A newly released study found that up to six times as many COVID-19 cases occurred in poorly ventilated school classrooms compared to those with regular ventilation. The study, conducted by Swiss researchers, confirms that aerosols play a key role in the transmission of SARS-CoV-2, the virus that causes COVID-19. People with the disease exhale aerosols loaded with the virus which then circulate in a room, exposing others in the room to infection. The study set out to tackle the premise that air quality in classrooms impacts infection rates in school and, ultimately, established that “significantly more individuals were infected with SARS-CoV-2 in poorly ventilated classrooms.”
This study confirms what infectious disease, aerosol, and healthy building experts have been saying throughout the entirety of this pandemic and long before this pandemic with regard to other infectious diseases. Fresh Air & How to Use It, published in 1913 by the National Association for the Study and Prevention of Tuberculosis, extolled the virtues of ventilation.
But what if you can’t increase ventilation?
Air disinfection with UVGI when ventilation can’t be increased
Buildings today are designed to be “tight” for energy efficiency and occupant comfort. But mechanically pumping in adequate amounts of fresh air cannot only be cost prohibitive, it can create a significant carbon footprint. Many modern buildings, including schools, have few or no operational windows to increase ventilation and, even with those that do, other practical factors come into play. Who’s opening windows when it’s below freezing outside or over 100°? And what about open windows versus security protocols, particularly for schools? Urban spaces must also contend with relentless street noise.
Simply put, increasing ventilation is not always an option. So, what should schools, as well as other indoor spaces, do when ventilation cannot be increased?
“Consider using ultraviolet germicidal irradiation (UVGI) in schools and non-home-based childcare programs as a supplemental treatment to inactivate the virus that causes COVID-19, especially if options for increasing ventilation and filtration are limited. Consult a qualified professional to help design and install any UVGI system.” – Centers for Disease Control and Prevention (CDC)
Does UV really work?
In Solving Problems: Debunking UVGI Myths, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) interviews William P. Bahnfleth, Ph.D., Professor of Architectural Engineering at Penn State University who addresses common misconceptions about UV. The first myth is that all UV lamps produce ozone (they do not) and, next, that UV’s effectiveness is unknown (it is proven effective). As Dr. Bahnfleth explains:
“A second misconception is that germicidal ultraviolet disinfection is a new and unproven technology, including with respect to its ability to inactivate SARS-CoV-2, the virus that causes COVID-19 and other coronaviruses. The technology has been successfully applied to indoor air disinfection since at least the late 1930s, and it is approved for use in control of tuberculosis by the U.S. Centers for Disease Control and Prevention, which, through the National Institute of Occupational Safety and Health (NIOSH), has published guidelines for application of upper room systems.”
What about using ionization when ventilation can’t be increased?
Unlike UV, ionization—known as bipolar ionization, needlepoint bi-polar ionization, ionizers, photohydroionization, or electronic air cleaners—is not a proven technology. Furthermore, as the EPA warns, “bipolar ionization has the potential to generate ozone and other potentially harmful by-products indoors, unless specific precautions are taken in the product design and maintenance.” School districts, in particular, have invested hundreds of thousands, if not millions, of dollars in ionization equipment. Now, a growing chorus of experts say ionization is an unproven—and potentially harmful—waste of money.
Benefits of air disinfection beyond COVID-19
Long before the current pandemic, other infectious diseases have taken their toll. From the December 2019 HR Daily Advisor:
“A recent report found nearly three in four Americans (74%) who contracted the flu in the last year had to miss work/school. The report also revealed that of those who called out sick from work/school, the majority (57%) missed 1–3 days, followed by 4–6 days (35%) and 7+ days (6%). With more than a third of Americans missing nearly a full week of work due to the flu, companies are at risk of their employees’ productivity decreasing significantly.”
Like COVID-19, the flu is an airborne disease spread by aerosol transmission. From a January 2018 report, “Study Confirms Flu Likely Spread by Aerosols, Not Just Coughs, Sneezes,” by the Center for Infectious Disease and Research Policy (CIDRAP):
“Sick people can pass flu to others just by breathing, according to a new study showing how the virus can spread by airborne routes, with the role of transmission from coughing and sneezing smaller than previously thought.”
Disinfecting the air with UV has a proven, well-established history that predates this current pandemic by many decades. Aerapy has manufactured researched, tested, and study-backed UV devices to disinfect the air since 2008. We are experts in air disinfection. Our UV product options include upper room systems with built-in fans for immediate airflow and faster air disinfection. We also have no fan upper air units and UV for HVAC systems.
Contact Aerapy today at 866-994-2473 or online for a free UV consultation to learn how Aerapy UV technology can improve the air quality in your indoor space.