Winter is here and outdoor dining is limited in many parts of North America. As food establishment customers and employees spend more time indoors, it's a great time to review some simple engineering controls designed to support an organization's airborne virus risk management program.
- 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.
The above recommendations are have been pulled from research and guidance published by ASHRAE. Specifically 2009 ASHRAE Scientific Position Paper on Airborne Infectious Disease. The updated recommendations from ASHRAE are specific to SARS/COV-2 however the same considerations and risk controls can be applied to all airborne virus transmission.
Source: ASHRAE Positions on Infectious Aerosols, 2022