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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The way to correlate bypass fraction with the manufacturer’s data sheet is through the approach temperature.
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">You adjust the bypass fraction so that the approach temperatures match the selection of the coil.
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">It’s somewhat iterative so I’ve created a separate small model with a constant air flow and water flow that I input and then adjust the bypass fraction until
the approach temperature is about right for my actual selection. <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">Fred<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#660000;text-transform:uppercase">Fred Betz</span></b><b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333">
</span></b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333">PhD., LEED AP
<br>
</span><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#333333;text-transform:uppercase">Sustainable Systems Analyst</span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333"><o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#660000">AEI</span></b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333"> |
AFFILIATED ENGINEERS, INC. <br>
5802 Research Park Blvd. | Madison, WI 53719<br>
<br>
</span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#660000">P: 608.236.1175 | F: 608.238.2614</span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333"> <br>
</span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#660000"><a href="mailto:fbetz@aeieng.com"><span style="color:#660000;text-decoration:none">fbetz@aeieng.com</span></a> |
</span><b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#660000"><a href="http://www.aeieng.com/"><span style="color:#660000;text-decoration:none">www.aeieng.com</span></a></span></b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333">
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<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""> Jean Marais [mailto:jeannieboef@gmail.com]
<br>
<b>Sent:</b> Wednesday, September 05, 2012 6:39 AM<br>
<b>To:</b> TRNSYS-users@cae.wisc.edu<br>
<b>Subject:</b> [TRNSYS-users] Coil ByPass Fraction<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Dear Group,<br>
<br>
I would love to know how you go about assigning the parameter "coil bypass fraction" for cooling coils that cool air. This parameter must be affected by the physical coil dimensions (pipe diameter, fins, number of rows, etc.) as well as by mass flow rate of
the air and the overall dimensions of the coil. I've never seen this on a manufacturer's data sheet. Please advise.<br>
<br>
Regards,<br>
<br>
Jean.<br>
<br>
PS I had hoped this was internally calculated without user input.<o:p></o:p></p>
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