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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Augustin,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>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. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Aaron J. Danenberg<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Graduate Research Assistant<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>University of Hartford<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><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"'> Augustin CUQ [mailto:augustin.cuq@gmail.com] <br><b>Sent:</b> Monday, June 06, 2011 10:03 AM<br><b>To:</b> trnsys-users<br><b>Subject:</b> [TRNSYS-users] Decrease of temperature with Type 56<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>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 <o:p></o:p></p></div></body></html>