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    <p>Toni,</p>
    <p> I have run into this problem from time to time as well and was
      never able to discover the cause. I found that if I increased the
      flow rate to about 1.1 times the stated required flow the the
      error usually went away. The other thing you can do, of course, is
      to segment the floor so that it will allow you to enter the flow
      that you wanted.</p>
    <p>kind regards,</p>
    <p> David</p>
    <p><br>
    </p>
    <div class="moz-cite-prefix">On 02/08/2021 03:08, Toni Calabrese via
      TRNSYS-users wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:VE1PR09MB32141041313CB9E36E6CB36DE98F9@VE1PR09MB3214.eurprd09.prod.outlook.com">
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        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US">Hi
            everyone,<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US">For a
            pilot project we are analyzing a heating system in which an
            "external wall heating system" is installed on the façade.
            Basically we have a wall with an active layer that is
            insulated on the back in order to decrease the losses of
            this active layer to the outside.
            <o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US">With a
            pipe spacing of 13.5 cm the system was working good. For a
            parametric study, I would like to run a study varying the
            pipe spacing. Setting the pipe spacing to 10 cm (instead of
            13.5 cm) the system does not simulate anymore. It gives me
            the following error:<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span style="font-size:10.0pt" lang="EN-US">Message              
            : Specific fluid mass flow of active layer in surface   24
            below minimum value of 8.01 kg/m2h Please, increase the
            minimum mass flow rate or use the autosegmentation feature
            of TRNBuild for subdividing the surface.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="font-size:10.0pt" lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US">I
            checked the massflow rate and I am sure that the mass flow
            rate is higher than the minimum. I tried to increase the
            massflow rate through the pump of the system but it does not
            work. Which is the problem?<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US">Here the
            data of my simulation:<o:p></o:p></span></p>
        <p class="MsoListParagraph"
          style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><span
              style="mso-list:Ignore">-<span style="font:7.0pt
                "Times New Roman"">       
              </span></span></span><!--[endif]--><span
            style="font-size:10.0pt" lang="EN-US">TRNSYS 17<o:p></o:p></span></p>
        <p class="MsoListParagraph"
          style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><span
              style="mso-list:Ignore">-<span style="font:7.0pt
                "Times New Roman"">       
              </span></span></span><!--[endif]--><span
            style="font-size:10.0pt" lang="EN-US">Wall area: 10.16 m2<o:p></o:p></span></p>
        <p class="MsoListParagraph"
          style="text-indent:-18.0pt;mso-list:l0 level1 lfo1"><!--[if !supportLists]--><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><span
              style="mso-list:Ignore">-<span style="font:7.0pt
                "Times New Roman"">       
              </span></span></span><!--[endif]--><span
            style="font-size:10.0pt" lang="EN-US">Massflow rate system:
            86 kg/h<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="font-size:10.0pt" lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D" lang="EN-US"><o:p> </o:p></span></p>
        <div class="MsoNormal" style="text-align:center" align="center"><span
style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">
            <hr width="100%" size="2" align="center">
          </span></div>
        <p class="MsoNormal" style="margin-top:4.0pt"><b><span
              style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">Toni
              Calabrese</span></b><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">,
            MSc.</span><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">Wissenschaftlicher
            Projektmitarbeiter<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"><a
              href="mailto:toni.calabrese@spf.ch" moz-do-not-send="true"><span
                style="color:#0065A3">toni.calabrese@spf.ch</span></a> |</span><span
style="font-size:10.0pt;color:#8C195F;mso-fareast-language:DE-CH">
          </span><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"><a
              href="mailto:toni.calabrese@ost.ch" moz-do-not-send="true"><span
                style="color:#0065A3">toni.calabrese@ost.ch</span></a></span><span
style="font-size:10.0pt;color:#8C195F;mso-fareast-language:DE-CH"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
style="font-family:"Calibri",sans-serif;color:#8C195F;mso-fareast-language:DE-CH"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">T
            +41 58 257 4827<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">SPF
            Institut für Solartechnik<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">OST
            – Ostschweizer Fachhochschule<o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH">Oberseestr.
            10 | CH-8640 Rapperswil | Switzerland |
          </span><u><span
              style="color:#8C195F;mso-fareast-language:DE-CH"><a
                href="http://www.spf.ch" moz-do-not-send="true"><span
                  style="font-size:10.0pt;color:#8C195F">www.spf.ch</span></a></span></u><span
style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"> |
          </span><u><span
              style="color:#8C195F;mso-fareast-language:DE-CH"><a
                href="http://www.ost.ch" moz-do-not-send="true"><span
                  style="font-size:10.0pt;color:#8C195F">www.ost.ch</span></a></span></u><span
style="font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:DE-CH"><o:p></o:p></span></p>
        <p class="MsoNormal"><span
            style="font-size:10.0pt;color:#1F497D;mso-fareast-language:DE-CH"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span style="font-size:9.0pt;color:#1F497D">OST
            – Ostschweizer Fachhochschule ist der Zusammenschluss aus
            FHS St.Gallen, HSR Rapperswil und NTB Buchs.<o:p></o:p></span></p>
        <p class="MsoNormal"><o:p> </o:p></p>
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      <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>
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