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<p>Seyedmostafa,</p>
<p> You're on the right track. At least your method is the same that
I used when I was modeling a similar situation. In my case there
was a thin vinyl skirt around the building so I used its thermal
resistance for my massless walls. I think the way to assess the
infiltration into the cavity is to couple the Type56 thermal model
either with CONTAM (using Type97 or Type98) or with TRNFlow. Both
are designed to estimate airflow between pressure nodes in
buildings.</p>
<p>kind regards,</p>
<p> David</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 06/11/2021 05:06, Seyedmostafa
Mousavi via TRNSYS-users wrote:<br>
</div>
<blockquote type="cite"
cite="mid:MEAPR01MB3047CD152264B2CE2A175C30A4349@MEAPR01MB3047.ausprd01.prod.outlook.com">
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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hope you are very well.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m modelling a cabin in SketchUp using the
TRNSYS3D plugin. In the real cabin structure, several steel
posts were used to elevate the cabin and separate its floor
from the ground. The air easily flows in this cavity under the
cabin, see
<b>Fig. 1</b>. To model the cavity, I’ve considered a bottom
zone in which the walls were defined as
<i>Massless Layers</i> with R-value of 0.044 h m^2 K/ kJ
(equal to the air gap), see
<b>Fig. 2</b>.<o:p></o:p></p>
<p class="MsoNormal">However, I’m not sure if this modelling
process is correct. Do we have any option in TRNSYS to
consider such cavity under buildings?<o:p></o:p></p>
<p class="MsoNormal">BTW, if this model is correct, how should I
calculate the infiltration rate for the cavity section? Any
idea is highly appreciated.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks a lot for your help.<o:p></o:p></p>
<p class="MsoNormal" style="text-autospace:none"><b><span
style="font-size:10.0pt;color:#002060" lang="EN-AU"><o:p> </o:p></span></b></p>
<p class="MsoNormal" style="text-autospace:none"><b><span
style="font-size:10.0pt;color:#002060" lang="EN-AU">Warmly,<o:p></o:p></span></b></p>
<p class="MsoNormal" style="text-autospace:none"><b><span
style="font-size:10.0pt;color:#002060" lang="EN-AU">Seyedmostafa
Mousavi<o:p></o:p></span></b></p>
<p class="MsoNormal" style="text-autospace:none"><span
style="font-size:10.0pt;color:#002060" lang="EN-AU">The
University of Melbourne, Victoria 3010 Australia</span><span
lang="EN-AU">
</span><span style="font-size:10.0pt;color:#002060"
lang="EN-AU"><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><b><span
style="font-size:10.0pt;color:#002060" lang="EN-AU">E:
</span></b><span style="font-size:10.0pt;color:#002060"
lang="EN-AU"><a href="mailto:sm.mousavi@unimelb.edu.au"
moz-do-not-send="true"><span style="color:blue">sm.mousavi@unimelb.edu.au</span></a></span><span
style="font-size:10.0pt;color:#002060" lang="EN-AU">
<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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</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>
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