Comparing the efficacy of UVC-LED and low-pressure mercury lamps upper-room UVGI systems for air disinfection

Research output: Chapters, Conference Papers, Creative and Literary Works (RGC: 12, 32, 41, 45)32_Refereed conference paper (with ISBN/ISSN)peer-review

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Detail(s)

Original languageEnglish
Title of host publication16th International Conference on Indoor Air Quality and Climate (INDOOR AIR 2020)
PublisherInternational Society of Indoor Air Quality and Climate
Pages819-824
Volume2
ISBN (Print)9781713823605
Publication statusPublished - Nov 2020

Publication series

NameConference of the International Society of Indoor Air Quality and Climate, Indoor Air

Conference

Title16th Conference of the International Society of Indoor Air Quality & Climate (Indoor Air 2020)
LocationVirtual
Period1 - 5 November 2020

Abstract

In this study, we compared the performance of a novel UVC light-emitting-diode and the conventional mercury lamp UV systems, hereafter named LED- and mercury-type UR-UVGI systems, respectively, in a room-type air disinfection scheme to inactivate bacteria aerosols. Under constant environmental and well-mixed conditions, Escherichia coli and S. epidermidis were aerosolized and subjected to endogenous or natural decay. They were also exposed to each of the two UR-UVGI systems, independently. For the natural decay experiments, the kn values were 0.0022±0.0005 s-1, and 0.0007±0.0003 s-1 for E. coli and S. epidermidis, respectively. The estimated decay rates, k, improved with the application of either the LED- or mercury-type UVGI system but varied between the two bacteria species. There was no significant difference (p = 0.3) between the inactivation of E. coli under the mercury-type (kUV-MV = 0.0045 ± 0.002 s-1) and the LED-type UV irradiations (kUV-LED = 0.0031±0.001 s-1). Likewise, the inactivation of S. epidermidis with LED-type (kUV-LED = 0.0019±0.0003 s-1) and mercury-type (kUV-MV = 0.0022±0.0005 s-1) UV irradiations were similar. However, S. epidermidis was more resistant to UV light than E. coli. These results showed that the LED-type UR-UVGI system can effectively inactivate microorganisms with equal performance as the conventional mercury lamp UR-UVGI system. This suggests that the LED-type UR-UVGI system can be used as a safe UV irradiation source to replace the conventional mercury vapor-filled UV lamps. Nevertheless, improvements in the UV-LED technology are necessary to enhance its performance for the disinfection of indoor bioaerosols, irrespective of species typology.

Research Area(s)

  • Bioaerosols, Indoor air quality, Infectious diseases, Light-emitting-diode, Room air disinfection, Upper-room UVGI

Bibliographic Note

Research Unit(s) information for this publication is provided by the author(s) concerned.

Citation Format(s)

Comparing the efficacy of UVC-LED and low-pressure mercury lamps upper-room UVGI systems for air disinfection. / Nunayon, Sunday S.; Zhang, Huihui; Lai, Alvin C.K.

16th International Conference on Indoor Air Quality and Climate (INDOOR AIR 2020). Vol. 2 International Society of Indoor Air Quality and Climate, 2020. p. 819-824 (Conference of the International Society of Indoor Air Quality and Climate, Indoor Air).

Research output: Chapters, Conference Papers, Creative and Literary Works (RGC: 12, 32, 41, 45)32_Refereed conference paper (with ISBN/ISSN)peer-review