Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room

International Journal of Environmental Research and Public Health

Huan Ma²  Henggen Shen¹  Tiantian Shui²  Qing Li²  Liuke Zhou² 

[1] School of Environmental Science and Engineering, Donghua University, Shanghai 201620, China

关键词: portable air cleaners;    PM_1.0;    single-pass efficiency;    effectiveness;    electret medium;   

DOI  :  10.3390/ijerph13010102

来源: mdpi

【 摘 要 】

Size- and time-dependent aerodynamic behaviors of indoor particles, including PM_1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3–3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 10⁴ m³/m². The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-filter (PR) or the active carbon granule filter (CF) was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE) showed maximum single-pass efficiency for PM_1.0 (88.6%), PAC with the HE was the most effective at removing PM_1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4–0.65 μm) exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in school office buildings.

【 授权许可】

CC BY   
© 2016 by the authors; licensee MDPI, Basel, Switzerland.