Which statement correctly describes the three compliance paths outlined in ASHRAE Standard 62.1-2022?

• A. Natural ventilation is prescriptive only.
• B. IAQ procedure (performance) is included only with natural ventilation.
• C. Ventilation rate procedure (prescriptive), IAQ procedure (performance).
• D. Ventilation rate procedure (prescriptive), IAQ procedure (performance), and natural ventilation (prescriptive or performance).

Answer: (D)

The concept being tested is that ASHRAE 62.1-2022 recognizes three distinct ways to demonstrate compliance: a prescriptive ventilation rate path, a performance-based IAQ path, and a natural ventilation path. The best statement is the one that lists all three and notes that natural ventilation can be used either prescriptively or via a performance approach. The ventilation rate procedure sets minimum outdoor air flows for spaces in a prescriptive manner. The IAQ procedure provides a performance-based option that evaluates indoor air quality through contaminant source control, emissions, filtration, and ventilation effectiveness, allowing designers to meet IAQ goals without strictly meeting fixed rates. Natural ventilation is also an approved path and can be used either prescriptively or through a performance evaluation, depending on the building design and climate.

Other options are incomplete because they omit one of the paths or incorrectly constrain natural ventilation to only one mode.