uly 8, 2020 -- As COVID-19 cases rise rapidly throughout the South, some scientists believe there could be an important, but overlooked factor in the spread of the virus in the region--air conditioning.
Just as chilly winter temps create the perfect conditions for passing colds and flu—driving people indoors and into closer proximity for more hours of the day where it’s easy to swap germs, researchers believe broiling heat in the southern U.S. could be having the same effect, sending people indoors where whirring air conditioners are running full blast.
“You go indoors for the cool, just as in the northeast and other cool places you go in for the warmth in winter, so you’re less socially distanced,” says Edward Nardell, MD, professor of environmental health and immunology and infectious diseases at Harvard’s T.H. Chan School of Public Health. “You’re more likely to be touching the same surfaces that have been contaminated by people speaking and coughing etc.,” he says.
And that’s not the only problem.
Air conditioning is also risky because of the way air handlers work. When outdoor temperatures are extreme, HVAC systems adjust the mix of fresh air they pull in to save energy. That means the hotter it is outside, the more indoor air recirculates, which means, “You’re breathing a higher percentage of the same air that other people are exhaling,” Nardell says. If someone in the building is shedding the new coronavirus, it can build up in the recirculated air.