What are the requirements for PM removal in ventilation systems according to ASHRAE Standard 62.1-2022?

• A. At least MERV 8 or ISO ePM10 filtration upstream of cooling coils and other wetted surfaces.
• B. Filters can be any MERV rating as long as energy use is low.
• C. Filtration is not required in this standard.
• D. Only HEPA filtration is allowed.

Answer: (A)

The key idea is that ASHRAE 62.1-2022 requires a minimum level of filtration to remove particulates from the air in ventilation systems. The standard specifies that filtration with at least MERV 8 or ISO ePM10 efficiency must be provided in the supply air and placed upstream of cooling coils and other wetted surfaces. Placing the filter before the coils protects those surfaces from particulate buildup, helps maintain coil heat transfer, and reduces downstream contamination, while also improving the air quality delivered to occupants. Higher-efficiency filtration may be used in more stringent IAQ situations, but the baseline requirement is a filter meeting or exceeding MERV 8 (or ISO ePM10) upstream of coils and wetted surfaces. The other options conflict with the standard because filtration is required, it’s not limited to any arbitrary low MERV for energy reasons, and HEPA-only filtration is not a mandatory requirement of 62.1.