Will a UV Light for AC Eliminate Mold?

You may have heard of UV (ultraviolet) rays or lights from your science teacher or eye doctor. They’re a spectrum within the light the sun creates and provide a critical function for the planet’s ecosystem. UV rays act as mother nature’s sanitizer. Anything organic that’s exposed to UV ultraviolet lights or rays won’t be able to reproduce. 

This form of sanitation acts as birth control. Whenever an organic substance meets UV lights, its DNA changes and it won’t be able to reproduce. This concept isn’t wasted on mother nature. Exterminators have borrowed it to eliminate insect populations. Biologists look for natural means of birth control to manage overpopulations. Building professionals use it to prevent the spread of infectious diseases in medical facilities and buildings of all kinds. Besides triggering allergies and asthma, mold can cause serious harm to your home’s structure and belongings. 

UV lights in the air conditioning system will kill mold indirectly. It’s not biologically toxic, but it will eliminate the viability of mold spores, along with other organic compounds like bacteria, viruses and some volatile organic compounds (VOCs). The best part is that the lights are harmless to pets and humans. 

How They’re Used in HVAC Systems 

UV rays damage eyesight with direct exposure, so HVAC professionals have designed the light fixtures to fit inside HVAC system ductwork and inside air handlers. These places eliminate the risk of exposure and have contact with much of the air inside a home. They make no sounds, have no moving parts and are energy efficient. 

One of the best places to install the AC ultraviolet lights is inside the air handler so that they shine on the evaporator coil for the air conditioner. Since mold spores are so light, they enter the air conditioner easily whenever the A/C runs. When placed near the evaporator coil, the UV light for AC exposes the mold spores to the damaging rays. They won’t be able to reproduce even if they do lodge on or inside the coil. 

UV Lights in the Air Handler 

The evaporator coil is an ideal environment for biological growths. Temperatures are ideal and there’s plenty of moisture for them to grow. When mold grows on the coil, the air conditioner loses energy efficiency. The mold acts as insulation and it will take the A/C longer to cool your home. 

Should the mold completely cover the coil, not only will your indoor air quality fall, you run the risk of the coil freezing over. The refrigerant that flows through it is extremely cold, and if it can’t absorb the heat from the air fast enough, it goes back to the compressor too cold. Eventually it’s possible for the refrigerant to start freezing the outside the coil. 

Frost will collect and cover the coil, prohibiting any warm air from contacting the surface of the coil. If your A/C continues to run, it’s possible for the compressor in the outdoor condenser to freeze over. The compressor is the A/Cs most important part and expensive part. UV lights in the air handler will largely prevent mold from growing on the coil. 

UV Lights in the Ductwork 

Sometimes HVAC professionals recommend UV light for AC to be placed in the ductwork as well as the air handler. In the ducts, the lights neutralize the mold spores that pass through them. It provides even more protection from mold spreading throughout your home. 

The spores that do go through the ducts and land in your rooms won’t be able to reproduce. The most vulnerable places for mold in your home are the kitchen and bathrooms where water is nearly always on a surface. If you have any condensation issues on windows or inside your walls from plumbing leaks, the mold spores won’t be able to grow new colonies in spite of a hospitable environment. 

Secondary Benefits 

Besides mold, the UV light HVAC also prevents viruses and bacteria from growing in your home. UV light is also one of the few ways to diminish the toxicity of VOCs, which is an important secondary benefit. Without UV lights, the only way to manage harmful VOCs in the air is through avoidance altogether or fresh air ventilation. 

Homes with basements benefit from UV lights. These spaces have enough moisture year-round to support mold and mildew growth. When the spores entering your home lose their ability to reproduce, the odds of it becoming an issue in the basement fall. 

Bottom Line 

UV lights are one of the best ways to tackle mold inside homes. The lights will prevent the spores from spreading unchecked. While mold has an important role of nature, it doesn’t belong in your home.