Is your air conditioner spreading COVID? We asked an expert – Eat this, not that

Does an air-conditioned environment increase the risk of contracting COVID-19? Reports from the start of the pandemic suggested this was a major cause for concern. “All the data we’re seeing from bars and from indoors, a choir rehearsal that resulted in 60 people getting infected, I think there’s a lot of evidence that aerosols really are a major source of spread.” said Ashish Jha, MD (currently the White House Coronavirus Response Coordinator) back in July 2020. Here’s what experts are saying today about the possible link between air conditioning and COVID-19. Read on – and don’t miss these to protect your health and the health of others Sure signs you already had COVID.


COVID-19 is often spread by airborne particles and droplets, both indoors and outdoors — but being outside is less risky, experts say. “Being outside allows for more air circulation, so the virus is more easily diluted.” says Daphne Darmawan, a pediatrician at UC Davis Children’s Hospital.

Woman coughing into her elbow while lying down on the sofa in the living room.

According to experts, ventilation is incredibly important to prevent the spread of COVID-19. “Science is airtight” says Joseph Allen, director of the Healthy Buildings program at Harvard University’s TH Chan School of Public Health. “The evidence is overwhelming … In the first year of the pandemic, I felt like we were the only ones talking about ventilation and it fell on deaf ears. But there are undoubtedly plenty of companies that have airborne in earnest. It’s not just a handful of people anymore.”

Woman using an air conditioner

Although not all air conditioners work the same way, “a lot of air is circulated”, says Linsey Marr, Charles P. Lunsford Professor of Civil and Environmental Engineering at Virginia Tech and an expert in aerosol science. “And if you’re recirculating that air, it means the virus is still staying in that building, rather than being replaced by more outside air, which is presumably virus-free.”

Woman checking air conditioner at home

“If turning off the air conditioning means turning off the ventilation and filtration functions, it’s entirely possible that the risk of infection increases, but if there’s no ventilation or filtration, the airflow in a room can contribute to the risk.” says William Bahnfleth, PhD, PE, director of the Indoor Environment Center in the Department of Architectural Engineering at Pennsylvania State University and chair of the ASHRAE Epidemic Task Force.

Air conditioner in the room with woman operating the remote control

The general consensus among scientists and virus experts is that the spread of COVID-19 is caused by the presence of other people indoors, not air conditioning. “It’s not the air conditioning that does anything special,” says Edward Nardell, professor of environmental health and immunology and infectious diseases at Harvard Medical School. “It’s the fact that you’re indoors, not social distancing, and rebreathing the air that people just exhaled.”


Follow public health principles and help end this pandemic no matter where you live – get vaccinated or boosted as soon as possible; If you live in an area with low vaccination rates, carry an N95 face masknot travelling, maintaining social distancing, avoiding large crowds, not going indoors with people you are not sheltering with (especially in bars), practicing good hand hygiene and protecting your life and the lives of others, not visiting any of these 35 places where you are most likely to contract COVID.

Ferozan Mast

Ferozan Mast is a science, health and wellness writer with a passion for bringing science and research-backed information to a wide audience. Continue reading

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