Design and development of ultraviolet germicidal irradiation device for controlling airborne bacteria in the workplace.

Abstract

To design and develop an ultraviolet germicidal irradiation (UVGI) device for controlling airborne bacteria in the workplace of hospitals. 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. 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. The constructed UVGI device was effective to reduce airborne bacteria in workplace of hospital.