Indoor air quality in the workplace during cold weather is especially critical while influenza, cold, and COVID-19 viruses are circulating.
Improving ventilation is a key engineering control that can be used to increase the delivery of clean air and remove or reduce the concentration of viral particles or other contaminants. Building managers may perform some steps to improve indoor air, while others should be conducted by a qualified heating, ventilation, and air conditioning (HVAC) professional.
Key steps to improve ventilation include:
• Inspect air intake and exhaust ports to ensure they are clean and free of ice or snow.
• Replace filters as necessary to ensure the proper function of the HVAC system.
• Have an HVAC professional conduct all regularly scheduled inspections and maintenance.
• Add portable air cleaners with High Efficiency Particulate Air (HEPA) filters in spaces with high occupancy or limited ventilation.
Maintaining a healthy HVAC system requires an HVAC professional to:
• Ensure all HVAC systems are operating in accordance with the manufacturer’s instructions and design specifications.
• Maximize the amount of outdoor air supplied consistent with the heating capacity of the HVAC system. Rebalance or adjust HVAC systems to increase total airflow to occupied spaces. Total airflow includes both outside and recirculated air.
• Install air filters with a minimum efficiency reporting value (MERV) 13 (or equivalent) or higher where feasible. If MERV-13 filters are not compatible with the HVAC system, use filters with the highest compatible filtering efficiency for the HVAC system.
• Clean HVAC system drain pans, heating and cooling coils, and supply/return registers to eliminate areas where contaminants can settle.
To learn more about improving ventilation, visit osha.gov/ventilation.