Optimising Thermal Comfort in The Classroom: High schools in the hot and humid tropical climate of Indonesia

Abstract

Thermal comfort significantly influences students' health, cognitive abilities, and academic performance. This thesis explores strategies to optimise thermal comfort in Indonesian classrooms, where dissatisfaction with thermal conditions is prevalent. These classrooms rely on natural ventilation, offering limited control over the indoor environment. Clothing insulation is crucial for individual comfort, but mandatory school uniforms restrict adaptations. Female Muslim students face additional challenges due to modesty requirements, exacerbating discomfort in Indonesia's hot and humid climate.

The research was conducted in three phases. First, thermal manikin tests assessed the thermal performance of 11 uniform configurations. Results showed that a loose, untucked long-sleeve shirt paired with trousers and a hijab reduced clothing insulation by 0.39 clo compared to the standard uniform, significantly improving thermal comfort.

The second phase used simulations to analyse the impact of classroom design features, such as natural ventilation, on thermal performance. The results indicated that cross-ventilation in top-floor classrooms enhanced air movement in both highland and lowland coastal climates. In contrast, single-sided ventilation was more effective for first-floor classrooms in Surabaya's coastal climate. Orienting top-hung windows at 45° to the prevailing winds further improved natural ventilation performance.

Finally, students' thermal comfort responses revealed that uniform modifications had a greater impact than building adjustments. Uniform changes reduced the Standard Effective Temperature (SET) by 3°C, increasing annual comfortable hours to 83%. Building modifications, such as optimising ventilation, provided smaller improvements. The study recommends climate-responsive uniforms, enhanced natural ventilation, and fan integration as essential strategies for creating thermally comfortable learning environments in Indonesia.