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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Everyone, recently we have had a code change in our area
requiring mechanical designers to submit energy model peak total load reports
to justify mechanical equipment sizing. So, I started looking through a typical
SZRH, 1 chiller, 2 boiler energy model simulation output and noticed that SS-D
report showed maximum heating and cooling loads that were less than the energy
model’s auto sized chiller (42% less) and less than the auto sized total
boiler (15% less). I then compared the SS-D maximum loads and the PV-A
equipment sizes to the Air Side Summary report outputs. The Air Side Summary
report cooling design capacity had a total cooling load that matched the
chiller size shown in the PV-A report, but the heating design capacity (Heat
Btuh/sf) showed a value 36% bigger than the total PV-A boiler capacity. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I believe what is happening here has something to do with
the way eQuest sizes the secondary loop for the chiller and boiler. I believe
this because the SZRH chiller, 2 boiler energy model ran successfully with the boilers
and chillers manually sized to meet the maximum heating and cooling loads shown
in the SS-D report. The hours outside throttling range for the auto sizing
chiller, 2 boiler energy model was 2.2, and the manually sized chiller, 2
boiler energy model was 2.7. So both models have acceptable and very similar
throttling ranges. The manually sized chiller, 2 boiler energy model simulation
output did include 2 warning messages that the heating and cooling primary loop
capacities were smaller than the secondary demand. The sizes of the heating and
cooling secondary demand issued in the warning message matched the original auto
sizing energy model chiller and boiler capacities.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>So, question 1 is: what is eQuest using to size the chiller
and boiler secondary loop sizes that is noticeably larger than the maximum peak
loads issued in the SS-D report?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Question 2: what is eQuest using to derive the Air Side
Summary heating design capacity (Heat Btuh/sf) which does not match the auto sized
boiler capacity?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I know I am going to be asked these 2 questions by someone
very soon so any hints or insight would be appreciated.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=section1 style='margin:0in;margin-bottom:.0001pt'><strong><b><font
size=3 color=black face=Arial><span style='font-size:12.0pt;font-family:Arial;
color:black'>Kathryn Kerns</span></font></b></strong><o:p></o:p></p>
<p class=section1 style='margin:0in;margin-bottom:.0001pt'><em><b><i><font
size=2 face=Arial><span style='font-size:11.0pt;font-family:Arial;font-weight:
bold;font-style:normal'>Systems Specialist</span></font></i></b></em><o:p></o:p></p>
<p class=section1 style='margin:0in;margin-bottom:.0001pt'><em><b><i><font
size=3 color=teal face="Times New Roman"><span style='font-size:12.0pt;
font-variant:small-caps;color:teal;font-weight:bold;font-style:normal'>BCE</span></font></i></b></em><strong><b><font
size=2 color=teal face="Times New Roman"><span style='font-size:10.0pt;
font-variant:small-caps;color:teal'> </span></font><font color=teal><span
style='font-variant:small-caps;color:teal'>Engineers, Inc.<o:p></o:p></span></font></b></strong></p>
<p class=section1 style='margin:0in;margin-bottom:.0001pt'><strong><b><font
size=1 color=black face="Times New Roman"><span style='font-size:9.0pt;
color:black'>| Ph: 253.922.0446 | Fx: 253.922.0896 |</span></font></b></strong><font
size=1 color=black><span style='font-size:7.0pt;color:black'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Arial><span style='font-size:
13.5pt;font-family:Arial;color:black'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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