Through the retail lens: HVAC and battling the spread of COVID-19

Sarah Maston, a registered mechanical engineer and LEED certified professional, works with building owners of a variety of spaces. She is committed to sustainable design and served as former vice chair of the American Society of Heating, Refrigerating and Air-Conditioning Engineers Building Commissioning Technical Committee, devoted to discussion of commissioning issues in the United States and throughout the world.

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Maston’s company, Green Footprints Commissioning Inc., is a corporate member of the U.S. Green Building Council. She spoke with NRF about the impact of heating, ventilation and air conditioning systems as a possible solution to reducing the spread of COVID-19.

What is the current thinking on the impact of HVAC systems on the spread of COVID?

We have research that has shown virus particles can move through an air handling unit, but research is still being done to determine if the virus is still viable after this process. Regardless, increasing filter efficiency or adding air-cleaning devices such as ultraviolet lights to the AHU would help capture more particles and/or make the particles not viable (can’t reproduce) respectively. Each HVAC system is different, and there are trade-offs that need to be accounted for before you can incorporate any change to your system.

What do retailers need to do to evaluate their current HVAC and air quality systems in preparation for reopening (or remaining open)?

Engage a professional engineer to review your HVAC system to confirm which of the following recommendations are most cost-effective:

• Increase filter efficiency to MERV (minimum efficiency reporting value) 13 if possible.
• Increase the amount of outside air being introduced into air handling units. Limiting the number of people in the building may help.
• Install UV lights or other proven air cleaning technology in air handling units.
• Provide portable HEPA cleaning units in areas where many people may be gathering, such as a cafeteria.

We’ve talked about HVACs, but what other air filtration/air cleaning systems should retailers be considering and in what use?

If a retailer does not have control of or access to their air handling equipment, portable air cleaners can help filter out contaminants in their stores. There are many new air-cleaning products on the market right now. The issue is that most of these are so new, independent efficiency testing has not been done. In other words, a manufacturer can make claims about how clean their product makes the air, but it is done in their facility, most likely under conditions beneficial to their product.

Independent testing sets a testing standard by keeping all variables like temperature and humidity the same and tests each product under the same conditions. Since this kind of testing is not yet available for many products, look for HEPA filters and the ability to do at least two air changes per hour.