A cool way to combat the coronavirus

Air conditioners can’t cure COVID-19, but, when used properly, they may mitigate the virus’ spread. Which is certainly hopeful news as the US heads into summer.

The standard air conditioner works by recirculating and filtering air inside a space and mixing it with outside air. Just by bringing in outside air, an A/C is helping combat the coronavirus in a small way: Outside air reduces virus transmission compared with what you breathe in a confined space. High-efficiency particulate air filters, considered the gold standard of A/C filters, are also capable of capturing small particles, including those that carry viruses, Bloomberg reports.

“Changes to building operations, including the operation of heating, ventilating and air-conditioning systems, can reduce airborne exposures,” the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) said in a statement. “Air-conditioning systems can reduce the airborne concentration of SARS-CoV-2 and, thus, the risk of transmission through the air.” But there are exceptions. “When we see reports of superspreading events that apparently involve air conditioning, it usually means there’s little or no ventilation in the space,” Penn State architectural engineering professor William Bahnfleth tells Bloomberg. “With pathogens . . . it takes a certain number of them to have a high probability of getting an infection. If you can reduce the concentration in the air, then the rate at which you can be exposed drops.”

In cases of poor ventilation , simply opening the windows is a better solution than recirculating musty air.

Still, ASHRAE stands by the fact that air conditioners do more good than bad in context. “In general, disabling of heating, ventilating and airconditioning systems is not a recommended measure to reduce the transmission of the virus.”