Thermal performance evaluation of a novel building wall for lightweight building containing phase change materials and interlayer ventilation: An experimental study

Abstract

In this work, to enhance the daytime insulation effect and prevent phase change material (PCM) from releasing heat into the room at night, a new composite phase change material (CPCM) with low thermal conductivity was synthesized and a novel solar-powered interlayer ventilation-phase change wall (SPIV-PCW) combining CPCM, air cavity, and solar powered fan system was presented. To evaluate the thermal performance of the SPIV-PCW, three experimental rooms, one experimental room with a west wall of a normal lightweight wall (Room 1), one with a west wall of phase change lightweight wall (Room 2), and one with a west wall of SPIV-PCW(Room 3), were built and experimental studies were conducted for three consecutive days. The results show that taking day 1 as an example, the maximum inner surface temperature of the west wall and the maximum indoor air temperature are 49.6 °C and 46.8 °C for Room 1, 46.0 °C and 45.3 °C for Room 2, and 44.6 °C and 44.4 °C for Room 3. The interlayer temperature difference between PCW and SPIV-PCW is up to 7.4 °C. More importantly, the thermal performance of SPIV-PCW is more outstanding than PCW in terms of peak temperature reduction (PTR), attenuation coefficient (AC), and total nighttime heat flow (TNHF), simultaneously, the maximum heat flow at night of SPIV-PCW was reduced by up to 78.5 % compared to PCW. In conclusion, SPIV-PCW is an outstanding candidate for building cooling energy conservation in hot climates.