Scientists have known that UV light can stop the growth of microorganisms and bacteria for over 100years. As a result, UV lights are used for sanitation purposes in the food industry, hospitals, and water filtration systems. Did you know that ultra violet lights can also purify the air we breathe? Today we’re discussing how ultra violet lights work in home HVAC systems to improve the quality of indoor air. Keep reading to find out more.

How do UV lights help improve air quality?

  1. In residential HVAC systems, most of the air used gets recirculated. This air can carry all sorts of pollutants, which we breathe in. UV lights work to remove the following from indoor air:
  2. Germs
  3. Pathogens and viruses
  4. Dust
  5. Bacteria
  6. Allergens
  7. Fungi or mold

Anyone can benefit from the installation of ultra violet lights in their home HVAC system. It’s an especially good idea for people with allergies, pets, or children. Additionally, if you live in a humid area that’s susceptible to mold growth, you’ll want ultra violet lights to remove those invisible particles from your air.

How it works

UV light cleans the air by trapping and eradicating pollutants. The DNA of these pollutants break down when they come into contact with the ultraviolet wavelength. As a result, they can’t reproduce and they gradually die off. When air travels through the chamber with ultra violet light bulbs, it gets purified.

Types of UV light for residential HVAC systems

You have two options when selecting UV lights for your home HVAC system: Coil Sterilization and Air Sterilization. Let’s examine both of these.

In Coil Sterilization, a UV light is positioned in your HVAC system’s return air duct. This stick-shaped light cleanses the air handler coil. Coil Sterilization systems run 24/7.

Your other option is an Air Sterilization system. Like Coil Sterilization, this system has a UV light installed in your HVAC system’s return air duct. Instead of a stick light, this option is a complete UV light. This light cycles on with the air handler blower, and it works to purify moving air.

Of these options, Coil Sterilization is the most popular UV light for residential HVAC systems. It also happens to be the most reasonably priced of the two.


Placement is the most important factor in how effective your ultra violet light is. For optimal use, the UV light should be mounted next to the evaporator or cooling coil. They need to be on the cold air side, which is the downstream side of the coil.

Your ultra violet lights need to illuminate the water drain pan underneath the coil, as well as the cooling coil itself. Since there’s water here, there’s always a possibility for mold growth. By positioning the UV lights in these parts, it purifies your air by destroying these pollutants.

Mounting your ultra violet lights elsewhere opens your system up for bacteria and mold to spread. This results in contaminated air, which no one wants in their home.


UV lights in home HVAC systems are effective at purifying indoor air, as long as they’re positioned correctly. They can help stop the spread of viruses, colds, and other bacteria. Given our current COVID-19 concerns, air purification systems are definitely worth considering these days.

Do you have questions about ultra violet lights for your home HVAC system? Our skilled technicians at Ron’s Mechanical can help you out. Give us a call today at ​(952) 445-8585. ​We look forward to serving you.