Ventilation performance of induction displacement units in indoor spaces within cold regions

Efficient ventilation systems play a crucial role in reducing occupants' exposure to indoor contaminants, including particles potentially carrying viruses like SARS-CoV-2. Displacement ventilation systems have demonstrated their effectiveness in improving indoor air quality during cooling modes. However, traditional displacement ventilation systems often struggle to achieve satisfactory distribution of contaminant concentrations during heating modes. To address this issue, this study focused on enhancing the ventilation performance of a dual-coil displacement-induction unit. Through a combination of experimental measurements and computational fluid dynamic (CFD) techniques, the study examined airflow and contaminant concentration distributions in an environmental chamber conditioned by these units. The results demonstrated good agreement between measured and simulated data, validating the CFD model. Further evaluation in a 25-occupant classroom under cold outdoor conditions showed that the dual-coil unit could achieve satisfactory ventilation performance in heating modes with proper design, comparable to traditional displacement ventilation in cooling modes. Additionally, the unit's versatility allows it to accommodate a wide range of air conditioning applications, from heating to cooling, making it a promising solution for displacement ventilation in various environments.