ASHRAE standards are typically updated on a five-year cycle. While the 70-2006 version is technically superseded, you may still find it referenced in older project specifications.
: Specifies commercially available test instruments with higher accuracy than those previously listed in the 2006 standard. ashrae standard 702006 pdf updated
The 2023 update introduces several critical improvements over the 70-2006 (RA 2021) version to better align with modern HVAC technology: ASHRAE standards are typically updated on a five-year cycle