[Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

Paul Grahovac paul.grahovac at prosoco.com
Tue Aug 25 10:43:01 PDT 2009


Sam Mason

Atelier Ten

 

6 derives from 1 -5.

 

7 is from the person who submitted the change proposal.

 

Paul Grahovac, LEED AP

 

________________________________

From: Sam Mason [mailto:sam.mason at atelierten.com] 
Sent: Tuesday, August 25, 2009 12:35 PM
To: Paul Grahovac; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

 

Paul,

Where did you get your information regarding number 6 and 7?

 

Sam

 

--

Sam Mason

Atelier Ten

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Paul
Grahovac
Sent: Tuesday, August 25, 2009 11:14 AM
To: David S Eldridge; bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1

 

1.       Recent posts to this listserv show that air leakage reduction
is successfully modeled in the UK.

 

2.       "The LEED point system drives designers to reduce the HVAC
system down to the optimal level."  US Green Building Council LEED
training, May 27, 2004, Dallas, Texas.

 

3.       Melding the data from across the US, air barriers would reduce
building natural gas consumption by greater than 40% and electrical
consumption by greater than 25%.  National Institute of Standards and
Technology, "Investigation of the Impact of Commercial Building Envelope
Airtightness on HVAC Energy Use, NISTIR 7238.

 

4.       Air barriers, if modeled under LEED, would reduce HVAC
construction costs.

 

5.       "There are barriers to implementation of radiant systems in
North America. One is that engineering fees are based on a percentage of
the mechanical and electrical construction budget. The lower the cost of
these systems, the lower the engineer's fee."  Geoff McDonell, P.E.,
senior mechanical engineer in the Burnaby, British Columbia, office of
Earth Tech's Global Facilities and Infrastructure division.

http://www.facilitiesnet.com/hvac/article/Windows-Pave-Way-For-HVAC-Inno
vation--1476  

 

6.       ASHRAE engineers have a financial incentive not to allow air
leakage reduction to enter into LEED point calculations.

 

7.       A change proposal to allow modeling of air leakage reduction
has been pending with the ASHRAE 90.1 simulation group for five months
without any action - and without any hope of action in the future.

 

Paul Grahovac, LEED AP  

 

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of David S
Eldridge
Sent: Monday, August 24, 2009 1:49 PM
To: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Air leakage, LEED, and Appendix G of ASHRAE 90.1
(Return of a Hornet's Nest?)

 

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

web site  http://www.prosoco.com/

 

 

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