Updated On

January 11, 2024

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    If you’re worried about indoor air quality, consider installing an ultraviolet (UV) light in your HVAC system. UV lights sanitize the air as it circulates through your ductwork, killing harmful bacteria, mold, and other airborne contaminants. We’ll cover the main benefits of UV lights, the cost to install and maintain them, and some safety tips for working with them.

    If you’re already sold on the benefits of UV lights for keeping your HVAC system clean and safe, use the tool below to find the best HVAC installers in your area to find the best deal on installing UV lights for your HVAC system.

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    • Air sanitizing systems are one of the best ways to keep the air circulating in your home free from contaminants and safe to breathe.
    • HVAC UV lights are relatively affordable, especially compared to air filtration systems like air purifiers and filters.
    • Installing UV lights in your HVAC system is straightforward, although most people should leave it to a professional.

    What Are the Benefits of a UV Light in Your HVAC System?

    Air sanitizing systems are one of the best ways to keep the air circulating in your home free from contaminants and safe to breathe. Ultraviolet (UV) light’s utility for sterilization has been known since the late 1800s and became prevalent around the turn of the century when it played a key role in disinfecting hospital equipment to prevent the spread of tuberculosis.

    UV light has germicidal properties, making it great for sanitizing air as it passes through your HVAC system. HVAC UV light systems use a special type of high-frequency low-wavelength UV light called UV-C to destroy the nucleic acids that make up the DNA in harmful airborne bacteria and sanitize the air as it passes through the system.

    HVAC UV lights are also good at limiting mold growth throughout your HVAC system, preventing certain respiratory illnesses. The most common type of HVAC light is an in-duct light that goes near your central air system’s blower. Some HVAC systems also use UV lights to prevent mold from growing on the evaporator coil. The evaporator coil holds the refrigerant that your AC unit uses to cool your home and is a breeding ground for mold spores that love cool, condensation-rich environments. You might also see these electronic air filters used to sterilize the condenser coil and drain pan.

    A final benefit to installing UV-C lamps in your HVAC system is that they also destroy volatile organic compounds (VOCs), which cause unpleasant odors reminiscent of tobacco smoke. While not all VOCs cause health issues, their strong smells are undesirable and hard to eliminate.

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    Once installed, UV lights require very little maintenance and only need attention when they need to be cleaned or replaced. The only downside is that working with UV lights can be dangerous, so you need to hire a professional to install them or take some safety precautions if you decide to DIY.

    Source: Regency Lighting

    How Much Do HVAC UV Lights Cost?

    HVAC UV lights are relatively affordable, especially compared to air filtration systems like air purifiers and filters. The initial cost of installing HVAC UV lights is between $200 and $600 for coil sanitizing lights and between $250 and $700 for air sanitizing lights. These estimates include equipment and installation, although labor rates will vary depending on your location.

    For both coil sanitizing and air sanitizing systems, the cost of replacement UV light bulbs ranges from $10 on the low end to about $75 on the high end.

    One thing to remember is that running HVAC UV lights will increase your electric bill. Your specific increase will depend on how many lights you need and what type you choose, but most people report an increase in their monthly energy bill of between $15 and $30.

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    How To Install UV Lights in Your HVAC System

    Installing UV lights in your HVAC system is straightforward, although most people should leave it to a professional. Most HVAC contractors don’t allow unlicensed work on their systems, so make sure you understand your service agreement before making any changes to your system. Your HVAC company might void your warranty or refuse to service your system if you work on it yourself.

    With that out of the way, here are the steps you’ll need to follow to install UV lights. The following sections will run you through the entire UV light installation process, step by step.

    Step 1: Prepare Tools and Materials

    The only tools you really need are a drill and a hole saw drill bit. The other equipment you need will come with the HVAC UV light system. Most hardware stores sell HVAC UV light kits.

    You should check the UV system you purchase for information about the mounting hole size before you start to make sure you have an appropriately sized drill bit. Most HVAC UV lights require a mounting hole between 1.5 and 3 inches.

    Step 2: Choose a Location

    We recommend installing a UV light system designed to sanitize the air in your air handler’s return air duct. This air-sanitizing UV lamp is well-suited for residential HVAC systems because they’re affordable, easy to install, and sanitizes the air when the AC or furnace runs. A more complicated system with lights mounted throughout the ductwork will be better at keeping your system clean, but it is more difficult and expensive to install.

    Step 3: Drill the Hole (or Holes)

    If you choose a system that can be mounted to the return air duct, you’ll probably only need to drill one hole. Mounting UV lights throughout your system’s ductwork will require more work and isn’t recommended.

    Make sure to check — and double-check — the instructions that come with your UV light before you start drilling. The hole’s location doesn’t need to be precise, but make sure it’s relatively centered on the return duct casing; you don’t want to install the light too close to the return filter. Installing the light as close to the center of the duct as possible will ensure that as much of the air is bathed in the UV light as possible when your AC or furnace is running.

    Step 4: Mount the Lamp

    Screw the lamp into the air handler with the included mounting screws. Mounting it this way will allow the UV light to scrub the air from your furnace and your central air system if you have one. Attach the unit to the duct with your drill or a screwdriver.

    Step 5: Connect the Power to the Furnace

    Most HVAC UV lamps are designed to be able to draw power from the blower so that they only run while the air handler is on. That means when your furnace or central AC system blows air through your home, the UV light will turn on — when no air is circulating, the light will shut off to conserve power.

    If you have experience with electrical work, you should consider hardwiring the UV lamp to your system. Otherwise, plug the UV light into a nearby outlet using an extension cord with the appropriate rating.

    Step 6: Maintain and Change the Bulb as Needed

    UV-C bulbs have a lifespan of around one year, but you’ll want to clean them a few times yearly since they tend to accumulate dust. Once every three months, turn your HVAC system off, remove the lamp, and wipe the UV bulb down with a soft cloth. If the bulb is especially dirty, you can use an ordinary glass cleaning solution.

    Safety Considerations When Installing an HVAC UV Light

    UV light isn’t good for our skin or eyes, so it’s important to install HVAC UV lights correctly to ensure your safety during the installation and throughout your day-to-day life. Never look directly at a UV lamp; even brief exposure to UV light can cause permanent damage to your eyes. Always wear eye protection when working with UV-C lights. Safety glasses that provide UV-C protection are incredibly cheap and offer insurance against accidental exposure.

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    It’s extremely important to ensure that it’s impossible to see the UV lamp once installed in your air conditioner system. Double and triple-check the enclosure and ensure no holes or gaps before powering on the UV light.

    Final Thoughts on UV Lights for HVAC Systems

    UV lights are one of the best upgrades you can do for your home HVAC system. UV lights are the best way to keep the air you breathe safe. They’re inexpensive, effective, and easy to maintain, making them a no-brainer for anyone with a home HVAC system.

    Even if your HVAC system has a high-quality air filter, adding a UV light will help kill microorganisms and bacteria that might be small enough to slip through the filter. It will also prevent mold and mildew from growing in your ductwork, which an air filter or purifier won’t prevent.

    We recommend hiring a professional HVAC contractor to install your UV light. You can use our tool to locate an HVAC technician near you who can set you up with a UV lamp. If you decide to install one yourself, make sure you understand your service contract and are aware of the possibility that you will void your warranty.

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    Frequently Asked Questions

    Can UV lights damage HVAC system components?

    While it’s true that UV light can damage some materials, you don’t have to worry about a UV lamp damaging your HVAC system. The metal used in most HVAC system ductwork is resistant to UV damage and won’t wear down and become brittle over time, like plastic or other composite materials. Since your germicidal UV light will most likely be installed in your air handler, you won’t have to worry about it affecting vulnerable plastic components.

    How often should UV lights be replaced?

    UV lights should be replaced annually and cleaned three to four times yearly. Since our eyes can’t detect UV light, it’s impossible to tell when a UV light needs to be replaced by looking at it, so you must stick to a strict replacement schedule. We recommend you add a reminder to replace your UV light to your HVAC maintenance checklist, so you don’t forget.

    How do UV lights work in HVAC systems?

    Ultraviolet lights for HVAC systems work by killing bacteria, microorganisms, and mold to keep the air inside your home clean and safe. UV radiation has a higher frequency than visible light. The higher frequency UV light has enough energy to destroy the DNA of bacteria and other microorganisms, killing them and sanitizing the air.

    What are the benefits of UV lights in air purification?

    UV air purifiers are more sanitary and easier to maintain than standard air purification systems. Filter systems are great at filtering dust and allergens out of the air but don’t prevent mold growth. Filters need to be replaced more frequently than the bulbs in a UV light system, making them harder to maintain and less effective if you forget to swap out the filter. A dirty filter will also reduce your air conditioning system’s energy efficiency and airflow, which can be a headache.

    Editorial Contributors
    avatar for Dan Simms

    Dan Simms


    Dan Simms worked in real estate management for five years before using his experience to help property owners maintain their own homes. He got his master’s degree in English Literature and Creative Writing, and he now enjoys sharing his knowledge about homeownership and DIY projects with others on Today’s Homeowner. When he’s not writing, he’s usually outdoors with his wife and his dog, enjoying mountain biking, skiing, and hiking.

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    photo of Roxanne Downer

    Roxanne Downer


    Roxanne Downer is a commerce editor at Today’s Homeowner, where she tackles everything from foundation repair to solar panel installation. She brings more than 15 years of writing and editing experience to bear in her meticulous approach to ensuring accurate, up-to-date, and engaging content. She’s previously edited for outlets including MSN, Architectural Digest, and Better Homes & Gardens. An alumna of the University of Pennsylvania, Roxanne is now an Oklahoma homeowner, DIY enthusiast, and the proud parent of a playful pug.

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