What Is Germicidal Ultraviolet-C (UVC) light?
Germicidal UV or also known as Ultraviolet-C (UVC) light is within the electromagnetic spectrum, which is divided into categories based on wavelength. Other recognizable categories include radio waves, microwaves, infrared light, visible light, X-rays, and gamma-rays. This technology has been used for many years as a method of surface and air purification.
Credit: NASA's Imagine the Universe
Our sun produces electromagnetic radiation, as do other celestial bodies such as stars and galaxies. Ultraviolet light is a shorter wavelength than visible light, and is usually divided into three sub-categories:
UVA (315-400 nanometers)
UVB (280-315 nanometers)
UVC (180-280 nanometers)
Is Germicidal UV effective?
The shorter the wavelength, such as UVC, the more damage can be done. UVC does not reach the surface of the earth due to the protective properties of the atmosphere, while UVA accounts for 95% of the UV that does, with UVB accounting for the other 5% (Lucas 2017). This is a good thing, as UVC with its short wavelength, is the most damaging of the three to our DNA, or deoxyribonucleic acid, the genetic material of our cells. With the correct amount of UVC exposure, germicidal UV can be an effective solution.
UVC light causes mutations in DNA via dimerization, which prevents correct copying of the DNA, and stops the reproduction of the germs exposed to the light.
The higher energy wavelengths of UVB and UVC cause mutations in DNA to form. DNA and RNA (ribonucleic acid, which is made from DNA) have 4 building blocks known as nucleotides (think of them as small legos that build a bigger structure). These nucleotides are in two categories- purines and pyrimidines. Purines include the bases adenine and guanine, while the pyrimidines include thymine in DNA/uracil in RNA and cytosine. The UVC causes pyrimidine dimers to form.
Top 3 Considerations When Looking at Germicidal UV such as UVC
All DNA/RNA copying and processing that is required for replication of an organism or virus needs two protein workers (enzymes) known as DNA polymerases and RNA polymerases. With the pyrimidine dimer mutation, these copiers cannot do their job, and the damaged DNA/RNA is unable to be used.
The mutation-producing property of UVB can lead to skin cancer in humans, but with the use of UVC as a germicide inside buildings, it means an incredibly useful tool for preventing airborne infections because it leads to the inability of germs like viruses, bacteria, and mold to replicate and spread.
Why Ultraviolet Light Disinfection?
The utilization of UVC as a germicide against viruses and bacteria has been tested and used for over a century, and with COVID-19 posing a barrier to re-opening the economy, a wide-scale implementation of germicidal UV is being evaluated by many businesses. UV light must be applied properly to achieve efficacy on airborne pathogens.
Does UV Light Kill COVID-19?
UV light, such as germicidal UVC can be an effective method of air purification against COVID-19 but it must be applied properly. What this means is that the pathogens must have exposure to enough UVC light energy for a proper amount of time to be able to affect the DNA/RNA structure and thereby neutralize COVID-19, other viruses mold and bacteria. When applied in an existing duct system or rooftop HVAC unit, often times there is too much air moving too fast across the UVC bulbs to very effective on air disinfection. Many existing UVC applications are for cleaning the surfaces of the coils in the HVAC units. This is why many facilities and homeowners choose a portable air purifier equipped with the proper amount of UVC.
UV Germicidal Air Purifiers
Germicidal UV air purifiers equipped with the correct amount of UVC can be an effective way to implement UVC into a commercial facility or home. This is because there is less air moving past the UVC bulbs at a slower rate than when implemented in the main ductwork system. Not all air purifiers are created equal and many lost cost bedroom type air purifiers have undersized UVC bulbs, resulting in little to no efficacy on air borne pathogens. Commercial-grade units have often far more efficacy because of the larger and more powerful UV lights used within them.
ISO-Aire Commercial Air Purifiers with UV Light
ISO-Aire commercial air purifiers are available with germicidal UVC and come standard with a medical-grade HEPA filter that lasts 5 to 6 years. Our air purifiers slow the air down properly through the UVC chamber and use a high amount of UV energy to properly neutralize viruses, including COVID-19, bacteria and mold. Combined with the medical-grade HEPA filter, this solution provides industry leading protection. Another option available on ISO-Aire air purifiers is ozone-free bipolar ionization would provides a third level of air purification.
Request a Quote for UV Air Purifiers
With over 55 years of HVAC and air purification experience our team of experts are here to help provide effective air purification with our ISO-Aire commercial air purifiers for your facility. Call us at 651-265-0605 or email info@ductsandcleats.com to request a quote or a free demonstration.