<div dir="ltr"><div class="gmail_default" style="font-size:large;color:#b45f06">Tom,</div><div class="gmail_default" style="font-size:large;color:#b45f06"><br></div><div class="gmail_default" style="font-size:large;color:#b45f06">A Combustion analyzer tells only part of the story. </div><div class="gmail_default" style="font-size:large;color:#b45f06"><br></div><div class="gmail_default" style="font-size:large;color:#b45f06">Some boilers cycle frequently due to being oversized (a common situation) and (of course) when operating at part load. The cycling brings some inefficiency and it can be substantial. Hot water boilers, as I understand it, are more impacted by these cycling losses than steam boilers.</div><div class="gmail_default" style="font-size:large;color:#b45f06"><br></div><div class="gmail_default" style="font-size:large;color:#b45f06">For one of our projects, a steam boiler was losing water regularly via condensate line leaks in a tunnel. Our energy model, with pretty good measurements of equipment power and other operating parameters, would only match their utility meter readings when we used 52% peak boiler efficiency. The leaks apparently had big impact on efficiency.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Jul 21, 2015 at 10:35 AM, Davidson, Tom <span dir="ltr"><<a href="mailto:TDavidson@dlbassociates.com" target="_blank">TDavidson@dlbassociates.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="#3333CC" vlink="#B2B2B2"><div><p class="MsoNormal">Dear Bldg-Sim list,<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">We are trying to determine the efficiency of an old gas-fired steam boiler that we plan to replace with a high-efficiency hot water boiler. We asked a company that tunes burners to take two combustion efficiency measurements – one before tuning and one after. Unfortunately the burner was operating so poorly prior to tuning that it messed up the combustion efficiency analyzer; it gave no readings and our opportunity to obtain a pre-implementation combustion efficiency value was lost. We do know that the burner was being starved of combustion air, but we aren’t sure by how much, or how low the efficiency of a gas-fired boiler can drop before its safeties shut it off.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">If anyone has successfully measured the efficiency of an operating boiler that is starved of combustion air, and is willing to share this efficiency, I would be quite grateful. I am looking your ‘worst of the worst’ efficiency measurements. The rest of our energy model Is nicely aligned with facility usage, but we would need to drop the overall efficiency of this boiler to less than 50% to align with utility data, and even this value assumes that we are generous in terms of modeling warm winter temperature setpoints, high infiltration rates, etc.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">For reference the steam boiler we looked at is about 45 years old, made by the Federal Boiler Co. (Model AST 6 350).<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Thanks,<u></u><u></u></p><p class="MsoNormal">Tom<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><table border="0" cellspacing="0" cellpadding="0" style="border-collapse:collapse"><tbody><tr><td valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in"><p class="MsoNormal" align="left" style="text-align:left"><span style="font-size:10.5pt;font-family:"Verdana","sans-serif";color:black">Thomas A. Davidson, PE</span><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:black"> <u></u><u></u></span></p></td></tr><tr><td valign="top" style="padding:0in 0in 0in 0in"><p class="MsoNormal" align="left" style="text-align:left"><b><span style="font-size:8.0pt;font-family:"Verdana","sans-serif";color:black">DLB Associates</span></b><span style="font-size:8.0pt;font-family:"Verdana","sans-serif";color:black"> | 265 Industrial Way West | Eatontown, NJ 07724</span><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-size:8.0pt;font-family:"Verdana","sans-serif";color:black"><br><a href="mailto:tdavidson@dlbassociates.com" target="_blank">tdavidson@dlbassociates.com</a> | <a href="tel:732-927-5108" value="+17329275108" target="_blank">732-927-5108</a> | f: <a href="tel:732-774-5000" value="+17327745000" target="_blank">732-774-5000</a></span><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:black"> </span><span style="font-size:8.0pt;font-family:"Verdana","sans-serif";color:black"><br><a href="http://www.dlbassociates.com" target="_blank"><span style="color:#0e4ead">DLB Website</span></a> | <a href="http://www.youtube.com/user/TheDLBAssociates" target="_blank"><span style="color:#cc181e">YouTube</span></a> | <a href="http://www.linkedin.com/company/dlb-associates" target="_blank"><span style="color:#1d87bd">LinkedIn</span></a> | <a href="http://twitter.com/DLBAssociates" target="_blank"><span style="color:#55acae">Twitter</span></a> | <a href="https://www.facebook.com/DLBAssociates" target="_blank"><span style="color:#43609c">Facebook</span></a></span><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:black"> <u></u><u></u></span></p></td></tr></tbody></table><p class="MsoNormal"><u></u> <u></u></p></div></div><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><p><span style="font-size:10pt;font-family:Arial,sans-serif;color:black;background-image:initial;background-repeat:initial"></span></p>James V Dirkes II, PE, BEMP, LEED AP<br>CEO/President<br>The Building Performance Team Inc.<br>1631 Acacia Dr, GR, Mi 49504<br><br>Direct: 616.450.8653<br><a href="mailto:jim@buildingperformanceteam.com" target="_blank">jim@buildingperformanceteam.com</a><br><br><a href="http://buildingperformanceteamcom" target="_blank">Website </a>l <a href="https://www.linkedin.com/pub/jim-dirkes/7/444/413" target="_blank">LinkedIn</a><p align="center" style="margin-bottom:0in;margin-bottom:.0001pt;text-align:center"><b><i><span style="font-size:14.0pt;line-height:115%;font-family:"MS Reference Sans Serif","sans-serif""> </span></i></b><span style="font-family:"MS Reference Sans Serif","sans-serif""></span></p><p style="vertical-align:middle">
</p><p style="margin-bottom:6.0pt;text-autospace:none"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""><font color="#0000ff">Life is not easy. It’s never been easy. Expecting it to be easy
is not a healthy attitude.<br>
Relax. Refresh. Regroup. Carry on.</font></span></p></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
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