When the air gets warm, the first thing millions of people do is turn on the air conditioning. It can be enjoyed at home and in workplaces and public buildings. With the arrival of Covid-19, questions have been asked as to the safety of using air conditioning units. People have been afraid to go to restaurants, gyms, and many other places that use it. Is there any cause for concern? Let’s take a brief look right now.
AC Units Can Spread Germs
According to the CIBSE Journal, the Coronavirus can be spread by two things:
- Droplets released when someone coughs, sneezes or talks.
- Direct contact, such as touching someone’s hand or an infected surface.
It is a fact that air-con units can be an issue for those who suffer from allergies. As soon as the room cools, the sneezing and coughing start. According to the professionals of filterbuy.com/resources/can-you-be-allergic-to-air-conditioning/, there are a number of unpleasant things that can be circulated:
- Mould and mildew if there is a damp humidifier.
- Pollen blew in from outside.
- Airborne pet dander.
- Dust mites that breed inside the AC units.
- Pollution from outside.
- Bacteria and viruses, including flu and measles.
No. 6 then leads to the obvious question of whether this includes Covid-19.
A Reported Instance in China
There was a much-publicized instance of a 63-year-old woman who was infected with Covid-19, but asymptomatic. She sat in front of the AC unit at a restaurant. After this event, a number of people from four different tables were said to have contracted the virus.
One response made by western scientists was that this is a very small sample size to make a far-reaching conclusion.
A Response From the UK
One government communication said that workplaces are legally required to provide fresh air. Air Conditioning units should pose only a small risk if the rooms are well ventilated. Some centralized aircon units actually move the air from one room to another. In these cases, say the government, this function should be turned off.
The report also said that any AC unit that merges extracted air with fresh air should be no cause for concern. Units designed for one room only, including portable units, were deemed safe because the air was one hundred percent recirculated.
Professor Manish Butte has been based at the University of California. His concern was that AC units speed up the flow of air from one place to another whilst reducing humidity. Manish said that a cough can release three thousand droplets into the air. By way of contrast, a sneeze can emit ten times as many.
A key consideration is the direction of the airflow from the AC unit, as that is where the droplets will be sent. Professor Bramage agrees with these comments and says that infectious virus particles could be among those circulated in this way.
Dr. William Schaffner is a Professor of Infectious Diseases based in Tennessee. He was more moderate with his conclusions, saying there has only been one instance of infection caused through an AC unit, and none have been linked to liquor stores, grocery stores, or pharmacies that have it.
Some scientists have based their conclusions on the fact that droplets do not circulate further than six feet. They drop to the ground before this, so if self-distancing is honored, it should not be a key route for transmission of the virus.
What Should Restaurants and Public Buildings Do?
Owners of shopping malls and restaurants should make their own assessments. Visitors should maintain self-distancing and handwashing. The staff should wear masks and be regularly washing their hands. Tables should be disinfected after use.
According to a specialist called Adalja, restaurant owners should assess the direction of the airflow coming from AC units, and move the chairs accordingly. The fewer the customers are seated indoors, the easier it will be to maintain self-distancing.
Poor ventilation would seem to be the main enemy here. Open windows are always going to be a good solution for this. If someone uses a fan, they should let the window be left slightly open as well. Exhaust fans can keep running, however as they do not pose a risk.
Aircon units should be regularly maintained and their filters replaced and/or upgraded if possible, to maximize their effectiveness.
The Aircon Industry and Building Design
Industry action groups were swiftly set up in the form of pandemic task forces. They have teamed up with scientists in response to the concern that Covid-19 is being spread through aerosol transmission.
It is the opinion of many professionals that when it comes to business or domestic buildings, ways should be found to save energy without using air-recirculation. If the air ventilation is one hundred percent, the result will be more hygienic air for people to inhale.
Calls have been made for offices, buildings, supermarkets, and even forms of public transport to put their hands up if they are using air recirculation equipment.
The World Health Organization is currently unsure whether the temperature has any bearing upon the growth of COVID.
The Risks at Home
The general opinion conveyed by a number of authorities is that people are pretty much safe at home when they use their AC units. This is provided no one has contracted the virus, and that social distancing and handwashing have been rigidly performed when going outside.
Anyone who feels unwell and may have the virus, should most certainly not venture outside for fourteen days.
The Risks Outside
Anyone who does go outside needs to conduct their own risk assessment. This is most important for those with secondary conditions such as Diabetes. Whatever the decision, the guidelines of not touching our faces, maintaining social distancing, and handwashing should be maintained.
No one can be one hundred percent sure they are safe. When it comes to AC units in commercial buildings, even some hospitals may be presenting a measure of risk. Having said that, it is also that AC units could be an easy target for people looking for something to blame.
As time progresses, the scientific world will have a greater understanding of the COVID risk. The place of aircon units in this scenario should hopefully become clearer. No doubt there will be a point where there is a COVID vaccine, and normal life will be able to resume.