Air Curtains in ASHRAE/IES Standard 90.1-2019

Based on their inclusion in 90.1-2019 I think you could agrue that you meet the mandatory provision with an air curtain.

Hello Nima, hello Marcus,

We asked the same question a few weeks back and our LEED coach doesn't agree:

"LEED v4 projects using ASHRAE 90.1-2010 for Minimum and Optimize Energy Performance could not apply ASHRAE 90.1-2016 addendum bf. While the addendum adds an exception for entrances with air curtains, the other envelope requirements of ASHRAE 90.1-2016 are more stringent compared to 90.1-2010, so individual changes to the mandatory requirements cannot be applied in isolation. [...] In order to use an addendum from ASHRAE 90.1-2016 the project must be using 90.1-2016 in full."

I'm just going to say I read this somewhere without any citations or ownership, but those interested can "follow the money".

Projects using earlier versions of ASHRAE 90.1 would technically still be subject to LEED Interpretation 10426 if they do not have a vestibule. Because ASHRAE 90.1-2016 has very similar mandatory air leakage requirements to ASHRAE 90.1-2010 (Section 5.4.3), I could see LEED v4 projects making a case for applying ASHRAE 90.1-2016 Addendum bf in lieu of LI 10426 if they model the proposed design to include the energy associated with the air curtains (fan + heating) and in the baseline to not include the energy associated with the air curtains.

Note: Addendum bf is published as a package of addendas. As such project teams using this would likely have to use all the changes in this package.

https://www.ashrae.org/file%20library/technical%20resources/standards%20...

As LEED Reviewers we don't agree with the LEED Coach. The more stringent envelop requirements are prescriptive measures and should not impact the mandatory provisions. This is really an issue of mandatory provision compliance. Such compliance is rarely enforced by the reviewer but if this was pointed out with reference to 90.1-2019 we would allow it to count toward mandatory provision compliance. Jamy's suggestion is also a good approach. However, in our expereince you do not have to apply all of the changes within a package of addendum changes.

Vestibules came up again. I pulled up this post and happened to notice PNNL's Energy Savings Analysis: ANSI/ASHRAE/IES Standard 90.1-2019 did not study air curtains in lieu of vestibules. 

Appendix A: Addenda Not Quantified in Energy Savings Analysis
Addendum bf
Description of Change: Allows self-closing doors with air curtains as an alternative to vestibules for particular climate zones and building heights.
Discussion: Changed provisions are alternative to the existing and unchanged ones.

I would interpret that as if they are functionally equivalent and not warranting an ECM or such, but who am I?