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--></style></head><body lang=EN-CA link=blue vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>Thank you Christina,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Please a quick clarification. I am inputting only outdoor temperature variation which is a sinusoidal daily temperature variation and all other weather inputs are zeroed. All forms of radiative heat exchange outside and inside the building are turned off. The daily temperature is prescribed to vary between a maximum value of 40°C and a minimum value of 0°C and the indoor temperature is set at 20°C. The result shows the mean of the convective heat flux to the outside surface from the ambient air and the convective heat flux from the inside surface to the air are zero as expected. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>However, for the heat flux through the windows, the mean is not zero. Is this because of the temperature dependent properties used for the calculation of the Uvalue of the window at each time step?<o:p></o:p></b></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thank you for your help.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Warm regards,<o:p></o:p></p><p class=MsoNormal>Oselen Imafidon</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows</p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal style='border:none;padding:0cm'><b>From: </b><a href="mailto:hotline@Transsolar.com">hotline</a><br><b>Sent: </b>November 12, 2021 6:06 AM<br><b>To: </b><a href="mailto:trnsys-users@lists.onebuilding.org">'trnsys-users@lists.onebuilding.org'</a><br><b>Cc: </b><a href="mailto:josephoselen@yahoo.com">'Oselen Imafidon'</a><br><b>Subject: </b>AW: [TRNSYS-users] Zeroing inside and outside longwave radiation of window surfaces</p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'>Dear Oselen,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'>you are right with your idea, if you set the longwave radiation mode to simple and set the combined heat transfer coefficient equal to the convective part, the <span style='background:white'>longwave radiation</span> is effectively zeroed. One thing to keep in mind is that this is then the case for all surfaces in the room.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'>If you want to consider the <span style='background:white'>longwave radiation</span> for all surfaces <b>but </b>the window, you can use the same method you did for the outside case. You can select <span style='background:white'>longwave radiation</span> detailed mode for the zone and set the back emissivity of the glazing + the frame to 0, too. In this case the window will behave like a <span style='background:white'>longwave radiation</span>-mirror so to speak and the <span style='background:white'>longwave radiation</span> exchange will still be calculated using view factors between the other surfaces in the zone. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'><img border=0 width=812 height=400 style='width:8.4583in;height:4.1666in' id="Picture_x0020_11" src="cid:image004.png@01D7D7BF.C6A13CE0"></span><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'>Best regards,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'>Christina<o:p></o:p></span></p></div><div><div><p class=MsoNormal><span lang=EN-US style='font-size:12.0pt;color:black'><o:p> </o:p></span></p></div><div id=Signature><div><div id=divtagdefaultwrapper><div><p class=MsoNormal><i><span lang=EN-US style='font-size:9.0pt;font-family:"Arial",sans-serif;color:black'>__________________________________________________________________________________________________</span></i><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black'> </span><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p><b><span lang=EN-US style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Transsolar KlimaEngineering</span></b><span lang=EN-US style='color:black'><o:p></o:p></span></p><p><span lang=EN-US style='font-size:9.0pt;font-family:"Arial",sans-serif;color:black'>Stuttgart</span><span lang=EN-US style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'> | München | Paris | New York</span><span lang=EN-US style='color:black'><o:p></o:p></span></p><p><span lang=EN-US style='color:black'><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-US><a href="https://www.trnsys.de/"><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'>https://www.trnsys.de</span></a><br><a href="https://transsolar.com/de"><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'>https://transsolar.com/de</span></a><o:p></o:p></span></p></div><p><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p><span lang=DE style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'>Transsolar Energietechnik GmbH | Curiestraße 2 | 70563 Stuttgart</span><span lang=DE style='color:black'><o:p></o:p></span></p><p><span lang=DE style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'>Geschäftsführer: Matthias Schuler, Thomas Auer, Stefan Holst, Dieter Schnelle </span><span lang=DE style='color:black'><o:p></o:p></span></p><p><span lang=DE style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#7F7F7F'>Registered at Amtsgericht Stuttgart HRB 23347 | USt-IdNr.: DE 152272639</span><span lang=DE style='color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=DE style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black'> </span><span lang=DE style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black'>The simulation project you have sent will be stored on the local servers of Transsolar Energietechnik GmbH for the duration of the project support. Our employees are obliged by us to confidentiality. After this period, all project-related data is deleted.</span><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black'> </span><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Arial",sans-serif;color:black'>The storage of your personal e-mail and other contact information is based on the mutual interest in the execution of this traffic and on a mutual business contact. If you have any questions, please contact our data protection officer at <span class=MsoHyperlink><span style='color:black'><a href="mailto:privacy@transsolar.com"><span style='color:black'>privacy@transsolar.com</span></a></span></span>. Our privacy policy can be found <span class=MsoHyperlink><span style='color:black'><a href="http://www.trnsys.de/docs/userservice/userservice_dataprivacy_en.htm"><span style='color:black'>here</span></a></span></span>.</span><span lang=EN-US style='font-size:12.0pt;color:black'><o:p></o:p></span></p></div></div></div></div></div><p class=MsoNormal align=center style='text-align:center'><span lang=EN-US><img border=0 width=555 height=2 style='width:5.7833in;height:.0166in' id="Horizontal_x0020_Line_x0020_2" src="cid:image005.png@01D7D7BF.C6A13CE0"></span><span lang=EN-US><o:p></o:p></span></p><div id=divRplyFwdMsg><p class=MsoNormal><b><span lang=DE style='color:black'>Von:</span></b><span lang=DE style='color:black'> TRNSYS-users <trnsys-users-bounces@lists.onebuilding.org> im Auftrag von Oselen Imafidon via TRNSYS-users <trnsys-users@lists.onebuilding.org><br><b>Gesendet:</b> Freitag, 29. </span><span lang=EN-US style='color:black'>Oktober 2021 15:21<br><b>An:</b> trnsys-users@lists.onebuilding.org <trnsys-users@lists.onebuilding.org><br><b>Cc:</b> Oselen Imafidon <josephoselen@yahoo.com><br><b>Betreff:</b> [TRNSYS-users] Zeroing inside and outside longwave radiation of window surfaces</span><span lang=EN-US> <o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-US> <o:p></o:p></span></p></div></div><div><div><p class=xmsonormal>Hello,</p><p class=xmsonormal> </p><p class=xmsonormal>To zero the inside longwave radiation of the window I used the simple model longwave radiation exchange within a zone. </p><p class=xmsonormal> </p><p class=xmsonormal>To zero outside longwave radiation of the window, I modified both the window frame emissivity to zero and the front emissivity of the first window glazing in the building input description file (BIU) to zero. </p><p class=xmsonormal> </p><p class=xmsonormal>I used hand calculation to verify the simulation results using the following equations for heat fluxes to the outside and inside surface and the results were same. <span style='color:black'>. The result shows inside and outside longwave radiation of window surfaces are zeroed.</span></p><p class=xmsonormal><span style='color:black'> </span></p><p class=xmsonormal>Is this the right way of zeroing <span style='color:black'>inside and outside longwave radiation of window surfaces?</span></p><p class=xmsonormal><span style='color:black'> </span></p><p class=xmsonormal><span style='color:black'>Thank you.</span></p><p class=xmsonormal><span style='color:black'> </span></p><p class=xmsonormal><span style='color:black'>Regards,</span></p><p class=xmsonormal><span style='color:black'>Oselen I</span></p><p class=xmsonormal> </p><p class=xmsonormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows</p></div></div><p class=xmsonormal> </p><p class=MsoNormal><o:p> </o:p></p></div></body></html>