Design and Development of Ultraviolet Germicidal Irradiation Device for Controlling Airborne Bacteria in the Workplace
Witaya Yoosook DEng*, Pornpimol Kongtip PhD*, Suttinun Chantanakul MD*
Affiliation : * Department of Occupational Health and Safety, Faculty of Public Health, Centre for Environmental Health, Toxicology and Management of Chemicals (ETM), Mahidol University, Bangkok, Thailand
Objective : To design and develop an ultraviolet germicidal irradiation (UVGI) device for controlling airborne
bacteria in the workplace of hospitals.
Material and Method: The constructed UVGI device was a chamber, consisting of a return air grille, an air
supply grille, two 30-watt ultraviolet lamps and a cross flow fan inside the chamber. The efficiency of the UVGI
device was tested at three different flow rates of 15.7, 31.6 and 46.1 m3/min, respectively by collecting bacteria
samples before and after operating the device for 30, 60, 90 and 120 minutes.
Results : The efficiency of the UVGI device at flow rates of 15.7, 31.6 and 46.1 m3/min was 60.6, 92.8 and 80.8%,
respectively and the bacteria concentration was reduced to less than 100 cfu/m3, except at the flow rate of 15.7
m3/min. The application of the UVGI device in the specimen-received room showed that the concentration of
bacteria was reduced to less than 100 cfu/m3 after 180 minutes.
Conclusion : The constructed UVGI device was effective to reduce airborne bacteria in workplace of hospital.
Keywords : Ultraviolet germicidal irradiation device, Bacteria, Workplace of hospital
