Hi Marion,<br><br>Thank you for your answer.<br><br>I am looking at Top, but the same phenomenon can be observed if you look at Tair.<br>The problem cannot be seen with the global chart of TRNSys. The best is to plot the derivative as the substraction between the temperature at <i>t </i>time and the one at <i>t-1, </i>dividing by the time step (0,25 hr). Then you will observe the problem focusing on the derivative from the time step 1195 to 1210.<br>
<br>Concerning the NTypes, I did what you have suggested to me:<br> - Surface temperatures follow the same trend as the operative ones. A peak for derivative value can be observed.<br> - Radiative and convective gains are positives while the heating device is switched on and remains equal to 0 from the interruption time step. QCOMIs derivative function evolves as the operative temperature does...<br>
<br>Find attached the results I have just plotted. I cannot explain why this appears... I have tried to change the walls' components but the problem doesn't desappear...<br><br>Looking at the results have you got any suggestion to solve this problem? Do you think it could be a problem of stability due to TRNBuild calculation?<br>
<br><br><br><div class="gmail_quote">2011/6/7 Marion Hiller <span dir="ltr"><<a href="mailto:hiller@transsolar.com">hiller@transsolar.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div link="blue" vlink="blue" lang="DE">
<div>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy">Augustin,</span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy"> </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">Assuming no
infiltration/ventilation the behaviour of the zone air temperature as well as
the operative temperature after switching </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">off gains depend on the
surface temperatures. </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">I run the attached files,
but the entities on the online weren’t sufficient to see your problem
(Top and Text).</span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">If you talk about
temperature are you looking at Top or Tair?</span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB"> </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">You may check surface
temperatures TSI and the NTYPE QCOMI for heat transfer. </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy" lang="EN-GB">I suggest add Onlines
with all relevant entities like TSI, TAIR, QCOMI, rad. </span></font><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy">GAINS, conv. Gains etc. .</span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy"> </span></font>
</p>
<p class="MsoNormal"><font color="navy" size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial;color:navy">Marion</span></font>
</p>
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</p>
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</p>
<div>
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<p class="MsoNormal"><b><font size="2" face="Tahoma"><span style="font-size:10.0pt;font-family:Tahoma;font-weight:bold">Von:</span></font></b><font size="2" face="Tahoma"><span style="font-size:10.0pt;font-family:Tahoma"> Augustin CUQ
[mailto:<a href="mailto:augustin.cuq@gmail.com" target="_blank">augustin.cuq@gmail.com</a>] <br>
<b><span style="font-weight:bold">Gesendet:</span></b> Montag, 6. Juni 2011
18:17<br>
<b><span style="font-weight:bold">An:</span></b> Aaron J. Danenberg<br>
<b><span style="font-weight:bold">Cc:</span></b> trnsys-users<br>
<b><span style="font-weight:bold">Betreff:</span></b> Re: [TRNSYS-users]
Decrease of temperature with Type 56</span></font>
</p>
</div><div><div></div><div class="h5">
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt"> </span></font>
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<p style="margin-bottom:12.0pt"><font size="3" face="Times New Roman"><span style="font-size:12.0pt">Dear Aaron,<br>
<br>
Thanks for answering so quickly.<br>
<br>
Changing the infiltration rates (setting it to 0) doesn't change the phenomenon
I describe... I had tried but the decrease can still be observed. Concerning
the weather data, I wanted to simplify as much as I could the model, to be sure
the problem wasn't the result of the weather variations. If you delete the
heating device (or set it to 0) and the soil temperature too, you will see that
the temperature decreases logically up to 0°C.<br>
The conditions for the external walls are set to a default value 0, in order to
be sure the evolution of the temperature remains constant (increase when there
is a heating device and decrease when there is no heating device). In that way,
the temperature shouldn't increase after stopping the heating device (it is the
case in my simulation for the third time step following the interruption of
heating), and it shouldn't decrease so fast for the two time steps following
this interruption (comparing with the evolution after 4 time steps = 1 hour).<br>
<br>
BR.<br>
<br>
Augustin CUQ</span></font>
</p>
<div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt">2011/6/6 Aaron J. Danenberg <<a href="mailto:danenberg@hartford.edu" target="_blank">danenberg@hartford.edu</a>></span></font>
</p>
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<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">Augustin,</span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US"> </span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">You infiltration rates seem relatively
high (0.6ACH), if it is this high I would assume you are in a windy location,
or the building is old and leaky (or you include some mechanical ventilation in
this number). Since the building is well insulated, I would assume the
problem lies within your control (signal) scheme, or double checking your ACH
assumption against the results of a blower door test. I use the data
reader and TMY2 weather data to define the conditions for external walls.
I did not understand how you defined your conditions for the external walls,
that may be something you want to double check on, I cannot say if it is
incorrect or correct, but may be a likely source of your problems. </span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US"> </span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">Aaron J. Danenberg</span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">Graduate Research Assistant</span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">University</span></font><font color="#1f497d" size="2"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US">
of Hartford</span></font><span lang="EN-US"></span>
</p>
<p class="MsoNormal"><font color="#1f497d" size="2" face="Times New Roman"><span style="font-size:11.0pt;color:#1F497D" lang="EN-US"> </span></font><span lang="EN-US"></span>
</p>
<div style="border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0cm 0cm 0cm;border-color:-moz-use-text-color -moz-use-text-color">
<p class="MsoNormal"><b><font size="2" face="Times New Roman"><span style="font-size:10.0pt;font-weight:bold" lang="EN-US">From:</span></font></b><font size="2"><span style="font-size:10.0pt" lang="EN-US"> Augustin CUQ [mailto:<a href="mailto:augustin.cuq@gmail.com" target="_blank">augustin.cuq@gmail.com</a>]
<br>
<b><span style="font-weight:bold">Sent:</span></b> Monday, June 06, 2011 10:03
AM<br>
<b><span style="font-weight:bold">To:</span></b> trnsys-users<br>
<b><span style="font-weight:bold">Subject:</span></b> [TRNSYS-users] Decrease
of temperature with Type 56</span></font><span lang="EN-US"></span>
</p>
</div>
<div>
<div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt" lang="EN-US"> </span></font>
</p>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt" lang="EN-US">Dear
all,<br>
<br>
I sent a mail two weeks ago to expose the problem I had but it was not very
clear. So I have made an Excel file to illustrate it.The model has been
simplified. <br>
<br>
It represents a two rooms building, with no internal gain. The outside
temperature remains constant to 0°C and all the other parameters used by the
.bui are equals to a default value: 0.<br>
The only parameter which is a variable input of the model is a heating power.
It remains constant until the steady state is obtained and then it is put to 0.<br>
<br>
The variation of the temperature, for the three time steps following the stop
of the heating device seems to be weird. The decrease of the temperature is
very fast, then it increases (???) before going down with an acceptable
derivative value (around 0.3°C/hr).<br clear="all">
Find attached the model I have used.<br>
<br>
Can anyone explain to me the reason of this phenomenon?<br>
Thanks in advance.<br>
<br>
Best regards.<br>
<br>
-- <br>
Augustin CUQ </span></font>
</p>
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<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt"><br>
<br clear="all">
<br>
-- <br>
Augustin CUQ </span></font>
</p>
<div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt">Elève-Ingénieur en dernière année à l'Ecole des Mines de Nantes,</span></font>
</p>
</div>
<div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt">Spécialisation en Génie des Systèmes Energétiques</span></font>
</p>
</div>
<div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt">Stagiaire chez ETAMINE, Bureau d'Etudes Techniques en thermique et
aéraulique et en conseil HQE</span></font>
</p>
</div>
<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size:12.0pt"> </span></font>
</p>
</div></div></div>
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</blockquote></div><br><br clear="all"><br>-- <br>Augustin CUQ
<div>Elève-Ingénieur en dernière année à l'Ecole des Mines de Nantes,</div>
<div>Spécialisation en Génie des Systèmes Energétiques</div>
<div>Stagiaire chez ETAMINE, Bureau d'Etudes Techniques en thermique et aéraulique et en conseil HQE<br></div><br>