Coronavirus (COVID-19)

UV-C Germicidal Technologies’ Effectiveness Against COVID-19

Ultra-violet (UV) light provides high-energy germicidal solutions against mold, bacteria, viruses and other microbial growth. The use of UV light as a germicidal application within a building’s HVAC system has been an accepted solution and growing in popularity over the past couple decades. The same technology can be used to disinfect hospital/patient rooms and personal protective equipment, however there are many unknown factors centered around COVID-19 and that leaves many people uncertain about the effectiveness of UV light as a disinfectant. In today’s post we’re going to share the science behind this technology.

What is Ultra-violet?

Ultra-violet light is one form of electromagnetic energy produced naturally by the sun. UV is a spectrum of light just below the visible light and it is split into four distinct spectral areas – Vacuum UV or UVV (100 to 200 nm), UVC (200 to 280 nm), UVB (280 to 315 nm) and UVA (315 to 400 nm).

Image provided by Steril-Aire.

The entire UV spectrum can kill or inactivate many microorganism species, preventing them from replicating. UVC energy at 253.7 nanometers provides the most germicidal effect. The application of UVC energy to inactivate microorganisms is also known as Germicidal Irradiation or UVGI.

UV-C exposure inactivates microbial organisms such as bacteria and viruses by altering the structure and the molecular bonds of their DNA (Deoxyribonucleic acid). DNA is a blue print” these organisms use to develop, function and reproduce. By destroying the organism’s ability to reproduce, it becomes harmless since it cannot colonize. After UV-C exposure, the organism dies off leaving no offspring, and the population of the microorganism diminishes rapidly.

Image provided by Steril-Aire.

Ultra-violet germicidal lamps provide a much more powerful and concentrated effect of ultraviolet energy than can be found naturally. Germicidal UV provides a highly effective method of destroying microorganisms.

UVGI COVID-19 Disinfection Applications

A variety of UVGI applications are available on the market. Many UV-C solution providers are willing to customize solutions based on your needs. Combat COVID-19 from all directions with any of the following applications.

Air-handler Disinfection Steril-Aire emitters inside an AHU at Amity High School
AHU/RTU & Airstream Disinfection
Make-up Air & Exhaust Disinfection
Room/Surface Disinfection (unoccupied)
Face Mask Disinfection
Schematic from ResearchGate article linked below.

Additional Resources

Below are links to provide you additional information related to using UV-C to combat COVID-19. Don’t take our word for it – take the science behind it!

UV Light Assists in Efforts to Contain COVID-19

Flow Tech is proud to represent Steril-Aire, a UVGI manufacturer. We are happy to work with you on a COVID-19 specific project or anything in the future. For more information contact Tom Proietti, call us at 860.291.886 or visit our website. You can always stay up-to-date on our latest news by following us on social media: Facebook, LinkedIn, Twitter and YouTube.


  1. Terry Dillon on August 30, 2020 at 1:31 PM

    Please explain how you determined that UVC is more effective than UVV (Vacuum UV). UVC inactivates particles the light comes in contact with. It is 2-dimensional and cannot neutralize the virus under, behind, beside or even inside of porous surfaces. UVV on the other hand, neutralizes the virus using ozone, not light. It is therefore 3-dimensional, and neutralizes the RNA above, beside, behind and even within porous surfaces.

    • Nichole Petersen on August 31, 2020 at 3:45 PM

      Hi, Terry,

      Thank you for your comment. UVV or Vacuum UV light refers to another wavelength in the ultraviolet spectrum. Some UVC devices also produce light in this wavelength. The manufacturers of these devices promote UVV as an added tool for IAQ control, saying that UVV attacks microorganisms, chemicals, and odors. While this may be true, it is important to understand that UVV (unlike UVC) will also “attack” occupants in treated spaces by adversely affecting human lungs!

      The reason for this is that the shorter (185 nanometers) wavelength of UVV light actually generates ozone. This occurs because UVV light reacts with oxygen to break it into atomic oxygen, a highly unstable atom that combines with oxygen to form O3 (ozone). The American Lung Association states that “exposure to ozone causes a variety of adverse health effects, even at levels below the current standard.” ( And the Environmental Protection Agency (E.P.A.) says: “In order for ozone to be effective as a germicide, it must be present in a concentration far greater than that which can be safely tolerated by man and animals.” ( The longer (253.7 nanometers) wavelength of UVC light, by contrast, provides highly effective air and surface disinfection without producing any harmful ozone.

      The materials and methods of UVC lamp construction determine whether a given UVC device will produce both UVC and UVV light or only the safer UVC wavelength. Steril-Aire and Fresh-Aire UVC devices do not produce any UVV. Flow Tech, Inc. is a manufacturer’s rep of both these companies because their technology supports our mission to improve the comfort and safety of facilities. If you have further questions about the use of UV-C in HVAC applications, I encourage you to reach out to either of these companies. or

      Thank you,
      Nichole Petersen
      Director of Marketing
      Flow Tech, Inc.

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