Standard 90.1 Addenda for Public Review - August 2011

Post date: Aug 12, 2011 4:50:52 PM

The public review of the following addenda have been announced in today’s ASHRAE Standards Action. For more information go to

30 day public review from August 12, 2011 to September 11, 2011

90.1z – First Public Review - This proposal relocates the existing water economizer requirements in the general economizer requirements in

90.1ac – First Public Review - This allows the inclusion of the R-value of an air space in enclosed cavities with or without insulation when calculating the total R-value of assemblies in Appendix A. This is consistent with what is allowed in Chapter 26 of the 2009 Handbook of Fundamentals.

45 day public review from August 12, 2011 to September 26, 2011

90.1x – First Public Review – This addendum puts limits on air leakage through the casing and through the damper for terminal air boxes in Section This requirement only applies to single duct and dual duct units.

90.1y – First Public Review – These tables will update the standard to include the new federal energy efficiency standards in Section 10.8 for motors used in HVAC equipment that will be in effect starting in 2015.

90.1aa – First Public Review - This proposed change eliminates references to the type of DDC control system, and just specifies how the system must perform in Section

90.1ab – First Public Review - This addendum adds a Filled Cavity metal building roof assembly to Appendix A.