UV light works!
Ultraviolet lights were understood to destroy mold, viruses, and bacteria more than 100 years ago. In fact, in 1903, Niels Finsen was awarded the Nobel Prize in Medicine for his use of ultraviolet light in the treatment of skin infections.
Furthermore, UV light’s ability to kill pathogens in water and air has been scientifically proven throughout the years. These amazing UV systems have been used in hospitals as far back as the 1930s to reduce the spread of diseases such as measles and tuberculosis.
More recently, UV lights are known to be successful against virus types such as rhinoviruses (common cold), influenza viruses, and Severe Acute Respiratory Syndrome (SARS) and hostile to bacteria such as Staphylococcus aureus (Staph infection) and Streptococcus variants.
Ultraviolet lights have been widely adopted for all kinds of uses such as sterilizing water, germicidal lamps in food establishments, and even curing nail polish faster.
Okay, if UV light is so effective, can it be used to improve indoor air quality for residential HVAC systems? Will it kill mold and bacteria in HVAC systems? The answer is yes, but you need to understand the priorities of indoor air quality and the types of UV lights available for residential HVAC systems.
Are mold and bacteria a concern for HVAC systems?
We all want to breathe clean air, but the significance of “clean” varies from person to person. For example, mold, bacteria or other indoor allergens are not problematic for everyone. On the other hand, loads of people are super sensitive to those things. If that description fits you, keeping indoor air free from these harmful contaminants is of prime importance. Inhaling invisible allergens simply isn’t beneficial to your health, or your sanity, for that matter.
Enter ultraviolet lights!
These little fellas can take up residence inside your HVAC system and zap any potentially hurtful bacteria before it moves into your living space.
UV lights for HVAC systems are typically known as ultraviolet germicidal irradiation (UVGI) systems. They’re directed at a very explicit kind of air contaminant, to be exact, microorganisms such as bacteria, viruses, and mold spores. You might be aware of the way hanging laundry out in the sunshine helps eradicate germs or mold sticking to it. UV lights work in essentially the same way.
Yes, UVGI systems produce the type of ultraviolet light that exists in the sunshine, but at a greater intensity than found in the sunshine that reaches the earth. This light obliterates microorganisms’ nucleic acids, damaging their DNA and either killing them or leaving them incapable of reproduction.
How exactly do they work?
UV lights for HVAC systems are constructed to make use of a specific wavelength of light – 254 nanometers – that’s absorbed by the DNA of microorganisms present in the system. Following exposure to the UV light, the organisms are incapable of generating the proteins required to stay alive. The UV light does not kill the germs instantly, rather, it quashes their capacity to cause harm and drastically reduces their lifespan.
Here are a few of the chief benefits homeowners can gain from investing in a UV light:
- Bacteria and virus elimination. For individuals who are highly prone to illness or for high-risk environments, built-in UV lights offer thorough sanitization. Some systems can even eliminate nearly all microscopic contaminants in an environment. Eradicating these contaminants will improve the smell and feel in the air, too.
- Mold and fungi management. Mold can cultivate inside a system, leading to health problems such as skin and eye irritations or respiratory illness. Getting rid of mold can be both costly and time-consuming. UV lights keep mold and fungi at bay.
- Peace of mind. Arming your HVAC system with UV light means not having to fret about a filter letting through various contaminants. The unit will sanitize all surfaces the light can reach and lessen the danger of contaminants in other parts of the system.
You have a choice of two types of UV lights.
There are essentially two ways UV light can contribute to your breathing easier: inhibiting microbial growth on your indoor coil via coil sanitizing lights and purifying your indoor air with air sanitizing lights.
Coil sanitizing lights: UV lights for preventing microbial growth.
If you have central air conditioning, then you have an indoor coil. And, it’s 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 A/C cycles. As air passes over the coil, dirt, pet dander and other debris stick to its wet surface. This combination produces an ideal environment for the growth of mold and bacteria that can be spread through your living space in the passing air.
Coil UV lights are the most common HVAC sterilizing lights and are produced in single-lamp and dual-lamp models. Coil sterilization lights are installed where they can shine directly onto the surface of the coil, and they are designed to be left on continuously.
Air sanitizing lights: UV lights for air purification.
If anyone in the household suffers from significant allergies or asthma, you don’t simply intend to keep the coil clean – you want to purify the indoor air. Some UV lighting systems go beyond simple “coil bathing” and employ activated carbon cells to get rid of harmful odors, VOCs and chemical vapors that may be making persons in your household sick.
In other words, they don’t just restrict microbial growth on the coil. They’re made to eliminate all or most everyday indoor pollutants from the air your household members breathe.
Studies help prove UV light effectiveness.
Two studies point to the effectiveness of UV light in killing mold and bacteria, one in hospitals and the other in a commercial HVAC system.
- Units Effectiveness of Germicidal UV Radiation for Reducing Fungal Contamination within Air-Handling Units. In this commercial office building, and after four months of operation, “the fungal levels following UV operation were significantly lower than the levels in control air handler units.”
- Ultraviolet Light Effective in Hospital Infection Control. In 2012, researchers at Duke University Medical Center for Ultraviolet Light used ultraviolet radiation to nearly eliminate drug-resistant bacteria in 50 hospital rooms, reducing the number of bacteria by more than 97 percent.
Added benefits of UV lights:
Okay, UV lights kill bacteria and mold before they can ever become airborne, reducing the risk of mold and other bacteria from infiltrating the rooms in your home.
But are there are other benefits when employing UV lights in your HVAC system? You betcha!
- Increased airflow. When it comes to maintaining the conditioned air without putting further strain on your A/C system, airflow is one of the basic essentials. As time goes on, debris develops inside the A/C system. Even though the air filter ensnares some of these particles, it’s limited in just how much it can do. Inserting a UV light can give your system a serious boost, helping to ensure the best possible airflow.
- Improved efficiency. Aside from debris, airflow is also reduced by microorganisms gathered on the HVAC coil. Often, to tweak this, you might be compelled to operate the system for a lengthy period to achieve the desired temperatures. UV lights on your coil help remove those microorganisms that impede smooth airflow. Note: You may have to clean the coils to improve the efficiency in the destruction of the microorganisms. The cleaning also helps to improve power consumption.
- Reduce clogging in the condensate drain line. As mentioned earlier, air conditioning systems create moisture from within. Over time, this moisture can accumulate and block the condensate drain line, causing a handful of issues you’d rather not encounter. A UV light will reduce moisture which can, in turn, prevent your condensate drain line from clogging.
- Energy-efficient homes are being constructed today where the emphasis is placed on sealing every little nook and cranny to stop conditioned air from escaping. Regrettably, this has brought about the textbook circumstances for these microorganisms to flourish. Installing UV lights for HVAC systems will help to manage or even destroy these potentially hurtful pollutants.
What are the limits of UV lights?
UV lights will destroy microorganisms that other filters cannot affect, but they do not directly eliminate most allergens, dust and other solids from the air. While they do still sanitize the air, improving its cleanliness and quality, they do not get rid of cigarette smoke, gases or other chemical fumes present in the air.
Also, if your HVAC system has broken or leaky air ducts, the vacuum produced in the ducts could draw in a bunch of other nasty pollutants from attics and crawl spaces, restricting the UV light effectiveness. The UV light is only helpful when microorganisms contact its light spectrum. Any of the above-mentioned contaminants sheltered from the light spectrum will continue to exist and flourish.
Are there other negatives?
As with most any method or device, there are several drawbacks with UV lights for HVAC.
- Functionally, UV systems are designed to operate with a particle filter rather than as a stand-alone device, so routine filter replacement or cleaning is required. Additionally, the UV bulbs will need to be replaced every 12 to 24 months, depending on the bulb model.
- Dust quickly gathers on the UV bulb, so it needs to be cleaned frequently to ensure its efficiency. Note: Because of the potential danger to people, the UV system must be completely shut down before anyone can perform any maintenance.
- The effects of UV light aren’t just limited to mold and bacteria. Nonstop exposure to UV light can also have harmful effects on certain plastics. Air conditioner workings that are frequently produced with plastics, including the condensate drip tray and flexible ducting, can stop working in just a few short years due to constant exposure to UV light.
- As with most any new technology, there are a number of companies still trying to figure out the best way to manufacture UV filters, and those UV systems field-proven to achieve the best results can be somewhat costly.
How are UV lights installed?
For the utmost results, a professional air conditioning technician should carry out the installation of UV lighting inside the evaporating unit of your home.The the light must be wired to the HVAC evaporating unit, so it’s triggered only when the system is operating. Before installing the equipment, the technician should also clean the air handler system thoroughly and inspect the ductwork for leaks. This will help deliver the best possible operating conditions for the UV light system.
The final verdict.
When you truly need to improve your home’s indoor air quality, it’s best to consider a UV air filtration system. It will give you that added level of purification that can significantly enhance your respiratory health and comfort.
By combining a UV air filtration system with your current A/C system, you can drastically increase the quality of the air that you breathe, which can result in the overall comfort of all members of your household and especially those that highly sensitive to airborne pollutants.