Stationary UV irradiation (left); Rotating UV irradiation (right)
Quantification of the anti-microbial efficacy of UVC-LED light under the poorly mixed long disinfection range. The survival fraction (S = Ci/C0) is plotted as a function of the exposure time. The lines represent the best-fit regression equation. The estimated decay rates are the average from at least triplicate experimental trials. Different colours of symbols and regression lines were used in each figure to indicate the decay i to n. Also, each symbol with its associated regression represents a single experiment.
Opportunity
Person-to-person transmission of airborne germs (i.e., bacteria and viruses) leads to outbreaks of diseases, such as tuberculosis and COVID-19. High-efficiency particulate air filters can remove germs from air, but multiple filters and strong pumps must be used, so these systems are best suited for industrial use. Alternatively, irradiation of air with ultraviolet (UV) light can effectively kill airborne germs. However, current mercury-type UV lamps are large and immovable, so can only be used in rooms that are well ventilated, as this ensures that airborne microorganism are carried into the path of the UV light. Moreover, mercury-type lamps are not energy efficient and emit only UV-C light. Thus, there is a need for a mobile, energy-efficient device capable of emitting UV-A, UV-B and UV-C light for cost-effective and efficient disinfection of air in indoor environments that are not well ventilated.
Technology
A moveable, light-emitting diode (LED) lamp system has been invented that can generate UV-A, UV-B and UV-C light in an energy-efficient manner. The system can be mounted near the ceiling of a room and set to rotate at a desired speed, allowing it to irradiate a large area of air in a room above the area occupied by people. Crucially, in a non-well-ventilated environment and compared with a stationary system, this moveable system exhibits 22–50% higher germicidal performance. Thus, this moveable system has excellent potential for application in indoor environments in which airborne germs are unevenly distributed due to a lack of efficient ventilation. Furthermore, the system can be directed toward the ceiling to kill insects and fungi, and it can be fitted with a fan to increase the number of germs swept into the path of the UV light. Moreover, multiple systems can be used, oriented in different directions.
Advantages
- Moveable
- Cost-effective
- Energy efficient
- Small-sized
- Efficacious in non-well-ventilated environments
Applications
- Offices or homes requiring cleaner indoor areas than current air-purification systems can provide
- Indoor environments with a lack of ventilation due to design limitations or necessity, e.g., rooms in which powders are processed
