Research (Jan 2021)

The Efficacy of Plant-Based Ionizers in Removing Aerosol for COVID-19 Mitigation

  • Ady Suwardi,
  • Chin Chun Ooi,
  • Dan Daniel,
  • Chee Kiang Ivan Tan,
  • Hongying Li,
  • Ou Yang Zhong Liang,
  • Yuanting Karen Tang,
  • Jing Yee Chee,
  • Anton Sadovoy,
  • Shu-Ye Jiang,
  • Srinivasan Ramachandran,
  • Enyi Ye,
  • Chang Wei Kang,
  • Wun Chet Davy Cheong,
  • Keng Hui Lim,
  • Xian Jun Loh

DOI
https://doi.org/10.34133/2021/2173642
Journal volume & issue
Vol. 2021

Abstract

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Small-sized droplets/aerosol transmission is one of the factors responsible for the spread of COVID-19, in addition to large droplets and surface contamination (fomites). While large droplets and surface contamination can be relatively easier to deal with (i.e., using mask and proper hygiene measures), aerosol presents a different challenge due to their ability to remain airborne for a long time. This calls for mitigation solutions that can rapidly eliminate the airborne aerosol. Pre-COVID-19, air ionizers have been touted as effective tools to eliminate small particulates. In this work, we sought to evaluate the efficacy of a novel plant-based ionizer in eliminating aerosol. It was found that factors such as the ion concentration, humidity, and ventilation can drastically affect the efficacy of aerosol removal. The aerosol removal rate was quantified in terms of ACH (air changes per hour) and CADR- (clean air delivery rate-) equivalent unit, with ACH as high as 12 and CADR as high as 141 ft3/minute being achieved by a plant-based ionizer in a small isolated room. This work provides an important and timely guidance on the effective deployment of ionizers in minimizing the risk of COVID-19 spread via airborne aerosol, especially in a poorly-ventilated environment.