[Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1 (Return of a Hornet's Nest?)

[David S Eldridge]

First, I feel that the statement that EAC1 methodology "penalizes air barrier suppliers" and "rewards concrete block producers" is completely off-base.  These are not either/or technologies.  There are many other factors going into the selection of these items besides energy performance.  If there is real energy and maintenance savings justification as an investment, then owners will consider it even without contributing to EAC1.  LEED covers many things, but it isn't an exhaustive manual of sustainability.  As well, the LEED process, although growing, still covers only a small fraction of new building projects, regarding Appendix G applicability.  This is an energy modeling forum, so let's focus on the Appendix G part of the discussion.

Specifically for 90.1 energy performance, it isn't a matter of arbitrarily accepting one or the other - we as an energy modeling community have many years of experience and research involved in accurately modeling the heat transfer in envelope components.  The capability of various modeling techniques have been demonstrated to be capable of relatively accurate modeling of the differences between thermal mass and insulation levels for many years, therefore these calculations are included in the standard as a path of calculating energy usage and savings between alternatives.

The modeling software are generally able to predict what would happen due to a given change in level of infiltration.  The modeling improvements need to be made in the area of showing that the calculations are accurate in determining those levels, rather than using a specified reduction.  Does the software available have the needed parameters to model a product such as yours?  On a case-by-case basis you may be able to show that you know all of the needed parameters to make these calculations.  I'm not sure if you could apply these to all projects, and all software packages though.  For instance, do you feel that your product has different effectiveness than other brands?  How would someone capture these differences in efficiency in eQuest or EnergyPlus?  Would it be okay with the USGBC to propose a straight percentage reduction?  What's the starting point for the base case?  How much variability is there in the construction process?

Your input would be welcomed if you offer some expertise in these areas.

You mention a study that shows benefits in many cases for 116 buildings (and common sense would agree with this).  Some focus should be on educating designers to use the strategy and contractors on proper installation, regardless of the "points" that are achieved, and under what conditions the strategy would be most effective.

Just my $0.02.

David

____________________________________________________________________________________________________________________

David Eldridge, PE
LEED(r) AP, HBDP

Grumman/Butkus Associates | 820 Davis Street, STE 300 | Evanston, IL 60201 | Ph: (847) 328-3555, ext 224 | Fax: (847) 328-4550

Energy Consultants and Design Engineers
____________________________________________________________________________________________________________________






From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul Grahovac
Sent: Monday, August 24, 2009 8:55 AM
To: sheffer at energyopportunities.com; bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

I am sure there is just as much baseline for air leakage reduction benefit as there is for the concrete walls and wooden studs that the User's Manual says can be modeled and their energy savings captured for inclusion in the overall modeling results.

I cannot accept that the USGBC and ASHRAE can arbitrarily say reduction in air leakage will not be considered, but that increases in thermal mass energy-savings from using concrete walls or energy benefits from using wooden studs will be used to compute building energy performance.  This obviously rewards concrete block producers and wood stud suppliers and penalizes air barrier suppliers.

I'm reminded of Lord Acton's famous observation:  "Power corrupts, and absolute power corrupts absolutely."  Fortunately, even the power of organizations like ASHRAE and USGBC are subject to some ultimate check.  Such organizations are prohibited by law from arbitrary practices that favor one group over another.  Below are excerpts from the leading United States Supreme Court case on the subject.

Paul Grahovac, LEED AP

American Society of Mechanical Engineers. Inc. v. Hydrolevel Corporation,
456 U.S. 556, 102 S.Ct. 1935, 72 L.Ed.2d. 330
(1982), Supreme Court Justice Blackmun, writing for the majority:

"Furthermore, a standard setting organization like ASME can be rife with
opportunities for anti competitive activity. Many of ASME's officials are
associated with members of the industries regulated by ASME's codes.
Although, undoubtedly, most serve ASME without concern for the interests of
their corporate employers, some may well view their positions with ASME, at
least in part, as an opportunity to benefit their employers. When the great
influence of ASME's reputation is placed at their disposal, the less altruistic of
ASME's agents have an opportunity to harm their employers' competitors
through manipulation of ASME's codes."
ID.., at 571, 102 S.Ct., at 1946.

In American Society of Mechanical Engineers, the U.S. Supreme Court affirmed a jury
verdict that awarded treble damages to the company that was injured by certain members of the
trade organization that had manipulated the trade organization and its role in the industry to set
standards designed to enrich those members' corporation and diminish the ability of its
competitors to fairly compete in the marketplace. In deciding to hold the trade organization
responsible for the actions of its members, the Court explained:

"It is true that imposing liability on ASME's agents themselves will have some
deterrent effect, because they will know that if they violate antitrust laws through
their participation in ASME, they risk the consequences of personal civil liability.
But if, in addition, ASME is civilly liable for the antitrust violations of its agents
acting with apparent authority, it is much more likely that similar antitrust
violation will not occur in the future. "Pressure will be brought on the
organization to see to it that its agents abide by the law." United States v. A&P
Trucking Co., 358 U.S. 121, 126, 79 S.Ct. 203, 207, 3 L.Ed.2d 165 (1958). Only
ASME can take systematic steps to make improper conduct on the part of all its
agents unlikely, and the possibility of civil liability will inevitably be a powerful
incentive for ASME to take those steps. Thus, a rule that imposes liability on the
standard setting organization- which is best situated to prevent antitrust violations
through the abuse of its reputation-is most faithful to the congressional intent that
the private right of action deters antitrust violations."
14:., at 572-573, 102 S.Ct., at 1946.



________________________________
From: Marcus Sheffer [mailto:sheffer at energyopportunities.com]
Sent: Monday, August 24, 2009 8:22 AM
To: Paul Grahovac; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

As I understand it the issue is that the 90.1 Standard does not establish a base line condition for air leakage so no savings can be claimed.  I certainly agree that the savings are real and should be counted.  I know that the Appendix G committee has this issue on their extensive "to do" list.

Marcus Sheffer, Chair - USGBC EA TAG
7group


From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul Grahovac
Sent: Wednesday, August 19, 2009 7:00 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

The National Institute of Standards and Technology (NIST) did an extensive study documenting a greater than 40% natural gas savings and a greater than 25% electricity savings across the nation for building energy consumption if buildings were uniformly constructed with air barrier systems installed.  They evaluated 116 existing buildings and computer modeled several different building types.  The purpose of their study was to provide information to ASHRAE concerning whether it would be desirable to add an air barrier requirement to ASHRAE 90.1.

As a result, I've always thought that Appendix G to ASHRAE 90.1 allows you to change the air leakage rate off the default and onto a rate corresponding to an air barrier installation, so that you could claim LEED points for the corresponding energy savings.  However, an architect at a presentation I did said you could not do that under the LEED and ASHRAE requirements.  (I know the models will do it, because I've done it on the TRANE model and obtained results that support the NIST findings.)

I see in Appendix G that:  "G3.1.2.5. Ventilation.  Minimum outdoor air ventilation rates shall be the same for the proposed and baseline building designs."  However, I searched the document for "outdoor air ventilation" and the phrase occurs only in the context of mechanical systems that are designed to intentionally bring air into the building.  If this section is the basis for concluding that air leakage barriers should be left out of the modeling, then I have trouble understanding why.

Appendix G says that all components of the building are to be modeled as designed.  That would preclude modeling as if an air barrier system did not exist in the design.  It says the baseline building model is to have steel-framed above-grade walls, and it is silent about the design building, but the User's Manual says that if the design building walls are block or cast concrete, then "the mass is credited in the building performance rating method."  Likewise, if the walls are wood stud instead of steel, then the Manual says credit is given for the superior energy performance of wood frame versus steel frame.  The User's Manual states that it:  "Offers information on the intent and application of Standard 90.1."  Given these examples in the Manual based on existing thermal mass energy-saving data and wood-versus-steel stud energy data, it is difficult to conclude that a wall that is constructed with materials meeting the air leakage limits and installation requirements of the Air Barrier Association of America and determined to produce significant energy savings by the NIST study based on those same limits and requirements should be modeled as if it leaked air like a building without an air barrier.

Please let me know what you think, and if you know of any reason why it is not proper to change the air leakage rate through the building envelope in the design model to show the benefit of air barriers.

Thanks,

Paul Grahovac, LEED AP
R-GUARD Air & Water-Resistive Barrier Product Manager
PROSOCO, Inc.
3741 Greenway Circle
Lawrence, Kansas  66046
(785) 830-7355
(888) 376-3417 fax
pgrahovac at prosoco.com<mailto:pgrahovac at prosoco.com>
web site  http://www.prosoco.com/


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