Indoor air quality and thermal comfort investigation in secondary school classroom / Abdul Rahim Jumah

A high indoor air quality (IAQ) environment and thermal comfort (TC) condition is utmost importance especially for educational institutions. This study attempts to provide more information about present IAQ and TC for school's classroom. The investigation was conducted in naturally ventilated (NV) classroom of a typical standardized government school (SMK Sultan Salahuddin Abdul Aziz Shah), located in Seksyen 2, Shah Alam. This study consist both physical measurements (CO₂, CO, RH, T, and v) and subjective assessments in order to give an appropriate evaluation of the indoor comfort conditions. The investigation was conducted during the occupied period in morning session of the classrooms (mostly at about 8.30a.m-9.30a.m). Measurements were taken at every 5 minutes interval for an hour, continuously for particular 20 days. The surveys were carried out among 600 respondents (students aged 15-16 years old). The subjective sensation of thermal comfort or comfort vote (CV) was assessed using ASHRAE seven point scale, together with an analysis of the preference votes. Correlation between the environmental variables and comfort votes were calculated and regression analysis was used to predict the comfort temperature. The mean CO₂ and CO for indoor concentrations obtained in the classroom were found to be 571.58 ppm and 7.187 ppm respectively, it was far below the limits stated in ASHRAE and the Institute of Environmental Epidemiologist, Ministry of Environment, Singapore (ENV) Guidelines. The mean RH, T and V were 76.92%, 27.83 °C and 0.4 m/s respectively. By regression analysis, the comfort indoor temperature obtained was 27.15 °C and it just 0.68 °C below than temperature obtained from measurement. This finding supported the sentiments on climatic adaptation.