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<p class=MsoNormal>Hi everyone,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>A discussion on [bldg-sim] prompted me to bring up a topic that’s
been bugging me in the “eQuest fundamentals” department…
<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have a general understanding that eQuest does not
fundamentally model airflow (specifically, convection of internal loads)
between zones.<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>The DOE-2 entry for INT-WALL-TYPE says an internal “air”
partition “ …designates a non-physical interior surface with no
mass (i.e., an opening between spaces) across which convection can take place.”<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>A wizard-generated “air” internal partition
has a construction with U-factor of 2.7… very conductive.<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]> To draw a conclusion – two zones connected with
an “air” partition are “connected” thermally. In
practice, the internal loads in one are “combined” with the other.<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>This means heat in one zone should travel to the other
in a rapid fashion during the hourly simulation, until the space temperatures are
identical between the two.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I hope my understanding thus far is correct, because from
here I have some questions that dig at what’s going on under the hood:<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>Imagine an air partition “connects” zones A
and B. These zones have separate systems and separate thermostats with
different setpoints. If zone A’s thermostat wants to be much warmer
than zone B, is it possible the systems will “fight” each other and
cause mutual unmet hours?<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>In the same setup, if Zone A is identical in geometry
to Zone B, but has 2x the internal/external loads, does it follow that the
system for System A will handle 2x the internal loads as System B, or are they summed
and applied equally to the two systems on an hourly basis? <o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>Is the “distribution of loads behavior” affected
if Systems A & B are specified with different capacities and/or airflows? <o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span
style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>If one space is larger in area/volume than the other,
does that affect how the collective loads are distributed to the corresponding systems?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have “exploited” air partition behavior in the
past to get around the “one system per zone” rule (need two RTU’s
serving that space? Just make an imaginary air wall!). However I
want to be sure before I continue this practice or advise others to do the same
that there aren’t any major potential pitfalls in how the loads/systems
are distributed/affected…<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>~Nick<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><img width=119 height=37 id="Picture_x0020_1"
src="cid:image001.jpg@01CBBD49.0FAADFB0" alt="cid:489575314@22072009-0ABB"><b><span
style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p></o:p></span></b></p>
<p class=MsoNormal><b><span style='font-family:"Stylus BT","sans-serif";
color:#2D4D5E'><o:p> </o:p></span></b></p>
<p class=MsoNormal><b><span style='font-family:"Stylus BT","sans-serif";
color:#2D4D5E'>NICK CATON, E.I.T.</span></b><b><span style='font-size:12.0pt;
font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p></o:p></span></b></p>
<p class=MsoNormal><span style='font-size:7.5pt;color:#CC9900'>PROJECT ENGINEER<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>Smith &
Boucher Engineers</span><span style='font-size:7.5pt;font-family:"Times New Roman","serif";
color:#CC9900'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>25501 west
valley parkway<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>olathe ks 66061<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>direct 913
344.0036<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>fax 913
345.0617<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><a href="www.smithboucher.com"
title="blocked::www.smithboucher.com"><span style='font-size:10.0pt;color:blue'>www.smithboucher.com</span></a></span><u><span
style='font-size:10.0pt;color:blue'> </span></u><span style='color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
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