Improving indoor ventilation ‘critical’ during cold weather, OSHA says

Washington — Citing the increased circulation of airborne viruses when temperatures drop, “indoor air quality in the workplace during cold weather is especially critical,” OSHA says in a new alert.

“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,” the agency continues. “Building managers may perform some steps to improve indoor air, while others should be conducted by a qualified heating, ventilation and air conditioning professional.”

Steps that employers can take include:

• Inspect air intake and exhaust ports to ensure they’re clean and free of ice or snow.
• Replace filters when necessary.
• Add portable air cleaners with HEPA filters in spaces with high occupancy or limited ventilation.

Employers should have an HVAC professional perform regularly scheduled inspections and maintenance as well as:

• Ensure all HVAC systems are operating in accordance with the manufacturer’s instructions and design specifications.
• Clean HVAC system drain pans, heating and cooling coils, and supply/return registers to eliminate contaminants in areas where they tend to settle.
• Maximize the amount of outdoor air supplied consistent with the heating capacity of the HVAC system.
• Install air filters with a minimum efficiency reporting value of 13 or better 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,” OSHA says.