There is still a lot to be known about Covid-19, but there is one thing we all agree on: it is highly contagious via airborne transmission. Primary spreads come from infected people who cough, sneeze, and even talk. If an action produces airborne droplets, it can spread the virus. Because Covid-19 can spread via air, it raises the question if an HVAC system plays a role in the spread.
While the virus particles are small in size, which is around .1 microns, they can travel greater distances. Larger droplets, around ten microns in size, can typically travel around one meter before it settles. Smaller droplets typically evaporate before settling, which means the virus particles can linger in the air (this is known as an aerosol).
While it is still not fully known how long they can last in the air, a study done by WHO found that active airborne particles containing the virus may stay in the air for a few hours. The World Health Organization initially claimed there was known airborne transmission, however, that has since been updated.
The Role of the HVAC System
HVAC systems could potentially spread virus particles between ventilated rooms. Because it is possible that airborne transmission could occur, there are ways to decrease the risk of spreading it with specific HVAC settings.
One way that a professional HVAC technician could take is to configure the system to increase the fresh air exchange rate and reduce circulation. Rather than shutting down the system, continuously running with zero interruptions could ramp up the air replacement while minimizing the airflow speed. Due to the concern over airborne transmission, it is crucial to optimize indoor ventilation to help limit the spread.
How To Limit Covid-19 Spread
Changing settings in an HVAC system could help improve air quality and prevent a possible viral spread. In older HVAC systems, it might be smart to upgrade some older parts, such as switching from fixed-speed motors with variable-speed, introducing more robust airflow systems, and installing air purification systems.
There are many options for purifying air. Installing a high quality air filter (such as HEPA or MERV 13), Ionization systems, and UVC light filtration will reduce the risk of virus transmission in your space. There are air filtration systems available that work independently of your existing HVAC systems to help improve air quality.
While there are still no definitive results as to whether an HVAC system can spread Covid-19 on a wide range, anyway we can combat and slow down the spread is worth doing. Make sure to always consult with the professional HVAC companies and never attempt to mess with your settings without the help and guidance of a skilled technician.