Lyle,<div><br></div><div>The short answer is no. IPLV cannot be used to create performance curves in eQUEST.</div><div><br></div><div>Part-load curves are a strange animal in eQUEST. You'll need cooperation from the chiller manufacturer to get the correct data. You need to have enough data to describe the way energy varies as a function of part-load, chilled water supply temp, and outside air temperature. Take a look at the attached spreadsheet which can be used to create curves in eQUEST. The data in yellow should be entered by the manufacturer or manufacturer's rep. The data in red should be entered into eQUEST. </div>
<div><br></div><div>If you look into the formulas, you'll note that EIR-FPLR is actually not an EIR factor, it is based on the power draw of the equipment at part-load compared to at full-load. This throws a lot of people off as it is not described that way in the help documentation.</div>
<div><br></div><div>The interesting question that arises when working with custom part-load curves is how accurate does the eQUEST default performance curve model the required IPLV for the baseline per ASHRAE 90.1? In my experience the default curve is approximately 10% worse than the IPLV requirement.</div>
<div><br></div><div>Hope this helps,</div><div><br></div><div>Robby Oylear, LEED AP BD+C</div><div>Mechanical Project Engineer</div><div>Energy Analyst</div><div>Rushing</div><div><br><div class="gmail_quote">On Wed, Jun 15, 2011 at 10:59 AM, Lyle Keck <span dir="ltr"><<a href="mailto:lkeck@aeieng.com">lkeck@aeieng.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div lang="EN-US" link="blue" vlink="purple"><div><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. </p>
<p class="MsoNormal"> </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’ </p><p class="MsoNormal"> </p><p class="MsoNormal">
>From previous posts: </p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""> </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</span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Where:</span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">A = COP or EER @ 100% Load</span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">B = COP or EER @ 75% Load</span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">C = COP or EER @ 50% Load</span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">D = COP or EER @ 25% Load</span></p><p class="MsoNormal"> </p><p class="MsoNormal">It is my understanding that EIR-PLR curves give the EIR as a function of part load ratio. </p>
<p class="MsoNormal"> </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? </p>
<p class="MsoNormal"> </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)</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?</p><p class="MsoNormal">
</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.</p><p class="MsoNormal"> </p><p class="MsoNormal">Any input, or reference to a previous post would be appreciated.</p>
<p class="MsoNormal"> </p><p class="MsoNormal">Thanks in advance,</p><p class="MsoNormal"> </p><p class="MsoNormal"> </p><table border="0" cellpadding="0" width="474" style="width:355.5pt"><tbody><tr><td width="167" valign="top" style="width:125.25pt;padding:.75pt .75pt .75pt .75pt">
<p class="MsoNormal"><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"></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"> </span></p></td><td width="283" valign="top" style="width:212.25pt;padding:.75pt .75pt .75pt .75pt"><p class="MsoNormal"><b><span style="font-size:9.0pt;color:#660000">AEI</span></b><span style="font-size:9.0pt;color:#333333"> | AFFILIATED ENGINEERS, INC. <br>
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