As you undoubtedly know, it is currently believed that COVID-19 spreads primarily through the air, through respiratory droplets.
What this means is that if someone in your facility has COVID-19, the air in your facility can literally make everyone else sick with this potentially deadly disease. Luckily, your heating, ventilation and air conditioning (HVAC) systems can be modified to help prevent this. Both OSHA and Cal/OSHA recognize this.
Cal/OSHA’s new regulation requires action
On November 30, 2020 Cal/OSHA’s new Emergency Workplace COVID-19 Regulation went into effect. This new regulation applies to all places of employment except those with just one employee who doesn’t have any contact with anyone else, and some workplaces (such as certain healthcare facilities) that are already covered by Cal/OSHA’s aerosol transmission standard.
Among many other things, this emergency regulation includes two mandates regarding your HVAC system. You must:
- Maximize the quantity of outdoor air provided to the extent feasible.
- Determine if you can increase filtration efficiency to the highest level compatible with your existing ventilation system.
OSHA has provided additional guidance
In addition to providing recommendations that mirror Cal/OSHA’s two mandates, OSHA also recommends that you:
- Work with an HVAC specialist to optimize building ventilation.
- Ensure all HVAC systems are fully functional.
- Remove or redirect personal fans to ensure workers aren’t blowing air from their workspace into someone else’s workspace.
- Ensure exhaust air is not pulled back into the building through HVAC air intakes or open windows.
- Consider installing portable HEPA systems, especially in high-risk areas.
- Check your restroom exhaust fans to be sure they’re full functional, operating at maximum capacity and are set to remain on.
We’ve been implementing these measures for months
Last May we published a white paper on “Using Your Building’s HVAC System to Help Reduce the Spread of COVID-19.” In this paper we recommended specific COVID-19 mitigation strategies. These include and go beyond the OSHA and Cal/OSHA guidelines:
- Increase ventilation into the building – Disable demand-based systems, keep the system running for longer hours and bring in extra airflow to “purge” the building.
- Avoid recirculating air – Close the recirculation dampers, turn off room-level circulation systems and consider installing a dedicated outdoor air system.
- Upgrade your filtration – Install single-space high-efficiency filtration units and increase the MERV of conventional air filters and consider adding HEPA filtration to your centralized HVAC system.
- Use ultraviolet germicidal irradiation (UVGI) – These systems are installed inside the HVAC system to kill microorganisms as they pass under a special UV light.
- Increase maintenance – Clogged air filters and infected surfaces can pose a significant danger during a pandemic.