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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Since you didn’t change the CHW supply temperature, the drop in chiller load is a result of warmer return water returning to the chiller and improving the rate of heat transfer to the evaporator. The drop in heat rejection is a direct result of the reduced chiller load.<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'>Depending on your HVAC system parameters, you may have seen an increase in fan energy to account for the less efficient heat transfer taking place at the cooling coils.<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><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><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"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Umesh Atre<br><b>Sent:</b> Tuesday, August 09, 2011 11:39 AM<br><b>To:</b> equest-users@lists.onebuilding.org<br><b>Subject:</b> [Equest-users] CHW delta T in eQUEST<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>I am trying to determine the effect of increasing the chilled water delta T on the energy consumption in an office building. I set up 2 models, </span><o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>one with 10 deg delta T, and the other increased to 15 deg on the chilled water loop (elec. centrifugal chiller was used). All other parameters are same in both models.</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>The results show a drop of ~14% in pump energy, but they also show a reduction on both the cooling (~6%) and heat rejection (~3%). </span><o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>Why does the increase in chilled water delta T show savings on these 2 other end-uses? </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>Thanks for any help</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div></div></body></html>