Indoor air quality is important, considering the average person spends a great deal of their time inside. Studies have repeatedly shown that the air in most buildings contains a three to five times higher concentration of certain pollutants than outdoor air. Mold, bacteria and allergens all contribute to air quality issues as well. UV lights are one effective option for overcoming certain air quality issues.
Eliminating Mold, Bacteria and Viruses
Ultraviolet light has extremely powerful germicidal and fungicidal properties, which is why it’s one of the primary tools hospitals and laboratories use to sterilize equipment. All types of ultraviolet radiation have the potential to cause DNA damage. Of the three wavelengths, UV-C is the most powerful and can almost instantly cause severe DNA damage.
The fact that UV-C radiation is so powerful is why it’s commonly being used as part of air purification equipment that eliminates mold and fungal spores, bacteria and viruses. When these microorganisms pass through the UV-C light, their DNA suffers extreme damage. As a result, they are no longer able to spread and reproduce. The result is that the concentration of germs and mold spores in the building is greatly reduced.
Types of UV Lights for HVAC Systems
There are two different types of UV light units specifically designed to work with central HVAC systems to improve indoor air quality. Although both work in the same way, they each are meant to serve a different purpose.
A coil-sanitizing UV light unit is mounted within the home’s air handler where the AC system’s evaporator coil is located, and its purpose is to ensure that no mold and bacteria can grow on the coil. It’s common for both mold and bacteria to grow on an evaporator coil since the moisture that forms on the coil and the warm air blowing over it create an ideal breeding ground. Whenever mold and bacteria growth are present, they then end up circulating with the air moving through the air handler and getting spread to every part of the house. That’s why many homes have issues with their AC system putting out musty, moldy-smelling air.
A coil-sanitizing UV light can be extremely helpful in terms of overcoming odors and preventing air quality issues. It shines directly onto the evaporator coil to destroy any mold and bacteria that are present and prevent them from being able to return. One other advantage of this type of UV light is that it can improve your AC system’s performance. That’s because mold and bacteria buildup on the evaporator coil can essentially create a shield that prevents the refrigerant flowing through the coil from being able to absorb as much heat. As a result, the AC system can’t cool quite as quickly as it should and will end up using more energy since it must stay on longer.
The second type is an air-sanitizing UV light, which is meant to do exactly what its name suggests. This type of unit is normally mounted within either the main supply or main return air duct so that the light completely shines through that entire part of the duct. As air gets circulated through the duct, any airborne germs and mold spores get destroyed when they pass through the light and get exposed to the UV radiation.
One major difference between the two units is that air-sanitizing lights improve air quality all year round. Coil-sanitizing lights are only effective during the warmer months when you have your AC running. There would be no point in leaving a coil-sanitizing light on all year. You only need to worry about mold and bacteria growing on the evaporator coil when your AC is on and the coil is frequently wet. This type of unit is also positioned in such a way that it has very little effect on airborne microorganisms. Most of them flow straight through the air handler without getting exposed to the UV light. Coil-sanitizing units stay on 24 hours a day throughout the air conditioning season. Air-sanitizing units are wired to automatically turn on and off alongside the HVAC system.
How UV Lights Work in Whole-Home Air Purification
There are many different whole-home air purification systems available that can be far more effective at improving air quality than UV lights on their own. The issue with UV lights is that they only tackle issues with mold and germs while having no effect on all the other contaminants that contribute to poor indoor air quality. That’s why many air purification systems combine air-sanitizing UV lights with a highly efficient air filter. As air passes through the system, any germs and mold spores get directly exposed to the UV lights and are quickly eliminated. The air then flows through the filter, which traps most other airborne particles. This includes things like pollen, pet dander, dust and dust mites, smoke particles and even some exhaust fumes and chemical contaminants.
Some units also use UV lights and a special catalyst to produce powerful oxidizing ions that are even more effective at eliminating many airborne chemical compounds. How this works is that the ions attract and bind to the chemicals and then produce a reaction that either destroys the chemicals or causes them to transform into less harmful compounds. This type of process can be especially effective at lowering the concentration of certain VOCs or volatile organic compounds that are found in almost every building. The reason VOCs are such a major issue is that they are naturally released into the air by so many different things. This includes everything from furniture, varnish, adhesives and building materials to cleaning products, fabric softener, dryer sheets and beauty products. Volatile organic compounds are an especially big concern in office environments since printers and copiers can release them.
The only issue is that the process of using UV light can potentially produce ozone. Ozone is a known respiratory irritant. Whether or not ozone is released as a by-product depends on the type of catalyst. The fact that ozone can contribute to other air quality issues is why experts recommend making sure any air purifier you choose is certified to not produce ozone.
Belle Air Services is a women-owned company specializing in all aspects of air conditioning, heating and indoor air quality. Our team has years of experience serving customers in Playa Vista, CA. We are ready to help you tackle any indoor air quality issues in your home. We install UV lights, air purification systems and other types of filtration equipment. We also offer professional air quality testing that can help you determine what issues you’re dealing with and the best way to overcome them. No matter what HVAC service you need, you can trust that we’ll use our expertise and experience to take care of everything in the most effective way without cutting any corners. To schedule an air quality test or any other HVAC service, like ductless AC maintenance, contact us today.
