Examination and optimization of classroom indoor environments in China’s hot summer and cold winter regions

Abstract

The school’s indoor environment significantly affects students’ health and learning performance. Although related studies have been carried out in many regions, only a few have examined indoor classroom environments and proposed the energy-saving optimization of heating and ventilation in winter in China’s hot summer and cold winter areas. This study aims to comprehensively investigate classroom indoor environmental quality in China’s hot summer and cold winter areas, and propose targeted optimization strategies. It first examined the indoor environment, including indoor air, acoustic, visual, and thermal quality, of two typical middle schools. The indoor CO2 concentration in winter was found to be unsatisfactory. Subsequently, how the indoor layout, outdoor wind and occupancy density influence indoor CO2 concentration was examined through simulation, which indicated that high occupancy density is the main cause. Finally, this study proposed several ventilation optimization strategies and performed an energy analysis to maintain sufficient air quality and a comfortable thermal environment in high-density classrooms. The results show that compared with the intermittent mode, the fixed ventilation and heating mode could maintain a more comfortable indoor environment and achieve a 30% energy saving. A reference for the improvement of classroom indoor environment in hot summer and cold winter areas was provided.