Within- and cross-domain effects of environmental factors on students' perception in educational buildings

Students in classrooms are exposed to environmental stimuli in the thermal, visual, acoustic and air quality domains, which affect their overall comfort and performance. Therefore, in recent studies, questionnaires are used to collect information about subjective perceptions and investigate links with physical parameters. Most field studies in educational buildings either focus on a single comfort domain, or consider multiple domains but provide inconsistent questions among the 4 domains (i.e., IAQ, thermal, visual and acoustic). Very few studies have investigated cross-domain effects in a consistent manner, considering satisfaction, comfort and perception aspects. To address this research gap, a survey with consistent questions among the 4 comfort domains was designed and used to collect more than 900 subjective responses from students. The analysis of subjective data together with objective measurements allows: (i) correlating the environmental physical parameters and students' perception in each of the comfort domains; (ii) understanding the students' preferred environmental conditions; and (iii) understanding cross-domain effects, i.e., the effects between the average conditions and the mean vote expressed for another domain. The results show that air temperature, illuminance and sound pressure level are correlated with the sensation in the respective domains, in contrast to CO2 concentration. Regarding cross-effects, the study confirms interference of CO2 concentration and illuminance on thermal sensation as well as the effect of sound pressure level on visual sensation.