Is the coronavirus spread through the air? Are there any HVAC system measures that can help reduce the risk of transmission? These are questions that many building operators are asking.
In most buildings, HVAC systems play only a small role in the spread of infectious diseases, such as COVID-19 and the novel coronavirus that causes it. This is because of the way HVAC systems work and the way that the coronavirus spreads.
Coronavirus transmission
According to the World Health Organization, the COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes. Droplets or particles can also be released when people talk or breathe.
Droplets typically fall to the ground or other surfaces within about 3 feet. Particles are lighter; they can travel through the air for longer distances, where than can transmit to people or settle on surfaces.
The virus can be transmitted to people who touch contaminated surfaces, or drawn back into the air when disturbed on surfaces. However, the most likely forms of virus transmission are direct person-to-person contact, indirect contact through surfaces and droplet spread between people close to each other.
Therefore, proper social distancing and hygiene practices are more important to containing the spread of the virus than any HVAC maintenance practices or modifications.
Protecting your facility
How do you reduce the risk of virus transmission in your workplace? Here are some tips:
- Provide tissues and no-touch disposal receptacles.
- Make soap and water and hand-sanitizer readily available in the workplace.
- Place signage encouraging proper hand hygiene at your workplace entrance, restrooms and other high-traffic areas.
- Remind employees to practice social distancing by staying at least 6 feet away from others whenever possible.
- Routinely clean and disinfect all frequently touched surfaces, such as workstations, keyboards, phones, handrails and doorknobs.
- Provide workers who need it with protective clothing and equipment — such as gloves and masks — and training on how to wear it and use it correctly.
The Occupational Safety and Health Administration (OSHA) and ASHRAE recommend some HVAC-related actions:
- Install high-efficiency air filters (MERV-13 or highest compatible).
- Increase ventilation rates in the work environment.
- Increase supply of outdoor air ventilation.
- Disable demand control ventilation (DCV).
- Provide negative pressure ventilation in specialized areas, such as infection isolation rooms in hospitals.
If OSHA & ASHRAE recommended the HVAC measures below to reduce the spread of COVID, then the facility will see an increase in their utility consumption and cost.
- Increase ventilation rates in the work environment.
- Increase supply of outdoor air ventilation.
- Disable demand control ventilation (DCV).
For more information on how keep your workplace safe, see COVID-19 from the Centers for Disease Control and Prevention and COVID-19 (Coronavirus) Preparedness Resources from ASHRAE.
