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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Pranita et al,<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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>In this situation, you must either (A) define separate zones to
define the multiple systems as they exist, or (B) stick to your guns
(assumption of thermal equivalency), and further “lump together”
the individual PTAC’s as large, “combined-equivalent” systems.<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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The first option would allow you to more easily specify the
systems as they exist – individually and independent in operation of each
other, will be more accurate if indeed the units have differing loads on an
hourly basis, as John is cautioning, and will render any concerns of whether
the assumption that the individual zones are thermally equal moot. <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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>If you are concerned that the “multiple systems in one
zone” is critical for accuracy, you can always define the adjoining
internal partitions as air walls to thermally connect the adjacent spaces (indirectly
the corresponding zonal PTAC systems will work together to handle the combined
spaces’ loads). This seems to match the real-world behavior
you’re seeking to model.<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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The second option will actually be harder for you (the modeler)
in the long run, as you must average-together /sum the units’ parameters
to come up with an equivalent collective system – efficiency/capacity/scheduling/etc…
if the validity of the “thermally equivalent” assumption is questionable,
so is the decision to have their systems to act as one – it’s your
call.<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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Combining zones for thermal equivalency is a great technique
when it saves you work and time, but the approach sometimes can result in more
work than would otherwise be required in the long run. If/when actual system
zoning is readily available at the wizard development stage of my models, I personally
tend to use that information when defining zones, unless I’m certain the flexibility/accuracy
benefits offered by a more zonally-accurate model will be unnecessary.<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>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>~Nick<o:p></o:p></span></p>
<div>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><img width=119 height=37 id="Picture_x0020_1"
src="cid:image001.jpg@01CB9628.6A4C61C0" alt="cid:489575314@22072009-0ABB"></span><b><span
style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p></o:p></span></b></p>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";
color:#2D4D5E'><o:p> </o:p></span></b></p>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";
color:#2D4D5E'>NICK CATON, E.I.T.</span></b><b><span style='font-family:"Stylus BT","sans-serif";
color:#2D4D5E'><o:p></o:p></span></b></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Calibri","sans-serif";
color:#CC9900'>PROJECT ENGINEER<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";
color:#2D4D5E'>Smith & Boucher Engineers</span><span style='font-size:7.5pt;
color:#CC9900'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";
color:#2D4D5E'>25501 west valley parkway<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";
color:#2D4D5E'>olathe ks 66061<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";
color:#2D4D5E'>direct 913 344.0036<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";
color:#2D4D5E'>fax 913 345.0617<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><a href="www.smithboucher.com"
title="blocked::www.smithboucher.com"><span style='font-size:10.0pt'>www.smithboucher.com</span></a></span><u><span
style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:blue'> </span></u><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p>
</div>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<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>John
Aulbach<br>
<b>Sent:</b> Tuesday, December 07, 2010 3:27 PM<br>
<b>To:</b> pranita kothuru; equest-users<br>
<b>Subject:</b> Re: [Equest-users] Systems /Zoning question.<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<div>
<p class=MsoNormal>Pranita:<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Careful about "all units have the same thermodynamic
conditions". End rooms have two exposures where those in the facing
directions have one.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#1F497D'>John
R. Aulbach, PE, CEM<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Senior
Energy Engineer<o:p></o:p></span></p>
<div>
<div class=MsoNormal><span style='font-family:"Calibri","sans-serif";
color:#17365D'>
<hr size=2 width="30%" noshade style='color:#17365D' align=left>
</span></div>
</div>
<p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";
font-variant:small-caps;color:navy'>Partner</span></b><b><span
style='font-family:"Calibri","sans-serif";font-variant:small-caps;color:green'>
</span></b><b><span style='font-family:"Calibri","sans-serif";font-variant:
small-caps;color:#006600'>Energy</span></b><b><span style='font-family:"Calibri","sans-serif";
font-variant:small-caps;color:navy'><o:p></o:p></span></b></p>
<p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#1F497D'>1990
E. Grand Avenue, El Segundo, CA 90245<br>
W: 888-826-1216, X254| D: 310-765-7295 | F: 310-817-2745<o:p></o:p></span></p>
<p class=MsoNormal><a href="http://www.ptrenergy.com/"><span style='font-family:
"Calibri","sans-serif"'>www.ptrenergy.com</span></a><span style='font-family:
"Calibri","sans-serif";color:#1F497D'> </span><a
href="mailto:%7C%20jaulbach@ptrenergy.com"><span style='font-family:"Calibri","sans-serif"'>|
jaulbach@ptrenergy.com</span></a><span style='color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
<hr size=1 width="100%" align=center>
</span></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><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"'> pranita kothuru
<pranita.kothuru@gmail.com><br>
<b>To:</b> equest-users <equest-users@lists.onebuilding.org><br>
<b>Sent:</b> Tue, December 7, 2010 12:41:53 PM<br>
<b>Subject:</b> [Equest-users] Systems /Zoning question.</span><o:p></o:p></p>
<div>
<p class=MsoNormal>Hello All -<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>I am modeling a multifamily 4 floors buildings in eQuest. I
created seperate zones for corridors and living spaces. My living spaces have
PTAC units and corridors have seperated HVAC system.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>In DD wizard screen 1 what do I have to choose for 'System
Per area'. <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>All the living spaces were zoned as one big zone
(considering that all units have same thermodynamic conditions).<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>If I choose system per zone, this can be wrong because
I have more than one PTAC units in that given zone(as several apats were
clubbed to be in one zone).<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Please advice.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><br clear=all>
<br>
-- <o:p></o:p></p>
</div>
<p style='margin:0in;margin-bottom:.0001pt'><b><span style='font-family:"Calibri","sans-serif";
color:#006600'>- Pranita </span></b><o:p></o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p>
</div>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
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