What We Know About Air Conditioning and COVID-19
As cases of COVID-19 continue to rapidly rise throughout the South, researchers think there might be an essential, but overlooked factor in the virus spreading in the region. This factor is air conditioning. Like cold winter temperatures create the ideal conditions for passing the flu and colds by forcing individuals inside and into close proximity of one another for hours where swapping germs is easy, according to researchers, the southern U.S.'s extreme heat could be creating the same effect, forcing individuals inside where AC units are operating full blast.
However, a Harvard infectious disease expert used insights from tuberculosis, another deadly airborne disease, to come up with the conclusion that across the southern U.S., air conditioning might be a factor in the rising cases of COVID-19.
The HVAC system just may be recycling this airborne virus throughout:
- Office buildings
- Grocery stores
Rather than drawing in humid and hot air from outdoors, the standard AC unit reuses most of the pre-cooled air that already has passed through the building. Doing it this way saves building owners a lot of money. But, doing it this way could also continue circulating airborne particles throughout the area.
Hot summer temps could make situations close to those in the wintertime, when there tends to be a surge in respiratory ailments, forcing individuals inside to breath and continue breathing air that basically is little refreshed from outdoors.
In June, the states already using AC due to high temperatures are also locations where the spread of COVID-19 are greater, which suggests more time spent inside as the temperatures increase.
Emerging Infectious Diseases published a study recently that found nine individuals in Wuhan, China were infected with COVID-19 just by sitting close to an AC unit vent in a restaurant. The researchers of this study said one asymptomatic diner sitting in front of the air conditioning unit spread the virus to four other individuals sitting at the table who later on had a positive test for COVID-19. Five individuals that sat at neighboring tables also tested positive.
Hospitals handle this air regurgitation by using high-quality HEPA filters, UV lights and routine cleaning to make sure their HVAC unit isn't spreading contagions. Some possible good news — Columbia University Irving Medical Center conducted a study that found Far-UVC lighting, which is safe for humans, are more efficient in killing some types of coronavirus. There is ongoing testing on SARS-CoV-2.
The average business or home, however, is very unlikely to carry this type of technology, therefore the chances of contagious particles recycling throughout the buildings or homes increases as a result.
An alternative to air conditioning that many climates in the U.S. could benefit from is whole house fans. These draw in fresh, outdoor air to cool and ventilate insider air. Whole house fans offer an added benefit of reducing utility and energy costs, when used as a substitution to or reduction in air conditioning use.