Helpful Ventilation Recommendations for the Food Safety Professional:


by Eric Moore, Director of Food Safety & Industry Relations, Testo North America


Having spent my career primarily focused on controlling food safety risks, I have tended to not dive too far into the complexities of facility engineering controls outside those directly related to mechanical refrigeration.

However; with more and more cross-functional collaboration occurring to combat the spread of SaRS-CoV2/COVID-19, I recently took some time to learn about some great research and science based recommendations developed by an organization called the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

Over the past weeks and months there has a plethora of information provided on mitigation strategies to help limit the spread of and exposure to SARS-CoV2/COVID-19. Some of this information (albeit vague) has been on airflow, and how bringing in more outside air into a facility can be useful. The most widespread examples are to increase ventilation or open windows and doors. While this may be an appropriate recommendation for non-food related businesses, it’s not realistic for food manufacturing and foodservice. Many restaurants may be doing this with the best intentions, but it creates additional challenges that can have adverse impacts to the safety of food in the establishment.

This is where ASHRAE comes into the focus. In 2009, they published a scientific position paper on Airborne Infectious Disease. The paper provides a detailed breakdown of the role building ventilation systems play in interrupting disease transmission.

This past April, ASHRAE released an updated version (ASHRAE Position Document on Infectious Aerosols) that includes the following statement: “Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.”


The paper provides a great deal of scientific evidence related to effective control measures to limit airborne disease transmission. Outlined below are what I found to be the most realistic takeaways that could be useful for food safety professionals.

Natural Ventilation Considerations:

  • Open windows and doors to increase natural ventilation
  • Ensure all open doors/windows are protected against pest entry by 16 mesh screens/doors
  • Install mechanical air curtain(s)

Ventilation, Air Cleaning and Humidity:

  • Keep systems running 24/7 when possible.
    • If not possible, purge the building air by running the HVAC system 1-2 hours before occupying the building, with Outdoor Air (ODA) dampers open 100%
  • Improve central air and other HVAC filtration to MERV13 or highest level possible
  • Increase outdoor air ventilation by opening air dampers to 100%
  • Increase ODA to a minimum of 20cfm/person and preferably 40 cfm/person
  • Install Ultraviolet lamps (capable of emitting 200-280 nm) in an air handling unit
  • Control Relative Humidity between 40-60% year-round
  • Bypass energy recovery ventilation that may leak contaminated air back into fresh air supply

It should also be noted that these recommendations are only part of an overall risk mitigation plan and  are intended to be used in conjuncture with various other control measures such as but not limited to  thorough and adequate cleaning and disinfection of high touch surfaces, employee health screening practices, frequent handwashing, physical distancing and adhering to the use of properly fitting face masks and other appropriate Personal Protective Equipment (PPE). 

Join our upcoming webinar entitled Airflow & IAQ - Baseline Commercial HVAC systems for Health Crisis Mitigation by registering below to learn more on this subject:



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