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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Unfortunately the IPLV is of little or no
value when setting up chiller curves. To set up the EIR-fT and EIR-fPLR curves
requires more data points than is available in the IPLV. IPLV basically
describes a two-dimensional curve, whereas the actual chiller performance is
3-dimensional. The IPLV assumes that condenser temperature drops as
chiller load drops, but this is not necessarily the case. Examples:<o:p></o:p></span></font></p>
<ol start=1 type=1>
<li class=MsoNormal style='color:navy;mso-list:l0 level1 lfo1'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial'>A
cooling tower has a fixed setpoint of 85°F. Or, the condenser
water source is a lake or river. In this case condenser temperature
does not drop as chiller load drops.<o:p></o:p></span></font></li>
<li class=MsoNormal style='color:navy;mso-list:l0 level1 lfo1'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial'>A
large plant has 3 chillers utilizing a single cooling tower. The
current load is 33% of design, so one chiller is running at full load.
IPLV assumes an entering condenser temperature of 85°F (full load),
whereas the cooling tower is actually lightly loaded and can achieve a smaller
approach to wetbulb.<o:p></o:p></span></font></li>
<li class=MsoNormal style='color:navy;mso-list:l0 level1 lfo1'><font size=2
color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial'>The
building is on the West coast (low wetbulb) vs. Florida (high wetbulb). Tower
performance and condenser temperature vs. load is entirely different in
these two climates.<o:p></o:p></span></font></li>
</ol>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>So while IPLV may be an interesting figure
for rough comparisons, it is insufficient for an hourly simulation program. This
is true for all energy simulation programs, not just eQUEST. Ultimately this
issue will need to be addressed by standards organizations such as ARI, and/or
equipment manufacturers.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Steve Gates<br>
eQUEST development team<o:p></o:p></span></font></p>
<div>
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text-align:center'><font size=3 face="Times New Roman"><span style='font-size:
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<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
bldg-sim-bounces@lists.onebuilding.org
[mailto:bldg-sim-bounces@lists.onebuilding.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Aulbach, John<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 19, 2007
4:04 PM<br>
<b><span style='font-weight:bold'>To:</span></b> bldg-sim@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Bldg-sim] Chiller part
load raw data points into eQuest</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>Hi Gang:<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>I have a part
load curve from a chiller manufacturer for input into eQuest. Unfortunately, it
has condenser temperature relief (this is an evaporatively cooled chiller, so
we are speaking of dry bulb outdoor temperatures.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>Normally, I ask
for a part load curve with a constant condenser temperature, and let eQuest
modify this curve based on changing outdoor air conditions.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>But now I have
the IPLV data and it deals with condenser relief. I DO have at what part load a
particular condenser temperature occurs (complimenting this IPLV data.<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>Can anyone help
me?<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
color=blue face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:blue'>John R. Aulbach, PE, CEM</span></font><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><em><i><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>Project
Manager</span></font></i></em><font size=2 face=Tahoma><span style='font-size:
10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
color=blue face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:blue'>Nexant, Inc</span></font><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>.</span></font><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>100 North Barranca,
Suite 820</span></font><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>West Covina, CA
91791 USA</span></font><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Phone: 626-430-9054</span></font><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Fax: 626-430-9060</span></font><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>email: <a
href="mailto:jaulbach@nexant.com" title="mailto:jaulbach@nexant.com">jaulbach@nexant.com</a></span></font><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><o:p></o:p></span></font></p>
<div>
<p class=MsoNormal style='margin:0in;margin-bottom:.0001pt'><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <o:p></o:p></span></font></p>
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