Chou, Hao-YuanHao-YuanChouCheng, Hsiu-JuHsiu-JuChengHsu, Ling-HangLing-HangHsuHuang, Chen-KangChen-KangHuang2025-09-162025-09-162025-05-30https://www.scopus.com/record/display.uri?eid=2-s2.0-105007784564&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/732110Indoor air quality (IAQ) is crucial for occupant health and sustainable urban living. Given the significant time spent indoors in urban areas, maintaining IAQ mitigates health risks and enhances quality of life. This study evaluates the effectiveness of installing a UV air-cleaning device at the outlet of an existing air-conditioning system. The experiments involved measuring the colony-forming units (CFUs) of airborne microorganisms before and after the installation of the UV device. Results demonstrated a significant reduction in CFUs, confirming the device’s efficacy in improving IAQ. Using the UV air-cleaning device for 30 min could reduce bacterial concentration by more than 70.7%. Furthermore, using a model from the literature, the time required to achieve a 90% reduction in pollutant concentration was calculated, providing a quantitative measure of the device’s performance. Using the energy recovery ventilators only requires 25.3 to 49.6 min to achieve a 90% reduction, whereas configurations incorporating UV lamps can reach 90% reduction in 7.1 min. Based on these findings, recommendations for the optimal use of UV air-cleaning devices are proposed, offering valuable insights for future designs of air purification systems.trueair changes per hourcolony-forming unitenergy recovery ventilationultraviolet germicidal irradiation[SDGs]SDG3[SDGs]SDG11journal article10.3390/buildings151118932-s2.0-105007784564