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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The performance map in the heat pump should account for this when you’re connected to the Lake/Well circulation loop. You can plot the hourly EIR from the heat
pump to confirm this. <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"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">That said, the ground temperature in the Earth is relatively constant if you go deep enough. Surface temperatures will fluctuate to a depth of about 2-3m. However,
if you only plan on rejecting heat to the ground, the temperature of the ground will increase unless you’re in a highly conductive area such as a swamp.
<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">In a typical geoexchange field with a starting temperature of 50F (10C), the ground temperature will vary between 40F (4C) and 85F(29C) over the course of a
year as heat is rejected to the ground in the summer, and removed from the ground over the winter.
<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">I would caution against solely rejecting heat to the ground from your heat pump unless your conductivity is sufficiently high and/or your geoexchange system
is sufficiently large to let the heat bleed away during the winter. <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">The real value in a geoexchange system comes from recovering this heat in the winter so you’re heating your building from a relatively warm source rather than
from a fossil fuel or electrical resistance. Often geoexchange systems use more energy than a high performance chiller with open cooling tower for cooling, but make that up by being a very efficient heat source. If you have no need for heat, a centrifugal
chiller with an open tower might be a better solution. <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">Hope that makes sense,<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>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><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> |
<b><a href="http://www.aeieng.com/"><span style="color:#660000;text-decoration:none">www.aeieng.com</span></a></b></span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#333333"> </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"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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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""> Sambhav Tiwari [mailto:tiwari.sambhav@gmail.com]
<br>
<b>Sent:</b> Monday, June 24, 2013 2:15 AM<br>
<b>To:</b> equest-users<br>
<b>Subject:</b> [Equest-users] Ground sourse heat pump(Geothermal system)<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Dear Equesters,<o:p></o:p></p>
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<p class="MsoNormal"> We have one building where we are proposing to cool the condenser of chiller by Ground sourse heat pump(Geothermal system) rather than cooling by cooling tower. As i have studied the literature about GSHP it
says that since earth tempearture remains constant through out the year and hence the COP of chiller will be better as condenser entering temperature is reduced but how can i model the increase of COP due to this ,should i reduce this value directly in chiller
EIR or there is some indirect method.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">Regards<o:p></o:p></p>
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<p class="MsoNormal">Sambhav<o:p></o:p></p>
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