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<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">Dear All.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">This question is about VAV in control function.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">Let me assume one zone to which 100 CMH air volume is supplied for heating. And the 90 CMH air volume is returned through diffuser in the same zone. </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">The surplus 10 CMH air supply volume plays the role of the source of positive net pressure that prevents the air infiltration from the adjacent zones.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">In this case, how should i set the the max air volume flow rate in control law? </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">1) Real volume 100 CMH? or net volume 10 CMH?</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">2) How can I describe the supply and return separately in VAV control law?</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt">And, I have done above simulation with the setting of the supply air volume as net volume 10 CMH.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:10pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt">I found some strange results which seem to be fluctuating.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt">In other words, in some nodes, the flow direction changes in every time step from positive to negative and from negative to positive.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt">I tried to adjust the time step. However, the flow direction fluctuates between positive and negative value regardless of the time step.</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt">3) Do you think this kind of pattern can be obtained in VAV control?</font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt"> </font></p>
<p align="justify" style="line-height:1.5;margin-top:0;margin-bottom:0"><font style="font-family:Arial;font-size:9pt">I appreciate for your interests and ideas.</font></p>
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