The impact of wall and roof material on the summer thermal performance of building in a temperate climate
Anna Staszczuk, Tadeusz Kuczyński
Abstract
The main objective of this study was to compare the effect of phase change material (PCM) and reinforced concrete on the summer thermal performance of existing building in a temperate climate. Research has shown that the use of reinforce concrete walls and roof has greatly improved thermal performance of the rooms during periods of consistently rising internal temperatures due to increasing outdoor temperatures and high solar radiation. Lining the wall and roof surfaces with PCM with an optimum melting point of 21.7 °C did not reduce the indoor temperature below 23 °C even in the coldest month of June, with an average outdoor temperature of 15.7 °C, completely preventing its solidification. This suggests that during heat waves, problems with PCM solidification can be expected even with materials with much higher optimum melting temperatures. The results indicate that in a building without air conditioning, it may not be possible to plan an optimum range of PCM melting temperature that would allow it to be effective during all summer months. Replacing the lightweight structure with a very heavy one allowed to reduce the maximum daily indoor temperatures by 2.0–2.5 K during a 15-day intensive heat wave with an average outdoor maximum temperature of 32.4 °C. An analysis of air-conditioning market development trends in residential buildings allows us to conclude that a reduction of maximum daily indoor temperatures in such a range in the temperate climate of Zielona Góra in Poland should significantly reduce the need to install new air-conditioning systems in residential buildings at least until 2050, even under the IPPC RCP8.5 scenario.