As concerns about indoor air quality and pathogens grow, some HVAC companies are now offering UV light duct cleaning as an added service during traditional duct cleaning. UV light is well known for killing bacteria and viruses, so using UV light within air ducts after they have been vacuumed and brushed could provide a disinfecting boost. However, there are still questions about how effective this duct cleaning actually is.
During traditional duct cleaning, technicians use vacuums and brush attachments to physically remove dust, debris and allergens from your HVAC system. However, microbes can remain even after a thorough physical clean. This is where this duct cleaning comes in.
The systems used emit primarily two types of UV rays:
- UV-C light has the shortest wavelength and is lethal to microbes. Many duct cleaning services rely on UV-C emitters placed inside ducts.
- UV-A light has a longer wavelength but can also help kill pathogens when combined with a chemical agent like hydrogen peroxide (UV-A/Peroxide). This process produces “advanced oxidation” that damages microbes.
Once UV lights are inserted, they sweep through the ducts for a specified time, typically 30-60 minutes. During this process, UV rays attack the DNA of microbes, rendering them unable to multiply and cause infections.
However, some questions remain regarding the effectiveness of this duct cleaning:
1) Penetration –
Most studies show that UV-C light cannot penetrate significantly into duct surfaces to properly disinfect recessed areas. So microbes deep within ducts may survive.
2) Dose –
The amount of UV rays that reaches all areas of complex duct layouts is difficult to determine. A sufficient “germicidal dose” may not reach parts of the system.
3) Regrowth –
Without coated surfaces that remain antimicrobial, microbes can quickly regrow within ducts after this cleaning.
4) Variability –
Many factors affect UV disinfection, so results tend to vary widely between duct systems and installations.
Overall, while it holds promise as a supplement to traditional cleaning, more research is needed to prove how well it actually works within residential and commercial HVAC ducts in real-world settings over the long term.
For now, experts recommend a multistep approach for the most effective duct disinfection:
- Thorough physical cleaning to remove as much debris as possible
- Applying a safe, EPA-registered antimicrobial coating to treated duct surfaces
- Performing UV light duct cleaning as an additional measure
In conclusion, UV light duct cleaning may provide some benefits, but physical cleaning and antimicrobial coatings currently offer more reliable methods for removing microbes from ducts. A comprehensive approach combining physical cleaning, antimicrobial coatings and UV light treatment when done by a qualified HVAC professional will likely yield the most sterilized ducts.