The COVID-19 pandemic produced a wave of interest in germicidal ultraviolet (GUV) products, notably UV-C sources. Manufacturers responded with solutions, but adoption proved more uneven than expected. While the market may not be as robust as predicted, design guidance, technology advancement and interest in GUV is enduring.

Seeing an opportunity for lighting practitioners, the interNational Association of Lighting Management Companies (NALMCO) launched a pilot-tiered training and certification program that builds and recognizes expertise with GUV technology. 

GUV devices emit ultraviolet radiation to neutralize pathogens. Within the UV range of wavelengths (100–400 nm), UV-C (200–280 nm) is considered most effective. This output may be produced by traditional low-pressure mercury GUV lamps, more recent krypton-chloride excimer lamps or UV-C-emitting LEDs, which are still in development. The challenge is that UV-C is harmful to humans, requiring expertise in a field new to many practitioners.

Recommended practice

In 2021, the Illuminating Engineering Society (IES) published ANSI/IES RP-44-21, Ultraviolet Germicidal Irradiation. This guide addresses the use of GUV radiation for disinfecting air and surfaces, potential dangers and effects on plants and materials, GUV technologies and safety.

RP-44-21 cites applications including in-duct systems, upper-room systems, whole-room systems and mobile systems such as robots and handheld and air-cleaning devices. In-duct solutions are installed in HVAC air handlers and duct runs to disinfect air and surfaces. Upper-room systems employ devices that irradiate the air at heights of 7 feet or higher, and are most effective when ventilation constantly mixes air in the space. Whole-room systems irradiate air and surfaces, which may require special safety measures. Mobile systems enter unoccupied rooms to disinfect exposed surfaces and, depending on air movement, a portion of the air as well.

Energy research

A 2022 white paper by the Pacific Northwest National Laboratory analyzed upper-room GUV use in buildings to minimize transmission of COVID-19. The authors found substantial evidence that it is effective, and that GUV is more energy-efficient than increasing the HVAC air change rate or introduction of outdoor air.

ASHRAE standard

In July 2023, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) released Standard 241, Control of Infectious Aerosols. This standard establishes minimum requirements to reduce the risk of airborne disease transmission in buildings like single- and multifamily homes, offices, schools and healthcare facilities. The standard applies to new and existing buildings and major renovations and provides requirements related to air system design, installation, operation and maintenance.

ASHRAE 241 establishes conditions for an “infection risk management mode,” which applies during periods of elevated disease transmission risk. It then imposes requirements for an equivalent clean airflow rate per occupant, which may be achieved using GUV, HEPA filters or air ionizers.

Independent product testing

In September 2023, the Department of Energy published round one of CALiPER testing for GUV products to provide information and discourage inaccurate product claims. Of the 13 products tested—seven portable GUV towers, one whole-room ceiling luminaire and five troffer and high-bay whole-room luminaires, with an overall mix of LED and mercury sources—eight revealed problems with product representation. 

“Claims were often untestable, contradictory, ambiguous, or used incorrect units and/or terminology,” according to the DOE. “When claims were testable, they often did not match test results.”

NALMCO training program

NALMCO’s program aims to train professionals to install, maintain and use UV-C equipment safely and effectively. Three certification levels are offered: Certified Apprentice GUV Technician, Certified Senior GUV Technician and Certified GUV Management Professional. The curriculum covers UV-C technology, disinfection, safety protocols and precautions, installation and maintenance of UV-C luminaires, case studies and applications, hands-on training and practical demonstrations.

“A network of qualified and certified GUV personnel would be valuable to deploying GUV systems in a safe manner and maintaining them to provide safe indoor air quality and energy savings,” said Erik Ennen, president-elect of NALMCO. “Having an educated community around GUV will enable us to take full advantage of the benefits of this technology.”

To learn more and enroll, visit NALMCO.org/guv-training.

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