An Experimental Study on the Applicability of HEPA Filter to Existing Air Conditioners for Enhanced Air Purification

This study investigated the integration of HEPA filters with air conditioning systems to improve indoor air quality, focusing on fine particulate matters (PM10 and PM2.5) recognized as carcinogens by the WHO. In South Korea, particulate matter levels increase from winter to spring due to domestic emissions and cross-border pollution. HEPA filters were attached to existing air conditioners. Their particulate removal efficiency and clean air delivery rate (CADR) were measured in a control chamber. Preliminary tests showed a 22% reduction in airflow with filters installed. Filters achieved a high efficiency of 93%. In a low airflow mode, the air conditioner with a HEPA filter achieved a CADR of 1.44 m³/min and a particulate removal efficiency of 61%. In a high airflow mode, the air conditioner with a HEPA filter achieved a CADR of 1.83 m³/min and a particulate removal efficiency of 70%. These results suggest that integrating HEPA filters with air conditioning systems can significantly enhance air purification, especially in high-occupancy areas such as classrooms, offices, and lecture halls. This approach not only optimizes the use of existing air conditioning infrastructure, but also offers a practical solution for improving indoor air quality during periods of high particulate matter levels. Future research needs to focus on large-scale implementation and effects on cooling efficiency and noise levels.