[Bldg-rate] LEED NC v2.2 EAc2

[David S Eldridge]

Mark, see if you have an on-line subscription to the reference guide and the $88,308 number is changed in the current version to $85,669.

The problem is that on p191 in your reference guide the values used aren't consistent - the $88k number isn't compatible with the example which was revised to use $85,669 as the EAC1 + renewable total, instead of $88,308.

If you enter the values into the LEED template, it is 3.1%.

The numbers should be:

Building without PV:             $85,669  < - aka "building annual energy cost"

Building with PV:                   $83,030  < - used as the basis for EAC1 points aka "Proposed Building Performance"

PV Contribution:                    $2,639   < - aka Renewable Energy Cost or "REC")

In the current reference guide the equation #1 is:  %Renewable =  REC / (Proposed Building Performance + REC)

In the current reference guide the equation #2 is:  %Renewable =  REC / Building Annual Energy Cost


Anyway, to make a long story short - yes, they have revised the reference guide, $88,308 is not appearing anymore.  This should be consistent with your LEED template for EAC2 which will output 3.1%.

David



David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, HBDP
Grumman/Butkus Associates


From: Kevin Kyte [mailto:KKyte at watts-ae.com]
Sent: Thursday, April 08, 2010 11:36 AM
To: Zoeteman, Mark R.; David S Eldridge
Cc: bldg-rate at lists.onebuilding.org
Subject: RE: LEED NC v2.2 EAc2

Does this have anything to do with simulation engines in general when computing identical files yet displaying mixed results on different terminals?  As far as I know this has been known to happen.

________________________________
From: bldg-rate-bounces at lists.onebuilding.org [mailto:bldg-rate-bounces at lists.onebuilding.org] On Behalf Of Zoeteman, Mark R.
Sent: Thursday, April 08, 2010 9:17 AM
To: David S Eldridge
Cc: bldg-rate at lists.onebuilding.org
Subject: Re: [Bldg-rate] LEED NC v2.2 EAc2

David,
Thank you for your response. Yes I agree that Reference Guide lists answers of 3.08% on page 191 and 3.1 % on 201. However when you plug in the numerical values into page 191 equation, result is actually 2.99%. The two equations are different and yield different results, but the Reference Guide lists same answer.
Mark

From: David S Eldridge [mailto:DSE at grummanbutkus.com]
Sent: Wednesday, April 07, 2010 7:18 PM
To: Zoeteman, Mark R.
Subject: RE: LEED NC v2.2 EAc2

I think your reference guide edition may be out of date, mine has 3.08% (rounded to 3.1% in EAC2) in both locations using your second example as the basis.

The example in your reference guide must have incorrectly used $88,308 as the total energy cost instead of $85,669.  This seems to be corrected now.

David



David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, HBDP
http://www.grummanbutkus.com
Grumman/Butkus Associates


From: bldg-rate-bounces at lists.onebuilding.org [mailto:bldg-rate-bounces at lists.onebuilding.org] On Behalf Of Zoeteman, Mark R.
Sent: Wednesday, April 07, 2010 3:14 PM
To: bldg-rate at lists.onebuilding.org
Subject: [Bldg-rate] LEED NC v2.2 EAc2

Question about EAc2 On-Site Renewable Energy:

The v2.2 Reference Guide indicates:

In EAc1 example on page 191
Percent Renewable = Site-Generated Renewable/(Proposed Building Performance + Site-Generated Renewable)
3.0% = $2,639/$88,308

In EAc2 text in top right section of page 201
Percent Renewable = Site-Generated Renewable/Proposed Building Performance
3.1% = $2,639/$85,669


The value indicated in both places is 3.08 or 3.1%. However, when you plug in values for EAc1 example, result is 3.0%, which agrees with the example entered into a EAc2 Template.

Has anyone investigated this discrepancy with USGBC or GBCI?

Mark Zoeteman, FTC&H

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