Student responses to classroom thermal environments in rural primary and secondary schools in winter

A comfortable classroom environment is conducive to the growth and education of young students. The goal of this study was to investigate the thermal environments in rural primary and secondary school classrooms in Northwest China and identify suitable values for the design parameters of heating systems to ensure the thermal comfort of the students. Surveys were conducted and field measurements were obtained from November 2014 to December 2015. The measurements included indoor and outdoor environmental parameters, such as the dry-bulb temperature, the relative humidity, the indoor air-flow speed, the globe temperature and the CO2 concentration. Data were collected in a total of 36 classrooms in 13 primary and secondary schools. The perceptions of 1126 students regarding the indoor environment were collected through questionnaires. Both the thermal sensation vote (TSV) and the predicted mean vote (PMV) were evaluated. The slope of the TSV curve was noticeably less than that of the PMV curve, which indicates that the students are less sensitive to temperature changes than predicted. The adaptive predicted mean vote (aPMV) model was also used to evaluate the students' mean thermal sensation and was more suitable for this research. The neutral temperature, the preferred temperature and the comfortable temperature range of students were obtained by analyzing the actual predicted percentage dissatisfied (PPD*) and the students' thermal comfort expectations. The findings can serve as a guideline for the design and evaluation of heating systems in primary and secondary schools in rural areas.