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<p class=MsoNormal><span style='color:#1F497D'>The outputs of the chiller-PLR
curve is not actually an efficiency, but a multiplier on the absolute energy
use of the chiller. As the PLR decreases, the chiller will obviously use less
energy, albeit less efficiently. Once you realize that the PLR curve is
spitting out kW numbers and not kW/ton, it should make more sense. <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><span style='font-family:"Franklin Gothic Demi","sans-serif";
color:navy'>Robby Oylear,</span><span style='font-family:"Franklin Gothic Demi","sans-serif";
color:#004080'> </span><span style='font-family:"Franklin Gothic Demi","sans-serif";
color:navy'>LEED</span><span style='font-size:8.0pt;font-family:"Franklin Gothic Demi","sans-serif";
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style='font-family:"Franklin Gothic Demi","sans-serif";color:#004080'><o:p></o:p></span></p>
<p class=MsoNormal><i><span style='font-size:10.0pt;color:navy'>Mechanical
Engineer<o:p></o:p></span></i></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:navy'>direct:
206.788.4571<o:p></o:p></span></p>
<p class=MsoNormal><i><span style='font-size:10.0pt;color:navy'>cell:
206.354.2721<o:p></o:p></span></i></p>
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color:#1F497D'><a href="http://www.rushingco.com/"
title="blocked::http://www.rushingco.com/"><span style='font-size:7.5pt'>rushingco.com</span></a></span><span
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
equest-users-bounces@lists.onebuilding.org
[mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Todd
Lagus<br>
<b>Sent:</b> Thursday, April 02, 2009 9:06 AM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> [Equest-users] Chiller Part Load Curves<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Hello All,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I searched the archives and found some mention of chiller
curves, but not much dealing with this particular issue. I understand the
concept of the three different ratios for the condenser water temperature, PLR
and dT, and capacity curve. What concerns me is the part load
curve. I was doing some investigation and put the DOE2 default
coefficients into an excel file (attached) for a water cooled, centrifugal
hermetic chiller. Only changing the part load ratio, the kW/ton of the
chiller decreases dramatically, which isn’t correct. Logic tells me that
decreasing the condenser water temperature should increase efficiency, and
decreasing the part load ratio should decrease efficiency. Am I missing
something here? Has anyone run into this issue or corrected it?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='text-autospace:none'><b><span style='font-size:10.0pt;
font-family:"Arial","sans-serif";color:#005480'>Todd Lagus, EIT<o:p></o:p></span></b></p>
<p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;
font-family:"Arial","sans-serif";color:#807F83'>Mechanical Engineer<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;
font-family:"Arial","sans-serif";color:#807F83'>Sebesta Blomberg <br>
sebesta.com</span><span style='font-size:8.0pt;font-family:"Arial","sans-serif"'>
<span style='color:#807F83'>| P 651.634.7236 | F 651.634.7400<o:p></o:p></span></span></p>
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