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<DIV id=idOWAReplyText52621 dir=ltr>
<DIV dir=ltr><FONT face=Arial color=#000000 size=2>James,</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>I disagree with the claim that R-value has little effect. Look at the number of all-glass buildings in northern climate, and I'll bet they barely meet LEED or ASHRAE energy pre-reqs. </FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>However, there is definitely a law of diminishing return at work. That is, after a certain R-value, additional insulation has very little effect. The curve of R-value vs. energy savings flatlines. In our case in Toronto, this happens beyond R-20 walls and R-30 roofs typically.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial size=2>The other thing to keep in mind is the type of building. Offices are very much dependant on skin losses, but hospitals for example are dominated by ventilation loads and envelope losses are almost insignificant by comparison.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>As for your question on CO2 control, our experince has shown that you need a very fine resulution to get any benefit. That is for a mixed-air system, you typically need one sensor per box/damper, so that you're not over-ventilating the rest as you pointed out. But mixed-air system are bad anyway so CO2 control is a marginal improvement. You get the most bang if you de-couple the ventilation from the heating/cooling by using compartmental system such as fan-coils or distributed heat-pumps. Why these systems aren't more popular in our market is beyond me...</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Luka Matutinovic, B.A.Sc., LEED AP</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>Halsall Associates Ltd.</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> bldg-sim-bounces@lists.onebuilding.org on behalf of James Geers<BR><B>Sent:</B> Wed 14/01/2009 1:09 PM<BR><B>To:</B> bldg-sim@lists.onebuilding.org<BR><B>Cc:</B> bldg-rate@lists.onebuilding.org<BR><B>Subject:</B> [Bldg-sim] CO2 sensors and outside air reduction. LEED forschools &ASHRAE 90.1-2004<BR></FONT><BR></DIV>
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<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Previous posts have confirmed my suspicions that increasing the R-value of walls and roofs has little to no effect on energy performance, due to the outside air requirements. </SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">This raises a few questions:</SPAN></FONT></P>
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<P class=MsoNormal style="TEXT-INDENT: 0.25in"><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">1. What is the most effective way to use CO2 sensors to dramatically reduce the outside air requirements?</SPAN></FONT></P>
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<LI class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Is it permissible to vary the CFM between the base case and design case in the ASHRAE 90.1-2004 Appendix G model, and consequently in the LEED template?</SPAN></FONT> <FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT></LI></OL>
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<LI class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">What is the most effective way to use CO2 monitoring in a building with 40 classrooms and other large spaces. If one sensor is triggered, won’t the entire zone get fresh air and defeat the energy savings?</SPAN></FONT> <FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT></LI></OL>
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<LI class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If every classroom has a sensor, does any one have experience with the replaceable / Mail in sensors to assure their accuracy.</SPAN></FONT> <FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT></LI></OL>
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<LI class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If I model this in Equest, do I need a zone for every classroom.</SPAN></FONT> <FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT></LI></OL>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Thank you for any feed back.</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Tahoma color=navy size=4><SPAN style="FONT-SIZE: 13.5pt; COLOR: navy; FONT-FAMILY: Tahoma">James F. Geers</SPAN></FONT><FONT face=Tahoma><SPAN style="FONT-FAMILY: Tahoma"></SPAN></FONT></P>
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<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">SFA Architects</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">300 West Fourth Street</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">Cincinnati</SPAN></FONT></B><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">, Ohio 45202</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">513.721.0600</SPAN></FONT></B><B><FONT face=Tahoma color=navy><SPAN style="FONT-WEIGHT: bold; COLOR: navy; FONT-FAMILY: Tahoma"> </SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">513.721.0611 (fax)</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Tahoma color=navy size=4><SPAN style="FONT-SIZE: 13.5pt; COLOR: navy; FONT-FAMILY: Tahoma">James F. Geers</SPAN></FONT><FONT face=Tahoma><SPAN style="FONT-FAMILY: Tahoma"></SPAN></FONT></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">Registered Architect</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
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<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">SFA Architects</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">300 West Fourth Street</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">Cincinnati</SPAN></FONT></B><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">, Ohio 45202</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">513.721.0600</SPAN></FONT></B><B><FONT face=Tahoma color=navy><SPAN style="FONT-WEIGHT: bold; COLOR: navy; FONT-FAMILY: Tahoma"> </SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
<P class=MsoNormal><B><FONT face=Tahoma color=navy size=2><SPAN style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Tahoma">513.721.0611 (fax)</SPAN></FONT></B><B><FONT face=Tahoma><SPAN style="FONT-WEIGHT: bold; FONT-FAMILY: Tahoma"></SPAN></FONT></B></P>
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