Do HVAC UV Lights Improve Indoor Air Quality?

Ben Kissam
Written by Ben Kissam
Updated June 8, 2021
box attached to HVAC system with UV light inside
An HVAC UV light appears as a small external box attached to your air handler or ductwork. (Photo by Summer Galyan)

HVAC UV lights can help everybody breathe a little easier

Get quotes from up to 3 pros!
Enter a zip below and get matched to top-rated pros near you.

The installation of an HVAC UV light benefits everyone in your home, especially those who suffer from allergies and respiratory issues.

That said, pretty much everyone benefits from breathing better air, especially considering that Americans spend as much as 90 percent of their time indoors (where pollutants are 2 to 5 times higher on average, according to the Environmental Protection Agency).

This guide will explain the benefits of installing an HVAC UV air purifier in your home, what you can expect after installation, and go over basic costs for the job.

What are HVAC UV Lights?

HVAC UV lights purify the air traveling through your HVAC systems. 

Ultraviolet lights installed inside of your furnace, air conditioner, heat pumps, or ductwork kill bacteria, mold, mildew, allergens, and other germs—before they enter your home (and lungs).

Eliminating these compounds from your home’s systems also keeps them running more efficiently. Without the buildup of microorganisms such as mold and even algae, air moves more freely and keeps your home heated or cooled to the temperature you desire.

Do UV Air Purifiers Work?

While an in-duct UV air purifier can’t guarantee complete removal of germs and bacteria, the UV-C light emitted from a UV light purifier bulb is proven to kill as much as 99% of microorganisms living in your HVAC system—which is pretty good if you ask us.

The level of intensity, length of exposure, lamp placement inside your unit, and amount of regular maintenance all determine the effectiveness of your HVAC UV light system.

Pros and Cons

When evaluating in-duct UV air purifiers, you should determine whether the pros outweigh the cons and whether a UV-C light air purifying system will meet your needs.


  • Improved airflow

  • Reduced heating or air conditioning costs

  • Reduced clogging in drain lines (preventing one of the more common air conditioning problems)

  • Disease and allergy prevention (gets rid of mold, mildew, and many bacterias)

  • Possible to install DIY


  • May not improve symptoms depending on what you’re allergic to (pet dander, dust, etc.)

  • Potentially expensive installation costs

  • Light bulb needs to be cleaned every few months to prevent dust buildup 

  • New light bulbs are expensive (starting at $100)

  • Filters are still required to ensure high air quality in home

How a UV Air Purifier for HVAC Works

An AC or furnace UV air purifier sanitizes surfaces in your air conditioning unit, furnace, or ducts by shining ultraviolet light waves on the interior of your devices. 

Designed to turn on and off with the system, the UV lights inside your device kill harmful compounds that form inside and can make you or your family sick.

Keep in mind, HVAC UV lights only get rid of germs and bacteria. They won’t eliminate viruses or some common allergens (dust, pet dander) that could still be making your family sick.

What Should I Expect After Installing HVAC UV Lights?

You can expect to feel relief—in both your wallet and your sinuses.

After installation, your home’s air quality can improve in just a few days. Because the UV lights only kill germs when your device is turned on, run your system for a few hours after installation.

In the long-term, you could enjoy lower electric bills due to more efficient heating and cooling. And among the less-recognized HVAC UV light benefits, they also help keep your coils and drain pan clean, reducing both wear and tear and maintenance requirements.

When Should You Install HVAC UV Lights?

You should seriously consider installing an in-duct UV air purifier when you or your family suffer from allergies or respiratory issues. If that isn’t happening, this project probably doesn’t need to be a top priority HVAC upgrade for your home.

However, installing a UV HVAC air purifier could be a proactive step for those living in wet and humid climates. High-moisture areas are more susceptible to mold growth, meaning installation now could be a good long-term investment.

Is Installing HVAC UV Lights worth the cost?

If you or a family member suffers from allergies or respiratory issues, an HVAC UV air purifier is pretty much a no-brainer. You’ll be safer and feel healthier at home and could even save money when you factor in fewer trips to the doctor, medications, and other expenses.

That said, it’s no secret that installing HVAC UV Lights can be a little pricey. 

Parts and installation could cost as much as $1,500, depending on your system and the type of device you choose.

Maintenance isn’t necessarily cheap, either. Expect to pay at least $100 per year for a new high-grade bulb each time it needs to be replaced (about once a year).

DIY or Hire a Pro?

Fortunately, installing HVAC UV lights is a project you can tackle by yourself to save money.

The key is to find the most effective location to install your bulb. Professionals tend to install near the coils, in the air handler, or in strategic places along the ductworks. 

This way, you get the maximum amount of UV-C light exposure in your unit, giving you the best possible indoor air quality in your home.

Ask an HVAC technician near you for advice or find a pro to handle the job for you.

Need professional help with your project?
Get quotes from top-rated pros.