Building Ventilation, Fresh Air And Reducing COVID-19 Risks Indoors Changes to ventilation — everything from opening windows to making pricey upgrades to HVAC systems — can help reduce the risk of the coronavirus being spread inside a building.

As We Return To Work And School During The Pandemic, Can The Air Inside Be Kept Safe?

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Experts say one crucial element in the fight against the coronavirus is invisible. It's indoor air quality. The risk of transmitting the disease is much higher if people gather indoors in poorly ventilated spaces. What does that mean for schools and businesses that are reopening? NPR's Camila Domonoske reports.

CAMILA DOMONOSKE, BYLINE: Dennis Knight talks to a lot of building owners who want one thing - one thing he can't give them.

DENNIS KNIGHT: You cannot guarantee that someone might not get sick.

DOMONOSKE: Knight is with ASHRAE, an organization of heating, ventilation and air conditioning professionals. The group has set guidelines for preventing the spread of COVID-19 through indoor air. And Knight says, watch out for anyone selling a device and promising it will eliminate the risk from the coronavirus.

KNIGHT: That's when the hairs stand up on the back of my neck. And I get really suspicious that it's - I'm being approached by snake oil salesman. Right?

DOMONOSKE: There is no silver bullet, he says. Big buildings like offices and schools need better air filters in their HVAC systems, and they need better maintenance and more fresh air coming in and fans running for longer.

KNIGHT: You've got to do everything, and you've got to do it with diligence. And even then, there's no guarantee.

DOMONOSKE: The guidance hasn't always been clear on what to do. For a while, experts couldn't even confirm if the disease could be spread through the air beyond 6 feet. Now there's growing consensus that is a risk. Kathleen Owen is an air filtration consultant in Cary, N.C.

KATHLEEN OWEN: It's tricky, and it's confusing. And in large part, it's scary.

DOMONOSKE: It's tricky and confusing in part because every building is different. And the best, most effective air filters - many heating, air conditioning and ventilation systems can't handle them.

OWEN: The answer to it is first, don't panic. Second, do what you can.

DOMONOSKE: Think about how we wear masks. An N95 is ideal, but not everyone can get one. So a cloth mask is better than nothing. Similarly, Owen says, if the most effective filter is not an option, use the best filter your machine can handle. Run your system for longer. Consider adding portable purifiers. And don't overlook the low-tech solutions like opening windows and doors. Raj Setty is an engineer in Washington, D.C., who says schools and businesses need to start thinking creatively. Like, can you set up a tent?

RAJ SETTY: Maybe you go virtual when the temperature is over 90 degrees. And then when it's under 90 degrees, you just hold class outside.

DOMONOSKE: His company has designed a spreadsheet other engineers can use to help think through the different options for improving air quality and reducing risk. He pulls it up to demonstrate it.

SETTY: Then, I put in the ventilation per person. Then, there's total air changes...

DOMONOSKE: And he starts plugging in different kinds of changes.

SETTY: So now, as an engineer, I'm going to go, I'm going to change the filters.

DOMONOSKE: A number representing risk goes down.

SETTY: Maybe I will go down to half the population.

DOMONOSKE: The risk goes down some more.

Setty knows that scientists are still discovering new things about this virus. But, he says, engineers need to use the data we have to make decisions right now.

SETTY: Look. Engineers apply. Scientists do science. We have to give you a solution. That's it.

DOMONOSKE: And when being outdoors isn't an option and people have to gather inside a building, he says there's no real downside to having fewer people, better filters and more fresh air. It might cost more money, but improving indoor air quality is good for human health, pandemic or not.

Camila Domonoske, NPR News.


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