Informational Guide

Do UV Air Purifiers Work? (What Does UV Light Do?)

UV air purifiers are new on the market & people are seeing impressive results. This guide will help you understand what they are & the benefits they can bring.

by Ian Haynes

Air purifiers are proven to improve your health and wellbeing by helping to cleanse the air around you. However, the bacteria, viruses, and contaminants in the air are constantly increasing, and you want to stay one step ahead.

Manufacturers have developed new technology to help counteract this problem and improve the quality of the air in your home by using new technology in more innovative ways. UV air purifiers are the newest product on the market, and people are seeing impressive results.

This guide will help you understand what they are and the benefits they can bring.

AP-T30 LightAir purifiers work by pulling air into the system, passing it through a filter, and releasing it back into your home.

The difference with UV air purifiers is that they have an extra step as the air is pulled into a separate chamber containing a UV light.

What Does UV Light Do?

The UV light deactivates certain microorganisms and pathogens in the air.

The UV light does this by fundamentally altering the DNA of some contaminants.

This effectively removes them from the air, purifying it before it flows back into your home.

There are three main types of ultraviolet (UV) light:

UV-A Light

UV-A light is 320-400 nanometers. The light isn’t visible to the naked eye and vibrates faster than the light you can see. It vibrates a little more than visible light, but the vibration isn’t generally strong enough to impact contaminants. For this reason, you rarely see UV-A light used in air purifiers.

UV-B Light

UV-B light is 280-315 nanometers and isn’t really visible either. It vibrates a little faster than UV-A light, but it’s still not that effective at purifying the air. You generally won’t find UV-B light in air purifiers.

UV-C Light

UV-C light is 100-280 nanometers. It has the fastest vibration and most energy. It’s commonly used in sterilization processes, and almost all UV air purifiers use UV-C light. While it is effective at purification and removing contaminants, it can cause skin and eye damage if exposed to it directly for too long.

UV-C Light

Do UV Air Purifiers Really Work Well?

UV light has been proven as an effective sterilizer, but there can be mixed results in an air purifier. Standalone or portable air purifiers often aren’t able to capitalize on the effectiveness of UV light, and UV light is not recommended with HEPA filter air purifiers. UV light can often be more effective in larger, whole-home air purifiers.

For the UV air purifier to work, the microbes within the air need to be exposed to the light directly. This is impacted by the filter, the air temperature, and the light itself.

These are the key factors that impact the effectiveness of the UV air purifier:

  • Contact
    Microorganisms and contaminants are extremely small, and it’s not guaranteed they will come into contact with the UV light. In smaller air purifiers, the UV light coverage isn’t as good, meaning that some air won’t actually be exposed to the light at all.
  • Exposure time
    To actually impact the pollutants, the UV light needs time. The air in the purifier needs to be exposed to the UV light for enough time to sterilize it properly, and smaller units often don’t allow enough time in the process.
  • Intensity and wavelength
    The more intense the light, the better it can deal with contaminants in the air. The optimal wavelength is around 255 nanometers which is where it will be most effective at deactivating pathogens.
  • Proximity
    The proximity of the pathogens and contaminants in the light will impact the effectiveness. You generally want a chamber that will keep the air close to the light for it to have the desired effect.
  • Air Changes Per Hour (ACH)
    The ACH of an air purifier is the number of times per hour it can purifier all the air in a room. This is essentially how efficient the purifier is and how quickly it can filter the air. The higher the ACH, the more effective it will be.

Effectiveness at Removing Different Pollutants

UV air purifiers are designed to deal with a number of different contaminants; however, they are more effective against some than others:

UV Air Purifiers Vs. Allergens

UV air purifiers are often bought to help deal with allergens and provide relief for those with allergies. UV air purifiers can help deal with some airborne allergens. This includes mold, dust, germs from your pet, and cigarette smoke.

However, it won’t remove them entirely, and some dangerous gasses are impervious to UV light. Mold is a common cause of allergies, and while it can be deactivated by the UV light, it can still trigger your allergic reaction.

UV air purifiers can have an impact against allergens but certainly won’t solve the problem entirely.

UV Air Purifiers Vs. Microorganisms

Viruses and microorganisms can be harmful, and many people buy UV air purifiers specifically to remove them. The UV light can deactivate some microorganisms. Still, the majority of common bacteria can only be destroyed with prolonged intense bursts of UV light you won’t get in an air purifier.

Air purifiers can be effective at removing viruses, though, and you should see a small reduction in microorganisms.

UV Air Purifier Vs. VOCs

Volatile organic compounds (VOCs) are often caused by cosmetics, paint, or cleaning products. UV air purifiers generally have minimal impact on VOCs and can actually make things worse by causing them to emit dangerous gases in your home. Find related air purifiers for VOCs here.

How To Reduce Indoor Air Pollution Negative Air Machines

Pros & Cons of UV Air Purifiers

UV air purifiers are still relatively new, but like any product, they have their pros and cons.

  • They can help reduce the number of viruses and microorganisms in the air in your home.
  • They can work effectively with filters to remove smoke and particles from the air.
  • They can make the air safer to breathe by removing bacteria.
  • They can make your air smell fresher and cleaner.
  • If not properly made, they can produce ozone which is harmful to humans.
  • UV filters aren’t very effective in portable air purifiers.
  • They only have limited effectiveness even in larger air purifiers.

People Also Ask (FAQ)

Do UV lights kill mold?

UV lights can deactivate mold; however, this does not stop mold particles triggering certain allergies. Find more about mold here.

Which is better, UV light or an air purifier?

Air purifiers are more effective at cleaning the air around you. UV lights, when used with an air purifying filter, can be effective.

Are these devices safe or dangerous?

UV air purifiers can be harmful if they produce ozone. The UV-C light can also damage your eyes and skin if you’re directly exposed to it.

Do hospitals use UV light to sanitize?

Hospitals have used UV light as a cleaning tool for decades. They use large industrial units to sterilize rooms.

How much does it cost to install UV light in HVAC?

A UV light for an HVAC system can cost between $500 and $800, depending on the type of light and the location.


UV air purifiers are among the most talked-about products on the market right now and are designed to make your air cleaner. They have mixed results, but they can help sterilize the air in your home if installed properly.

Make sure you avoid any UV air purifier that produces ozone as it can be dangerous and, if possible, avoid portable air purifiers as the UV light in them isn’t very effective.

Last Updated on April 3, 2022

Ian Haynes

Ian Haynes is an HVAC writer, and researcher. He has worked on hundreds of articles relating to home cooling, heating and air quality with a vast knowledge of the technical aspects of these types of appliances. Outside of his work, Ian likes exploring Brooklyn with his Labrador. Learn more about the AC Lab team here.