If an HVAC technician recently inspected your air conditioner and strongly recommended installing an ultraviolet (UV) light system for several hundred dollars, you are likely asking a very justified question: Do HVAC UV lights actually work, or is this just an expensive upsell? The answer is yes, they absolutely work—but only if you understand exactly what they are designed to do. There is a massive misconception in the HVAC industry. Many homeowners are led to believe that a UV light acts as an ultimate air purifier, magically erasing dust, pet dander, and smoke from their home. This is completely false. UV-C light does not filter particles. What a UV-C germicidal light actually does is scramble the DNA of biological contaminants like mold, bacteria, and viruses, preventing them from reproducing.
When a UV light is properly installed shining directly onto your indoor evaporator coils, it is incredibly effective at stopping toxic black mold from growing in the dark, damp belly of your AC unit.
Before you agree to the installation or write it off as a scam, use our Interactive IAQ Upgrade Assessor below. By answering a few questions about your home environment and primary health concerns, the tool will instantly tell you if a UV light is a smart investment, or if you simply need to upgrade your standard air filter.
Find out if a UV light is actually the right solution for your home.
Does the air conditioner HVAC UV light work?
Yes, the HVAC UV light works. UV light for HVAC comes in two forms: air sterilization and coil sterilization. If the air sterilization, which is also known as the In-Duct UVC system, is properly installed, it can help to disinfect the air from the unit as it cycles around the return ducts.
On the other hand, a rightly installed coiled sterilization can help to protect sensitive components of the unit that are prone to damage, like condensation pans, filters, and cooling coils.
What is a UV light for an HVAC system?
These special ultraviolet lights are installed in HVAC systems to kill or deactivate bacteria, mold, viruses, and other airborne pathogens. This technology is used both in commercial and residential areas and has remained relevant in several industries for almost a century.
How does HVAC UV light work?
The HVAC UV light simply works by disinfecting the air as it circulates through the return ducts.
Pros and Cons of UV light in the HVAC system
Pros of UV light in the HVAC system
- If air from the HVAC system passes through the UV light, the killing rate of bacteria or mold in the duct is 99%, making it an effective way of controlling the growth and spread of airborne pathogens within the unit.
- UV light is effective at killing mold, mildew, and every other bacteria and can also help disinfect infectious airborne organisms.
- With the use of UV light and the filter system, a lot of energy can be saved. Not only that, but it can also make the unit run more efficiently.
Cons of UV light in the HVAC system
- For the UV light to work effectively, you must make sure to clean the UV bulb regularly as dust builds up quickly around it.
- Contrary to popular belief that UV light cab is used as a filter, UV light doesn’t filter the air; it can only help to eliminate particulates. Therefore, you will have to ensure that your filter is working for an effective filtration system.
- UV bulbs are not durable; hence, you may need to replace them quite often.
- UV light may be very effective at killing bacteria, but they are not effective at killing viruses.
How long does UV light in HVAC last?
I may not be able to say precisely how long a UV light can last, but what I can tell you is that your UV light will need replacement after a year of use. This is because the more you use UV light, the less effective they become.
How much does a UV light for an AC system cost?
The average cost of acquiring UV light for an air handling unit ranges between $3000 to $6000. Notwithstanding, you can still find some types of UV lights that are cheaper. An excellent example of this is the air sanitizing light which can cost between $80 to $400.
When is a UV Light NOT Worth It?
Many homeowners are pressured into buying a $600 UV light when all they really needed was a $20 high-efficiency filter. If your system is old and failing, throwing expensive accessories at it is a waste of money. If a technician tries to sell you a UV light immediately after giving you a massive repair bill for a dead outdoor unit, take a step back. Use our HVAC Quote Analyzer to see if their pricing is fair, and check our guide on what causes an AC compressor to stop working to ensure you aren’t being taken advantage of.
Does UV light in the HVAC damage the AC coil?
Yes, UV light in HVAC can damage the coil of an AC. Ordinarily, UV light should not adversely affect your unit, but if they are improperly installed. Furthermore, the coil of the air conditioner might be exposed to the light from the UV bulb, which could lead to oil leakages. The exposure of the coil to the light can also lead to rust or total breakdown of the component over time.
Do UV lights in HVAC help with allergens?
Yes, UV lights in the HVAC help with allergens. UV light is not only effective at killing bacteria or disinfecting the air against microorganisms, but it can also help to reduce allergies to some extent which could lead to improved health conditions, especially for people who suffer from allergens. UV light can render certain allergens like pollen, dust mites, and mold spores inactive.
Does HVAC UV light kill mold?
Yes, UV light kills mold. The growth of mold in an air conditioner can be curtailed with the use of UV light. UV light produces shortwaves of energy that can penetrate and destroy mold by breaking up its DNA. However, for this method to be effective, the mold must be directly exposed to UV light.
Are UV lights in HVAC systems effective?
Yes, UV light in HVAC systems is very effective. With a properly installed UV light, you can kill up to 99% of germs, bacteria, and allergens that may be breeding within your unit. This estimate is accurate and speaks a lot about how effective this method is.
Do the HVAC UV lights stay on all the time?
Yes, the HVAC UV light stays on all the time. The lightwaves produced by UV light helps to produce help to eradicate all sorts of airborne allergens or bacteria hiding within the unit. And to do this, they must stay on continuously for them to work efficiently and effectively.
Preventing Biological Sludge
The dark, damp environment inside your indoor air handler is the perfect breeding ground for fungal spores. Without a UV-C light neutralizing them, these spores grow into thick, jelly-like sludge that clogs your drain lines. If you are already noticing a ‘dirty sock’ smell when your AC kicks on, the mold has likely already taken root. Before installing a light, check your system’s current contamination level using our AC Mold Risk Calculator.