Is Commercial Air Conditioning System Safe During This Pandemic?

Coronavirus has been termed a pandemic. It has infected millions of people worldwide. With such high infection rates, it becomes important to understand how the virus gets transmitted. This is the only way by which safety measures can be taken and people can adopt ways to safeguard themselves against the virus.

One important question that was foremost in everyone’s mind was whether the virus could be air transmitted. Specifically, whether it was safe to use commercial air conditioning or whether using HVAC systems would aid in its spread.

The data available on the mode of transmission of the virus indicates that it can only be transmitted through droplets. Precisely speaking, when a person talks, sneezes, coughs, laughs out loud, etc., the cough lets that come out transmit the virus from one person to another. Since information about the size of the cough or droplet that can cause infection is still not known and practical data on HVAC and coronavirus transmission is very less, nothing can be said for sure yet.

There are several factors that need to be considered here like:

  • Size of the particles: If droplets are large about 60µm or more, they will land on surfaces where some of the fluid will evaporate making the droplet smaller in size of about 2.5 µm to 10 µm. Droplets of this size remain suspended in the air for quite a long time and hence chances of their entering the HVAC systems are also quite high.

  • Filtration: Each commercial air conditioning unit has a process that filters out particles in different ways and levels. Thus, if the AC has a capacity for filtering out particles bigger than a coronavirus droplet, then COVID 19 can be spread through the AC filtration system. But there is no evidence that amply justifies or proves the fact.

  • Air usage: There are two different ways of air usage in HVAC systems. Some recycle air while others draw air from the outside. The ones that depend on outside air are relatively safer as they reduce the risk of environmental exposure.

  • Temperature and humidity: There is evidence that low temperature and low humidity levels, as is common when using commercial air conditioning in Sydney, enable respiratory infection causing viruses like SARS to survive. But according to AIRAH, there is yet no evidence that proves that aircons aid the transmission of the COVID19 virus.

Aircons are typically air-circulation systems wherein a small portion of outside air is added, and an equal amount expelled. Before the air is recirculated, it is filtered and moved within the system using fans. Heating and cooling are provided by the finned coils present.

A virus infected droplet needs to undergo a journey involving ducted airways with multiple direction changes and varied air velocities. It also experiences multiple impacting surfaces like fans, dampers, grills, and air filters. Thus, there is a high chance that during this journey, the particle would impact surfaces, entrain and then dry on surfaces.

Thus while the transmission is theoretically possible, it is practically not very feasible in well designed and maintained HVAC systems of the commercial air conditioning Sydney. Any person needing more information on whether HVAC systems transmit COVID19 should ideally call up Endeavour Air Conditioning at (02) 9585 9955 for the same.

Leave a Reply

Your email address will not be published. Required fields are marked *