Experimental thermal characterization of a Mediterranean residential building with PCM gypsum board walls

A two-storey typical family house was built in the mid-western part of Greece, comprising a load bearing steel skeleton and dry wall systems. Its walls consist of multiple layers of insulation materials and gypsum plasterboard panels containing Phase Change Materials (PCMs) for thermal energy storage purposes. A detailed matrix of sensors was installed in different locations of all external walls of the house, as well as indoors, in order to provide detailed temperature measurements and thus lead to a thorough depiction of the houseʹs thermal behaviour. In this work, experimental data obtained during the first year of monitoring (2011) are presented. Throughout this particular monitoring period the house purposely remained closed, unoccupied and no energy systems were installed. Hence the presented analysis focuses on the thermal characterization of the houseʹs walling system. Average monthly temperature, decrement factor and time lag values are presented for each room–wall and are discussed with respect to their orientation and exposure to the external weather conditions. Furthermore, measurements conducted on different layers of the living roomʹs east wall aim to examine the influence of PCMs in the wallʹs thermal response. It is shown that within the adopted conditions (unoccupied house/no energy systems), the thermal mass of the walling system is enhanced during late spring, early summer and autumn, due to the PCM implementation, resulting also in a decrease of the decrement factor by a further 30–40% and an increase on the time lag of approximately 100 min.