A comprehensive objective and subjective assessment survey of indoor environmental quality in higher education classrooms in a hot arid climate

A few research studies about IEQ in university classrooms are reported from the hot arid climate despite the severity of this climate. In the reported study, the indoor conditions of university classrooms from a hot arid climate were evaluated considering the collective effect of the four main factors of IEQ, which are the thermal, visual, acoustic, and indoor air quality. The physical measurements were conducted for air temperature, globe temperature, relative humidity, air velocity, illuminance, sound pressure, and carbon dioxide levels. A questionnaire collected the students' sensation, satisfaction, and preferences of the classrooms' environments. The results reveal the sensitivity of the students' environmental experience to the thermal and acoustic conditions. In light of this, a novel IEQ model that considers the air temperature and sound pressure level has been proposed. The model is statistically reliable as it has an RMSE of 0.002. Griffith's method was used to calculate the comfort temperature at 23.0 ± 2.5 °C with a slope of 0.5/K. The findings of this study attempt to fill a gap in the knowledge regarding the IEQ conditions of university classrooms from the hot arid climate.