Thermal comfort and IAQ conditions of naturally ventilated classrooms during the Covid-19 pandemic

Abstract

In order to achieve good thermal comfort and indoor air quality (IAQ) conditions in naturally ventilated classrooms, adequate air change rates must be ensured. In 2020, this issue became especially relevant due to the Covid-19 pandemic, since it may contribute to minimize the transmission potential of respiratory diseases. This study aims to evaluate the thermal comfort and IAQ conditions of a naturally ventilated classroom, in order to identify scenarios that contribute, simultaneously, to the reduction of the risk of dissemination of the SARS-CoV-2 virus and to the maintenance of thermal comfort for users. Environmental variables were monitored in a classroom before and during the Covid-19 pandemic and a simulation model was calibrated. Scenarios varying the number of occupants and the air change rate were simulated in order to assess the impact of these variables on the CO ₂ concentration, on the infection probability and on the indoor operative temperature. The best scenario showed a reduction of 42% in the concentration of CO ₂ and 33% in the infection probability and an increase of 60% in comfort hours, compared to the worst scenario. However, the strategies adopted must be analysed for each situation, as well as the risks and benefits for classroom occupants.

Keywords:
Indoor air quality (IAQ); Thermal comfort. Natural ventilation; School building; Covid-19