Study on Indoor Thermal Environment and Thermal Comfort in an Air-Conditioned Mosque during Prayer Times in the Tropical Climate of Malaysia

Understanding the environmental dynamics of air-conditioned mosques hosting five daily prayers with fluctuating occupancy is essential for informed design decisions. This study investigates a Malaysian mosque's thermal environment and worshippers’ perceptions, including comfort temperatures. Field measurements spanned a week and included various prayer times. A questionnaire-based adaptive thermal comfort was conducted after Friday midday prayer when worshippers fully occupied the mosque’s main hall. The mean indoor air temperature (T_a), relative humidity (RH), and air velocity (V_a) for all prayers were recorded at 25.3 °C, 62%, and 0.5 m/s, respectively, aligning with local standards. It was found that the mean operative temperature at the neutral thermal sensation was 26.1 °C. Similarly, the mean operative temperature when respondents preferred no temperature change and comfortable overall comfort was 26.1 °C. Therefore, the temperature set point can be raised while maintaining thermal comfort.