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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The problem is you do not have a minimum outside air percentage
specified under your system. On top of that you have specified a cfm per
sqft for outside air under each of your zones. This is causing your model
to use a specified amount of oa anytime the system is running. This will allow
your unit to economize. You will also need to make a min oa schedule if
you want your oa damper to close during unoccupied hours.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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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>Patrick
O'Donnell<br>
<b>Sent:</b> Tuesday, March 02, 2010 3:18 PM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> [Equest-users] OA damper barely modulating<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>Hi all,</span><o:p></o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>I had similar OA damper
question last</span> <span style='font-family:"Calibri","sans-serif"'>week
which the</span> <span style='font-family:"Calibri","sans-serif"'>OA</span> <span
style='font-family:"Calibri","sans-serif"'>damper was stuck open with 100% OA</span>
<span style='font-family:"Calibri","sans-serif"'>(which was resolved thanks to
the board!) I have a new issue…</span><o:p></o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>The system is a: boiler +
chiller + VAV with HW reheat and air-side</span> <span style='font-family:"Calibri","sans-serif"'>economizer.</span>
<span style='font-family:"Calibri","sans-serif"'> The problem is</span> <span
style='font-family:"Calibri","sans-serif"'>the OA damper is open</span> <span
style='font-family:"Calibri","sans-serif"'>about the same %</span> <span
style='font-family:"Calibri","sans-serif"'>(about .45 which is equal to the</span><b><i>
</i></b><b><i><span style='font-family:"Calibri","sans-serif"'>min</span></i></b><span
style='font-family:"Calibri","sans-serif"'> dsn OA CFM)</span> <span
style='font-family:"Calibri","sans-serif"'>whenever the air-side system is
operating in</span> <span style='font-family:"Calibri","sans-serif"'>my hourly
reports all year. I am thinking that this should open up close to 100% at
least some times of the year and close</span> <span style='font-family:"Calibri","sans-serif"'>back
down</span> <span style='font-family:"Calibri","sans-serif"'>to min OA during
unoccupied modes, etc. The</span> <span style='font-family:"Calibri","sans-serif"'>as-designed
system is capable of it I am just don’t think my model is set up to work
that way.</span><o:p></o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>I am thinking</span> <span
style='font-family:"Calibri","sans-serif"'>with this as-designed system, I have
gotten over zealous with modifying defaults and have</span> <span
style='font-family:"Calibri","sans-serif"'>not entered or incorrectly entered
some values on cooling/heating controls, OA, economizer, or a combination of a
few things. I have manipulated all of these things trying to figure this
out but without luck.</span><o:p></o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>Could someone please take a
quick look at the model attached and let me know if they see anything
suspect? Your input and help is greatly appreciated! Thanks, </span>
<o:p></o:p></p>
<p><span style='font-family:"Calibri","sans-serif"'>-Patrick</span><o:p></o:p></p>
<p><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'><<Retail1.inp>>
<<Retail1.pd2>> </span><o:p></o:p></p>
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