How To Install UV Light In an HVAC System

By | April 17, 2023

How To Install UV Light In an HVAC System
UV lights are a great option for an HVAC system to kill off mold, mildew, and airborne viruses.

This makes them ideal in many scenarios for keeping the air cleaner and safer to breathe.

What Are HVAC UV Lights?

What Are HVAC UV Lights
HVAC UV Lights are bulbs that radiate UV light that kills mold, mildew, and airborne viruses.

UV (Ultraviolet) light is on the lower end of the light wavelength spectrum and is electromagnetic radiation.

The Sun also radiates UV light, with roughly 10 percent of the Sun’s output containing Ultraviolet light.

When a person is sunburned, this is from the Ultraviolet light the Sun emits.

One of the benefits of short-wave ultraviolet light is it sterilizes areas it comes into contact with.

For HVAC systems, this means it can help to sterilize air as it passes a UV light.

How Hard are UV Lights to Install in an HVAC System?

How Hard are UV Lights to Install in an HVAC System
The difficultly of installing UV lights depends on the location of the air handler.

The air handler often contains the evaporator A-coil from the air conditioner and is also usually the supply for air into the system.

If there is a gas furnace in the home, the air handler is usually located at the bottom of the furnace.

The bottom panel from the furnace should be removed to see the best spot to locate the UV light.

Best Location to Install HVAC UV Light

How To Install UV Light In an HVAC System Location
The air handler is usually the best location to install a UV Light.

While usually mounted in the air handler, they can also be mounted at other locations.

All the air in an HVAC system will flow through the air handler, making an ideal location.

Where to Buy an HVAC UV Light?

HVAC UV lights can be bought at hardware stores, HVAC companies, and online.

If an HVAC company is hired to install the light, they will have them available.

If you plan to install one yourself, buying it online such as Amazon, is a good place to read reviews and get the best option.

Example UV Light on Amazon
REKO Lighting R2000 Air Purifier Whole House Uv uvc Light in Duct for HVAC Ac (Air Conditioning) Duct

Do not stare directly at a UV light as, like the Sun, it emits electromagnetic radiation that can hurt your eyes.

How To Install UV Light In an HVAC System

  1. Locate the best spot to install the UV light, usually in the air handler box.
  2. How To Install UV Light In an HVAC System Step 1

  3. Drill a hole through for the UV light.
  4. How To Install UV Light In an HVAC System Step 3

  5. Insert the UV light and attach it with screws.
  6. How To Install UV Light In an HVAC System Step 4

  7. Plug it in and test it.
  8. How To Install UV Light In an HVAC System Step 5

Installing a UV light is beneficial for many reasons, mainly to kill off mold, mildew, and airborne viruses.

Before buying a UV light, be sure to examine your HVAC system for the best location to install it.

Many systems can install a UV light in the air handler at the bottom of the furnace.

If your home doesn’t use a furnace and has a heat pump, the air handler will be in the packaged unit.

Package units have the return air on one side and the supply on the other side circulating the air in a home.

Often UV lights are located on the return side of a packaged system, but they can also be located on the supply side.

Have you installed a UV light in your HVAC system? Let us know your thoughts below.

Category: HVAC how to

About Aaron H. Benetti

Aaron H. Benetti an HVAC technician who has worked in the field since 1991. He began his career as an HVAC installer and later began doing troubleshooting and repairs. Around 2010, he began to write books on HVAC topics, mainly tutorials and how-to information. Currently, Aaron works as an HVAC tech and also writes many articles and posts for websites as well as books and videos on HVAC topics.

10 thoughts on “How To Install UV Light In an HVAC System

  1. Darius

    Will this help protect against the a virus and kill it off.

    1. Ken Sendeloski

      Since UV light does kill off most airborne viruses it likely does but I hesitate to confirm this.

  2. Tdtradiner

    Question: since the UV light sits on the underside of the A-coil, it is in close proximity to the filter (ours is a thick MERV 11 filter, 16×20) and it seems to be deteriorating the filter material. I usually change the filter every 3 months (even though it should last longer), but the filter is deteriorating and breaking down in even shorter than 3 months. Any suggestions?

    1. Ken Sendeloski

      UV light does break down cardboard and plastics quicker than normal.

    2. Tony Rigdon

      I would install some type of metal “shield” or “reflector” to put between the UV light and the filter so it only shines on the coil and not on the filter. The one I just purchased came with this “optional” metal shield.

  3. Unsure Homeowner

    You say above “Often UV light are located on the return side of a packaged system but it can also be located on the supply side. ” The manufacturer of the unit I am considering through my HVAC contractor specifies that the “Unit should be installed after the air handler in the HVAC system.” The HVAC contractor expands on this by stating, “The manufacturer of the [name of unit deleted by writer] recommends installing their unit on the Supply Air side of the system. The filter is on the return air side. The reason for installing it in this location is to allow the light to hit the air as it is coming into the system. This will eliminate condensation, mildew from developing on the coil.” I don’t know whether the contractor’s comment about “coming into the system” means the UV will treat only fresh air coming from outside, or means air within the distribution ductwork. Or, is this a comment having to do with treating air in an air mixture chamber? Comments appreciated, please.

  4. Justine Clark

    I am curious as to why the uv light needs to be on 24/7. Wouldn’t it be better to come on when the fan comes on and go off when the fan goes off.

    1. Ken Sendeloski

      I suppose you could wire it in on the systems fan motor but this would require modifying the unit.

    2. Anthony

      Mold grows 24/7, not just when the fan is on. I want mine on all the time. When the fan kicks on, I want the air clean.


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