Operating Safely GUIDE
How restaurants and foodservice operations can adopt safe practices while operating efficiently
Managing Indoor AirFlow In a Restaurant or Foodservice Operation – Guiding Principles
The data and recommendations below are from The Acheson Group for US Foods®
Can Air Conditioning Systems Spread Coronavirus?
There continues to be no clear evidence of COVID-19 spread through heating, ventilation, and air conditioning (HVAC) systems. However, in principle, increasing ventilation and filtration can reduce the risk of airborne transmission of infectious agents.
How To Optimize Your Business’ Indoor AirFlow
Recommendations for facilitating engineering controls include:
- Ensuring or increasing ventilation rates to adequacy (if applicable)
- Increasing the percentage of outdoor air that circulates into the system (if applicable)
As there is no one-size-fits-all answer, and all systems are designed differently, it is imperative to consult with an HVAC expert to understand the airflow in your facility and your particular air-handling system configuration and capabilities. Optimization of HVAC systems is complex and specific to the exact conditions of your facility. If not properly managed, changes to the HVAC system can result in other challenges that can both impact the comfort and safety of a building’s occupants. Below are a few resources regarding HVACs:
o The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has published some comprehensive resources. An HVAC engineer is needed to follow the guidance.
o The Chartered Institution of Building Services Engineers (CIBSE) in England has also published guidance and recommendations. These guidelines are not very prescriptive.
While optimizing airflow, incorporating more outdoor air, seeking maximum feasible filter efficiency, and trying to avoid air movement between zones are sound recommendations, these are not always easy to achieve.
Be alert and careful to the HVAC’s impacts on pressure, relationships in facilities. and experimenting with increased air movement without regard to airflow patterns (e.g., with fans) could actually cause the situation to worsen, as droplets from an infected person could be carried across the room and land on others before they are picked up by the HVAC system. Consult an HVAC engineer or industrial hygiene specialist for recommendations on your facility.
Additional Equipment Available
The Environmental Protection Agency (EPA) states that “when used properly, air purifiers can help reduce airborne contaminants including viruses in a home or confined space. However, by itself, a portable air cleaner is not enough to protect people from COVID-19”.
At this time, there is currently no evidence that applying ozone or using ozone generators will be protective from COVID-19, and the EPA discourages its use. When used incorrectly, ozone can be both (a) harmful to human health, and (b) ineffective.
Ultraviolet A, B, and C (UVA, UVB, and UVC) for Disinfecting Spaces
The FDA has recently published/provided further information on using UV-A, UV-B, and UV-C lamps for disinfection during the COVID-19 pandemic.
The efficacy of UVC against the SARS-CoV-2 coronavirus is currently unproven; not all UVC lights are the same; and UVC can be toxic. While UVC radiation has been shown to inactivate the original SARS-Coronavirus (the original 2003 SARS virus), it has not been proven against SARS-CoV-2 (COVID-19), as there is limited published data about the wavelength, dose, and duration of UVC radiation required to inactivate it. There is scant research on UVC’s effectiveness to inactivate viruses, generally.
- For surfaces. UVC radiation can only inactivate a virus if the virus is directly exposed to the radiation. Therefore, UVC radiation may not be effective on surfaces due to blocking of the UV radiation by soil (e.g., dusts) or other contaminants (e.g., bodily fluids).
- For air ducts. This is the safest way to employ UVC radiation because direct UVC exposure to human skin or eyes may cause injuries. As such, installation of UVC within an air duct is less likely to cause exposure to skin and eyes. However, efficacy is still unproven.
UVC lights can vary significantly – emitting specific or broad ranges of UV wavelengths, with some emitting visible and infrared radiation – if you are considering using UVC for surfaces or air ducts, be sure to discuss the lights and options with the manufacturer to ensure that you are fully aware of the specifications and hazards.
Ultraviolet-A (UVA) and Ultraviolet-B (UVB)
UVB and UVA are expected to be even less effective than UVC. Additionally, both are much more hazardous! UVB radiation can penetrate even deeper than UVC into the skin and eyes, leading to DNA damage, skin cancer, and cataracts; UVA is implicated in skin aging and increased skin cancer risks.