Does Air Conditioning Aid Coronavirus Transmission?

As America suffers in the throes of a deadly pandemic that appears to be picking up steam in many areas of the country, it must also deal with the sweltering temperatures that have become a staple of recent summers. Add to that the recent speculation that air conditioning may contribute to the spread of coronavirus, and people have every right to fear the dog days of summer.

With summer heat waves becoming more common, people are likely to spend even more time indoors in the next few months. Unfortunately, we already know that the risk of catching coronavirus is much higher in closed quarters. While it’s possible to make inside spaces safer simply by opening windows, it’s just economical or practical for large, commercial air-conditioned spaces.

Does Air Conditioning Worsen Health Problems?

Some health experts blame air conditioning for spreading the bacteria and mold spores which gave rise to the term “sick building syndrome.” Furthermore, studies in Europe and both North and South America indicate that people who work in air-conditioned spaces tend to have more health issues than those who work in non-cooled spaces. Nevertheless, air conditioning is generally regarded as a health benefit because it cuts down on the number of deaths from weather extremes like heat waves.

However, those who succumb to intense heat are usually older or suffer from pre-existing health conditions. They may also come from lower income households that may not be able to afford air conditioning. Unfortunately, the communities that are most vulnerable to heat waves are also the ones most vulnerable to contracting coronavirus.

Vicious Circle of Air Conditioning and Climate Change

The problem with air conditioning is that people use it as a response to the higher temperatures brought about by global warming. However, running AC units actually contributes to global warming itself. Indeed, air conditioning comprises 17 percent of year-round home electricity consumption. Thus, we find ourselves in a vicious circle in which decades of greenhouse emissions lead to much hotter summers in which we rely more heavily on air conditioning which adds to greenhouse emissions.

But Can Air Conditioning Actually Spread Coronavirus?

Many health experts claim that there’s little evidence that air conditioning can spread coronavirus germs, and that the greater risk results from the amount of time people spend indoors around other people.

Nevertheless, recent incidents may suggest otherwise. A study just published in Emerging Infectious Diseases showed that nine people in a restaurant in Wuhan, China contracted coronavirus merely by sitting close to an air conditioning vent. The researchers pointed out that the virus was spread by an asymptomatic diner who sat in front of the AC unit.

How HVAC Units Work

To fully understand how air conditioning might spread Covid-19, it helps to know a little about how these systems impact indoor air quality. When outside temperatures rise, HVAC systems change the mix of fresh air they use to save energy. In other words, the hotter it gets outside, the more indoor air recirculates.

As a result, you wind up breathing in more of the same air that other people are breathing out. If someone in your area happens to be shedding coronavirus, it can potentially build up in the recirculated air. Since AC units blow air around, smaller particles can remain in the air longer. In addition, these units take moisture out of the air, which also helps viruses.

WHO Issues New Guidance on Airborne Transmission

Due to emerging evidence of airborne transmission of Covid-19, an international group of over 200 scientists appealed to the World Health Organization to recognize this threat. In response, the WHO issued new guidance yesterday regarding the role of airborne droplets in the transmission of coronavirus.

For months, the WHO emphasized that the virus is transmitted mainly through droplets when people cough or sneeze. They also claimed that airborne transmission of Covid-19 was only a problem in healthcare settings during procedures such intubating a patient with a breathing tube.

Now, however, they acknowledge that the virus can be spread by smaller particles, which may linger in the air after someone has left the area.

The WHO’s admission is significant because, if the evidence is confirmed, it should impact our current guidelines for indoor spaces. Essentially, we’ll need to rethink our behavior in indoor environments regarding everything from the use of masks to social distancing, especially in crowded or poorly ventilated spaces.

Where Do We Go from Here?

Although the evidence linking air conditioning to the spread of this deadly pandemic is still limited, it demonstrates that we cannot take this possibility lightly. Even though people can minimize their risk by bringing in more air from the outside, it’s just not feasible for large commercial spaces that need to be kept cool.

While we still have a long way to go in our understanding of how Covid-19 is transmitted, public health experts need to update their guidelines to reflect the potential danger of air conditioning and coronavirus.