HVAC Best Practices Post COVID-19

As businesses open back up everyone’s attention is on keeping their employees & coworkers safe. While CDC guidelines regarding face coverings, frequent hand washing, and disinfecting protocols are the best way to slow the spread of COVID-19, there are other ways for organizations to slow the spread. The ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) formed a task force to provide guidelines on how a building’s HVAC systems can help slow the spread.

Building Filtration

While COVID-19 has shown to spread mainly through person-to-person contact the virus can attach itself to airborne particles. Those airborne particles can then find themselves in your HVAC system. Hearing that most organizations may be thinking they should increase the frequency of filter changes but the ASHRAE recommends reducing the frequency of filter changes, if possible. This will reduce the exposure of Maintenance personnel to the contaminates as well as reduce the risk of these particles being reintroduced back into the building. When replacing filters Maintenance personnel should:

• Wear appropriate PPE
  • Respirator (N95 or higher)
  • Eye Protection (safety glasses & face shield)
  • Disposable gloves
  • Disposable coveralls
• Place contaminated filters in sealed bags
• Dispose of bagged filters in trash
• Immediately wash their hands

When replacing filters, an organization may want to consider using a higher efficiency filter to potentially capture more contaminated particulates. Filter are assigned a MERV (Minimum Efficiency Reporting Value) based on their efficiency. Typical HVAC grade MERV filters range from 1-16. The ASHRAE suggests using a filter with a MERV of 14 or better. Always make sure your HVAC system can handle a higher efficiency filter before switching.

Building Ventilation & Recirculation

In general, the ASHRAE recommends increasing building ventilation and decreasing building recirculation as much as possible. The idea being to bring in as much “fresh” outside air rather than continually recirculating the same indoor air (Although this won’t always be feasible as we move into the hotter summer months). ASHRAE also suggests a “flushing cycle” prior to occupancy. This means either opening outside air dampers, exhaust fans, or simply opening the windows for at least 2 hours to allow fresh air in the building. Also leaving on restroom exhaust fans on continuously to help “flush out” any contaminants.

Following CDC guidelines for face coverings, frequent hand washing, and disinfecting protocols should still be your first line of defense in slowing the spread of COVID-19 but following these simple best practices can also help keep your employees and coworkers safe and health.

Please refer to the Illinois Manufacturer Return to Work and Recovery Guide for more recommendations on reopening safely to protect your employees and your business.