Karen,<br><br>Great job on the letter. I got out my special editor's pen, shook the dust off, and have some suggestions below:<br><br><div>
<p class="MsoNormal">It has come to our attention from a posting on the eQuest
listserv 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 <font color="#cc33cc">(DCV)</font>. We have <font color="#cc33cc">re</font>searched the ASHRAE 90.1 documentation<font color="#cc33cc">,</font> as well as the LEED reference
documentation<font color="#cc33cc">,</font> 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.</p>
</div>
<div>
<p class="MsoNormal">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<font color="#cc33cc">. We think that the requirement for the ventilation rate not to change between the baseline and proposed buildings already limits this possibility, however, and</font> our main concern is that energy modelers be made aware <font color="#cc33cc">that</font>
changes to<span style="color: rgb(204, 51, 204);"> the LEED </span>guidelines <font color="#cc33cc">may be made </font>during the<span style="color: rgb(204, 51, 204);"></span><font style="color: rgb(204, 51, 204);" color="#6633ff"> </font>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. <br></p>
</div>
<div>
</div>
<div>
<p class="MsoNormal">We <font color="#cc33cc">think</font> 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 <font color="#cc33cc">think </font>that any
changes made to EA Credit 1 energy modeling guidelines should be made with
adequate notice to the energy modeling community.</p>
</div>
<div>
<p class="MsoNormal">Thank you for your consideration on this issue,</p><p class="MsoNormal">I would be happy to be a cosigner but since I am not a LEED AP or a BEMP or anything except a PE you may be able to find someone more impressive.<br>
</p><p class="MsoNormal">With respect to James' comment below, I have also modified the occupancy schedule to model DCV. I simply renamed it "DCV Occ Sch", or something like that and applied it only to the space that was using DCV. Easy enough to do and no impact on the mechanical cooling at all. This reminds me of the discussion the other week about using a schedule to reflect lighting W/sf reductions vs, just reducing the W/sf itself. When I have some spare time to mull the costs/benefits of using schedules vs. direct reductions I will. If others have some thoughts I encourage them to share them.</p>
<p class="MsoNormal">The last thing I want to say is that this listserv is great! I guess I'm a real nerd cause I love discussions like this one here about DCV where people have obviously given the matter a lot of thought and feel free to express their opinion, whether popular or not. We are really a lucky group of professionals to have such a resource.</p>
<p class="MsoNormal">Carol<br></p>
</div>
<br><br><div class="gmail_quote">On Tue, Jul 27, 2010 at 9:57 AM, James Hansen <span dir="ltr"><<a href="mailto:JHANSEN@ghtltd.com">JHANSEN@ghtltd.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal"><span style="font-size: 10pt; color: red;">“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.”</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Ron, that’s an interesting statement in itself –
modifying occupancy schedules has an impact on the mechanical cooling (not just
the cooling associated with reduced ventilation air), which isn’t really
fair. Was that approved by GBCI? If so, I guess it’s further
proof that there is still a lot of inconsistency in the review of EAc1. </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Karen, I think your letter does a good job of requesting an official
“ruling” from the USGBC.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: teal;">GHT Limited<br>
</span></b><b><span style="font-size: 11pt;"><span style="color: black;">James Hansen</span></span></b><b><span style="font-size: 11pt; color: black;">, PE,
LEED AP</span></b></p>
<p class="MsoNormal"><b><span style="font-size: 10pt; color: black;">Senior Associate</span></b><b><span style="font-size: 11pt; color: black;"></span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt;"><span style="color: black;">1010 N. Glebe Rd, Suite 200</span></span><span style="font-size: 11pt; color: rgb(31, 73, 125);"></span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt;"><span style="color: black;">Arlington</span><span style="color: black;">, </span><span style="color: black;">VA</span><span style="color: black;"> </span><span style="color: black;">22201-4749</span></span><span style="font-size: 11pt; color: black;"></span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: black;">703-338-5754 (Cell)</span><span style="font-size: 11pt; color: black;"></span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: black;">703-243-1200 (Office)</span><span style="font-size: 11pt; color: black;"></span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: black;">703-276-1376 (Fax)</span><span style="font-size: 11pt; color: black;"></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: teal;"><a href="http://www.ghtltd.com/" target="_blank"><span style="font-size: 10pt; color: blue;">www.ghtltd.com</span></a></span></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(49, 132, 155);"> </span></b></p>
</div><div class="im">
<div>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;"> </span></p>
<div>
<div class="MsoNormal" style="text-align: center;" align="center"><span style="font-size: 10pt;">
<hr align="center" width="100%" size="1">
</span></div>
<p class="MsoNormal" style="margin-bottom: 12pt;"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> Karen Walkerman
<<a href="mailto:kwalkerman@gmail.com" target="_blank">kwalkerman@gmail.com</a>><br>
<b>To:</b> equest-users <<a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a>><br>
<b>Sent:</b> Tue, July 27, 2010 12:10:27 PM<br>
<b>Subject:</b> [Equest-users] Demand Controlled Ventilation and EA Credit 1</span></p>
<div>
<p class="MsoNormal">All,</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">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.</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">Thanks,</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">--</p>
</div>
<div>
<p class="MsoNormal">Karen</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">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.</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">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.</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">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.</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">Thank you for your consideration on this issue,</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal">--</p>
</div>
<div>
<p class="MsoNormal">Karen Walkerman</p>
</div>
<div>
<p class="MsoNormal">Second Law</p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
</div>
</div>
</div>
<p class="MsoNormal"> </p>
</div></div>
</div>
<p align="left"><font size="2"><font face="Tahoma"><font color="#0000ff">
<hr>
</font></font><font color="#0000ff"><font color="#000000"><font face="Arial">The information contained in this communication is confidential, may be privileged, and is intended only for the use of the addressee. It is the property of GHT Limited. Unauthorized use, disclosure or copying of this communication or any part thereof is strictly prohibited and may be unlawful. If you have received this communication in error, please notify me immediately by return e-mail or by e-mail to </font><a href="mailto:ght@ghtltd.com" target="_blank"><font face="Arial">ght@ghtltd.com</font></a><font face="Arial">, and destroy this communication and all copies thereof, including all attachments. Thank you.</font></font><font color="#000000" face="Tahoma"></font></font></font></p>
<br>_______________________________________________<br>
Equest-users mailing list<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org" target="_blank">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a><br>
<br></blockquote></div><br><br clear="all"><br>-- <br>Carol Gardner PE<br>
<div style="visibility: hidden; display: inline;" id="avg_ls_inline_popup"></div><style type="text/css">#avg_ls_inline_popup { position:absolute; z-index:9999; padding: 0px 0px; margin-left: 0px; margin-top: 0px; width: 240px; overflow: hidden; word-wrap: break-word; color: black; font-size: 10px; text-align: left; line-height: 13px;}</style>