Seoul has installed mechanical air filters in the heating, ventilation, and air conditioning (HVAC) systems of city buses to improve their indoor air quality since late 2019. We evaluated particle removal efficiencies of the filter in a wind tunnel, and clean air delivery rates (CADRs) of the systems and a household air purifier in the buses, following the test standards. The filter showed the efficiencies of 91% and 97.6%, 88% and 97.9%, and 78% and 95.2% for 0.35 μm particles and PM2.5 at 1.0m/s, 1.5m/s, and 2.0m/s, respectively. The efficiencies rose with an increase in the particle size and the filters had a minimum efficiency reporting value (MERV) rating of 15. The CADRs for PM2.5 and flow rate of the systems were 12.7m3/min and 17.9m3/min, 16.6m3/min and 25.4m3/min, 18.7m3/min and 33.6m3/min, and 23.3m3/min and 47.1m3/min on the operation mode of 1, 2, 3, and 4, respectively. The CADRs of the systems were 3.8-7.1 times higher than those of the air purifier, but single-pass removal efficiencies of the former were 0.56-0.81 lower than those of the latter.

The objective of this study is to identify the emission characteristics of VOCs from small-scale painting facilities, such emissions being pollutants that impact nearby living areas and to devise improvement measures to enhance management plans regarding pollutant emissions from painting facilities. VOCs emissions from painting facilities were estimated according to Clean Air Policy Support System (CAPSS) data based on the National Institute of Environmental Research (NIER)'s emission list in 2017. Three automotive painting facilities in Seoul were chosen for evaluation of the adsorption system. We analyzed the characteristics of VOCs generated by type of different operation and measured the removal efficiency of the adsorption system. Therefore, we analyzed current emissions of VOCs from automotive painting facilities based on field measurements. According to such detailed analysis, a systematic management plan was proposed.