Reader’s note: Three more posts on the LEED certification challenge.
If you have taken a look at the Northland Pines High School LEED certification challenge documents, you know that the documents are extremely technical. I am not an engineer but I will share with you some of the more interesting parts of the documents that caught my attention.
Taylor Engineering was retained by the United States Green Building Council (USGBC) to review the challenge allegations. I was immediately drawn to the first substantive paragraph of the Taylor Engineering report:
"While I disagree with most of the complainants’ claims, there were several violations of Standard 62.1 and Standard 90.1 requirements in the design as originally documented. As such, the original design did not meet Indoor Environmental Quality (EQ) Prerequisite 1 and Energy and Atmosphere (EA) Prerequisite 2 of LEED NC version 2.1. However, based on follow-up documentation provided by the design team in response to our comments, I feel the project provides a sufficient level of compliance with these Standards and hence the LEED prerequisites. While I am not fully confident the project merits all of the EA Credit 1 Enhanced Energy Performance points awarded to it, the design team diligently responded to several rounds of comments based on our detailed review of the DOE-2.2 simulations and it appears that they reasonably followed the modeling rules established by ASHRAE Standard 90.1. Hence I accept their EA Credit 1 claim of 7 points."
The most important statement to me in the preceding paragraph is that the original design did not meet the LEED requirements: "the original design did not meet Indoor Environmental Quality (EQ) Prerequisite 1 and Energy and Atmosphere (EA) Prerequisite 2 of LEED NC version 2.1." After reading this paragraph, I have many unanswered questions:
- What additional documentation was provided – "the design team diligently responded to several rounds of comments" – to satisfy Taylor Engineering?
- How can follow-up documentation ensure that a project is in compliance with ASHRAE standards and LEED prerequisites when it was determined that there were violations in the original design?
- What are the standards for LEED certification? Is "diligently" responding to comments and "reasonably" following ASHRAE energy modeling rules enough?
The remainder of the Taylor Engineering report highlights responses to each of the LEED challenge allegations. Much of the challenge focused on violations of ASHRAE Standard 90.1, which is essentially an energy modeling standard. One response in particular drew my interest, not based on substance, but because of the disclosure of revised energy models:
"Allegation: Violation of Standard 90.1-1999 6.2 Mandatory Provisions (page 18). The complaint says the chiller does not meet minimum requirements. Independent consultant review comments: Per Table 6.2.1C of the 1999 version, the minimum COP at ARI conditions is 2.8 and the minimum IPLV is 2.8. The chiller schedule on H1.1 shows a COP of 2.9. It is not clear from the schedule if this is at ARI or design conditions. The installed chiller per submittals has an ARI EER of 2.81. The IPLV is not scheduled, but if the full load efficiency is 2.8, it is almost certain that the IPLV will be higher. Thus the chiller does meet Standard 90.1-1999. (Note that the chiller efficiency in the energy model, according to EAp2 documentation, has a COP of 3.0, which is not consistent with the equipment schedule. This was corrected in a revision to the energy models starting with the version dated December 10, 2009 that USGBC requested to fix this and other inconsistencies between the model of the proposed design and the actual design.) No apparent violation."
Again, I am not an engineer. From these descriptions, I understand that after the school’s LEED certification was challenged, the USGBC determined that the energy modeling was inadequate and requested revisions. Based on these revised energy models, Taylor Engineering and the USGBC determined the school was reasonably in compliance with LEED.
Do I have that right?
Photo credit: nielsvk