Hi,
Can anyone please check if my understanding is correct, which is on the relationship between LEED V.4.1 and ASHRAE90.1 2016? Below is how I understand;
First of all, LEED-NC EAp2 of v.4 and v.4.1 require the ASHRAE90.1 Mandatory Provision. ASHRAE90.1 has continuous air barrier requirement to meet, which is same 2010 and 2016 version. Ver.2016 adds Whole Building Testing with pass/fail criteria, which ver.2010 did not require. There are 3 ways to meet the requirements in ver.2016,
Whole Building Testing (a): conduct a blower door test and prove air-tightness, or check material (b) , or check assembly (c).
(It is obvious that these 3 ways are not equivalent, air can leak from connection between perfect-airtight-assemblies. There established several standards for (a), but not any manuals to check the integrity of connection for (b) and (c) )
LEED v.4.1 deals with the three as equivalent options. LEED v.4.1 gives 2 points to the test as EAc1 option2, which is same as v.4.
It means the only change is specification of pass/fail criteria, 0.4 cfm/ft2 0.3in wc. Is it right?
I hope someone correct my idea and say that LEED v.4.1 deals with the 3 options not equally.
Jamy Bacchus
Associate PrincipalME Engineers
20 thumbs up
January 24, 2020 - 1:12 pm
There are a few items here which cross a few EA prereqs and credits. Yes, EAp2 Min Energy Perf (which is the topic where this LEEDuser comment was posted) will require compliance with Section 5.4.3.1.3 as you've noted using one of three acceptable methods. For this prereq, any of those 3 (albeit unequal) methods is fine.
Looking at EAc2 if you choose to test per ASTM E779, then you can take credit for any reduced air leakage in your Appendix G proposed model and keep the baseline at the minimum compliant level.
Note: there other building enclosure items in EAp1 & EAc1, which you appear to be aware of.
Takashi Hasegawa
3 thumbs up
January 28, 2020 - 7:58 pm
Thank you very much for your reply, I have understood EAp2 deals with 3 methods equally.
It is possible to get 2 points if BECx is performed according to EAp1 and EAc1. In this case also, anyone of the 3 methods is acceptable.
So, LEED v.4.1 not differs from v.4, for EAp1, EAp2 and EAc1.
From another point of view, LEED v4.1 is different from v.4 dramatically. Only v.4.1 reffers to ASHRAE 90.1. It is possible to gain plural credits via EAc2 according to the degree of air leakage rate reduction. And it is possible to apply 0.4cfm75 into baseline, which is minimum requirement of ASHRAE. It is permitted for blower door testing only (if performed as ASTM E779) .
Is it right?
It should be easy and profitable for projects in North America, where requirement of Appendix G is not difficult to be satisfied. We are afraid it might be not so easy for other countries including our Japan.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5868 thumbs up
January 29, 2020 - 9:53 am
LEED 2009 and V4 projects are also allowed to use the baseline value you mention and claim savings for infiltration.