A holistic performance assessment of duct-type electrostatic precipitators

Epidemiological surveys have shown a significant association between indoor airborne particle exposure and adverse health effects. Duct-type electrostatic precipitators (ESPs) are effective in controlling airborne particles in buildings. Although several studies have examined the initial performance of duct-type ESPs, there are no comprehensive data on the holistic performance of commercially available ESPs. In addition, there are no published comparisons of the performance of ESPs with and without dielectric coatings considering the impact of dust loading and washing. In this study, laboratory tests were conducted to determine the holistic performance including initial, dust-loaded, and postwashing filtration efficiencies and ozone emission rates of ESPs with and without dielectric coatings. ESPs with dielectric coatings showed enhanced removal efficiency of submicron particles, with overall efficiencies comparable to those of F7 filters and 85% lower energy consumption. The removal efficiency of the ESP with dielectric coatings was superior to those of ESPs without dielectric coatings, but the higher energy consumption of the former led to slightly lower comprehensive performance. The filtration efficiency for submicron particles differed most between the two types of ESPs and was more suitable for evaluating their performance. The ozone emission rates were almost 2-7 times higher for ESPs without dielectric coatings than for the ESP with a dielectric coating (5.9 +/- 2.2 mg/h). Based on the initial comprehensive quality factors of the ESPs, the maximum reductions caused by dust loading and washing were 55.3% and 17.5%, respectively. This study demonstrates the importance of considering multiple criteria when evaluating the performance of duct-type ESPs.