With healthcare facilities including nursing homes taking precautions against viruses as never before, an effective tool in their arsenal is a new type of “germicidal” LED fixture. This specialized, enclosed LED fixture draws in air and irradiates it with ultraviolet light (UV), significantly improving indoor safety by providing continuous airborne disinfection of airborne viruses, bacteria and germs.
While traditional UV fixtures have been used for many years to clean surfaces, they could not be safely used in occupied spaces. The new type is designed to safely and constantly disinfect indoor air in occupied rooms.
Although LED light fixtures normally emit non-harmful visible light with a 400-nm to 700-nm wavelength, lower frequency UV light LEDs can effectively kill such pathogens. UVC, a very powerful ultraviolet light wavelength between 180 nm and 280 nm, is virucidal, bactericidal and fungicidal since it passes through the outer wall of the pathogen and causes damage at the molecular level. The destruction ultimately leads to inactivation of the pathogen, making the cells unable to reproduce.
UVC is known to disinfect air, water and nonporous surfaces and has effectively been used for decades to reduce the spread of bacteria such as tuberculosis, influenza and Legionnaires’ disease. According to the Centers for Disease Control and Prevention, UVC is the only recognized technology for effective germicidal treatment for airborne pathogens.
The CDC has also determined that the integration of in-room UVC sources in conjunction with building-wide HVAC systems has great promise, particularly given the growing knowledge of the dangers of airborne viruses. Best of all, these stand-alone UVC fixtures can be used continuously throughout the day, in occupied rooms, even when the HVAC system is off.
“In indoor settings, one of the best ways to combat airborne viruses is to continuously recycle individual room air while safely treating it with UVC radiation,” says Michael Fischer, president of Energy Harness Corporation, a designer and manufacturer of LED lighting. “Unlike traditional wide spectrum fluorescent or mercury vapor UV tubes, LEDs can produce UVC by controlling the specific wavelengths of light emitted. In addition, they don’t contain extremely toxic substances like arsenic or mercury that are inherent in the traditional UV tubes.”
When the COVID pandemic began, Fischer’s team quickly used its technology to design a fixture to treat the airborne organisms. To do so meant being able to safely deliver the proper UVC in a specific combination of three main factors – dosage, distance and wavelength.
According to Fischer, to eradicate pathogens effectively, the UVC wavelength should be in the germicidal effective range, with a peak of approximately 268 nm. The intensity must be high enough to irradiate the space, and the duration must be long enough to affect the organism.
Energy Harness eventually landed on a patent-pending, ceiling-mounted UVC system that circulates room air many times per hour into an enclosed chamber, where UVC disinfection occurs. Internal germicidal chambers are filled with hundreds of high-powered LEDs arranged in very close proximity to the airborne pathogens as they move through the fixture.
Because the unit houses the UVC LEDs internally, it does not produce any visible light in the room it disinfects. With the unit mounted in the ceiling, the people occupying the space are completely shielded from the UVC. Each LED fixture can typically disinfect a 256 sq. ft. area, depending on average occupancy, occupant activity level, etc., and multiple units can be deployed in larger rooms, according to Fischer.
To help mitigate the spread of viruses, Union Health, an integrated health system in Indiana, installed 48 UVC ceiling light fixtures last year at its facilities, primarily at entry points, waiting areas and testing areas. This year Union Health is installing a second round.
“We are looking for different ways to protect our patients, our visitors and our staff.
So, after in-depth research, we were happy to move forward with the purchase and the installation of these devices,” said Mike Mullins, System Director of Facilities, Union Health System in a TV interview last year.
The standalone approach of some UV disinfection systems could make them simpler for facilities to install. Units can also be designed with aesthetically pleasing architectural designs to complement a variety of interiors.
As healthcare facilities are seeking to make their indoor areas safer while occupants are still in the room, the installation of fixtures that can continuously kill airborne pathogens will be vital to aid safe operation.
Del Williams is a technical writer who lives in Torrance, CA.
The opinions expressed in McKnight’s Long-Term Care News guest submissions are the author’s and are not necessarily those of McKnight’s Long-Term Care News or its editors.