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Michael,<br>
There are a few likely causes. First, make sure that you have
changed the default zone thermal capacitance. In TRNBuild, the
default zone capacitance is set to 1.2*1.007*ZoneVolume, which
accounts only for the thermal capacitance of air in the zone. A
value 5 times higher than the default is usually appropriate.
Second, make sure that your infiltration and ventilation are set up
properly. In normal commercial building operation, the outdoor air
dampers are turned OFF during the heating (and cooling) system off
periods. You also may see this effect if your infiltration rate is
high.<br>
Kind regards,<br>
David<br>
<br>
<div class="moz-cite-prefix">On 10/12/2012 08:23, Michael Diekerhof
wrote:<br>
</div>
<blockquote
cite="mid:trinity-f3d71baf-8066-4b92-9812-4a5d0a3f48ce-1350048224139@3capp-webde-bs35"
type="cite">
<div style="font-family: Verdana;font-size: 12.0px;">
<div>Dear all,<br>
</div>
<div><br>
</div>
<div>I´ve simulated an two hour heating off-period for my Type
56 (year of construction 2002). To keep it easy, i was just
working with 1 Zone and a total volume around 500m3. <br>
</div>
<div><br>
</div>
<div>My problem is that the roomtemperature decrease during the
off-period is extremly high. For example: It decreases from
20°C to 17°C (of course depending on Tambient) in the space of
one or two hours. I think this decrease is much to high. In
this case TRNSYS is not simulating the thermic inertia right
?! <br>
</div>
<div><br>
</div>
<div>Does anyone have already experiences with this problem and
knows if my decrease is correct or seriously wrong ?! In my
case i think it´s wrong because of both the huge volume
(without internal walls etc) and the missing thermic inertia.
<br>
</div>
<div><br>
</div>
<div>Best,<br>
</div>
<div><br>
</div>
<div>Michael <br>
</div>
</div>
<br>
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<br>
<pre class="moz-signature" cols="72">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI 53703 USA
P:+1.608.274.2577
F:+1.608.278.1475
<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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