Dynamic Thermal-energy Performance Analysis of a Prototype Building with Integrated Phase Change Materials

AbstractThe use of PCMs for improving buildings’ thermal comfort conditions and reducing summer cooling need has been largely investigated in the last decade. The capability of these materials of storing heat in latent form has been pointed out, especially when integrated in building envelopes. This paper deals with the analysis of the benefits in terms of buildings’ energy saving generated by the integration of PCMs inside two types of membrane for roofing applications, i.e. a traditional bitumen membrane and an innovative cool polyurethane-based membrane. To this aim, the dynamic simulation of the energy performance of a test-room was carried out. Four configurations were simulated and compared: (i) roof covered by a bitumen sheet membrane, (ii) roof covered by a cool membrane, (iii) the cool membrane with integrated PCMs, and (iv) the bitumen membrane with integrated PCMs. Both winter and summer conditions were studied. The results showed that PCMs integrated into the cool membrane are able to guarantee a 10.4% cooling energy saving, while PCMs integrated into the bitumen membrane generate a 12.6% of energy reduction for cooling if compared to the only bitumen membrane. The same roof configurations without taking into account the roof insulation layer generate a reduction of the cooling energy requirement of about 9.4% and 16.6%, respectively. In winter conditions, the reduction of the heating demand generated by the integration of PCMs inside the bitumen membrane is about 4.4% and 6.9%, with and without considering the roof insulation, respectively. Additionally, the heating energy saving generated by including PCMs into the cool membrane is equal to 5.4% and 8.4%, with and without considering the roof insulation layer, respectively. These results demonstrated that the integration of PCMs in both cool and non-cool roof membranes is able to reduce building energy requirement in both summer and winter conditions, especially in non-insulated roof configuration