Seventeen addenda were issued to modify the 2017 edition of the American National Standards Institute/ASHRAE/American Society for Health Care Engineering Standard 170, Ventilation of Health Care Facilities, and thus create the new Standard 170-2021. 

The standard is changed by addenda, which are voted on by the committee. It is not uncommon for the committee to start on a proposed change as a work group first, then seek input from the whole committee before putting the addendum draft before the members committee for final approval. Building consensus, listening to input from all committee members and reaching out to experts in the field are keys for ensuring the committee’s efforts are heading in the right direction. 

Once an addendum is approved by the committee, the process ensures the further opportunity for public input as the addendum is posted on the ASHRAE website for 30 to 45 days for anyone to offer comments about the proposed change. The committee is tasked by the ASHRAE standards process to review and consider all input and encourages that the committee works to resolve comments whenever possible by aligning the goals of the committee and the public comments. Any changes to the addendum are again issued for public review and the cycle continues. 

Ultimately, the committee approves a fully vetted addendum for publication, where it can be found on the ASHRAE website under the “Standards Addenda” section of the “Technical Resources” tab. When any ASHRAE standard is republished, usually on a multiple year cycle, all the approved addenda are integrated into the existing standard, and the process of creating addendum to the standard starts anew.