Comparative thermal comfort study in educational buildings in autumn and winter seasons

Maintaining thermal comfort throughout an entire year is complicated because conditions vary greatly throughout the seasons. The aim of this article was to understand the influence of seasonal characteristics on the thermal comfort in classrooms and to propose a method to select suitable adaptive coefficients for different conditions. Field investigations were conducted in an educational building in Tianjin during autumn and winter. In the study, multiple environmental parameters were investigated, including air temperature, black globe temperature, relative humidity, air velocity, and the vertical temperature difference (VTD). The respondents' thermal sensations were collected via questionnaires. The respondents' thermal sensation and the influence of seasonal characteristics on thermal sensation were analyzed. The results showed that the thermal neutral temperature varied in different seasons, and the deviations between the mean thermal sensation vote (MTSV) and the predicted mean vote (PMV) showed obvious discrepancies throughout the different seasons. Furthermore, the adaptive coefficient alpha s for the adaptive thermal comfort prediction model (APMV) were 0.25 and 0.57 for autumn and winter, respectively. Based on the aforementioned result, a discriminant function (DFA) using the seasonal factors to select the suitable alpha was obtained.