<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";
color:black;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";
color:black;}
span.EmailStyle21
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body bgcolor="white" 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">Adam,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I think you are conflating the
<i>rated</i> hot water return temperature input for the eQUEST <i>boiler</i> model, and simulated hourly hot water loop return temperatures.
<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">When that
<i>rated</i> return temperature input for the eQ boiler model is changed, that is a change in the boiler rating point, not a change in the simulated hourly temperatures of the modeled hot water loop. Increasing the
<i>rated</i> <i>boiler</i> HWT, implies that the boiler is <i>more</i> efficient at warmer return temperatures. The parametric doesn’t show any changes to HW loop-design T, control strategies, reset schedules if applicable, design dT, minimum flows or other
loop inputs that would actually change the hourly HW return Ts. So I think the program is doing what it should do given the varied inputs; that is the simulated hourly HWRT is really staying the same, but the modeled boiler efficiency is increasing at those
temperatures as you increase the <i>boiler</i> <i>rated</i> HWRT.<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">If you leave the boiler rated HWRT input constant at an appropriate value for the selected boiler you are trying to simulate, and vary the HW loop design and
control characteristics to simulate raising or lowering the loop HWRT, you should see results more in line w/your expectations; the annual boiler efficiency will go up as the simulated hourly
<i>loop</i> return temperatures go down. There is no direct input for HW loop return temperature; it is a function of the inputs mentioned above, and probably a few others. Achieving these desired low HWRTs is not a trivial matter in actual operation of commercial
HW heating loops, so be careful not to be too optimistic. <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"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Fred Porter, BEMP, LEED</span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">©</span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">
AP<o:p></o:p></span></b></p>
<p class="MsoNormal" style="margin-bottom:2.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F">Principal Engineer<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:2.0pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F">Sustainability Services<o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#005DAA">NORESCO<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F">2540 Frontier Ave, Suite 100, Boulder, CO 80301<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F"><a href="mailto:fporter@noresco.com">fporter@noresco.com</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#807F83"><a href="http://www.noresco.com">www.noresco.com</a></span><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#807F83"><o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:8.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F">Confidentiality Note:<o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Calibri","sans-serif";color:#7F7F7F">Dissemination, distribution or copying of this e-mail or the information herein by anyone other than the intended recipient, or an employee or agent of a system
responsible for delivering the message to the intended recipient, is prohibited. If you are not the intended recipient, please inform the sender and delete all copies.<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"><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";color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> Equest-users [mailto:equest-users-bounces@lists.onebuilding.org]
<b>On Behalf Of </b>Adam Barker<br>
<b>Sent:</b> Friday, September 25, 2015 2:39 PM<br>
<b>To:</b> Brian Fountain<br>
<b>Cc:</b> 'equest-users'<br>
<b>Subject:</b> [External] Re: [Equest-users] Condensing boiler curve issues<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Sure Brian, thanks, and thanks to the others that responded.<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 believe what’s happening has to do with the part load, which as you say seems to have a big influence, as well as how the boilers are staged (or aren’t staged).
My boilers are at very low part loads most of the time. As mentioned if I increase that return water temperature, not touching anything else, my fuel use goes down. Looking at PS-C, it is going
<i>up </i>at higher part loads, but getting better, i.e. going <i>down</i>, at very low part loads – where my boilers are spending most of their time operating, hence the net decrease in energy consumption.<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">PS-C results for my lead boiler (does most of the work)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">At 80F return water temp:
<o:p></o:p></span></p>
<p class="MsoNormal"><img border="0" width="914" height="129" id="Picture_x0020_4" src="cid:image002.png@01D0FA04.0AEEA6D0"><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">At 100 F return water temp:<o:p></o:p></span></p>
<p class="MsoNormal"><img border="0" width="901" height="64" id="Picture_x0020_1" src="cid:image004.png@01D0FA04.0AEEA6D0"><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">At 120F return water temp (which is probably closest to reality, but I don’t trust the results):<o:p></o:p></span></p>
<p class="MsoNormal"><img border="0" width="907" height="70" id="Picture_x0020_2" src="cid:image005.png@01D0FA04.0AEEA6D0"><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"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Am I getting to the fringes of this curve’s limits so its starting to go out of whack?<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">Regards,<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">Adam<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";color:windowtext">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext"> Brian Fountain [<a href="mailto:bfountain@greensim.com">mailto:bfountain@greensim.com</a>]
<br>
<b>Sent:</b> Thursday, September 24, 2015 9:54 AM<br>
<b>To:</b> Adam Barker<br>
<b>Subject:</b> Re: [Equest-users] Condensing boiler curve issues<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt">Hi Adam,<br>
<br>
That is not what I have seen with the curve. Note that there is a rated return water temperature field in the boiler at which the boiler achieves the rated HIR (thermal efficiency). I have seen the curve be strongly dependent on loading -- i.e. much more
efficient when the boiler has a low part load.<br>
<br>
I did see an overlay of the default eQUEST condensing boiler curve and a Lochinvar Benchmark curve and they corresponded reasonably well.<br>
<br>
I'd be interested in taking a peek at your file if you are able to share (perhaps a generic version of it).
<br>
<br>
Brian<o:p></o:p></p>
<div>
<p class="MsoNormal">On 22/09/2015 4:02 PM, Adam Barker wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<pre>Has anyone come across issues with the default condensing boiler curve in eQuest? This curve is a function of part load and return water temperature, and based on how condensing boilers work you would anticipate the part load efficiency to get worse as return water temperature increased (assuming part load is the same).<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>I am seeing the opposite in eQuest, where the default 80F RWT is giving me a poor seasonal efficiency, and a temperature like 160 RWT (in the non-condensing spectrum) is giving me a very high seasonal efficiency.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Any insight into why this might be happening?<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Adam Barker, MBSc, C.E.T., LEED AP BD+C<o:p></o:p></pre>
<pre>Energy Project Manager<o:p></o:p></pre>
<pre>Provident Energy Management Inc.<o:p></o:p></pre>
<pre>T: 416-736-0630 x 1874 | <a href="mailto:abarker@pemi.com">abarker@pemi.com</a><a href="mailto:abarker@pemi.com"><mailto:abarker@pemi.com></a><o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<p class="MsoNormal" style="margin-bottom:12.0pt"><br>
<br>
<o:p></o:p></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Equest-users mailing list<o:p></o:p></pre>
<pre><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><o:p></o:p></pre>
<pre>To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a><o:p></o:p></pre>
</blockquote>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>