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<DIV>Hi Karen:</DIV>
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<DIV>I would suggest that you include the original GBCI "Clarification Required" comment and their technical advice within the body of your letter. Then, state the root issue and suggested resolution. This way LEED will know the specific issue that raised this concern.</DIV>
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<DIV>With regard to the specific LEED comment that started this debate; the LEED reviewer may be "wrong" or "testing" the modeler. I've responded to some LEED review comments with an explanation of the models and their final review accepted the models as originally submitted. </DIV>
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<DIV>In this case, it may make sense to e-mail GBCI with the explanation before submitting the EAc1 template for final review. They allow you to submit questions, which they then forward to the review team for further clarification. I think if it's stated that the proposed & baseline design ventilation rates are the "....same, as required by LEED, page, verse, etc..." and the DCV credit is "....taken utilizing a different occupancy schedule between the two models, as required by LEED, page, verse, etc..."; then the LEED reviewer will either accept this or will have to provide a further explanation of what they now require. Especially if you also ask them to send you the LEED requirement for utilizing the ASHRAE 62.1 minimum where-ever DCV is used; instead of utilizing the same rates between the baseline and proposed as documented in the LEED reference manual, page.....</DIV>
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<DIV>Each model that I've done for LEED utilizes the same ventilation rates between the proposed and design; whether it was ASHRAE 62.1 or IMC 2003; however, the occupancy schedules changed in spaces where DCV was installed.</DIV>
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<DIV>Having said all this, I've never worked on a project where an Owner has thought it was a good "energy-efficient / green" idea to provide more outdoor ventilation than required by code (the increased ventilation point); especially in a space where the engineer would require DCV to make sure the space is not over ventilated. </DIV>
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<DIV>Hope this helps.<BR> </DIV>
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<DIV><FONT size=1 face=verdana><STRONG>Ron Lamarre, AIA, NCARB</STRONG></FONT></DIV>
<DIV><FONT face=verdana><FONT size=1>Architect - <STRONG>LEED AP BD+C</STRONG></FONT></FONT></DIV>
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<DIV><SPAN style="FONT-FAMILY: verdana; FONT-SIZE: 10px" class=Apple-style-span><SPAN style="FONT-WEIGHT: bold" class=Apple-style-span>Design + Energy Modeling + LEED Administration</SPAN></SPAN><BR></DIV></DIV></DIV></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Karen Walkerman <kwalkerman@gmail.com><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> equest-users <equest-users@lists.onebuilding.org><BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Tue, July 27, 2010 12:10:27 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> [Equest-users] Demand Controlled Ventilation and EA Credit 1<BR></FONT><BR>
<DIV>All,</DIV>
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<DIV>below is a draft letter to the EA Credit 1 TAG chair. I welcome any edits, or critiques, and if anyone would like to be a co-signer of the letter, please let me know.</DIV>
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<DIV>Thanks,</DIV>
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<DIV>--</DIV>
<DIV>Karen</DIV>
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<DIV>It has come to our attention from a posting on the eQuest list-serve that a fellow energy-modeling professional has been asked to model proposed design and baseline design ventilation rates differently where the proposed design model utilizes demand controlled ventilation. We have searched the ASHRAE 90.1 documentation as well as the LEED reference documentation and consistently find the requirement that baseline ventilation rates be modeled the same as the proposed design, and that credit can be taken for demand controlled ventilation.</DIV>
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<DIV>We understand that large energy savings can be gained from demand controlled ventilation and that in certain cases, 'gaming' of the system could result in abnormally high ventilation rates for the baseline design, while the DCV system keeps ventilation rates low in the proposed design, however, our main concern is that energy modelers are being made aware of changes to guidelines during the design review process. At this stage, the energy modeler has already completed a significant amount of work in preparing the proposed and baseline design energy models, and all associated documentation. Changing the baseline design ventilation rates requires re-modeling of the building and increases the likelihood that the project will have to challenge a 'rejected' result if the LEED reviewer is not satisfied with the energy modeler's response and modeling changes.</DIV>
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<DIV>We feel that it may be time to develop modeling guidelines for demand controlled ventilation, and that these guidelines should be developed, released, and required in a similar fashion to the district energy guidelines published by LEED for NC 2.2 Furthermore, we feel that any changes made to EA Credit 1 energy modeling guidelines should be made with adequate notice to the energy modeling community.</DIV>
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<DIV>Thank you for your consideration on this issue,</DIV>
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<DIV>Karen Walkerman</DIV>
<DIV>Second Law</DIV>
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