A large part of COVID-19’s ability to spread—so rapidly, and so broadly—is thanks to how easily the virus travels through the air, ultimately landing on surfaces, which we then touch. Its origin story in a seafood market in Wuhan City, China, illustrates this: The virus was circulating in the densely populated area for so long (a few hours) that countless people transmitted it, without even realizing.
A researcher at Washington University in St. Louis’s Sam Fox School of Design & Visual Arts has developed a system for killing the virus before it has a chance to even land on surfaces. In essence, it’s a portable furnace that would be placed in hospitals and instantly kill the virus patients expel when they cough and sneeze.
Most treatment centers vent contaminated air outside, which expels it from the interior architecture but spreads the air outdoors. “Some very strong papers responding to the avian flu in 2015 showed chicken farms in Iowa and Nebraska [having it], and it was transmitted by air flow for 100 miles from one farm to another farm,” says Hongxi Yin, the InCEES associate professor in advanced building systems and architectural design at WashU.
Based on that paper, Yin developed a theory that when a large quantity of people are gathered in relatively tight quarters breathing the same air, the rate of infection increases. “Wuhan has more than 10 [million] to 12 million people, similar to New York and San Francisco, so we had a suspicion that a high-density urban environment would be the major way [this is passed],” he says. Temporary quarantine hospitals that began popping up in Wuhan housed upward of 2,000 to 3,000 patients at a time, which likely compromised the buildings’ air. “The exhaust from the hospital, which has a virus that’s alive in the air, is spreading the virus through the HVAC air conditioning system,” Yin says. Though attachments like HEPA filters help purify the air, Yin and his research team believe their system can stop the virus in its tracks.
Yin and his team of researchers are designing a “high-temperature sterilization system” that works to kill the airborne virus—which manifests as an attack on human respiratory systems—before it has the chance to land on surfaces and infect people. “COVID-19 is different because it stays in the air for hours so the plume [of exhaust that hospitals release] is not helping to prevent spreading but helping to spread more quickly elsewhere,” Yin says. “The only way [to solve this] is to kill the germ before it gets outside.”
The system will essentially suck up contaminated building air; push it through a small, portable heat chamber (which will sterilize it at extremely high temperatures); and release it back into the atmosphere—purified and virus-free. The device is in early design stages; Yin and his team are currently working on a research proposal for it in collaboration with the National Security Administration. He and his team have also been in touch with manufacturers that are interested in working with them on assembling these devices.
Why use a device rather than retrofit a hospital’s HVAC system? The architecture of built environments like hospitals (and other enclosed spaces, like airports) is generally inflexible. Rerouting the airflow of complete HVAC systems isn’t always realistic, but supplementing them with devices designed to purify the air inside of buildings before it gets expelled into the larger environment is. Based on their research, Yin’s team believes that the system will be able to deactivate 99.999% of COVID-19 if it filters through the system for three seconds at 257 degrees Fahrenheit. “The higher temperature, the faster it kills . . . it’s a very simple concept,” says Yin. “If we make it a higher temperature we can make the system smaller.”
The researchers have yet to determine how many systems a large-scale building would need and where exactly they’d need to be placed, but Yin says that they are “trying to build a model of the system and want to develop research to see the virus in the air before and after [it passes through].” Then, they’ll be able to confirm that expelling exhaust after sterilization will not spread the virus beyond the confines of hospitals and other buildings.
In the meantime, Yin suggests that citizens approximate this design by using similar small-scale furnaces in the home. “I told my family in China, ‘You don’t need to panic, what you need to do is buy space heaters and turn them on and keep them running for hours in the home and your room could be close to having zero virus in the air.’ It’ll kill the germs on the surfaces and fix the air flow.”