<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Franklin Gothic Medium";
panose-1:2 11 6 3 2 1 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal">One of the interior wall types in DOE-2 is “AIR”, for which there is a default library member “<b>Default Air Wall Construction</b>” with heat transfer of
<b>U = 2.7 Btu/h-ft<sup>2</sup>-°F</b>. The help menu describes this as the recommended value but gives no reference for it. How might we come up with a range of values?<o:p></o:p></p>
<p class="MsoNormal">I frequently model air walls for everything from open doors to transfer grills to stairwells etc. It is also critical to my method of modeling DOAS systems where I assign the DOAS to plenum spaces and the zonal systems to the spaces below.<o:p></o:p></p>
<p class="MsoNormal">There are many situations where I suspect the default 2.7 value is too small, such as the DOAS system method I described, or any time you have forced air systems on either or both sides of the air wall. Other examples could be displacement
ventilation systems, or high bay systems with fans to avoid stratification.<o:p></o:p></p>
<p class="MsoNormal">The relevance of changing the number is that higher values simulate higher rates of mixing of air, and can impact the unmet hours substantially if the zone temperatures separated by the air wall have a high delta-T between them.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">What say you, simulationists?<o:p></o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">~Bill<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Franklin Gothic Medium",sans-serif;color:black">William Bishop, PE, BEMP, BEAP, CEM, LEED AP
</span></b><b><span style="font-size:10.0pt;font-family:"Franklin Gothic Medium",sans-serif;color:#006600">|</span></b><b><span style="font-size:10.0pt;font-family:"Franklin Gothic Medium",sans-serif;color:black"> Pathfinder Engineers & Architects LLP<o:p></o:p></span></b></p>
<table class="MsoNormalTable" border="0" cellspacing="0" cellpadding="0" width="658" style="width:394.8pt;border-collapse:collapse">
<tbody>
<tr style="height:13.45pt">
<td width="431" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:13.45pt">
<p class="MsoNormal" style="line-height:105%"><b><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:black">Senior Energy Engineer<o:p></o:p></span></b></p>
</td>
<td width="227" rowspan="6" style="width:136.35pt;padding:0in 5.4pt 0in 5.4pt;height:13.45pt">
<p class="MsoNormal" style="line-height:105%"><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:black"><img width="56" height="38" id="Picture_x0020_4" src="cid:image007.jpg@01D27E2A.35CF25E0">
<img width="46" height="39" id="Picture_x0020_2" src="cid:image008.jpg@01D27E2A.35CF25E0"><o:p></o:p></span></p>
</td>
</tr>
<tr style="height:4.55pt">
<td width="431" valign="top" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:4.55pt">
<p class="MsoNormal" style="line-height:105%"><span style="font-size:5.0pt;line-height:105%;font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
</td>
</tr>
<tr style="height:9.8pt">
<td width="431" nowrap="" valign="bottom" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:9.8pt">
<p class="MsoNormal" style="line-height:105%"><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:#1F497D">134 South Fitzhugh Street</span><span style="font-size:9.0pt;line-height:105%;color:#1F497D">
</span><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:#1F497D">Rochester, NY 14608<o:p></o:p></span></p>
</td>
</tr>
<tr style="height:12.4pt">
<td width="431" valign="top" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:12.4pt">
<p class="MsoNormal" style="line-height:105%"><b><i><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:#002060">T: (585) 698-1956</span></i></b><b><i><span style="color:#002060">
</span></i></b><span style="color:#1F497D"> </span><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:#1F497D">F: (585) 325-6005</span><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:black"><o:p></o:p></span></p>
</td>
</tr>
<tr style="height:9.8pt">
<td width="431" valign="top" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:9.8pt">
<p class="MsoNormal" style="line-height:105%"><a href="mailto:wbishop@pathfinder-ea.com"><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:blue">bbishop@pathfinder-ea.com</span></a><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:black">
</span><a href="http://www.pathfinder-ea.com/"><span style="font-size:9.0pt;line-height:105%;font-family:"Arial",sans-serif;color:blue">www.pathfinder-ea.com</span></a><span style="color:#1F497D"><o:p></o:p></span></p>
</td>
</tr>
<tr style="height:24.6pt">
<td width="431" valign="top" style="width:258.45pt;padding:0in 5.4pt 0in 5.4pt;height:24.6pt">
<p class="MsoNormal" style="margin-top:3.0pt;line-height:105%"><img border="0" width="34" height="32" id="Picture_x0020_5" src="cid:image009.png@01D27E2A.35CF25E0" alt="http://png-5.findicons.com/files/icons/977/rrze/720/globe.png"><span style="font-size:7.5pt;line-height:105%;color:#00B0F0">Carbon
Fee and Dividend - simple, effective, and market-based.</span><span style="color:#1F497D"><o:p></o:p></span></p>
</td>
</tr>
</tbody>
</table>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>