<html><head><style type="text/css"></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:10pt"><DIV>Hi,</DIV> <DIV> </DIV> <DIV>Thank you for your mail Jon. </DIV> <DIV> </DIV> <DIV> <DIV>One <STRONG><U>question</U></STRONG> to see if I'm interpreting things in a correct manner: </DIV> <DIV> <STRONG>When looking to volume flow rate and selecting a infiltration connection via Volume Flow Rate of AirFlow Result File the flow rate becomes sometimes negative! What does Negative result mean actually? Does it mean that the air is towards outdoors or from outdoors?</STRONG></DIV></DIV> <DIV> </DIV> <DIV><STRONG><U>Jon's question:</U></STRONG> </DIV> <DIV>Well, I checked the results by choosing the timstep itegration turned OFF. The results stayed the same. I looked to the energy balance per thermal zone, and the results weren't so strange at all. Especially when looking to the ratio of chimney's main stream and what comes in as infiltration air rate. It is 1/10 of the chimney's main stream with dT of 5 - 8 Kelvin depending on the height of the chimney!  </DIV> <DIV> </DIV> <DIV>What attracted my attention was the infiltration rate direction per thermal zone! When looking more in detail - for a particular problem -  the ambient infiltration in the upper level of the chimney becomes negative. This means that the upper level air of the chimney goes simply to outside before it reaches the outlet of the system?! </DIV> <DIV>On the other side, the zones in the lower level have positive infiltration rates when looking to these connections. </DIV> <DIV> </DIV> <DIV>Thanking you in advance.</DIV> <DIV> </DIV> <DIV>Kind Regards,</DIV> <DIV style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 10pt">Ehsan </DIV> <DIV style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 10pt"><BR> <DIV style="FONT-FAMILY: arial, helvetica, sans-serif; FONT-SIZE: 13px"><FONT size=2 face=Tahoma> <HR SIZE=1> <B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Jon Hand <jon@esru.strath.ac.uk><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Ehsan Baharvand <ebaharvand@yahoo.com>; Achim.geissler <achim.geissler@intergga.ch>; "esp-r@lists.strath.ac.uk" <esp-r@lists.strath.ac.uk><BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Sun, April 3, 2011 10:57:56 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> RE: [esp-r] Re: solar chimney<BR></FONT><BR><BR>In an earlier email the simulation parameters were stated.  What caught my attention<BR>was the 60 timesteps per hour with timestep integration turn ON.  This will write out<BR>information once per hour.  I suggest that you save the information at each timestep<BR>so that the actual flows and flux at each timestep is available for inspection.<BR><BR>-Jon Hand<BR>________________________________________<BR><BR>. . .<BR>b) how long is your pre-simulation period, how long is your simulation period and what does "temperature does not change" mean? "Not at all" or "not as much as expected"?<BR>Pre-simulation = 12 days<BR>Simulation period = 1 day (24h)<BR>Time-step = 60<BR>Integration per hour = yes<BR>. . .<BR>Kind regards,<BR>Ehsan<BR>________________________________<BR></DIV></DIV></div></body></html>