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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>All, <br><br>I am trying to create a part load curve for an air-cooled screw chiller. I have the EER & COP data for 100%, 75%, 50%, and 25% loading. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have read through the various posts in the archives and I am still unsure if I should input this data as ‘raw data’ or ‘coefficients’ <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>From previous posts: <o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>IPLV (or NPLV) = 0.01A+0.42B+0.45C+0.12D<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Where:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>A = COP or EER @ 100% Load<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>B = COP or EER @ 75% Load<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>C = COP or EER @ 50% Load<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>D = COP or EER @ 25% Load<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It is my understanding that EIR-PLR curves give the EIR as a function of part load ratio. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>SO, if I create a ‘cubic’ curve with input type ‘curve coefficients’, and input a=(1/COP-100%), b=(1/COP-75%), c=(1/COP-50%), and d=(1/COP-25%) and specify this curve as the EIR - f(part load ratio) curve, would that be accurate? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Additionally, this chiller has a condenser water temp of 95 degF and design conditions that differ from AHRI conditions (design EWT=58 degF and LWT=44 degF)<o:p></o:p></p><p class=MsoNormal>Do these values have direct correlation to the curve creation ? Or can the condenser and CHW temp simply be defined in the ‘basic specifications’ tab for the chiller, and the EWT defined via the CHW loop deltaT?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I know this topic has been widely discussed, but I am still uneasy about the actual inputs for the creation of the part load performance curve.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any input, or reference to a previous post would be appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks in advance,<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><table class=MsoNormalTable border=0 cellpadding=0 width=474 style='width:355.5pt'><tr><td width=167 valign=top style='width:125.25pt;padding:.75pt .75pt .75pt .75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-size:10.0pt;color:#660000;text-transform:uppercase'>Lyle Keck</span></b><b><span style='font-size:9.0pt;color:#333333'> </span></b><span style='font-size:9.0pt;color:#333333'><br></span><span style='font-size:10.0pt;color:#333333;text-transform:uppercase'>SustainablE Systems Analyst</span><span style='font-size:9.0pt;color:#333333'><o:p></o:p></span></p></td><td width=10 valign=top style='width:7.5pt;padding:.75pt .75pt .75pt .75pt'><p class=MsoNormal><span style='font-size:9.0pt;color:#333333'> <o:p></o:p></span></p></td><td width=283 valign=top style='width:212.25pt;padding:.75pt .75pt .75pt .75pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-size:9.0pt;color:#660000'>AEI</span></b><span style='font-size:9.0pt;color:#333333'> | AFFILIATED ENGINEERS, INC. <br>Westlake Center Office Tower, 1601 Fifth Avenue, Suite 1400 | Seattle, WA 98101<br><br></span><span style='font-size:9.0pt;color:#660000'>P: 206.256.0800 | F: 206.256.0423</span><span style='font-size:9.0pt;color:#333333'> <br></span><span style='font-size:9.0pt;color:#660000'><a href="mailto:lkeck@aeieng.com"><span style='color:#660000;text-decoration:none'>lkeck@aeieng.com</span></a> | </span><b><span style='font-size:9.0pt;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;color:#333333'> <o:p></o:p></span></p></td></tr></table><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>