Top 5 Ventilation Interventions to Reduce Viral Spread in Your Facility

This week the CDC updated its outlook on the transmission of COVID-19 and recommended a layered approach to reduce exposure to SARS-CoV-2, the virus that causes COVID-19, within facilities. This approach includes using multiple mitigation strategies, including improvements to building ventilation, cleaning and disinfecting surfaces, redesigning workspaces and common area spaces to allow for physical distancing, advocating wearing face masks and hand hygiene, and encouraging employees to get their vaccination.

Since SARS-CoV-2, viral particles spread between people more readily indoors, the CDC has determined that air quality and ventilation are now characterized as more important than surface disinfection, to reduce the spread of COVID-19, especially within commercial facilities.

For COVID-19 to infect someone, a certain number of particles need to enter the body. When the concentration of virus particles is lowered, it is less likely viral particles can be inhaled into the lungs (potentially lowering the inhaled dose); contact eyes, nose, and mouth; or fall out of the air to accumulate on surfaces. When you incorporate protective ventilation practices and interventions, it can reduce airborne concentrations and reduce the overall viral dose in the air, helping to keep your occupants safer and healthier.

Where should you start?

According to the CDC, facilities that provided healthy, code-compliant indoor air quality prior to the pandemic can be improved for pandemic occupancy using less costly interventions.

To better manage your ventilation and indoor air quality (IAQ), apply multiple ventilation interventions, if possible. The more you can implement, the greater chance you have of reducing the concentration of virus particles in the air and reducing the risk of viral spread.

Please note: These ventilation interventions can reduce the risk of exposure to the virus and reduce the spread of disease, but they will not eliminate risk completely.

The CDC and the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) have suggested many ventilation interventions through their guidance for building operations during the COVID-19 pandemic.

Here are the top five ventilation interventions to help you get a jump start on reducing viral spread within your facility:

Increase the introduction of outdoor air

Reduce or eliminate HVAC air recirculation and open outdoor air dampers beyond their minimum settings. When possible, take advantage of mild weather, because it will have less of an effect on thermal comfort or humidity. However, in climates with more extreme temperatures, you should consult an experienced HVAC professional.

If your facility has the ability, open windows, and doors when weather conditions allow. It will increase outdoor airflow and introduce beneficial outdoor air.

Improve central air filtration

When increasing outdoor air delivery options are limited, increase the air filtration to as high as possible without significantly reducing design airflow. Make sure the system’s air filters are properly sized and within their recommended service life. And inspect filter housing and racks to ensure appropriate filter fit. This will minimize any air that may flow around the filter instead of through it.

Add portability filtration options

Portable high-efficiency particulate air (HEPA) fan/filtration systems can enhance air cleaning, especially in higher-risk areas. Adding a portable HEPA unit can increase the effective ventilation rate and improve room air mixing.

Areas frequently inhabited by large numbers of people or people with an increased risk of contracting COVID-19 can greatly benefit from portable HEPA filtration systems. But make sure the filtration device you purchase is a portable HEPA air cleaner. There are portable air cleaners that use filters less efficient than HEPA filters, and while they can contribute to room air cleaning, they will not be as effective at removing viral particles and respiratory droplets from circulation.

Direct airflow

Generate clean-to-less-clean air movement through the facility. The creation of directional airflow can be accomplished within a particular space or between two adjacent spaces. By evaluating and repositioning as necessary, you can direct the supply louvers, exhaust air grilles, and/or damper settings to follow a standard controlled flow.

Install supplemental air treatments

Consider using ultraviolet germicidal irradiation (UVGI) as a supplemental treatment to inactivate SARS-CoV-2, especially if options for increasing room ventilation and filtration are limited. UVGI can inactivate viruses in the air and on some surfaces. The technology uses ultraviolet (UV) energy to kill microorganisms, including viruses when designed and installed correctly.

If improving the air quality at your facility is important to you, make sure you check out the recording: Peace, Love, and IFM – Beyond HVAC: Indoor Air Quality and COVID-19. In this previously-recorded discussion, top experts in IFM and IAQ talked about indoor air quality (IAQ) changes that should be made during COVID-19 and some strategies to improve your facilities’ IAQ that go beyond the HVAC system.