What does 'acceptable indoor air quality' mean according to ASHRAE Standard 62.1-2022?

• A. Air that is free from any contaminants at all times.
• B. Air with no known contaminants at harmful concentrations, with which 80% or more of people exposed do not express dissatisfaction.
• C. Air that is free of all odors.
• D. Air that feels comfortable in temperature.

Answer: (B)

Acceptable indoor air quality in ASHRAE 62.1-2022 means air that has no known contaminants present at harmful concentrations and, for occupants, at least 80% do not express dissatisfaction with the air quality. This sets a health-based limit on contaminants while requiring broad occupant acceptability. It does not require the air to be completely free of every contaminant or odor, nor does it equate IAQ with thermal comfort. Odors may be present as long as they don’t indicate harmful concentrations and overall acceptance remains high.