What is Ultraviolet?

Ultraviolet light is part of the light spectrum, which is classified into three wavelength ranges:

  • UV-C, from 100 nanometers (nm) to 280 nm
  • UV-B, from 280 nm to 315 nm
  • UV-A, from 315 nm to 400 nm

What is Germicidal Ultraviolet?

  • UV technology can be used for disinfection between wavelengths from 200 nm to 300 nm.
  • Specifically, radiation in UVC band has a strong germicidal effect.
  • Germicidal ultraviolet (UVC) used for UV disinfection inactivates microorganisms, such as viruses, bacteria, yeasts and fungi, by disrupting their cellular membranes and by damaging their DNA or RNA.
  • The UV light initiates a reaction between two molecules of thymine, one of the bases that make up DNA. UV light at 253.7nm wavelength (germicidal UV or UVC) causes adjacent thymine molecules on DNA to form covalent bonds between certain adjacent bases in the DNA.
  • Due to formation of such bonds on a microorganism's DNA, its replication is inhibited, resulting in effective UV disinfection by rendering the microorganisms harmless.
  • Moreover, the microorganisms cannot become resistant to UV radiation. In fact, when the organism tries to replicate, it dies.

What are the beneficial uses of Germicidal Ultraviolet?

Airborne microorganisms such as viruses, bacteria, yeasts and mold (fungi) are especially present in heavily frequented areas such as airports, hospitals, theatres, hotels, offices, restaurants, residential areas, industrial areas etc, and circulates through the central HVAC system. By using our UVC air purifiers on the supply side of the AHU can have huge benefits:

  • They can inhibit colony formation in greater than 99% of airborne microorganisms and make them ineffective for humans.
  • Ultraviolet technology does not use any chemicals for disinfection.
  • In this method of disinfection, a certain dosage of ultraviolet is the only thing required and nothing is added to the environment, which has any harmful side effects.
  • This makes this process simple, inexpensive and requires very low maintenance.
  • The principle of design is based on a product of the time of exposure and intensity of UVC for achieving successful results for various applications.

How does UVHeal™ SafeAir work?

UVHeal™ SafeAir units contain one or more germicidal ultraviolet lamps. Germicidal Lamps are shortwave, low-pressure tubes that produce ultraviolet wavelengths lethal to microorganisms. Approximately 95% of the ultraviolet energy emitted from germicidal lamps is at 254 nano-meters, the region of germicidal effectiveness most destructive to bacteria, mold and virus. Therefore, the air that passes through the HVAC duct is exposed to the germicidal UV light and the genetic material of the microorganism is deactivated, which prevents them from reproduction and rendering them harmless.

What is Ultra-violet Light?

Ultraviolet light is a part of the light spectrum, which is classified into three wavelength ranges:

  • UV-C, from 100 nanometers (nm) to 280 nm
  • UV-B, from 280 nm to 315 nm
  • UV-A, from 315 nm to 400 nm

What is Germicidal Ultraviolet (UVC)

Germicidal ultraviolet (UVC) used for UV disinfection inactivates micro-organisms, such as viruses, bacteria, yeasts and fungi, by disrupting their cellular membranes and by damaging their DNA or RNA. The UV light initiates a reaction between two molecules of thymine, one of the bases that make up DNA. UV light causes adjacent thymine molecules on DNA to form covalent bonds between certain adjacent bases in the DNA.Due to the formation of such bonds on a micro-organism's DNA, its replication is inhibited, resulting in effective UV disinfection by rendering the micro-organisms harmless.Moreover, the micro-organisms cannot become resistant to UV radiation. When the organism tries to replicate, it dies.

Is all ultraviolet considered germicidal ultraviolet (GUV)?

No. Germicidal ultraviolet (GUV) – refers to short-wavelength ultraviolet "light" (radiant energy) that has been shown to kill bacteria and spores and to inactivate viruses. Wavelengths in the photo-biological ultra-violet spectral band known as the "UV-C," have been shown to be the most effective for disinfection, although longer, less energetic UV can also disinfect if applied in much higher doses. UV-C wavelengths comprise photons (particles of light) that are the most energetic in the optical spectrum (comprising UV, visible, and infrared) and therefore are the most photo-chemically active.

Can UV-C kill viruses as well as bacteria?

Yes, UV-C kills living bacteria, but viruses are technically not living organisms; thus, we should correctly say "inactivate viruses." Individual, energetic UV-C photons photo-chemically interact with the RNA and DNA molecules in a virus or bacterium to render these microbes non-infectious. It all happens on the microscopic level. Viruses are less than one micrometer (μm, one-millionth of a meter) in size, and bacteria are typically 0.5 to 5 μm.

How do the airborne viruses get transmitted through centralized AC air?

Air conditioning units, especially in corporate offices and other public places such as malls and restaurants, can be a substantial contributing factor in the transmission of airborne viruses and bacteria from one person to several others. The centralized AC units block the outdoor air from entering the building. Hence, all the people in the enclosed premises end up breathing in the air circulating inside the building. If a single person is carrying a virus, then the air exhaled by that person will be inhaled by the others present. In such circumstances, the deadly micro-organisms get transferred from one person to the other even if people are maintaining a safe distance from each other.

Can UV-C effectively inactivate the SARS-CoV-2 virus, responsible for COVID-19?

Yes, if the virus is directly illuminated by UV-C at the effective dose level. UV-C can play an effective role with other methods of disinfection, but it is essential that individuals be protected to prevent UV hazards to the eyes and skin. UV-C should not be used to disinfect the hands!

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