As winter in the northern hemisphere turns to summer, air conditioning units begin to rattle into life as people begin to feel the heat. However, with the coronavirus pandemic underway, some have asked the question as to whether it is safe to use air conditioning units and whether the novel coronavirus can be transmitted via air ducts.
Studies conducted after the SARS outbreak in 2003 suggest that some infections occurred in high-rise buildings as contaminated air rose through the buildings’ airshafts into different apartments. COVID-19 is from the same family as SARS, known as coronaviruses, and the two share many similarities.
“So far, we have not seen any evidence that the virus that causes COVID-19 can be spread through air conditioning systems. The virus is spread through droplets that can be suspended in air for short periods of time before settling on surfaces,” said Dr. Maher Balkis, associate staff physician of infectious diseases at Cleveland Clinic Abu Dhabi.
A study conducted in China earlier in the year on a cluster of coronavirus cases all originating from the same restaurant suggested that the virus did not spread through the air conditioning system.
“However, it is possible that air currents caused by air conditioning may have allowed droplets in the air to spread further than they otherwise might,” Balkis explained. “These findings are backed up by what we know of other viruses such as influenza, which are not known to spread through air duct systems, rather, they spread through close contact and infected droplets,”
Coughs and sneezes may travel between five and 200 times further than previously thought, found a 2014 study by MIT. This could exacerbate the problems associated with preventing the spread of coronavirus.
“When you cough or sneeze, you see the droplets, or feel them if someone sneezes on you,” John Bush, a professor of applied mathematics at MIT, and co-author of a new paper on the subject told MIT News at the time.
“But you don’t see the cloud, the invisible gas phase. The influence of this gas cloud is to extend the range of the individual droplets, particularly the small ones,” he added.
Coughing and sneezing are two of the main symptoms of the coronavirus that has spread rapidly across the world. There are over 1.2 million infections worldwide, with over 70,000 dead. Borders have been closed, businesses shuttered, and people have been told not to leave home as authorities move to slow the virus’s spread and put in place extensive social distancing measures.
“By maintaining physical distance and avoiding interacting with sick people, particularly in confined spaces, the risk of infection can be minimized,” Balkis concluded.