Experimental study of the thermal behavior of PCM and heavy building envelope structures during summer in a temperate climate

Abstract

The main objective of the study was to evaluate the effects of PCM and traditional masonry construction on the summer thermal performance of the non-air-conditioned residential building in a temperate climate. The research was conducted in three rooms. In the first case, the lightweight frame construction of the walls and ceiling was covered with gypsum board on the inside, while in the second, a layer of Rubitherm® RT25HC was placed. The third room used masonry walls and a reinforced concrete roof. All rooms had identical flooring. The study was conducted between 13.08 and 18.09.2020. For the night period, various rates of mechanical ventilation were used to maintain the room temperature within the range of optimal PCM melting temperatures. The results of the study indicate significantly higher effectiveness of traditional high thermal capacity building materials than PCMs for lowering high indoor temperatures in summer. This occurs when there is a marked increase in outdoor temperature on at least one day, while at the same time the indoor temperature does not significantly exceed the PCM's melting temperature range specified by the manufacturer. Studies have further shown that the cooling efficiency of PCMs remains at a reasonably high level only for a small number of days in summer. This occurs when there is a marked increase in outdoor temperature on at least one day, while at the same time the indoor temperature does not significantly exceed the PCM's melting temperature range specified by the manufacturer.