Steril-Aire will celebrate 30 years of success this year by highlighting the key innovations that have spurred the ultraviolet disinfection industry's growth, beginning with introducing and later patenting the application of UVC for HVAC to evaporator coils.

The manufacturer is responsible for 17 technical patents that still define the HVAC ultraviolet air and surface treatment industry.

Steril-Aire founders knew they could use UV energy to enhance HVAC coil-heat-transfer efficiency, reduce maintenance, and deactivate microorganisms like bacteria and viruses on air handler surfaces and conditioned airstreams.

For nearly a century, short-wave ultraviolet UVC energy — similar to sunlight — has been used to destroy airborne and surface-bound microbes, including chickenpox, measles, mumps, tuberculosis, and cold viruses. Despite nearly eight decades of research and thousands of applications in healthcare, education, municipal and commercial buildings, the UVC market in the United States historically has focused on the germicidal wavelength’s ability to clean fouled cooling coils and restore cooling capacity.

In the 1940s, many hospitals and some schools began using UVC energy to control airborne infectious diseases. The use of germicidal UV surged again during the 1990s to combat drug-resistant “superbugs” and sick-building syndrome.

Demand for UVC air treatment solutions truly exploded following the outbreak of the COVID-19 pandemic, according to Dan Jones, president of Steril-Aire.

“UVC disinfection systems gained widespread public awareness and scientific credibility (CDC, ASHRAE) during the pandemic, so there is now a universal desire to improve the air we breathe and mitigate airborne pathogens,” he said. "Building managers, restaurant owners, and school administrators now view UVC in the same way as air filtration, that is, 'every application works better, longer and users are healthier when UVC is installed in air conveyance systems.'"

How it Began
Steril-Aire was founded in 1994 and led by the late Forrest Fencl, a 40-year veteran of HVAC/R air treatment who is credited with pioneering the modern application of UVC energy in HVAC/R equipment. Specifically, Fencl and his team led the way to coil irradiation and optimized UVC effectiveness in HVAC/R systems' hostile cold and fast-moving air.

Today, Steril-Aire is known worldwide as a leader in the design and engineering of science-based germicidal solutions that significantly enhance the indoor air quality of customer working environments, such as hospitals, schools, nursing homes, churches and airports.

Saving HVAC Energy
The 253.7nm Ultraviolet Germicidal Irradiation (UVC) wavelength is an invaluable tool for maintaining an HVAC/R system’s performance. By leveraging germicidal energy to keep cooling coils free of microbial growth, facility managers have a tool to restore heat transfer efficiency and improve indoor air quality on new and aging systems.

Government agencies and the HVAC community are increasingly aware of the benefits of UVC applications. The U.S. General Services Administration requires that UVC be included in airhandling units for all new facilities and alteration projects to maintain coil cleanliness and improve air quality.

The U.S. Centers for Disease Control and Prevention supports using UVC as an adjunct to mechanical ventilation and filtration to prevent and control the spread of tuberculosis. Similarly, the Federal Emergency Management Agency and the U.S. Environmental Protection Agency (EPA) note that UVC technologies can be used to protect against bioterrorism.

How it Works
The dark, damp environment of an HVAC system is a prime breeding ground for pathogens like mold and bacteria. The build-up of these microorganisms (biofilm) on HVAC coil fins can cause coil fouling, which reduces heat transfer efficiency and can increase energy consumption by up to 20%.

UVC energy alters a cell’s nucleic acids and protein structure through a process known as photodimerization. This process causes two consecutive DNA/RNA bases to bind together. This genetic damage inhibits cell reproduction, meaning affected organisms cannot spread infection.

Steril-Aire high-output UVC emitters continuously clean coils, eliminating the biofilm that causes reductions in operational efficiency.

Legacy of Innovation
The company’s longevity and reputation for superior germicidal performance have been driven by its commitment to customers and the HVAC industry.

“Our success is a result of our legacy of industry innovation, education and advocacy and of using our leadership to build solid relationships with our employees, manufacturer representatives, distributors, facility managers, HVAC contractors and specifiers,” Jones concludes. “Steril-Aire has a long history of bringing high-output, best-in-class performance to its customers, driven by the knowledge, expertise, and dedication of the outstanding people who have been part of the organization over the last 30 years."