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<p class="MsoPlainText">Ben,<o:p></o:p></p>
<p class="MsoPlainText">I would first go back to your base model and examine what percentage of the building load is actually coming from the glass. Your LS-C reports will give you your peak load components, and LS-F will give you your Monthly load components
- a better indicator of overall energy usage. <o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Keep in mind this doesn't factor in ventilation loads. You will need to look at the SS-D report to get an overall picture of the loads your system sees, and work backwards from that to get a picture of what the ventilation component
is. So for example - if your LS-C shows a peak cooling load of 1000kBTU/hr and your SS-D Shows 1500 kBTU/hr, then your ventilation loads will be 500 kBTU/hr.
<b><span style="color:red">[eQUEST users - please correct me if I'm wrong here]<o:p></o:p></span></b></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">So if your glass conductance + Solar is 15% f the overall load, then a 5% savings is pretty significant, however, if its 50% of the load, then there might be a problem with your model.
<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Hope this helps<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoNormal" style="text-autospace:none"><b><span style="font-size:9.0pt;
font-family:"Arial","sans-serif";color:gray">Vikram Sami</span></b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:gray">, LEED AP<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.0pt;
font-family:"Arial","sans-serif";color:gray">Sustainable Design Analyst<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.0pt;
font-family:"Arial","sans-serif";color:gray">1382 Peachtree St. NE, Atlanta, GA 30309<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:9.0pt;
font-family:"Arial","sans-serif";color:gray">t: 404-443-7462 f:
</span><span lang="ES" style="font-size:9.0pt;font-family:"Arial","sans-serif";
color:gray">404.892.5823 </span><span style="font-size:9.0pt;
font-family:"Arial","sans-serif";color:gray"> e: vikram.sami@perkinswill.com </span><a href="http://www.perkinswill.com/"><span style="font-size:9.0pt;font-family:
"Arial","sans-serif";color:gray;text-decoration:none">www.perkinswill.com</span></a><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:gray"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:3.0pt;text-autospace:none"><b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:gray">Perkins+Will.</span></b><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:gray">
</span><span style="font-size:9.0pt;font-family:"Arial","sans-serif";color:#ADD425">Ideas + buildings that honor the broader goals of society</span><span style="font-size:
9.0pt;font-family:"Arial","sans-serif";color:green"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoPlainText">-----Original Message-----<br>
From: equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] On Behalf Of Ben Pressman<br>
Sent: Tuesday, August 24, 2010 12:21 PM<br>
To: equest-users@lists.onebuilding.org<br>
Cc: Justin Murray<br>
Subject: [Equest-users] window replacement<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"> Thanks, Carol, for your quick response. I think my question might have
<o:p></o:p></p>
<p class="MsoPlainText">been too specific. My baseline model agrees to within 5% of the actual
<o:p></o:p></p>
<p class="MsoPlainText">gas and electric bills for the building. The exterior walls, especially
<o:p></o:p></p>
<p class="MsoPlainText">north and south elevations, are about 30% windows by area. By replacing
<o:p></o:p></p>
<p class="MsoPlainText">single-paned windows with double-paned, modern windows, I am expecting
<o:p></o:p></p>
<p class="MsoPlainText">about a 23% reduction in energy usage based on simple heat equation
<o:p></o:p></p>
<p class="MsoPlainText">estimations. eQuest is only returning a 5% savings. I suspect I am not
<o:p></o:p></p>
<p class="MsoPlainText">defining the replacement windows correctly, but it seems there must also
<o:p></o:p></p>
<p class="MsoPlainText">be a problem with how eQuest is calculating my heating loads through the
<o:p></o:p></p>
<p class="MsoPlainText">windows. I specified the windows' estimated percent wall area, and also
<o:p></o:p></p>
<p class="MsoPlainText">drew custom windows everywhere to match what the actual building looks
<o:p></o:p></p>
<p class="MsoPlainText">like. What is the best way to approach solving this problem?<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Thanks again,<o:p></o:p></p>
<p class="MsoPlainText">Ben<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">_______________________________________________<o:p></o:p></p>
<p class="MsoPlainText">Equest-users mailing list<o:p></o:p></p>
<p class="MsoPlainText">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org<o:p></o:p></p>
<p class="MsoPlainText">To unsubscribe from this mailing list send a blank message to EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
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