HVAC UV lights are a fantastic option for improving your home’s indoor air quality and keeping your family healthy. These units emit powerful ultraviolet rays that are effective for preventing issues with mold growth and also eliminating bacteria and viruses. One common question we get about these HVAC UV light units is whether they are meant to stay on all the time, and the answer to this depends on the specific type of unit. To understand why this is, here is a guide to the different types of UV light units and how they work as well as how to know which type of unit is the better choice for your home.

Coil-Sanitizing UV Lights

Coil-sanitizing UV lights are mounted inside the air handler compartment so that they shine directly down onto the AC evaporator coil. This type of unit is specially designed to prevent mold, mildew and bacteria from growing on the evaporator coil, which are all common issues due to the warm, moist air that constantly flows into the air handler when the air conditioning system is running.

If any mold or bacteria is growing on the evaporator coil, it can worsen your home’s air quality since it will then be spread throughout the home via your ductwork. Mold and mildew on the evaporator coil can also lead to your air conditioning making your home smell moldy or musty, which a coil-sanitizing UV light will help to prevent. Coil-sanitizing lights will also destroy some bacteria, viruses and mold spores in the air that flows through the air handler, but they aren’t all that effective at this since much of the air won’t come into contact with the UV rays.

To work effectively, coil-sanitizing lights run for 24 hours a day and are meant to be used throughout all of the months when your air conditioning is turned on. When you shut your AC down for the last time in the fall, you will then need to manually turn off the light or unplug the unit. There is no point in leaving the unit on after this point since moisture only ever collects on the evaporator coil when your AC is running. Once you shut your AC off and turn the heat on, you can then shut the light off since you’ll no longer need to worry about bacteria and mold growth on the evaporator coil.

Coil-sanitizing lights won’t just improve indoor air quality and prevent your AC from smelling bad. Studies have also shown that they can potentially reduce your annual cooling costs by up to 20%. This is because they help to prevent something known as coil fouling, which is when the evaporator coil becomes covered with a build-up of biological contaminants. This build-up can greatly reduce the effectiveness of an air conditioning system so that it starts needing to run for longer periods and uses more energy.

What happens is that the layer of bio-contamination acts as a barrier that prevents the air flowing through the system from directly contacting the evaporator coil. As a result, the coil won’t be able to remove nearly as much heat and moisture from the air, and the AC system will cool much more slowly.

Coil fouling is a problem that affects virtually all AC systems and usually starts to occur within five years of installation. Having the evaporator coil professionally cleaned every year can help to lessen the effect, but it won’t ever fully eliminate the problem. The only way to fully overcome and prevent this issue is by installing a coil-sanitizing UV light unit.

Air-Sanitizing UV Lights

Air-sanitizing UV lights are generally slightly larger and more powerful than coil-sanitizing lights. This type of UV light unit can be installed anywhere in the existing ductwork and is mounted in a way that the lights completely fill that part of the duct. As air flows through the duct, the UV rays will destroy any organic microorganisms like mold spores, dust mites, pollen, bacteria and viruses to help improve indoor air quality and prevent illness.

Air-sanitizing lights are much better at improving indoor air quality for several reasons. One is that any particles in the air are guaranteed to come into contact with the UV rays, which isn’t the case with coil-sanitizing lights. Another reason is that coil-sanitizing lights are meant to be used throughout the entire year whereas air-sanitizing lights only work during the summer when your AC is running.

An air-sanitizing UV light unit is hard-wired into the HVAC system, which allows the light to turn on and off automatically. The lights will automatically turn on whenever the furnace or AC starts and then shut off when the heating or cooling system does. The fact that this type of unit eliminates particles from the air flowing through the duct system means that there is no point in the unit staying on when the HVAC system is off since there won’t be any air flowing through the ductwork.

The fact that air-sanitizing lights can be mounted anywhere in the duct system means that this type of unit is perfect for overcoming issues with existing mold growth in your ductwork. Ducts that run through non-air conditioned areas like an attic or crawl space often have issues with condensation forming and leading to mold growth. If there is mold in your ductwork, you can have the unit installed directly at the source of the problem and it will quickly kill all of the mold and prevent it from returning.

How to Know Which Type of UV Light Unit Is Best for Your Home

The choice between air-sanitizing and coil-sanitizing lights really comes down to what your specific goals are and/or what issues you’re currently facing. Coil-sanitizing lights tend to be slightly less expensive and are much better at improving the energy efficiency of your air conditioning system. Air-sanitizing lights, on the other hand, are a better choice for people with severe allergies, asthma and any other respiratory issues. A coil-sanitizing unit will eliminate virtually all pollen, mold and other organic allergens from the air as it flows through the ducts and is exposed to the UV rays.

You can also choose to have both types of units installed without needing to worry about them causing your energy bill to rise. On average, either type of UV light will cost less than $3 per month to run plus anywhere from $20 to $100 each year for a new replacement bulb. This means that UV lights are far more efficient and will use much less energy than most other indoor air quality units such as whole-home air purifiers.

Oviedo’s Indoor Air Quality Experts

If you’re looking to upgrade your HVAC system with UV lights, you can trust the team at American Air & Heat. We also install a wide range of other IAQ units, including mechanical air cleaners, electronic air cleaners and electrostatic filters. We also offer professional air duct cleaning, which can also immediately improve your home’s indoor air quality and make your HVAC system more energy efficient. For more information on our indoor air quality services or if you need any cooling or heating service in the Oviedo area, contact us today.

company icon