How Do Natural Ventilation Strategies Affect Thermal Comfort in Educational Buildings? A Comparative Analysis in the Mediterranean Climate

The COVID-19 pandemic highlighted the importance of indoor air quality in buildings for the well-being of their occupants. In long-term occupancy buildings such as schools, where environmental conditions also impact academic performance, this importance was heightened. Despite the significant changes in ventilation practices resulting from the pandemic, recommendations have varied across different countries. This study aimed to provide a comparative analysis of the environmental conditions and air quality in classrooms in southern Spain and northern Italy (representative Mediterranean locations with different post-pandemic heating and natural ventilation approaches). Data measured on-site during periods with similar outdoor conditions were analysed to ascertain how ventilation strategies influence thermal comfort and indoor air quality. According to the results, during mild periods, high-intensity ventilation ensures excellent indoor air quality results based on CO2 concentrations, without compromising thermal comfort. Nevertheless, ventilation rates should be controlled in more adverse climate conditions to avoid negative effects on thermal comfort.