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<p class="MsoNormal"><span style="color:#1F497D">Hello, Joylan.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I don’t know why the walls of your model do not seem to be demonstrating the expected capacitance effect, but I can answer your question about the capacitance value in the Air node regime data. This value is
just an average value of the capacitance of all the zone contents. The default value is set to 1.2 times the volume because an approximate value of the heat capacity of air in standard conditions is 1 kj/(Kg.k), and an approximate value of the density is 1.2
Kg/m<sup>3</sup>. The assumption type 56 is making is that your zone only contains air. This value of capacitance will be higher the more furniture, etc. you have in your zone.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">So no, you should not be increasing this value to account for wall capacitances.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Hope this helps.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-family:"Arial","sans-serif";color:#1F497D">Mohamed Al-Hamahmy.<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">Research Engineer.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="color:#1F497D"><img width="339" height="57" id="Picture_x0020_1" src="cid:image001.jpg@01CF46A3.3E11C800" alt="InstDual"></span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">PO Box 54224, Abu Dhabi,
<br>
United Arab Emirates<br>
Office +971 2 810 9151<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">Email
<u><a href="mailto:malhamahmy@masdar.ac.ae"><span style="color:#1F497D">malhamahmy@masdar.ac.ae</span></a></u><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><a href="http://www.masdar.ac.ae/"><span style="color:#1F497D">http://www.masdar.ac.ae</span></a><br>
</span><span style="font-size:10.0pt;font-family:Webdings;color:#1F497D">P </span>
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<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<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""> trnsys-users-bounces@cae.wisc.edu [mailto:trnsys-users-bounces@cae.wisc.edu]
<b>On Behalf Of </b>Joynal Abedin<br>
<b>Sent:</b> Sunday, March 23, 2014 1:36 PM<br>
<b>To:</b> trnsys-users@cae.wisc.edu<br>
<b>Subject:</b> [TRNSYS-users] Help needed with Type-56 thermal mass thermal time constatnt problems<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">I’m simulating a domestic building using Type-56 with three thermal zones. All the building fabrics such as the external walls are massive with the correctly defined conductivity, heat capacity and density. However, when
I simulate the building the thermal response of the rooms appear to have very low thermal time constant i.e. it changes very rapidly and it seems that the massive walls with specific heat capacity are not having any heat storage impact. The capacity value
in the Air Zone Regime gets automatically to 1.2 times the volume of the room. If I manually increase this value the thermal time constant does increase, but should I be increasing this value? The main problem I think is that the thermally massive walls are
not having any thermal mass effects on the temperature response of the rooms. What am I doing wrong? Why is the heat capacity of the air zone set to 1.2 times the zone volume? One building in TRNSYS17 Example projects have this set to 3 times the Volume.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">If anybody as any ideas or suggestions please please email me. Your help will be very much appreciated.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Thanking you in advance.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Kind regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Joynal Abedin.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Loughborough University, UK.<o:p></o:p></span></p>
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