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<DIV dir=ltr align=left><SPAN class=707430001-20122007><FONT face=Arial
color=#0000ff size=2>So I cannot "reverse engineer" a part load curve that uses
condenser water relief in calculating the points, knowing what condenser temps
are used at what part load point (100%, 75%, 50%, etc)
???</FONT></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> Steven Gates [mailto:steve.gates@doe2.com]
<BR><B>Sent:</B> Wednesday, December 19, 2007 4:57 PM<BR><B>To:</B> Aulbach,
John; bldg-sim@lists.onebuilding.org<BR><B>Subject:</B> RE: [Bldg-sim] Chiller
part load raw data points into eQuest<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 type=1>
<LI class=MsoNormal style="COLOR: navy; mso-list: l0 level1 lfo1"><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; 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 class=MsoNormal style="COLOR: navy; mso-list: l0 level1 lfo1"><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; 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 class=MsoNormal style="COLOR: navy; mso-list: l0 level1 lfo1"><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; 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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">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 face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Steve Gates<BR>eQUEST
development team<o:p></o:p></SPAN></FONT></P>
<DIV>
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align=center><FONT face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
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<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><B><FONT face=Tahoma size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</SPAN></FONT></B><FONT
face=Tahoma size=2><SPAN style="FONT-SIZE: 10pt; 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 face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">Hi
Gang:<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; 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 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; 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 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; 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 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">Can anyone help
me?<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Tahoma color=blue
size=2><SPAN style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Tahoma">John R.
Aulbach, PE, CEM</SPAN></FONT><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><EM><I><FONT face=Arial
size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Project
Manager</SPAN></FONT></I></EM><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial color=blue
size=2><SPAN style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Nexant,
Inc</SPAN></FONT><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">.</SPAN></FONT><FONT face=Tahoma
size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">100 North Barranca, Suite
820</SPAN></FONT><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">West Covina, CA 91791
USA</SPAN></FONT><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Phone:
626-430-9054</SPAN></FONT><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Fax: 626-430-9060</SPAN></FONT><FONT
face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">email: <A
title=mailto:jaulbach@nexant.com
href="mailto:jaulbach@nexant.com">jaulbach@nexant.com</A></SPAN></FONT><FONT
face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"><o:p></o:p></SPAN></FONT></P>
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