Impact of personal and contextual factors on multi-domain sensation in classrooms: Results from a field study

In indoor spaces shared by many people, such as school classrooms, the contextual and individual characteristics can affect the perceived indoor environmental quality and explain the distribution of the occupants’ subjective comfort evaluations. Understanding the impact of these factors on the subjective assessment of the indoor environmental quality (IEQ) and multi-domain comfort is crucial for reliable post-occupancy evaluations and retrofit solutions. This work presents the impact of personal (i.e., gender, clothing level, body mass index, age, use of glasses) and contextual (i.e., sitting position inside the classroom, facade orientation/outdoor view) factors on the students’ thermal/air quality/visual/acoustic sensation votes collected in 50 classes during regular lectures, through the administration of 825 questionnaires. Students’ sensation votes regarding the four perceptual domains were collected and correlated with environmental parameters (i.e., indoor and outdoor air temperature and relative humidity, indoor mean radiant temperature, indoor CO2 concentration and TVOC, indoor horizontal illuminance, indoor sound pressure level). Multi-linear regression analyses were performed to identify environmental variables significantly correlated with sensation votes, exploring cross-domain interactions. Then, the sensation votes were grouped according to different levels of personal and contextual factors to study correlations between votes and related binned environmental parameters for each set, by means of covariance analysis and post-hoc tests. Among personal factors, age and gender were proven to impact on the sensation votes in all the four domains. Furthermore, Body Mass Index and clothing level influence thermal sensation while the use of glasses do not affect visual sensation. The sitting position in the classroom impacts thermal, IAQ, visual sensation votes in relation to the proximity to the windows and the visual and acoustic sensation in relation to the proximity to the teacher and blackboard. Finally, groups identified by classroom orientation and occupant density significantly differ in terms of sensation votes.