling. These conclusions further confirm the rationality of determining the appropriate phase change temperature and the placement of the phase change layer in the wall in the study. [PERSON] [31] analyzed and compared the thermal performance of the direct incorporation of PCMs into mortar. The results showed that phase change mortar also has good thermal performance, capable of reducing peak temperatures by 3 \({}^{\circ}\)C to 5 \({}^{\circ}\)C. However, the compression test showed a reduction in compressive and mechanical strength with the addition of PCMs. This phenomenon demonstrates the advantages of macro-encapsulation in practical applications.