How can HEPA filters help fight COVID-19?

New York Governor Andrew Cuomo is mandating that all malls in the state install High-Efficiency Particulate Air Filters (HEPA) in order to reopen.

HEPA filters are a special type of filter that captures microscopic particles, which according to the governor have shown to help reduce the presence of COVID-19 in the air. 

“These filters are tested using .3 micro-meter particles and they have to remove at least 99.97% of those particles,” said William Bahnfleth, a professor of architectural engineering at Penn State University. 

According to Bahnfleth, the filters are already used in airplanes and in operating rooms and can protect you from viruses in the air. 

“The important thing isn’t getting every last bit of the air contaminants out, it’s reducing the concentration to low enough levels that there’s minimal risk,” Bahnfleth said.

The filters are made out of fibers in a mat, so when air is blown through the filter, various removal mechanisms capture the particles.

There are portable HEPA filters you can purchase online or at a building supply store, however, the filters can be costly depending on the cooling system you have.

“Most of the HVAC equipment that is in buildings like malls and stores and offices can’t simply accept a HEPA filter by pulling out what’s there and putting in another one,” said Bahnfleth.

Meanwhile, both American Airlines and Delta have air filtration systems already in use. Delta says many of its planes are equipped with an industrial-grade HEPA filter, blending outside air that is sterilized with existing cabin air. American Airlines says HEPA filters have purified the air on its entire mainline fleet since the 1990s.