The world of HVAC is always advancing, making use of new technologies and new approaches to improve the capabilities of the average homeowner’s heating, cooling, and ventilation systems. Along with energy efficiency, one of the biggest categories of breakthroughs has been the emergence of products and technologies to improve your indoor air quality.
Under normal conditions, ventilation systems can contribute pollutants to your living or working space; spreading bacteria, mold, dust, dander, and other particles that can aggravate respiratory conditions or contribute to the spread of illnesses.
Installation a UV light can help to counteract these pollutants. But how exactly do UV lights work, and are they worth the investment?
What is an HVAC UV Light?
Let’s start with a basic introduction to UV lights, including how they’re designed to work, and what they do.
The main purpose of a UV light is essentially to “improve air quality.” Your HVAC system is responsible for circulating air throughout your home, so it has the potential to introduce or distribute particulate matter that could be detrimental to you and your family, interfering with your comfort or in some cases, your health. Depending on the nature of the pollutant, these particles could have short-term effects, causing people to experience eye irritation, sneezing, or even headaches and fatigue. Long-term effects could include the development of contagious diseases, or the aggravation of asthma or allergies.
Some of the most common particles responsible for these negative health effects include bacteria, viruses, mold, and other types of fungi. These pathogens can negatively interfere with our health if they spread through the air.
UV lights are designed to stop these particles at the source, before they can enter your home’s air supply. Positioning UV lights in your systems air conditioner evaporator coils or in your core ductwork is intended to kill these microorganisms in a clean, efficient way, to purifying the air in your home.
So do UV lights for HVAC systems really do what they’re supposed to?
How UV Lights Kill Bacteria and Mold
It’s clinically proven that UV lights work. UV lights are capable of killing 97% of bacteria—even bacteria resistant to antibiotics—and can kill viruses and mold. In fact, we’ve known this for a long time; the Nobel Prize in Medicine was given to Niels Ryberg Finsen in 1903, thanks to his work in using UV radiation to cure skin infections. Today, many hospitals, grocery stores, restaurants, and other businesses where hygiene is a concern are using UV-based lights for germicidal purposes.
The UV light sparks a reaction between molecules of thymine, which is one of the structural units that makes up DNA. This damage caused by UV often prevents the cell from carrying out normal cellular processes, stopping it from reproducing and eventually killing it.
It’s not just shown to work in clinical purposes, either; The Journal of Applied and Environmental Biology reported that germicidal UV radiation significantly reduces airborne fungi in air handling units.
Types of UV Lights for HVAC Systems
There are several types of UV lights available for HVAC units, and they go by different names.
For example, you might hear them referred to as a purifying, germicidal, sterilizing, or sanitizing, and you might hear them called lights, lamps, or other names. For example, the Lennox UV Filtration Germicidal Lamp uses ultraviolent radiation to kill harmful microorganisms in the air; the term “germicidal” refers to its ability to kill microorganisms, and the term “lamp” refers to the light attachment used to do it. If you’re ever in doubt about the mechanism of a unit you’re considering buying, check the product description for references to ultraviolet or UV radiation.
There are two main types of UV lights, though both can share similar product names according to the nomenclature standards above. They differ in where they’re placed:
- Air (and ductwork) UV lights: Air UV lights are installed in the ductwork that brings return air to the system. When turned on, they have the capacity to kill microorganisms in the air, sterilizing the air as it’s distributed to the rest of the home. There are many sub-varieties of these types of lamps; for example, you could find a stick-shaped or U-shaped lamp, which both perform the same basic function. Some emit radiation constantly, and others are coordinated with the blower motor to turn on and off as it does. These must be hardwired with the system, so installation cost is on the high end of the spectrum.
- Coil-based UV lights: If you have central air conditioning, then you have an indoor coil. It is a prime location for the development of mold and bacteria. Why? Because the coil is used to condense moisture from the air to dehumidify your home during AC cycles. As air passes over the coil, dirt, pet dander and other debris stick to its wet surface. The combination creates an ideal setting for the growth of mold and bacteria that can be spread through your home in the passing air. Coil UV lights are the most common HVAC sterilizing lights. Single-lamp and dual-lamp models are produced. Coil sterilization lights are installed where they can shine directly onto the surface of the coil, and they are left on continuously.
Cost of a UV Light for Your HVAC System
It sounds good to have a unit that sterilizes the air you breathe in your home, but is it really worth the money?
There are four costs associated with getting a UV HVAC light: UV light fixture cost, installation cost, replacement lamp/bulb cost and energy cost. Your initial investment is really for the fixture and installation, which will most likely range between $300-$500. This depends on the complexity of the installation and which fixture you decide on, which Pro-Tech HVAC Home will walk you though to determine what’s best for your home.
The other associated cost you have to factor in is replacement lamps (or bulbs) for the UV lights. Just like light bulbs eventually burn out, the UV bulb in your unit has a finite lifespan. Eventually, you’re going to need to replace this component to keep it functioning properly. Depending on the unit, coil sanitizing bulbs cost between $10 and $60. Air sanitizing units tend to be more expensive, ranging from $15 to $125 for more complex designs. Most bulbs will last you somewhere between 9 and 14 months, depending on whether they’re being run continuously or periodically. Replacement of the UV bulb is something Pro-Tech HVAC Home can do during your preventative HVAC maintenance appointment.
There’s also the energy cost of the light to keep in mind. If you’re running a UV light constantly, you’ll be constantly feeding it a stream of electricity, which can modestly increase your electric bill. Fortunately, either unit type will only increase your energy costs by something like $15 to $30 each year.
Other Changes to Improve Your Air Quality
If you’re reading about UV lights, your primary goal is probably improving the quality of your indoor air. While UV lights can be effective to these ends, there are also several steps you can take, some of which are less expensive and more important, to improve the quality of your air:
- Clean and/or replace your filters regularly.Your first line of defense against airborne microorganisms is your HVAC filter, which is designed to trap particles before they enter your HAVC unit (and before the air is redistributed throughout the home). This is useful not just for keeping your air cleaner, but also ensuring no particles accumulate in your furnace or air conditioner, lengthening their lifespan. Over time, your filter will accumulate more particles, making it less efficient. It’s recommended that average homeowners change their air filters at least every 90 days, or more often if they own pets or produce more particles than average. It’s easy and cheap to do this, so there’s no good reason to avoid it.
RELATED: Why Changing Your Air Filter is So Important
- Consider high-MERV filters.Filters are rated on a MERV scale, which stands for Minimum Efficiency Reporting Value. The higher the MERV rating, the smaller the particles the filter can capture. Lower MERV ratings can still capture a great deal of typical airborne particles, and are often recommended to homeowners, since they permit higher airflow to the HVAC system than their higher MERV-rated counterparts. However, if you seem to have trouble with your indoor air quality, or if you’re interested in preserving the best possible breathing conditions, a high-MERV filter (17 to 20) may be better.
- Keep your house clean. Your filters and UV lights will be doing a lot of heavy lifting, but don’t make them work harder than they have to. It’s important to take the preventative measure of keeping your house clean, thereby reducing the number of particles and microorganisms that make their way into your HAVC system in the first place. Make sure you wipe down all surfaces throughout your home on a regular basis to eliminate germs and dust. If you own pets, vacuuming and sweeping are especially important to reduce fur and dander from making their way into the air.
RELATED: 7 HVAC Maintenance Tips for Pet Owners
- Consider investing in an air purifier: If you’re allergic to indoor allergens and can’t control the source of the problem, it may help to use an air purifier. Placed in the most commonly used areas of the house, these devices, in particular ionic purifiers, can help capture some of the irritants that may trigger your symptoms. You’re probably not going to be able to remove these allergens completely, but you can cut down on them, which may help the problem. A great place to keep one is your bedroom!
The Bottom Line: Are HVAC UV Lights Worth It?
Are UV lights for your HVAC system worth the money?
That depends on several factors. For starters, let’s make it clear that UV lights work the way they’re described to work; they’re capable of killing airborne microorganisms like mold, bacteria, viruses, and fungi. They’ll run continuously and cleanly, giving them a key advantage over household cleaners and holistic products that claim to have similar air-purifying effects.
The costs are also reasonable. Even considering professional installation, you can get a new unit running for less than $500 in many cases, and keep it running for just a few dollars a month.
In areas particularly susceptible to mold and bacteria growth, such as high-humidity areas, UV light units are a no-brainer for your HVAC system. In addition to installing a UV light, you’ll want to change your air filter regularly, keep your home clean, and make other positive changes to improve your air quality.
Want to Install a UV light? Call Pro-Tech HVAC Home!
We offer UV HVAC light installations throughout Annapolis and the surrounding communities. Call us today at (240) 298-6521 or schedule an appointment for a free in-home estimate and we will advise you on which type of UV light will do the best job of purifying your home’s air.
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