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<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2>David,</FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>I
think you are confusing two different issues. The rated/design
chiller conditions used to calculate the EIR and the operation of the
CW loop are somewhat independent so your concern may be
unecessary. I think this will help answer your
question. </FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>First:
</FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>When
you define the design or rated conditions of the chiller you are giving eQuest
the information it needs to use the custom bi-quadratic performance curves that
describe how chiller power (EIR) changes for different operating
conditions. Rated conditions refer to ARI conditions of 44F LCHWT and
85F ECWT, while the design conditions refer to the actual chiller design (Should
only be used for chillers designed at non-ARI conditions). When you
enter the chiller EIR and capacity you need to make sure that they match
the chillers rated or design conditions that you enter.
</FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2>Second: </FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>The
operation of the circulation loops (assuming a reset strategy is being
used) is dependent on the values you enter for COOL-SETPT-T,
COOL-SETPT-CTRL, MAX-RESET-T and MIN-RESET-T and not the chiller design/rated
conditions. </FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>The
important thing in your case is that if your chiller is designed to operate at
low CW temperatures you probably want to create your own chiller performance
curves. In my experience the default curves don't give good
results when the CW temp is that low (55F-65F especially at full
load) because they are intended for chillers operating much closer to rated
ARI conditions. </FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff size=2>The
best way to check whether your data is good is to run an hourly report on the
chiller and then compare whether the corrected EIR for certain ECWT and LCHWT
conditions match the chiller manufacturer's rated performance at those same
conditions.</FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2>MIke</FONT></SPAN></DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006></SPAN><SPAN class=223544411-12062006><FONT
face=Arial color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=223544411-12062006></SPAN><SPAN lang=en-us><B><FONT face=Arial
size=2>Michael Tillou, PE<BR>etc Group, Inc.<BR>PO Box 7, Williamstown, MA
01267<BR>ph. (413) 458-9870 fx. (413) 458-9875<BR></FONT><FONT face=Arial
color=#000000 size=2>www.etcgrp.com</FONT><BR></DIV></B></SPAN>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B>
BLDG-SIM@GARD.COM [mailto:BLDG-SIM@GARD.COM] <B>On Behalf Of </B>Kenny,
David<BR><B>Sent:</B> Friday, June 09, 2006 4:36 PM<BR><B>To:</B>
BLDG-SIM@GARD.COM<BR><B>Subject:</B> [BLDG-SIM] EQUEST: CW Temperature and
Chiller Performance<BR><BR></FONT></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I am attempting to model the
chiller performance benefit associated with reducing CW temperature.
However, I am running into trouble. The minimum CW loop temperature is
defined at 55 degF. The return temperature is 65 degF. However,
eQuest is using a temperature of 70 degF to calculate chiller
performance. The loop never gets above 65 degrees, so how is this
possible? I can not find a location in the software where the entering
CW temperature has been defined as 70 degF.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Any and all advice is
appreciated!<o:p></o:p></SPAN></FONT></P></DIV><PRE>
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