<html> <head> <style></style></head> <body class='hmmessage'><div dir='ltr'>  <p class="MsoNormal"><span lang="EN-US">Hello ESP-r esperts, Could someone help me with the following questions?</span></p> <p class="MsoNormal" style="margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1; tab-stops:list 18.0pt"><span style="mso-fareast-font-family: "Times New Roman"" lang="EN-US"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman"">       </span></span></span><span lang="EN-US">About the emissivity ,In material database, we are provided with “Emissivity out” “ Emissivity in”<span style="mso-spacerun:yes">  </span>choices. I made a small test , for a given material on a given surface, If I only reduce “ Emissivity out” , the simulation results remains the same. If I only reduce ” Emissivity in”, leaving “Emissivity out” the same as before, in result analysis the longwave radiation to sky will be reduced, while the temperature for this surface increases. Does this mean that if I change the “ Emissivity in” , “ Emissivity out “will be automatically changed as the same value of “ Emissivity in”? What can I do if I want to simulate an external Low-E coating to reduce the longwave to sky?</span></p> <p class="MsoNormal" style="margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1; tab-stops:list 18.0pt"><span style="mso-fareast-font-family: "Times New Roman"" lang="EN-US"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman"">       </span></span></span><span lang="EN-US">About the airflow network .I coupled the simulation with an airflow network .However I found that the ambient temperature from the output of .mfr is half an hour “earlier” respect to the output of .res. While on the contrary I found when I inquire the heat storage in the air , the output from .res is half an hour “earlier” respect to the calculation from the .mfr output(I made the calculation based on the output from .mfr). I run the simulation 1 step per hour with hourly result integration.</span></p> <p class="MsoNormal" style="margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1; tab-stops:list 18.0pt"><span lang="EN-US"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman"">   </span></span>Something very strange. I have an airflow network including an fixed temperature node<span style="mso-spacerun:yes">  </span>with heating setpoint at 18 degree. It works well when I set this fixed temperature node to be 20 degree ,but when I changed it to be 50 degree, there is no flow anymore .This is the only parameter I changed. Why? I appreciate if someone could give me a hand, also I can send you the model I made.</span></p><p class="MsoNormal" style="margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1; tab-stops:list 18.0pt"> <span lang="EN-US"></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">Best Regards,</span></p> <br><br><div><i>Suo Hua</i></div> <div><i> </i></div> <div><i>Ph.D Student in Tecnologia e Progetto per l'Ambiente Costruito/Technology and Design for Environment and Building</i></div> <div><i> </i></div> <div><i>Il Dipartimento B.E.S.T.Dipartimento di Scienza e Tecnologie dell’Ambiente Costruito/ The Department of Building Environment Science & Technology</i></div> <div><i> </i></div> <div><i>Politecnico Di Milano</i></div><br> <div><a href="mailto:Email%3Ahua.suo@mail.polimi.it"><i>Email:hua.suo@mail.polimi.it</i></a></div><br>  <br>  <br>  <br>  <br>  <br> </div></body> </html>