Thermal comfort and air quality in Chilean schools, perceptions of students and teachers

we present findings of naturally ventilated classroom conditions in primary school buildings in the city of Concepción, Chile, where there is no adherence to indoor environmental quality standards. We focused on thermal comfort and environmental perceptions of students and teachers, during fall and winter seasons. The goal is to examine the perceptions of children and teachers by analyzing responses to conditions in their classrooms, related to their socioeconomic context driven by school type. Approximately 888 students, aged 10-14 years old, were surveyed from nine schools during fall season, and 333 students from four schools during winter. A total of 2,271 subject responses were collected in two campaigns. Physical measurements included: ambient air temperature, relative humidity, airspeed, radiant temperature, and CO2. Simultaneous subjective responses were collected through electronic surveys on tablets which included questions on thermal sensation, thermal acceptability, and thermal preference. We examined thermal sensation trends, perceptions of comfort and air quality, across public, private-subsidized, private-nonsubsidized schools. Results show that about ~80% of teachers and students voted their thermal sensation primarily within the three central categories of the scale (-1, 0, +1). A small distinction can be seen in fall season in the private-subsidized school with a tendency towards a warm thermal sensation (+1), which corresponded to higher indoor temperatures. High indoor CO2 concentration levels were measured in all of the classrooms, with a maximum of 4327 ppm in winter in public schools, and a minimum of 858 ppm in fall in private-subsidized schools.