Full-scale field investigation of a bio-climatic house under Thailand tropical climate

The main objective of this paper is to present a full-scale field experimental investigation of a Bio-Climatic House (BCH) under the tropical climate of Thailand. The BCH included several innovative building envelope configurations, i.e., a Roof Solar Collector (RSC), a Bio-Climatic Roof (BCR), a Modified Trombe Wall (MTW), and a Glazed Solar Chimney Wall (GSCW) with the aim of maximizing natural ventilation for heat gain and indoor heat accumulation reduction as well as to improve the indoor air condition while providing appropriate natural daylighting. The field experimentation was set up to measure the indoor temperature, relative humidity, illuminance, and air velocity inside the BCH in the summer, rainy and winter seasons in 2014. Construction cost was also analyzed and presented. The experimental results demonstrate that the BCH design could efficiently operate year-round under the tropical climate conditions of Thailand; it reduced indoor air temperature by 2-3 °C compared to that of ambient air temperature and the indoor relative humidity was also lower than the ambient conditions by 10%-20%. The indoor illuminance varied between 450 and 700, 450-800, and 450-765 lx in winter, summer, and rainy, respectively. The indoor air velocity was in the range of 0.04-0.09 m/s and the corresponding ACH in the range of 9-14. Finally, economic analysis revealed that with labor and material costs of 560 USD/m2 and 1120 USD/m2, a payback period of approximately 7.39 years would be feasible. Therefore, the BCH with RSC, BCR, and MTW applications is an appropriate building envelope technology for residential house integration and deserves promotion in a tropical climate region.