<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>The method by which airflow between adjacent air nodes is
computed is by adding a TRNFlow or CONTAM (Type97) model in
parallel with your Type56 building model. You'll define airflow
paths in between your air nodes. Both of those engines, however,
are based on the assumption that the resistance to airflow between
two air nodes (i.e. through the paths that you define) is high in
comparison to the resistance to airflow of the nodes themselves.
Think of two large rooms connected by a small opening; the opening
offers much more resistance to airflow than do the rooms
themselves. Now thing of a long narrow room that is broken into
two adjacent air nodes. The airflow resistance offered by the
connection is basically the same as the air flow resistance of the
nodes themselves. Both TRNFlow and CONTAM do a better job
predicting airflow in the first case than they do in the second. <br>
</p>
<p>There are certainly reasons why you might want to break up a
large zone into a number of adjacent airnodes, natural ventilation
being one of the most common. Given that the simulation methods
for estimating the mixing airflow are somewhat limited, I would
only split that zone into multiple airnodes if there was a very
compelling reason to do so.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 08/29/2021 22:34, Huijie Pu via
TRNSYS-users wrote:<br>
</div>
<blockquote type="cite"
cite="mid:2de325f0.1ad6.17b951fcbe0.Coremail.huijiepu@163.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div
style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial">
<p style="margin:0;">Hello!</p>
<p style="margin:0;"><br>
</p>
<p style="margin:0;">I built a large space area model, which is
8 meters long, 8 meters wide and 3 meters high. The space area
is provided with four air nodes. There are no adjacent walls
between the air nodes, and only two outer walls are provided
in each area. Is it correct to set the area with multiple air
nodes in this way? Do you need to set adjacent walls between
each air node? How to determine the coupled flow between these
air nodes?</p>
<p style="margin:0;"><br>
</p>
<div style="margin:0;">Thank you very much.</div>
<div style="margin:0;"><br>
</div>
</div>
<br>
<br>
<span title="neteasefooter">
<p> </p>
</span><br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
TRNSYS-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:TRNSYS-users@lists.onebuilding.org">TRNSYS-users@lists.onebuilding.org</a>
<a class="moz-txt-link-freetext" href="http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI 53703 USA
P:+1.608.274.2577
<a class="moz-txt-link-abbreviated" href="mailto:d.bradley@tess-inc.com">d.bradley@tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.tess-inc.com">http://www.tess-inc.com</a>
<a class="moz-txt-link-freetext" href="http://www.trnsys.com">http://www.trnsys.com</a></pre>
</body>
</html>