An integrated low-energy ventilation system to improve indoor environment performance of school buildings in the cold climate zone of China

This study proposed an integrated low-energy ventilation (ILEV) system for the primary school buildings located in the cold climate zone of China to solve the indoor air pollution and thermal discomfort issues in classrooms. The system comprises three main parts: fans, EAHEs, and a sunspace with plants. To explore the performance of the ILEV system, a typical school building located in the cold climate zone of China was selected. The research methods involved the dynamic thermal modelling (DTM) and experimental measurements. The simulation results and experimental data indicated that the air temperatures inside the classrooms were maintained in the range of 15 °C–27 °C throughout the year. The internal CO₂ concentrations averaged approximately 900 ppm in all classrooms. The indoor PM_2.5 and PM₁₀ concentrations were significantly improved and met the requirements of the Chinese standard. In addition, the ILEV system consumed approximately 12% of the energy currently used by the original benchmarked case study. The payback period of the ILEV system was 8 years. Compared to other renewable technologies, the ILEV system only required 16% of its lifespan to recoup the initial costs and provided economic benefits approximately 42 years.