Ep. 102: Do I Need A HEPA Filter?
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COVID-19’s Omicron variant is airborne-transmitted. So does it make sense to buy a HEPA filter to reduce spread? Or are there more cost-efficient ways to increase safety? We assembled a panel of experts to provide their guidance, including two members of Medcan’s Medical Advisory Services team, Dr. Peter Nord (above, second from left) and Dr. Matthew Burnstein (above left), as well as NASA consultant R. Vijayakumar (above right) and Prof. Frank Kelly of Imperial College London (second from right).
LINKS:
R. Vijayakumar is a global expert on the filtration of particulate air particles who chairs the ISO and US committees on HEPA standards. He also teaches courses on filtration geared to varying levels of expertise. His consultancy is Aerfil, located near Syracuse, New York. Vijayakumar coauthored a seminal publication on the study of COVID and HEPA filtration, which you can find here. He also coauthored this seminal NASA study.
Learn more about Prof. Frank Kelly of Imperial College London, and the way he leads the Environment Research Group, the leading UK air quality lab. And check out a video that Dyson produced that features Prof. Kelly on air pollution and health.
JAMA: Indoor Air Changes and Potential Implications for SARS-CoV-2 Transmission. Link.
Both Dr. Peter Nord and Dr. Matthew Burnstein are members of Medcan’s Medical Advisory Services, which advises some of Canada’s largest corporations on how to keep their employees and customers safe through the pandemic and beyond: Learn more.
INSIGHTS:
“With Omicron, we've got a variant of COVID that we know is predominantly airborne transmitted,” says Dr. Nord. In order to lower transmission rates, schools and businesses are prioritizing their air quality and filtration more than ever before. There’s a new demand for HEPA filters, although there are several other (more affordable) steps that should be taken first. [2:30]
HEPA stands for “High Efficiency Particulate Air”. HEPA filters can capture 99.97 percent of particle sizes, and are often used in sterile spaces like chemical laboratories or hospitals. “Now, HEPA is a bastardized term,” says Vijayakumar. “Everybody's calling anything better than your furnace filters, a HEPA filter.” For a filter to be considered a HEPA filter, it needs to be individually tested and labeled at a specific air rate. Since this doesn’t always happen, many filters claim to be HEPA filters, but are not. [9:04, 10:33]
To improve air quality and lower risk of infection, business owners should increase the flow rate of the systems in their office spaces. “This creates more air exchange, more removal of bad air in your closed space, and the ventilation is much better,” says Vijayakumar. [17:10]
Do families need a HEPA filter at home? “Not unless they're planning to do surgery in their homes,” says Dr. Burnstein. Do offices need HEPA filters? The answer there also is probably no. Instead of spending up to $500 on HEPA filtration, opt to upgrade your current filtration system to the next step or two. “A HEPA filter is 20 steps higher,” says Vijayakumar. [21:26, 22:54]
Vijayakumar says that humidity level also is an important factor to reduce risk of transmission. He suggests setting your humidity level between 40 and 60%. “That’s the sweet spot for the safest humid conditions,” he says. His logic? Viruses are expelled from humans in water droplets. Dry conditions evaporate the droplets and allow virus particles to float free. If the humidity is between 40-60%, the droplet falls to the floor before it evaporates. Vijayakumar acknowledges that too much humidity can cause moisture to build up on windows in winter in colder climates, so he suggests trying to get as close to 40% as possible. [31:31]