Effectiveness of VIPs and PCMs on the energy performance and thermal comfort in buildings

A strategy for improving the buildings energy efficiency is to diminish the energy demand for space heating and cooling. The European Directive has established a high standard of thermal insulation, involving stringent limits for building energy performance. However, such approach determines an increase of the cooling energy demand and noteworthy overheating of indoor spaces in the summer period. This study investigates through dynamic thermal simulations the effectiveness of new thermal insulation materials, such as Vacuum Insulation Panels (VIPs) and Phase Change Materials (PCMs), on reducing heating and cooling energy demands, as well as guaranteeing the thermal comfort into a test room located in three different locations (Catania, Rome and Wien). The energy demand for space cooling and heating have been evaluated for the different facade configurations, as well as the attainable indoor thermal comfort. The outcomes of the simulations in air-conditioned spaces highlight that the wall configurations that adopt VIPs allow reducing the heating energy needs but may increase the cooling energy needs. Remarkable differences are not detected for the heating and cooling energy demands when the PCMs are used. The daily fluctuation of the indoor operative temperature and the adaptive comfort model suggest that the PCM placed on the inner side of the walls shows a good thermal performance. The outcomes of the study outline the strengths and weakness of the analyzed facade configurations, which may help designers in the search for suitable solutions.