Do UV Lights In HVAC Systems Actually Kill Mold?

UV Lights In HVAC Systems

Mold, mildew, fungi, and bacteria are likely the last things you want circulating through your home and lungs while you’re cooped up inside during the winter months. Unfortunately, these types of allergens thrive in the cool, dark, damp areas of your home. Most often inside your HVAC system!

If you’ve done any research into indoor air quality solutions, you’ve likely come across a few articles informing you to replace your HVAC air filter regularly throughout the year. You may have also run into an article or two talking about UV light air purifiers and are now wondering – do UV lights in HVAC systems actually kill mold or are they just an over-hyped fad? Let’s discuss if UV lights in HVAC systems actually kill mold, how they do so, and if it’s worth investing in UV lights for your home HVAC system.

How Mold Spreads Throughout Your Home

Mold is a very opportunistic fungal growth that thrives in dark, wet, and cool areas of homes. Ohio homeowners will often find mold in their basements. It thrives in our area’s humidity. Finding refuge on basement walls, cinder blocks, carpet, drywall, insulation, and other cool porous surfaces that remain sheltered under darkness. Unfortunately, your basement isn’t the only target for mold growth.

The inside of your HVAC unit provides the perfect habitat for mold. Condensation created from cooling/heating, the cool dark interior of your ductwork, and the nutrients from collected dust and debris create a breeding ground for mold within your home. When mold grows on your unit’s evaporator coils, it can easily circulate around your home. This carries mold spores throughout your HVAC system and home then into the lungs of your family and pets. Unchecked, this mold will continue to recirculate. Settling itself throughout your home, causing or worsening asthma and allergy symptoms. Possibly contributing to other health issues due to exposure.

Do UV Lights In HVAC Systems Actually Kill Mold

The short answer is, yes!

According to the United States Environmental Protection Agency (EPA.gov), if UV Light Systems in HVAC systems are “properly designed, ultraviolet germicidal irradiation (UVGI) cleaners that use ultraviolet radiation from UV lamps may destroy indoor biological pollutants such as viruses, bacteria, and some molds that are growing on the moist interiors of HVAC surfaces (e.g., cooling coils, drain pans, or ductwork).”

When faced with indoor air quality issues, such as mold prevention, proper design and installation matters most. Which is why installing a UV light in your HVAC system to kill mold should be done by a professional.

Is a UV Light In Your HVAC System Right For Your Household Needs?

Now that you know that UV lights in HVAC systems actually kill mold, the next question to ask yourself is whether or not you think it’s worth investing in for your home. If you or your family members struggle with asthma or severe seasonal allergies, it might be something to consider.

If you have questions about installing UV lights or want to explore other options for your home, give us a call! As your trusted provider of HVAC service in Dayton, Ohio, we’ll help you determine if a UV light in your HVAC system is the right solution to combat mold and improve your home’s air quality.

Frequently Asked Questions

What does a UV light in an HVAC system do?

A UV light in an HVAC system is designed to target and neutralize microscopic biological particles that may accumulate inside the system’s components, such as coils and ductwork. This helps improve overall indoor air quality.

How do UV lights work inside HVAC systems?

UV lights emit a specific wavelength of ultraviolet radiation that disrupts the DNA and cell structure of microorganisms, making them inactive. When installed near key components—like cooling coils or drain pans—they prevent unwanted growth from spreading.

Are UV lights effective at improving indoor air quality?

Yes, many homeowners and businesses use UV lights as part of a comprehensive indoor air quality strategy. By reducing harmful particles that can circulate through the air, UV systems help create a cleaner and healthier environment.

Do UV lights in HVAC systems require professional installation?

Professional installation is highly recommended. Placement matters—lights must be positioned correctly to target areas where moisture and particles tend to collect. A licensed HVAC technician ensures both safety and effectiveness.

How often do HVAC UV lights need maintenance or replacement?

Most UV bulbs lose intensity over time and should be replaced every 12–24 months, depending on the system and manufacturer. Routine HVAC maintenance can also ensure the light remains effective.

Can a UV light system lower allergy or asthma triggers?

For households with asthma or allergy concerns, UV lights may help reduce exposure to airborne irritants. While they are not a cure-all, they can be part of a multi-layered approach that includes filtration and proper ventilation.

Is a UV light system a good investment for every home?

It depends on your household’s needs. Homes with higher humidity levels, recurring indoor air quality issues, or sensitive family members may benefit the most. A consultation with an HVAC professional can help determine if UV technology is right for you.