HVAC UV-Light-Virus-Protection

Can UV Light Stop COVID-19 Spread Through a Building?

When the first wave of COVID-19 hit Australia in March 2020 the experts believed that transmission via surfaces was the primary method of infection. However, it is now believed that catching COVID-19 through surfaces is rare.

In fact, most people catch COVID-19 through the air, either directly from droplets, or through aerosols. And this almost always happens indoors.

In early July, over 200 scientists from 32 different countries penned a letter to WHO asking them to recognise the significance of aerosol transmission.

What Is Aerosol Transmission?

Aerosol are very tiny droplets (of 5 microns or less in diameter) that you emit when you breathe, speak, and laugh. Because these particles are tiny and light, they can remain suspended in the air and then inhaled by someone else

While scientists don’t know exactly how long micro-droplets can linger in the air, it could be hours.

Can A Buildings’ HVAC Spread COVID-19?

The short answer is YES, it is possible for an HVAC system to spread COVID-19. This can be done in 2 ways:

  1. The airflow from the HVAC can push aerosol droplets containing the virus further than they would have otherwise travelled. There have been several cases of this happening in China.
  2. The aerosol droplets containing COVID-19 can travel through the HVAC system to the cooling coils. The COVID-19 virus can attach itself to bacteria on the cooling coils which then act as a host. The bacteria host will help the virus particle stay active for longer.