Disingerm™ Industrial Portable UV-C Sanitation Service Kills 99.9% of Germs, Bacteria, and Viruses. Watch the demo below.
Paul Salfen talks with Disingerm’s UVC Light specialist Robert Martinez on how UVC is enhancing Disingerm’s product and services. Watch Mr. Martinez demo how simple and easy it is to sterilize a room with Disingerm's UVC light.
The effect of UV light on human skin becomes obvious during the warmer months of summer when people experience sunburn when exposed to direct sunlight for too long. UV light from the sun can also cause skin cancer, which damages cells in the body. Considering these effects of UV light from the sun on humans it makes sense that UV light on a shorter and stronger wavelength can be just as effective, if not more effective, in immobilizing and killing viruses and bacteria.
In order to inactivate and kill a virus, it has to be directly exposed to shortwave UV – UV-C at 254nm. When this happens in a constant and consistent manner, the UV irradiation bombards the virus with UV light and breaks down its cell walls. This is crucial because as mentioned earlier a virus cannot produce its own protective shell of protein or other material, so once it is severely damaged by UV-C the virus cell itself cannot repair the damage.
More specifically, microorganisms such as viruses and bacteria suffer damage to their nucleic acids when bombarded with high-energy, short wavelength UV light – UV-C at 254nm. The UV light is absorbed by the RNA or DNA creating new bonds between the UV energy and the virus’ or bacteria nucleotides.
This bonding creates double bonds, or dimers, that typically affect the thymine molecules. This damage to the thymine molecule is the most common type of photochemical damage that occurs in this process. When the formulation of multiple thymine dimers occurs in the DNA or RNA of a virus, the virus cannot replicate and is unable to continue infecting the host.
If a virus cannot replicate it loses its ability to infect the host and eventually dies off. This is especially important when trying to contain a virus that can spread rapidly by physical contact with humans or surfaces or through the air. With bacteria, which is a single-celled microorganism that has both DNA and RNA, once the DNA or RNA is attacked by the UV light the bacteria is damaged and cannot replicate itself.
How Does UV Light Inside HVAC Systems Help Mitigate the Spread of Viruses and Bacteria?
Killing viruses and bacteria at the source or before they spread to where they can be inhaled or come into physical contact with humans is the best way to mitigate their spread and stop infections. HVAC systems (heating, ventilation and air conditioning systems) provide acceptable air quality and thermal comfort. HVAC can be found in single-family homes, apartment buildings and condominiums, hotels, senior living facilities, hospitals, industrial facilities, schools and universities, office buildings and more. Given the broad use of HVAC systems and how many people around the world rely on them for clear and breathable air it makes sense that UV light would be used inside the system to kill bacteria and viruses to make the air as clean as possible.
The type of UV light used inside HVAC systems is called UVGI, which means ultraviolet germicidal irradiation. There are two ways HVAC UV lights are used inside systems: coil sterilization and air sterilization. Coil sterilization is the most common type of HVAC UV light method because it can run 24 hours a day, seven days a week to ensure maximum sterilization. With this type of application, “a ‘stick-type’ light is installed inside the return air duct and it sterilizes the air handler coil,”. On an HVAC system the coil and drain pan are typically the places where contaminants such as viruses and bacteria can originate. By adding a UV light to the coil, the origin of the contamination is treated before any bacteria, virus or mold spores are able to become airborne and contaminate the air.
The air sterilization method, on the other hand, is where a UV light “is installed in the return air duct and cycles on with the air handler blower… [and] a complete UV light unit sterilizes moving air itself as it is pushed through the HVAC system,”. With this method, the air is already assumed to be or is contaminated and is itself treated, as opposed to treating the coil before the contamination makes it into the air as with the previous coil sterilization method. With this method, the UV light only turns on when the heating or cooling system is running, unlike the previous method.
However, it should not be assumed that sticking a UVGI light inside of an HVAC system will be sufficient in cleaning the air. There are a few factors that need to be considered before installing a UVGI into an HVAC system, including the wavelength and intensity of the UV lamp (as discussed above – UV-A, UV-B, UV-C), the number of lamps installed, the position of the lamps inside the system, and the reflectivity of the air duct. Once UVGI lights are installed inside the HVAC system, the UV-C light kill’s bacteria, viruses and mold spores as described above the sections explaining how UV light kills these contaminants.
In conclusion, the use of UVGI light inside HVAC systems can be extremely effective in purifying and sterilizing the air inside homes, commercial buildings and industrial facilities to help mitigate the spread of airborne pathogens. As we’ve seen, UV light has been found to be a very effective method in killing viruses and bacteria if used properly and within the germicidal wavelength of 254nm. As long as the HVAC system type and size, as well as the sterilization method being used, number of lamps needed, placement of lamps and strength of UV lamps are taken into consideration, UVGI is an ideal solution to air sterilization and airborne pathogen mitigation.