The Standards for Ventilation and Indoor Air Quality
ANSI/ASHRAE Standards 62.1 and 62.2 are the recognized standards for ventilation system design and acceptable indoor air quality (IAQ). Both standards specify minimum ventilation rates and other measures in order to minimize adverse health effects for occupants.
ANSI/ASHRAE Standard 62.1-2025, Ventilation and Acceptable Indoor Air Quality
ASHRAE Standard 62.1 Ventilation and Acceptable Indoor Air Quality has been the industry standard for building ventilation systems since 1973. The standard includes requirements for both mechanical ventilation systems and natural ventilation systems, including requirements for filtration, controls, air cleaning systems, and building operations and maintenance. New in the 2025 edition are additional humidity control requirements, mandatory adjustments for air density, demand control ventilation control sequences, ventilation system emergency control requirements, and new calculation methods for exhaust airflow rates, separation distances, and filter efficiency. Included with the standard are links to online calculators to aid users with compliance.
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Superseded Editions of 62.1
ASHRAE offers superseded editions of Standard 62.1 and User's Manuals in the ASHRAE Bookstore. Browse previous editions of Standard 62.1 here.
ANSI/ASHRAE Standard 62.2-2025 Ventilation and Acceptable Indoor Air Quality in Residential Buildings
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.
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).
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Related Courses
Air-to-Air Energy Recovery Applications: Best Practices
Air-to-Air Heat Recovery Fundamentals and Applications (MENA)
Complying with the Requirements of Standard 62.1-2016
Designing for IAQ: Complying with Standard 62.1 (MENA)
Fundamental Requirements of Standard 62.1-2016
Operations & Maintenance of High-Performance Buildings – 6 hours
Optimizing Indoor Environment: Increasing Building Value – 6 hours
Indoor Air Quality Guide
ASHRAE's Indoor Air Quality Guide: Best Practices for Design, Construction and Commissioning is designed for architects, design engineers, contractors, commissioning agents, and all other professionals concerned with IAQ. This comprehensive publication provides both summary and detailed guidance in the form of a printed book and accompanying CD.
The complete text may purchased from the ASHRAE Bookstore, or downloaded for free.
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