Comparative analysis of bamboo integrated with thermally adaptive materials for the development of energy-efficient building envelope in tropical climate

The escalating crisis of global warming and climate change necessitates an urgent paradigm shift toward sustainable construction practices, particularly in the building sector which accounts for a significant portion of global energy consumption and CO₂ emissions. In this study, bamboo was used as sustainable lightweight building element integrated with various passive cooling technologies such as PCM 29, PCM 35, thermal paint, and polyurethane foam in varying order. These materials were used to develop Energy-Efficient Bamboo Roof (EEBR) which were tested for indoor thermal performance of the developed test houses namely, RR, EEBR-1, EEBR-2, EEBR-3, and EEBR-4. These EEBRs were tested in real outdoor tropical climate for five consecutive days. It was observed that using PUF as insulation in building envelope will outperform other passive cooling strategies of improving indoor thermal environment of the building in tropical climate. Here, EEBR-4 shows the best indoor thermal performance among all other EEBRs followed by EEBR-2, EEBR-3, EEBR-1, and RR. EEBR-4 depicts highest peak temperature reduction of 16.4% followed by EEBR-2 by 12.8% in comparison with RR. Maximum magnitude of average MTR, %DHR, and average heat flux reduction of 12.5 °C, 17.3% and 34.8% was observed by EEBR-4. Additionally, EEBR-4 and EEBR-2 outperformed RR, EEBR-1, and EEBR-3 in terms of time lag and decrement factor. Cooling load reduction ranging between −33.3 W to 77.3 W along with energy saving between −15.01% to 36.96% was observed. Furthermore, CO₂ emission saving ranging between −0.043 kg/day to 0.803 kg/day was observed in EEBRs in comparison to RR.