As schools scramble to stop the spread of COVID-19, classrooms are typically the main focus, while perhaps a more threatening setting is an afterthought: the school bus. Most disinfection efforts on school buses focus on cleaning surfaces, “but that doesn’t deal with the airborne transmission [of SARS-CoV-2],” says Lumin-Air co-owner and principal Dan Fillenwarth. The Indianapolis-based startup has created an air filtration device called Lumin-19 that can attach to any school bus or mass transit bus to apply the power of germicidal UV-C in a setting with unique challenges.
Fillenwarth says the amount of recirculated air on a school bus is about 10 times the amount in a typical office, school or building.
“The amount of air circulating on a bus is very high, because there’s a high people load, and lots of glass without much insulation; it’s basically a building moving down the road at 40 miles per hour, so there’s lots of infiltration,” says Fillenwarth. “Because of the high rate of air circulation, the need to clean that air is also very high.”
The Lumin-19 device relies on UV-C to perform that cleaning. UV-C light, also known as “ultraviolet germicidal irradiation” (UVGI) deactivates the DNA of bacteria, viruses and other pathogens, which destroys their ability to multiply and cause disease. The U.S. Food & Drug Administration says UVGI is a well-established disinfectant for air and has been used effectively for decades to reduce the spread of bacteria, such as tuberculosis.
The FDA notes UV-C radiation may also be effective for killing the SARS-CoV-2 virus, “However, currently there is limited published data about the wavelength, dose, and duration of UV-C radiation required to deactivate the SARS-CoV-2 virus.” The Centers for Disease Control and Prevention recommends UVGI disinfection systems among “potential intervention strategies” for COVID-19.
Fillenwarth likens the startup’s Lumin-19 device to a light box, which encapsulates the UV-C lamps; the light must be used inside the system, because direct UV-C exposure may harm the skin or eyes. The system can be retrofitted on school or mass transit buses; a standard size school bus would need one system in the front and one in back.
“The UV-C is kept inside an enclosure that keeps it from being on the occupants, but as the air is recirculated through this enclosure, the air passes close to the bulbs, which basically zap the pathogens,” says Fillenwarth. “As air is recirculated through the bus, it passes through the lights and inactivates [pathogens].”
Founded just months ago, Lumin-Air is using UV-C bulbs from another Indiana company, American Ultraviolet (AUV). Headquartered in Lebanon, AUV has manufactured more than 100,000 UV-C germicidal fixtures for medical facilities, laboratories and many other locations throughout the world.
Fillenwarth, who has decades of experience in the HVAC industry and studied mechanical engineering at Purdue University, says because of the high rate of air turnover in a bus, “that also means the air will circulate through the enclosure with the UV-C quite often.”
About $3,500 per unit, Lumin-19 would cost around $7,000 for a standard-sized school bus, which includes installation by a certified technician. Fillenwarth says the only potential maintenance needed is replacing the UV-C bulbs; with a 17,000-hour expected lifetime, the bulbs will most likely outlast the life of a school bus, which is typically replaced about every 12 years. A school system in Indiana is among Lumin-Air’s first clients, as well as one in Florida and a bus at the Orlando International Airport that transports employees. Fillenwarth says regional transportation systems, similar to IndyGo, are also expressing much interest.
“A lot of people are trying to get some ‘shovel-ready’ projects lined up. They’re anticipating some funds and know some [money] is going toward keeping kids safe with school. And the [regional transportation systems] are also expecting some funding.”
Fillenwarth notes the benefits of Lumin-19 extend beyond COVID-19; Lumin-19’s “dose” of UV-C light also kills RNA viruses that cause influenza, for example.
“If I can try to think of something positive about this pandemic, it might that we are rethinking so many things—considering, ‘Is there another way?’” says Fillenwarth. “In 2015 and 2016, 7 million kids missed at least 15 days of school. There are a lot of things we can do to improve health in schools, and from that, help the whole population be safer.”
Fillenwarth explains how UV-C has been established for decades and is now recommended by the CDC to help fight COVID-19.
Fillenwarth says the messaging about UV-C’s effectiveness is a critical piece of attracting clients.