Adaptive thermal comfort in university classrooms in Malaysia and Japan

The range of students’ classroom-based activities is generally restricted; therefore, individuals have limited options for adjusting themselves to the indoor thermal environment. This study investigated the comfort temperature and adaptive behaviour of university students in Malaysia and Japan. Classrooms in three universities (Universiti Teknologi Malaysia; Universiti Teknologi MARA, Malaysia; Kyushu University, Japan) were set to one of two conditions during the summer season: mechanical cooling (CL) mode, where AC was switched on for cooling purposes, and free-running (FR) mode, where AC was switched off. A total of 1428 responses were obtained. In Japan, 93.5% of the sample was male, while more even gender distributions were found in Malaysian samples. Additionally, clo values were generally higher amongst male respondents. In Japan, the mean comfort operative temperatures in FR mode was found to be 25.1 °C, while in Malaysia it was 25.6 °C. In CL mode, mean comfort operative temperatures were found to be 26.2 °C and 25.6 °C for Japan and Malaysia, respectively. Comfort temperatures in FR mode were compatible with Comité Européen de Normalisation (CEN) and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards, while those in CL mode were mostly within Chartered Institute of Building Services Engineers (CIBSE) guidelines. While high proportions of students in both countries claimed that they did nothing to maintain their thermal comfort, the most common activity observed amongst Malaysian students was changing the AC temperature setting, due to the prevalence of CL in Malaysia.