Determining the efficiency of using led sources of ultraviolet radiation for ionization and disinfection of room air

Abstract

This paper reports a study into the possibility of using LED systems of ultraviolet radiation for air ionization and disinfection of air and indoor surfaces in the presence of people. It has been established that UV LED lamps with 120° opening angles have parameters under which radiation intensity does not exceed 30 J/m2 at distances of 2 meters. Based on experimental data, a methodology for designing the placement of lamps in the room was devised, which meets the requirements of the SBM-2015 standard and the European Directive 2006/25/EU. The use of LED emitters with a total intensity of up to 25 J/m2 increases the concentration of aero ions. The background concentrations were 140‒180 cm-3 (positive) and 160‒190 cm-3 (negative). The minimum permissible level is 500 cm-3. As a result of irradiation, the concentrations were 1100‒1460 cm-3 (positive) and 1260‒1470 cm-3 (negative). The influence of the recirculator-air purifier on the concentration of aero ions has not been established. The ionization process began immediately after turning on the irradiation systems in the entire volume of the premises (4‒5 meters from the source). The dynamic equilibrium of aero ion concentrations was established within 10‒15 minutes after the irradiation was switched on. The presence of a large number of people (up to 0.97 m2 per person) did not affect the concentration of aero ions. Under the combined effect of ultraviolet radiation and a recirculator-air purifier, the number of mold fungi colonies decreased by 20 times. Under the influence of only ultraviolet radiation – by 2.3 times. The decrease in the number of microbes under the combined effect was 1.6 times, and under the effect of only ultraviolet radiation – 2.8 times