ASHRAE 62.2-2025 ✓ Most Recent

Standard 62.2 is the consensus ventilation and indoor air quality (IAQ) standard for dwelling units in residential occupancies in which the occupants are nontransient. The standard describes the minimum requirements to achieve acceptable IAQ via dwelling-unit ventilation, local mechanical exhaust, and source control.

Dwelling-unit ventilation is intended to dilute the unavoidable contaminant emissions from people, materials, and background processes. Local mechanical exhaust is intended to remove contaminants from locations such as kitchens and bathrooms that, because of their design function, are expected to contain sources of contaminants.

The standard includes secondary requirements that focus on properties and performance of residential ventilation systems. Examples include sound and airflow ratings for fans, controls, and labeling requirements. The standard provides additional compliance pathways for existing dwellings.

Significant updates in the 2025 edition of the standard include a change from MERV 6to MERV 11 filtration, a new (optional) IAQ Procedure path to meet the dwelling-unit ventilation rate, a requirement for local exhaust in toilet rooms, a new exception allowing for a shorter separation distance between an air intake and a dwelling unit's exhaust, ozone requirements for air-cleaning devices, a replacement of hydraulic diameter with equivalent diameter in the prescriptive duct sizing section, requirements for a ground cover over exposed earth, and an informative appendix on how to manage infectious aerosols (based on ASHRAE Standard 241).