<div dir="ltr"><div>Thanks Rob & James for your prompt input to my dilemma....after I sent the email to the list, I went back in my plants to try and make sense why the secondary wasn't seeing a load--so for a random test I switched the assignement of the two chillers (just reversed which loops they are on.) and then ran the sim without errors. That was the good news. I don't have my head around the logic of why that worked on the first try, but maybe I was having some dislexia-input moments and spec'd my chiller conditions backwards (i.e. high chiller & low chiller in the series).</div>
<div> </div>
<div>Since it has ran I noticed an immediate reduction in chiller energy use, but I haven't yet verified if the reduction is realistic and if there are any other QC error type things to verify that this approach is indeed modeling the chiller temps in series. I don't think I will mess with custom chiller curves at this point because this project model is only SD. Therefore I won't be held to any compliance reviews and strict performance results...at least not at this point in time.</div>
<div> </div>
<div>I'll try to send feedback when I can verify that this is a valid input option for chillers in series, or if it holds no water at all...</div>
<div> </div>
<div>Cheers,</div>
<div>Pasha<br><br></div>
<div class="gmail_quote">On Fri, Apr 22, 2011 at 12:18 PM, James Hansen <span dir="ltr"><<a href="mailto:JHANSEN@ghtltd.com">JHANSEN@ghtltd.com</a>></span> wrote:<br>
<blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote">
<div lang="EN-US" vlink="purple" link="blue">
<div>
<p class="MsoNormal"><span style="COLOR: #1f497d; FONT-SIZE: 11pt">Most manufacturers will give you a “single chiller” performance curve for the two chillers in series. I typically just make custom chiller curves to represent series chillers as a single chiller. If a designer creates valving that allows water to NOT have to flow through both chillers during low load operation, this gets a little tricky, and I end up averaging the delta P across the chillers to represent partial operation thru both chillers and partial operation thru a single chiller. No easy way to do this.</span></p>
<p class="MsoNormal"><span style="COLOR: #1f497d; FONT-SIZE: 11pt"> </span></p>
<p class="MsoNormal"><b><span style="COLOR: teal; FONT-SIZE: 11pt">GHT Limited</span></b><b><span style="COLOR: teal; FONT-SIZE: 11pt"><br></span></b><b><span style="FONT-SIZE: 11pt"><span style="COLOR: black">James Hansen</span></span></b><b><span style="COLOR: black; FONT-SIZE: 11pt">, PE, LEED AP</span></b></p>
<p class="MsoNormal"><b><span style="COLOR: black; FONT-SIZE: 10pt">Senior Associate</span></b><b><span style="COLOR: black; FONT-SIZE: 11pt"></span></b></p>
<p class="MsoNormal"><span style="FONT-SIZE: 7.5pt"><span style="COLOR: black">1010 N. Glebe Rd, Suite 200</span></span><span style="COLOR: #1f497d; FONT-SIZE: 11pt"></span></p>
<p class="MsoNormal"><span style="FONT-SIZE: 7.5pt"><span style="COLOR: black">Arlington</span><span style="COLOR: black">, </span><span style="COLOR: black">VA</span><span style="COLOR: black"> </span><span style="COLOR: black">22201-4749</span></span><span style="COLOR: black; FONT-SIZE: 11pt"></span></p>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 7.5pt"><a href="tel:703-338-5754" target="_blank" value="+17033385754">703-338-5754</a> (Cell)</span><span style="COLOR: black; FONT-SIZE: 11pt"></span></p>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 7.5pt"><a href="tel:703-243-1200" target="_blank" value="+17032431200">703-243-1200</a> (Office)</span><span style="COLOR: black; FONT-SIZE: 11pt"></span></p>
<p class="MsoNormal"><span style="COLOR: black; FONT-SIZE: 7.5pt"><a href="tel:703-276-1376" target="_blank" value="+17032761376">703-276-1376</a> (Fax)</span><span style="COLOR: black; FONT-SIZE: 11pt"></span></p>
<p class="MsoNormal"><span style="COLOR: teal; FONT-SIZE: 11pt"><a href="http://www.ghtltd.com/" target="_blank"><span style="FONT-SIZE: 10pt">www.ghtltd.com</span></a></span></p>
<p class="MsoNormal"><b><span style="COLOR: #31849b; FONT-SIZE: 11pt"> </span></b></p>
<p class="MsoNormal"><span style="COLOR: #1f497d; FONT-SIZE: 11pt"> </span></p>
<div style="BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt">
<p class="MsoNormal"><b><span style="FONT-SIZE: 10pt">From:</span></b><span style="FONT-SIZE: 10pt"> <a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a> [mailto:<a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Rob Hudson<br>
<b>Sent:</b> Friday, April 22, 2011 2:15 PM<br><b>To:</b> Pasha Korber-Gonzalez<br><b>Cc:</b> eQUEST Users List; Arunabha Sau<br><b>Subject:</b> Re: [Equest-users] Chillers in Series inputs</span></p></div>
<div>
<div></div>
<div class="h5">
<p class="MsoNormal"> </p>
<p class="MsoNormal">I won't claim that this is correct whatsoever, but briefly looking at your set up, it is clear that the water isn't pulling extra load from the second chiller. I think you may want to set up a single chiller because I don't see a way to get the water to go through both chillers. You could also create your own custom curves so that you match the combined performance of the modeled chiller.</p>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">Just a thought.</p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p style="MARGIN-BOTTOM: 12pt" class="MsoNormal">Rob</p>
<div>
<p class="MsoNormal">On Fri, Apr 22, 2011 at 1:55 PM, Pasha Korber-Gonzalez <<a href="mailto:pasha.pkconsulting@gmail.com" target="_blank">pasha.pkconsulting@gmail.com</a>> wrote:</p>
<div>
<div>
<p class="MsoNormal">Hi,</p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">I could use some guidance to make sure I'm assuming the correct inputs to set up chillers in series. This is the first time I'm trying to model this and I have it set up with a primary & secondary loop for a total delta T of 16 across 2 chillers. I'm getting a run error of the secondary loop having NO DESIGN FLOW/LOAD, but I'm not sure how to show that load on the secondary loop.....maybe I have the chillers listed backwards???</p>
</div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">Can anyone take a quick look at the setup in the Plant Module and let me know what I am missing on this? I couldn't find any info on chillers in series in the DOE-2 docs to guide me on the correct inputs and setup.</p>
</div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">.pd2 & inp files attached.</p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">Thanks in advance for your keen eye and guidance on my model.</p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal"><span style="COLOR: #888888">Pasha</span></p></div></div>
<p style="MARGIN-BOTTOM: 12pt" class="MsoNormal"><br>_______________________________________________<br>Equest-users mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org" target="_blank">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG" target="_blank">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a></p></div>
<p class="MsoNormal"><br><br><br>-- <br>Rob Hudson</p></div></div></div></div></div></blockquote></div><br></div>