With the resurgence of COVID-19’s Delta variant coinciding with the opening of schools and colleges this Fall, this piece on practical approaches to ensuring clean, filtered air to students becomes especially critical. This article has been written by Christian Hendriksen, CEO & Co-Founder of Rensair. Rensair provides portable hospital-grade air purifiers to government, schools, hospitals, health care facilities, businesses and more. They are working with customers like the City of Miami, the NBA, as well as the UK’s National Health Service and numerous hospitals and businesses. Rensair is part of Public Spend Forum’s GovMarket Growth Program.
The World Health Organization’s latest advice on COVID-19 places far greater emphasis on transmission from inhaling airborne droplets, rather than from touching contaminated surfaces. That shifts the emphasis from surface cleaning to air purification.
Every school has a duty of care to protect the health & safety of students, teachers and their respective families. Without additional mitigation to combat new variants, the risk of transmission will increase. Last month it was reported that, to help curb the spread of COVID-19, the education department would equip all 56,000 New York City public school classrooms with two air purifiers by September.
That’s a positive step and similar initiatives are under way in other states. But what kind of air purifier should be specified for the job?
The classroom context
First, it’s important to understand the learning environment. According to the Lancet’s COVID-19 commission, schools are chronically under-ventilated. The likelihood of airborne virus transmission is amplified in crowded indoor spaces, particularly if people are in the same room together for an extended period of time or when enhanced aerosol generation is likely, for example through singing, projected speech and aerobic activity. That means that any air purification solution must be a serious piece of equipment with strong airflow that delivers a high air change rate.
However, the scale of the problem is not matched by large budgets. A report from the Government Accountability Office in June 2020 concluded that one-third of public schools are estimated to have inadequate heating, ventilation, and air conditioning systems. But funds are already over-stretched as most of the country’s school buildings are in a state of disrepair, with plumbing, roofing, and fire protection systems in need of major updates or total replacement. Competing priorities, such as structural repairs, may make a complete overhaul of ventilation impossible.
Portable air purification
Fortunately, integrated ventilation systems are not the only solution. Portable air purifiers can do an effective job, either enhancing an existing ventilation system or working in isolation. They must be high performing, hospital-grade units with a powerful fan to ensure adequate air circulation – residential air purifiers simply won’t cut it.
The investment is just a fraction of what it would cost for an in-built ventilation system and, with products that can prove independent testing by recognized research laboratories, the performance can be at least as good if not better than their larger counterparts. Further savings can be made by saving on energy costs for heating or cooling fresh air intake.
The right technology
Having identified heavy-duty, portable air purifiers as a viable solution, it’s essential to select the right technology to trap and destroy COVID-19.
In its June 2021 update, the Centers for Disease Control and Prevention (CDC) recommends high-efficiency particulate air (HEPA) filtration systems with a powered fan system to capture COVID-19 particles, with germicidal ultraviolet light as a supplemental treatment to inactivate the virus.
A recent article in the Journal of the Royal Society of Medicine has called for higher standards of ventilation in classrooms and also cites portable HEPA filtration units as a practical option to complement fresh air. In assessing the risk of airborne infection with SARS-CoV-2, atmospheric researchers from Goethe University have demonstrated that air purifiers with an H13 HEPA filter can lower aerosol concentration in a classroom by 90% within 30 minutes. By deploying a unit that can process up to 560m3 of air per hour, a typical 240m3 school lab (larger than a classroom) would in fact have clean air within the same short time frame.
In her open letter, Dr. Marwa Zaatari – eminent Indoor Air Quality expert and Member of the Board Of Directors at U.S. Green Building Council – advocates caution when specifying air purification devices. She warns that many schools are “relying on incomplete data and exaggerated claims to make a well-intended, but incorrect decision.” She highlights “the general lack of regulations and standards, making it a challenge for most engineers and consultants to discern fact from fiction, let alone school district facilitators, administrators, and board members.”
Dr. Zaatari quotes the UK’s Scientific Advisory Group for Emergencies, which stresses the importance of independent testing and warns that “technologies based on UVA/UVB, ionisation, plasma, electrostatic precipitation and oxidation methods have limited evidence of efficacy against the virus and/or significant concerns over toxicological risks during application”. She goes on to endorse proven measures including portable HEPA filter units and germicidal ultraviolet light systems as practical, easily implemented, and not costly.
The argument for clean air in schools is clear. Now, thanks to portable air purification using a combination of HEPA filtration and UVC light to trap and destroy COVID-19, so too is a practical solution.
Rensair is a specialist in air purification, protecting and enhancing lives through clean air. The company’s technology was originally developed to meet the strict standards of Scandinavian hospitals and is independently validated by scientific research laboratories.