On Clothing Adaptation and Its Impact on Thermal Sensation and PMV in Classrooms

In real environments, the application of Fanger's comfort model to field contexts could suffer from limitations related to its definition, based on laboratory experiments and steady state approach, and to the differences between the experimental setup and real applications, including uniformity and degree of control on the testing conditions, the interactions with other comfort domains, occupants' expectations and their adaptation strategies. This work aims to assess to which extent the adjustment of clothing as adaptation strategy in schools, impacts on Thermal Sensation Votes (TSV) and on the difference between TSV and PMV. Nearly 900 questionnaires in high-school classrooms were collected with the environmental conditions the subjects were exposed to. The dataset displays a significant correlation between average clothing level of groups and indoor air temperature, showing that students probably adapt their clothes according to the indoor air temperature. Relationship between the TSV and (i) PMV calculated using standard winter clothing levels, (ii) PMV calculated using the mean clothing level of each students' group and (iii) the metabolic rate estimated based on students' body surfaces were analyzed. The winter clothing suggested by EN ISO 16798:2019 - 1 would overestimate the actual clothing level of subjects. Finally, PMV calculated accounting for the average observed clothing levels and students' metabolic rate was used to explain part of the difference between standard PMV and observed thermal sensation.