<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Arianna,<div><br></div><div>in addition to the below, it sometimes helps to reduce simulation time steps (increase number of steps per hour). Also, you can change the parameters used for convergence checking (either every run manually or in the code and recompile).</div><div><br></div><div>Best</div><div>Achim</div><div><br></div><div><br></div><div><br><div><div>On Oct 22, 2013, at 9:04 AM, Aizaz Samuel <<a href="mailto:aizaz.a.samuel@strath.ac.uk">aizaz.a.samuel@strath.ac.uk</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> <div text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">Arianna,<br> <br> Somewhere in your model there is mass imbalance that is more than the tolerance allowed within the solver. Usually happens if you close a flow path using control (e.g. window closes but air is still being blown into the room from a fan). I would recommend to check this by removing control and then running the model. Another way forward is to make a sketch of the flow network and visually check if a bad flow path occurs given the constraints of the control you are trying to impose. A usual solution is to always have a flow path from internal nodes to external ones via small cracks (which is correct for most situations).<br> <div class="moz-signature"><br> </div> Another (rarer) reason is that you may have two components in series that have hugely different flow resistances. <br> <br> Regards,<br> Aizaz<br> <br> <div class="moz-signature"><br> </div> On 22/10/13 12:22, Arianna Sdei wrote:<br> </div> <blockquote cite="mid:43AC8FF96AEAFA43B65D1EDF7FD1C121BC3DA881@ALUDRA.university.brighton.ac.uk" type="cite"> <meta http-equiv="Context-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 12 (filtered medium)"> <div class="WordSection1"><p class="MsoNormal">Dear All,</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">I am simulating using an air flow network and while running the simulation I get the following message: </p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Please check (in the following order) that:</p><p class="MsoNormal">-each node has some flow path to a boundary pressure and</p><p class="MsoNormal">-iteration convergence control is not too strict</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Can someone help me to interpret what that means and what should I look at in the model? Thank you,</p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal">Arianna   </p><div> <br class="webkit-block-placeholder"></div><p class="MsoNormal"><b>Arianna Sdei</b><span></span></p><div><span> </span><br class="webkit-block-placeholder"></div><p class="MsoNormal"><span>Research Fellow IFORE (Innovation For Renewal) </span></p><div><span> </span><br class="webkit-block-placeholder"></div><p class="MsoNormal"><span>UNIVERSITY OF BRIGHTON</span></p><div><span> </span><br class="webkit-block-placeholder"></div><p class="MsoNormal"><span>Moulsecoomb, Lewes Road, Brighton, BN2 4AT</span></p><div><span> </span><br class="webkit-block-placeholder"></div><p class="MsoNormal"><span>direct line: 0044 (0)2036747268</span></p><p class="MsoNormal"><b> </b></p><p class="MsoNormal"><span>mobile: 0044 (0)7981739024</span></p><p class="MsoNormal"><b> </b></p><div> <br class="webkit-block-placeholder"></div> </div> <br> ___________________________________________________________<br> This email has been scanned by MessageLabs' Email Security<br> System on behalf of the University of Brighton.<br> For more information see <a class="moz-txt-link-freetext" href="http://www.brighton.ac.uk/is/spam/">http://www.brighton.ac.uk/is/spam/</a><br> ___________________________________________________________<br> <br> <fieldset class="mimeAttachmentHeader"></fieldset> <br> <pre wrap="">_______________________________________________ esp-r mailing list <a class="moz-txt-link-abbreviated" href="mailto:esp-r@lists.strath.ac.uk">esp-r@lists.strath.ac.uk</a> <a class="moz-txt-link-freetext" href="http://lists.strath.ac.uk/mailman/listinfo/esp-r">http://lists.strath.ac.uk/mailman/listinfo/esp-r</a></pre> </blockquote> <br> </div> _______________________________________________<br>esp-r mailing list<br><a href="mailto:esp-r@lists.strath.ac.uk">esp-r@lists.strath.ac.uk</a><br>http://lists.strath.ac.uk/mailman/listinfo/esp-r</blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div><a href="mailto:achim.geissler@intergga.ch">achim.geissler@intergga.ch</a></div><div><br></div><div><br></div></span><br class="Apple-interchange-newline"> </div> <br></div></body></html>