The discovery that ultraviolet (UV) light can be used to kill germs more than 100 years ago has led to its use in a variety of applications today, including hospital sterilization processes, water purification and germicidal food lamps in restaurants. Understanding the compelling science behind ultraviolet germicidal irradiation (UVGI), a clever inventor realized that UVs could also be a powerful tool in improving indoor air quality for residential and commercial HVAC systems.
UV Lamps Can Eliminate Microbes in HVAC Systems
UV lights work surprisingly well in the elimination of fungi, bacteria, germs, viruses, and pathogens, helping to eradicate microbes residing within HVAC systems. In fact, two different studies have gauged the accuracy of UV effectiveness in killing HVAC mold and bacteria:
- Ultraviolet radiation virtually eliminated drug-resistant bacteria in 50 hospital rooms at Duke University Medical Center.
- An NCBI study found after four months, that on certain floors of an office building where UV lights were installed, the fungal levels were much lower in the air handler units.
How Do UV Lights Help?
Growing on air filters, insulation, cooling coils and in ducts, fungal contamination is rampant within HVAC units. These spores promote building-related illnesses, including infectious diseases, allergic rhinitis, asthma and hypersensitivity pneumonia. Further, respiratory exposure to mycotoxins (toxic compounds that are naturally produced by certain types of molds/fungi) can also lead to cancer and acute toxicosis. While UV lights have no effect on pet dander, dust or other allergens, when placed within an HVAC air handler, UV lights can prevent mold from forming inside this vital component, enabling mold-free coils, cleaner indoor air and improved airflow for a more efficient system overall. In addition, UV lights can also cut down on the need for regular duct cleaning. And while filters certainly have their use, UV lights are more successful in disinfecting and sterilizing air, and can be particularly beneficial for those suffering from health issues or in humid regions predisposed to mold growth.
Factors for Effectiveness of UV Lights
A UV light purification system should be mounted next to and downstream of the evaporator coil, with light directed on both the cooling coil and the water drain pan under the coil, a prime breeding spot for spore germination. And while lamp placement and direction are exceedingly crucial to preventing bacteria growth, several other factors boost the effectiveness of UV lights in HVAC mold remediation, including:
- Number of lights
- Temperature and humidity of the home
- Reflectivity of surrounding areas
These elements must be taken into consideration when selecting the right UV filtration approach for your HVAC system. Also, to increase air purity, UV lights should be used in conjunction with a high MERV-rated particle filter to remove inorganic particles such as dust or dander, and should be changed monthly. Additionally, ductwork must be sealed and the entire HVAC system tuned up annually.
UV Light Filters Are a Cost-Effective Solution for Healthier Homes
As an HVAC contractor, being able to offer your customers UV light air purifiers delivers an affordable solution that improves both indoor air quality and system efficiency. While the initial investment may seem costly to some, each UV stick light bulb boasts a 9,000 hour lifecycle—that’s more than a year’s worth of germ irradiation—and can typically be replaced for around $70 during the yearly HVAC tune-up, offering effortless maintenance and purified air for just under $100 per year, including electricity! Eliminating microbes, mold spores and viruses while neutralizing VOCs that can aggravate respiratory issues, a UV filtration enhancement to your customers’ HVAC systems can have them breathing healthier air for years to come, reducing the likelihood of colds and asthmatic symptoms while providing relief from allergies.
At Field Controls, we’ve been focused on developing products that help HVAC contractors improve indoor air quality for their customers since 1927. Our line of UV lamp products is specifically designed to reduce microorganism growth throughout a space for just pennies a day. Learn more today about UV air purification in our Field Report: How Effective is UV for Air Purification?