Dynamic evaluation of composite roofs: thermal optimization with PCM under extreme climate conditions

The thermal performance of different roof configurations was analyzed, comparing the integration of phase change materials (PCM) with polystyrene insulation under extreme climatic conditions. The decrement factor (DF), time lag (TL), and thermal load were examined. The results indicated that configuration with PCM, either in double layers or with increased thickness, showed the best thermal performance. The optimal configuration, C45, which includes a double layer of PCM with RT25 HC on the bottom layer and RT35 HC* at the top layer, achieved a DF of less than 0.2, a TL between 2 and 10 hours, and a thermal load of 2.5 kWhm-2 . This study confirms that adding a PCM layer is the most effective strategy, followed by the increase of the thickness, as well as the addition of insulation, and finally, an additional layer.