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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi there,<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">Sounds like you are getting yourself turned around… There are a few schools of thought out there regarding exactly how cooling EIR should be derived from a
fan-inclusive energy rating (it’s my understanding future versions/addenda to 90.1 may address/clarify this with a sort of generic set of “non-fan cooling/heating efficiency factors”), but you should not be entering 0.0 energy for your fan in any case.
<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">Presently, one can choose to figure a baseline system cooling EIR using either the baseline Pfan or ARI procedure fan power figures… I have used both without
consequence, and the two methods (usually) produce similar results, but I have gathered over time approaches based on ARI fan energies are easier to pick up and may be more widely practiced, so I’ll describe that approach here. The archives contain a few
discussions (look for my name) describing Pfan-based methods as well:<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="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Use the modeled capacity (SV-A) and prescribed EER to determine the Total system energy at full capacity. <o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Determine the fan power as specified by the ARI rating procedures (365W/CFM) using the modeled baseline system airflow (SV-A). This is distinct from
Pfan. <o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Subtract the ARI fan energy from the total system energy. The result is the non-fan energy.
<o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Divide this remainder (non-fan energy) by the capacity (SV-A) and adjust/convert as necessary to make the ratio unitless – now you’ve found cooling
EIR.<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"><u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Interesting to note</span></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">: I’ve learned HAP’s baseline automation tools
use an ARI-based procedure much like the above, but further tweaks the numbers to account for local design conditions differing from ARI test conditions. In practice this makes the same baseline system in very hot design conditions like Arizona cool less
efficiently than in more temperate design conditions... It took me awhile but I’ve come to wrap my head around the logic. Does anybody using eQuest or otherwise doing these baseline calcs “by hand” perform a similar efficiency ‘de-rating’ in their spreadsheet
calcs?<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">~Nick<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"><img width="119" height="37" id="Picture_x0020_1" src="cid:image001.jpg@01CD22F8.8BB28A20" alt="cid:489575314@22072009-0ABB"></span><b><span style="font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E"><o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Stylus BT","sans-serif";color:#2D4D5E">NICK CATON, P.E.</span></b><b><span style="font-family:"Stylus BT","sans-serif";color:#2D4D5E"><o:p></o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:#CC9900">SENIOR ENGINEER<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:#CC9900"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E">Smith & Boucher Engineers</span><span style="font-size:7.5pt;color:#CC9900"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E">25501 west valley parkway, suite 200<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E">olathe, ks 66061<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E">direct 913.344.0036<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E">fax 913.345.0617<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><a href="www.smithboucher.com" title="blocked::www.smithboucher.com"><span style="font-size:10.0pt;color:blue">www.smithboucher.com</span></a></span><u><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:blue">
</span></u><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 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"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org]
<b>On Behalf Of </b>Aaron<br>
<b>Sent:</b> Tuesday, April 24, 2012 11:26 PM<br>
<b>To:</b> equest-users<br>
<b>Subject:</b> [Equest-users] how to simulate PTAC reasonably<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:15.75pt">
Dear all<br>
If baseline is system 1 (PTAC), the equipment is decided according to table 6.8.1D which is for the whole equipment, while 90.1 Manual says the supply fan energy (0.3W/cfm for system 1&2) should be separate from cooling system energy, shown as the picture
below<br>
<img border="0" width="189" height="354" id="_x0000_i1025" src="cid:image002.png@01CD22F8.8BB28A20"><br>
About how to calculate the COP except supply fan energy, the manual also gives the equation as shown below:<br>
<img border="0" width="494" height="207" id="_x0000_i1026" src="cid:image003.png@01CD22F8.8BB28A20"><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:.25in">
I try to find the Cooling Capacity for every PTAC system in SV-A report and calculate the COP for the cooling section(Compressor and condenser), while when I input the cooling EIP (1/COP) in cooling uni and 0.3W/cfm for supply fan, the energy consumption is
much higher than inputting the whole EER for the cooling EIR and 0 W/cfm for the supply fan before. From the energy breakdown contrast, what surprises me is that the energy for cooling is more than before.
<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:.25in">
When I try to change the fan delta t from 0.93 to 0 and find the cooling energy is decreasing than inputting the whole EER, but the sum of cooling and fan is still more than inputting the whole EER ,
<b>have anyone met the same confusion before and tell me the reason and how to simulate PTAC reasonably.</b><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:18.05pt">
<b>Thanks a lot</b><o:p></o:p></p>
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