Capability of electronic-filter air purifier on airborne microorganism removal

Abstract

The performance of the electronic-filter air purifier that uses the principle of electrostatic field on airborne fungi

(

Aspergillus niger and Penicillium citrinum) and bacteria (Staphylococcus epidermidis and Bacillus subtilis)

removals was tested in this study. The experiment was conducted in the 8-m

3 chamber by injecting each type of

microorganism and sampling the bioaerosol at two height levels, 0.5 and 1.5 m. Since the air purifier was located

at the floor with the height of 0.67 m, the microbe concentrations at these two height levels were observed for any

difference in its performance. However, the main objective was to compare the microbe concentrations when

turning on the air purifier and turning off for duration of 4 hours. The results were that the air purifier could remove

the microbes from the initial concentrations of 34,000 - 80,000 cfu/m

3 to comply with the recommended concentration

of 500 cfu/m

3 within 30-40 min except for B. subtilis that needed longer time. The height level did not affect

the performance of the air purifier in this study at the level of confidence of 99 %.