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<p class="MsoNormal"><span style="color:#1F497D">Right, that is a bit trickier. I would say that it is going to be very infrequent that it would call for a load between 0 and 6%. The AHU fan can only go down so much so by the time it comes out of economizer
you should have more than enough load to justify it running. I guess the question would be if you had something with a much lower turndown. The curve that modifies the HIR(PLR) is pretty much linear even though it is in cubic form so there is no variation
in efficiency as you go down in capacity, but check that against your equipment info. Not a whole lot of options, but I’m sure that’s why you asked in the first place.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Brendan Hall, PE, LEED AP</span><span style="font-family:"Arial","sans-serif";color:black">
</span><span style="font-size:8.0pt;font-family:"Arial","sans-serif";color:black">BD+C</span><span style="font-family:"Arial","sans-serif";color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Engineer, Mechanical<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:13.5pt;font-family:"Arial","sans-serif";color:red">karpinski<br>
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</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">3135 Euclid Avenue<br>
Cleveland, OH 44115</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><br>
</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red">P</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">
<a href="tel:216.391.3700" target="_blank">216.391.3700</a> Ext 3111<br>
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</span><u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">www.<a href="http://www.karpinskieng.com/" target="_blank" title="http://www.karpinskieng.com/">karpinskieng.com</a></span></u><span style="color:#1F497D"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Michael Campbell [mailto:mike@sustainablesolutionscorporation.com]
<br>
<b>Sent:</b> Wednesday, March 12, 2014 3:49 PM<br>
<b>To:</b> Hall, Brendan; equest-users@lists.onebuilding.org<br>
<b>Cc:</b> mike@sustainablesolutionscorporation.com<br>
<b>Subject:</b> RE: [Equest-users] Modulating furnace<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks for the reply. However, to clarify, this is an AHU with gas furnace heat, so there is no boiler.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<div>
<p class="MsoNormal"><b><span style="font-family:"Arial","sans-serif";color:#17109C">Mike Campbell, E.I.T., LEED AP O+M</span></b><span style="font-family:"Arial","sans-serif";color:#1F497D"><br>
</span><b><span style="font-family:"Arial","sans-serif";color:#17109C">Sustainability Specialist</span></b><span style="font-family:"Arial","sans-serif";color:#1F497D"><br>
</span><b><span style="font-family:"Arial","sans-serif";color:#4F6228">Sustainable Solutions Corporation</span></b><span style="color:#1F497D"><br>
</span><span style="color:#000099">Office:</span><span style="color:#1F497D"> <a href="http://610-569-1047/" target="_blank">
610-569-1047</a></span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#000099">Mobile:</span><span style="color:#1F497D">
<a href="http://610-569-1047/" target="_blank">609-923-1743</a><br>
<a href="http://www.sustainablesolutionscorporation.com/" target="_blank">www.SustainableSolutionsCorporation.com</a><br>
</span><i><span style="color:#000099">Sustainable Solutions Corporation is WBENC and BCorp Certified.</span></i><span style="color:#1F497D"><br>
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</span><i><span style="font-size:7.5pt;color:#999999">This email message and any attachments are for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Hall, Brendan [mailto:<a href="mailto:BHall@karpinskieng.com">BHall@karpinskieng.com</a>]
<br>
<b>Sent:</b> Wednesday, March 12, 2014 3:45 PM<br>
<b>To:</b> Michael Campbell; <a href="mailto:equest-users@lists.onebuilding.org">
equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> RE: [Equest-users] Modulating furnace</span><o:p></o:p></p>
</div>
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<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D">Under the boiler, set the min ratio = .06.
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span><o:p></o:p></p>
<div>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Brendan Hall, PE, LEED AP</span><span style="font-family:"Arial","sans-serif";color:black">
</span><span style="font-size:8.0pt;font-family:"Arial","sans-serif";color:black">BD+C</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Engineer, Mechanical</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:13.5pt;font-family:"Arial","sans-serif";color:red">karpinski<br>
</span><span style="font-size:7.5pt;font-family:"Arial","sans-serif";color:#1F497D">ENGINEERING</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><br>
</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">3135 Euclid Avenue<br>
Cleveland, OH 44115</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D"><br>
</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red">P</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D">
<a href="tel:216.391.3700" target="_blank">216.391.3700</a> Ext 3111<br>
</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red">E</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:navy">
</span><u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><a href="mailto:bhall@karpinskieng.com" target="_blank" title="mailto:myuhasz@karpinskieng.com">bhall@karpinskieng.com</a></span></u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><br>
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</span><u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue">www.<a href="http://www.karpinskieng.com/" target="_blank" title="http://www.karpinskieng.com/">karpinskieng.com</a></span></u><o:p></o:p></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<a href="mailto:equest-users-bounces@lists.onebuilding.org">equest-users-bounces@lists.onebuilding.org</a> [<a href="mailto:equest-users-bounces@lists.onebuilding.org">mailto:equest-users-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>Michael Campbell<br>
<b>Sent:</b> Wednesday, March 12, 2014 3:41 PM<br>
<b>To:</b> <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> [Equest-users] Modulating furnace</span><o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">What is the appropriate way to model a gas furnace that modulates with a 16:1 turndown?<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Thank you,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><b><span style="font-family:"Arial","sans-serif";color:#17109C">Mike Campbell, E.I.T., LEED AP O+M</span></b><span style="font-family:"Arial","sans-serif""><br>
<b><span style="color:#17109C">Sustainability Specialist</span></b><br>
<b><span style="color:#4F6228">Sustainable Solutions Corporation</span></b></span><br>
<span style="color:#000099">Office:</span> <a href="http://610-569-1047/" target="_blank">
610-569-1047</a><o:p></o:p></p>
<p class="MsoNormal"><span style="color:#000099">Mobile:</span> <a href="http://610-569-1047/" target="_blank">
609-923-1743</a><br>
<a href="http://www.sustainablesolutionscorporation.com/" target="_blank">www.SustainableSolutionsCorporation.com</a><br>
<i><span style="color:#000099">Sustainable Solutions Corporation is WBENC and BCorp Certified.</span></i><br>
<br>
<i><span style="font-size:7.5pt;color:#999999">This email message and any attachments are for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited.
If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.</span></i><o:p></o:p></p>
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