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</o:shapelayout></xml><![endif]--></head><body 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'>Paul,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kudos to those who are improving the fan, system, and lab aspects in 90.1. And the intent of the specific section below is good, logical, and apparently needed if some modelers are putting all of the baseline power on the supply fan. <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'>However, given all of the all of the possible model complexities, it is still not does not preclude the need for judgment. As one example, several clauses in G3.1.1 can cause a deviation from a one-to-one relationship between baseline and proposed systems. So the section </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>cannot state “ </span><span style='color:#1F497D'>same proportion as the proposed <i><u>system</u></i> design.” </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>And I highly doubt the intent is “</span><span style='color:#1F497D'>same proportion as the <i><u>aggregate of all the systems in the</u></i> proposed design”. </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>So it is somewhere in </span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>between and hence the modeler needs to apply some judgment. <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 reviewers really care about this, then I suggest requiring separate documentation of the power and energy of the supply, return, relief, and exhaust for the building or even for each proposed and baseline system.<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><p class=MsoNormal style='text-autospace:none'><b><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#5F574F'>Paul Riemer, PE, LEED AP</span></b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><b><span style='font-family:"Verdana","sans-serif";color:#C4262E'>DUNHAM</span></b><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:#5F574F'><br>Celebrating 50 Years of Service</span><span style='font-size:11.0pt;font-family:"Verdana","sans-serif";color:#5F574F'><o:p></o:p></span></p></div><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"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Paul Erickson [mailto:perickson@aeieng.com] <br><b>Sent:</b> Tuesday, March 15, 2011 9:45 PM<br><b>To:</b> Paul Riemer; 'Andrew Craig'; James Hansen; bldg-sim@lists.onebuilding.org<br><b>Subject:</b> RE: [Bldg-sim] pro-rating fan power to supply/return fans per 90.1-2007?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Paul,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I think your point about “proportioning power (kW) across fans with different operation” is exactly the intent of this addition to 2010 (though perhaps I’m twisting your angle on it). The intent of it is to provide consistency in the review process and undue penalty with regards to fan power. Using your example, if the Proposed design uses CAV exhaust fans and VFD driven supply & return fans, then the Baseline should as well. Some modelers (because the requirement has been unclear to date) put all of the fan kW on the Supply fan for the Baseline, which would skew the results so as to under-account for the Baseline energy/cost. Others may actually game the system and place the bulk of the allowable kW on the CAV fan and not the Baseline’s SA and RA fans. It can go either way so I think this new clarity is helpful.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I wasn’t sure about the last part of your comment but assumed you were referring to “professional judgment” when selecting fans in the design process. Did I miss an important modeling insight?<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Paul<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><table class=MsoNormalTable border=0 cellpadding=0 width=474 style='width:355.5pt'><tr><td width=167 valign=top style='width:125.25pt;padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>Paul Erickson </b>LEED® AP BD+C <br>Sustainable<o:p></o:p></p></td><td width=10 valign=top style='width:7.5pt;padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></td><td width=283 valign=top style='width:212.25pt;padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>AEI</b> | AFFILIATED ENGINEERS, INC. <br>5802 Research Park Boulevard | Madison, WI 53719<br><br>P: 608.236.1112 | F: 608.238.2614 <br><a href="mailto:perickson@aeieng.com">perickson@aeieng.com</a> | <b><a href="http://www.aeieng.com">www.aeieng.com</a></b> <o:p></o:p></p></td></tr></table></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> bldg-sim-bounces@lists.onebuilding.org [mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Paul Riemer<br><b>Sent:</b> Tuesday, March 15, 2011 4:54 PM<br><b>To:</b> 'Andrew Craig'; James Hansen; bldg-sim@lists.onebuilding.org<br><b>Subject:</b> Re: [Bldg-sim] pro-rating fan power to supply/return fans per 90.1-2007?<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Mike Rosenberg’s section is a welcome improvement but it is still a challenging aspect.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>You could be proportioning power (kW) across fans with different operation. For example: <o:p></o:p></p><p class=MsoListParagraph>- CAV exhaust fan vs. VFD driven supply & return fans<o:p></o:p></p><p class=MsoListParagraph>- “Powered exhaust” fans that only operate to provide relief during economizer mode vs. normal supply fans<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>In some instances, applying a bit of professional judgment will get better results in terms of fan energy (kWh) and fan heat (DT and resultant heating and cooling loads).<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>Paul Riemer, PE, LEED AP</b> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>DUNHAM</b><br>Celebrating 50 Years of Service<o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> bldg-sim-bounces@lists.onebuilding.org [mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Andrew Craig<br><b>Sent:</b> Tuesday, March 15, 2011 4:24 PM<br><b>To:</b> James Hansen; bldg-sim@lists.onebuilding.org<br><b>Subject:</b> Re: [Bldg-sim] pro-rating fan power to supply/return fans per 90.1-2007?<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>James---<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>This was discussed recently in the posts. See the attached response from last Tuesday. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Mike Rosenberg commented that this is being addressed in the upcoming 90.1-2010 as such:<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>G3.1.2.10.1 </b>The calculated system fan power shall be<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>distributed to supply, return, exhaust, and relief fans in the<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>same proportion as the proposed design.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Regards,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>Andrew Craig PE, LEED AP<br></b>Project Mechanical Engineer<br><br><b>INTERFACE ENGINEERING<br>email </b><a href="mailto:andrewc@interfaceeng.com">andrewc@interfaceeng.com</a><br><b>direct </b>503.382.2696<br><br><b><a href="http://www.interfaceeng.com/">www.interfaceeng.com</a></b><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> bldg-sim-bounces@lists.onebuilding.org [mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>James Hansen<br><b>Sent:</b> Tuesday, March 15, 2011 12:05 PM<br><b>To:</b> bldg-sim@lists.onebuilding.org<br><b>Subject:</b> [Bldg-sim] pro-rating fan power to supply/return fans per 90.1-2007?<o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>App G says that if the proposed building has return fans, the baseline building is to be modeled with them as well, sized either at the minimum required to ensure ventilation, or 90% of the supply volume, whichever is greater. And the fan power calculations show that the KW allowance is for all supply, return, exhaust and relief fans combined. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>How do you generally pro-rate the fan power between supply and return fans in the baseline model? Ultimately it probably doesn’t make too much difference, but is there an actual ruling that tells you how to do this?<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thanks,<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>GHT Limited<br><ns0:PersonName>James Hansen</ns0:PersonName>, PE, LEED AP<o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>Senior Associate<o:p></o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><ns0:Street><ns0:address>1010 N. Glebe Rd, Suite 200</ns0:address></ns0:Street><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><ns0:place><ns0:City>Arlington</ns0:City>, <ns0:State>VA</ns0:State> <ns0:PostalCode>22201-4749</ns0:PostalCode></ns0:place><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>703-338-5754 (Cell)<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>703-243-1200 (Office)<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>703-276-1376 (Fax)<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><a href="http://www.ghtltd.com/">www.ghtltd.com</a><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><o:p> </o:p></b></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><o:p> </o:p></p></div></div></div></body></html>