Air purifiers - an affordable route to a clean bill of health

Schools have had a tough time during the pandemic and remain a breeding ground for the virus. Now that the World Health Organization’s advice on mitigating the risk of Coronavirus has shifted from cleaning surfaces to cleaning air, ventilation and air purification have rightly risen up the agenda.

Post lockdown, the priority is to keep schools open, while protecting the health & safety of students, teachers and their respective families. Without additional mitigation to combat new variants, the risk of transmission will increase. Hence the campaign from teaching unions asking the Education Secretary to provide funding for air purification units to be installed in schools.

The challenge for schools

The issue of indoor air quality poses a substantial problem for the education sector.. 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. 

However, budgets are severely stretched. Many school buildings are old, with antiquated ventilation systems. Others are listed, demanding bespoke and costly retrofits. One in six schools in England requires urgent repairs: competing priorities, such as structural repairs, may make a complete overhaul of ventilation an impossibility.  

An affordable solution that adds value

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 can be installed instantly, with no disruption, and can easily be moved around to where they are needed most. However, they must be high performing (not residential/domestic) products that can ensure adequate air circulation. 

For that reason, Rensair’s portable, hospital-grade unit - originally developed for use in hospitals and now being adopted by schools - uses a powerful centrifugal fan, positioned before the filter, to create high pressure and clean up to 560m3 of air per hour. That means a typical 240m3 school lab would have clean air within 30  minutes. With independent validation from scientific laboratories and a listing in Newsweek’s list of Best Infection Prevention Products 2021, schools can rely on science to make an informed choice.

The investment is just a fraction of what it would cost for an in-built ventilation system and the performance can be at least as good, if not better. Purifying indoor air can also be more cost-effective than bringing in and heating fresh, cold air. 

Choosing the right technology

A recent article in the Journal of the Royal Society of Medicine has called for higher standards of ventilation in classrooms and cites portable HEPA filtration units as a practical option to complement fresh air. 

There is conclusive evidence not just from SAGE - but also from the WHO, CDC, and CIPSE - that only HEPA filtration and germicidal UVC technologies are fit for purpose against Coronavirus. SAGE also 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”.

Rensair’s unit has been rigorously tested by the Danish Technological Institute (DTI) to determine its performance in reducing the concentration of Covid-19 particles in the air. The result was a particle reduction rate of 99.98 % in 15 minutes and above 99.99 % in 30 minutes. No virus particles were detected on the filter, demonstrating the effectiveness of the UVC in destroying all traces of captured particles.

Government guidance is overdue

The Department for Education has now said that around 300,000 carbon dioxide monitors are to be made available to schools in England next term to help identify areas where more air-flow is needed. Teaching unions have welcomed the pledge, but have rightly pointed out that any ventilation needs picked up by the monitors must be acted upon.

Now the Government’s Chief Scientific Adviser has commissioned a study from the Royal Academy of Engineering: unsurprisingly, the initial report endorses SAGE’s findings. The examination is done and, hopefully, government guidance will soon come. The only technologies that get an A* rating for schools and other shared spaces are HEPA filters and UVC light, backed by independent test reports.

For a clean bill of health, schools must have pure air. Now, thanks to portable, hospital-grade air purification, there is a viable solution that is both affordable and practical to implement.