Performance of wearable ionization air cleaners: Ozone emission and particle removal

ABSTRACT

Wearable ionization air cleaners are compact in size and marketed for personal respiratory protection by removing air pollutants from users' breathing zone. In this study, ozone emission and particle removal rates of four wearable ionization air cleaners (namely, AC1 through AC4) were evaluated inside a 0.46 m³ stainless steel chamber. Continuous measurements were conducted for ozone concentration, PM_2.5 concentration, and particle size distribution in the size range of 18.1–289 nm. Two of the four wearable air cleaners (i.e., AC1 and AC2) had detectable ozone emissions. The 10-h average ozone emission rates were quite different (i.e., 0.67 mg·h⁻¹ for AC1 and 3.40 × 10⁻² mg·h⁻¹ for AC2); however, the ozone emissions were negligible for AC3 and AC4. The number removal rates for particles within the measured size range were highly variable (i.e., 2.20 h⁻¹, 0.52 h⁻¹, 8.10 h⁻¹, and 27.9 h⁻¹ for AC1 through AC4, respectively). The corresponding mass removal rates of PM_2.5 were 1.85 h⁻¹, 0.48 h⁻¹_,1.52 h⁻¹, and 5.37 h⁻¹, respectively. Regulatory guidelines are needed to assure these devices can effectively remove particles without ozone emissions to protect public health.

Copyright © 2016 American Association for Aerosol Research

EDITOR :

• Tiina Reponen

Funding

This study was financially supported by the Innovative Research Groups of the National Natural Science Foundation of China (grant number 51521005), Public Scientific Research Project of Ministry of Environmental Protection of China (No. 201409080), and the Shanghai Tongji Gao Tingyao Environmental Science & Technology Development Foundation (STGEF).