Relationships between indoor environmental quality and environmental factors in university classrooms

Indoor environmental quality (IEQ) is co-determined by several environmental factors (thermal, indoor air, lighting, and acoustics). In this paper, a four-layer IEQ assessment model for university classrooms was proposed based on fuzzy comprehensive evaluation (FCE) methods. The assessment model was evaluated based on a survey with a sample of 224 respondents in selected eight university classrooms in Hong Kong. Besides, objective measurements were performed in each classroom. Several parameters were included, such as operative temperature, CO₂ concentration, illuminance level, and A-weighted background noise level in the measurements. Then a set of prediction formulas were proposed to illustrate the relationships between IEQ and the environmental factors. The analysis results showed that the quality of the thermal environment was the most essential factor in the indoor environment. The results also discussed the significance rankings of sub-factors based on the weightings calculated from the analytic hierarchy process (AHP). The methods can give proper suggestions to authorities to manage the appropriate treatment and improve the indoor environmental quality. It is also useful for indoor environment design based on the proposed prediction formulas.