<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:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:rtc="http://microsoft.com/officenet/conferencing" xmlns:D="DAV:" xmlns:Repl="http://schemas.microsoft.com/repl/" xmlns:mt="http://schemas.microsoft.com/sharepoint/soap/meetings/" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ppda="http://www.passport.com/NameSpace.xsd" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcs="http://schemas.microsoft.com/data/udc/soap" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:udcp2p="http://schemas.microsoft.com/data/udc/parttopart" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:dsss="http://schemas.microsoft.com/office/2006/digsig-setup" xmlns:dssi="http://schemas.microsoft.com/office/2006/digsig" xmlns:mdssi="http://schemas.openxmlformats.org/package/2006/digital-signature" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:spwp="http://microsoft.com/sharepoint/webpartpages" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:pptsl="http://schemas.microsoft.com/sharepoint/soap/SlideLibrary/" xmlns:spsl="http://microsoft.com/webservices/SharePointPortalServer/PublishedLinksService" xmlns:Z="urn:schemas-microsoft-com:" xmlns:st="" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
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</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'>I’m curious as to what people think is better for having a thermal zone that is open to another thermal zone. Is it better to delete the interior wall completely, or is it better to put an air wall in place of the interior wall? Which way models more appropriately?<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><b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#87C139'>James M. Newman, EIT, LEED AP<o:p></o:p></span></b></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'>project engineer / energy analyst<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#87C139'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="http://www.me-engineers.com/"><b><span style='color:#87C139'>M-E Engineers, Inc.</span></b></a></span><b><u><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#87C139'><o:p></o:p></span></u></b></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'>10055 west 43rd avenue<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'>wheat ridge, co 80033<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'>office: 303.421.6655<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'>direct: 720.898.3148<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="mailto:james.newman@me-engineers.com"><span style='font-size:10.0pt;color:#595959'>james.newman@me-engineers.com</span></a></span><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#595959'> </span><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#48494A'><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"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Nick Caton<br><b>Sent:</b> Wednesday, January 26, 2011 7:09 PM<br><b>To:</b> Arpan Bakshi<br><b>Cc:</b> equest-users@lists.onebuilding.org<br><b>Subject:</b> Re: [Equest-users] What's in an Air Wall?<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'>I think the “disparate-zone-instability” concern goes away because the “gyp equivalent” air constructions will only permit a finite amount of heat transfer each hour, and this transfer rate/direction is based directly upon the hourly conditioned temperature difference (as calculated from the previous hour), not directly from the amount of internal heat loads generated in the present hour to be handled by the associated systems.<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'>Replacing air constructions (which use the U-factor input method) with a frame partition or similar (layer method) will only fundamentally add mass/thermal-lag to the equation (and will likely have a higher R-factor). I suppose adding mass to the partitions would be a mitigating remedy if you did have crazy swings of this nature causing “instability” with regard to temperature throttling setpoints, but again I don’t think in the course of a normal model one would encounter this problem. You’d have to almost be trying to create the problem – i.e. making a an air partition with a monstrous area or re-defining the u-factor of the air construction to be 9999 instead of 2.7 between two disparate spaces… <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'>Kudos again to everyone helping me keep my head on straight =)!<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><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><img border=0 width=119 height=37 id="Picture_x0020_1" src="cid:image001.jpg@01CBBE3B.374BBF10" 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-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E'>NICK CATON, E.I.T.</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'>PROJECT ENGINEER<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<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'>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></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"'> Arpan Bakshi [mailto:arpanbakshi@gmail.com] <br><b>Sent:</b> Wednesday, January 26, 2011 6:09 PM<br><b>To:</b> Nick Caton<br><b>Cc:</b> Fleming, Joe; David Eldridge; <equest-users@lists.onebuilding.org><br><b>Subject:</b> Re: [Equest-users] What's in an Air Wall?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>I second the setpoint-related zone instability concerns, particularly as it pertains to unmet hours. What are everyone's thoughts on replacing virtual air walls with constructed partitions along zone-to-zone adjacencies, with disperate conditioning requirements?<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'> <o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Arpan Bakshi<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span class=apple-style-span> </span><o:p></o:p></p></div></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><br>On Jan 26, 2011, at 5:47 PM, "Nick Caton" <<a href="mailto:ncaton@smithboucher.com">ncaton@smithboucher.com</a>> wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Thanks everyone for the replies – from this collective advice I’ve identified an assumption related to my third “bullet” that led me astray (and also makes all 4 “cases” seem like silly questions in hindsight): </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Air partitions are not “thermal superconductors.” The wizard-generated (and DOE-2 help files suggested) U-2.7 value for an Air wall construction is comparable in thermal resistance to a single layer of 3/8” Gyp, without the mass. I had the picture in my mind’s eye that these constructions were by default a few orders of magnitude higher in conductivity, permitting any delta-T to be “instantly” resolved between spaces, effectively tying the two spaces into one (thermally). From that, I was concerned with how that might lead to setpoint-related instability in the model or unpredictable behavior in how loads would be distributed between in-equal systems and so forth… </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>I’m also concluding the practice of defining air walls to have two systems working together in the same zone is sound, however the temperatures between the divided spaces will not “instantly equalize” as I assumed. </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>I think I’m on much more solid footing now – thanks fellas!</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>~Nick</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'><image001.jpg></span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'> </span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'>NICK CATON, E.I.T.</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:7.5pt;color:#CC9900'>PROJECT ENGINEER</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>Smith & Boucher Engineers</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>25501 west valley parkway</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>olathe ks 66061</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>direct 913 344.0036</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>fax 913 345.0617</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'><a href="www.smithboucher.com" title="blocked::www.smithboucher.com"><span style='font-size:10.0pt'>www.smithboucher.com</span></a></span><u><span style='font-size:10.0pt;color:blue'> </span></u><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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"'> Fleming, Joe [mailto:joe.fleming@tlc-eng.com] <br><b>Sent:</b> Wednesday, January 26, 2011 2:43 PM<br><b>To:</b> David Eldridge; <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br><b>Cc:</b> Nick Caton<br><b>Subject:</b> RE: [Equest-users] What's in an Air Wall?</span><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'><span style='color:#1F497D'>With these ideas in mind, for assigning 2 systems to one zone. Maybe you could set your second zone up as being contained entirely within the other zone (set up as best as equest will allow for zone within a zone), this way there is a maximum amount of heat transfer happening between the two zones. </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Let's say the goal is to try and see if a VAV box, in a given hour, has enough air to cool both spaces so that a dedicate system doesn't need to run to supplement it. The VAV minimum would be reached before overcooling began (although you could double the minimum airflow, assuming each zone is half of the space served by 2 systems), and once enough overcooling occurs the reheat will initiate. So, in this case there won't be much shared load between the two spaces separated by an air wall, and the dedicated system will run as well... </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Hmmm... Equest can't be entirely steady state, because iterations seem to occur to decide if certain parts of a system need to initiate or not. If equest wanted to decide whether or not to bring on a humidifier, it should first need to run the loads one time to see if the unit, given its airflow and supply temp, would lower the %rh enough to require humidification, before initiating humidification. It would need to see the final space temp after one iteration right?</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>If this is the case then there would be a chance to shut off a system in one of the zones if the heat transfer, after iteration #1, is enough to satisfy the load.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:#1F497D'>Joe Fleming</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><i><span style='font-size:10.0pt;color:#333333'>E.I., LEED AP BD+C, BEMP</span></i><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><i><span style='font-size:10.0pt;color:#333333'>Mechanical Engineer II</span></i><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:#006363'>TLC Engineering for Architecture<br></span></b><b><span style='font-size:10.0pt;color:#006363'>Your 2030 Challenge Partner</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'>800 Fairway Drive, Suite 250</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'>Deerfield Beach, FL 33441-1816</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p></div><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0><tr><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'><span style='font-size:9.0pt;color:#333333'>phone: </span><o:p></o:p></p></td><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'>954-418-9096</span><o:p></o:p></p></td></tr><tr><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'><span style='font-size:9.0pt;color:#333333'>fax: </span><o:p></o:p></p></td><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'>954-418-9296</span><o:p></o:p></p></td></tr><tr><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'><span style='font-size:9.0pt;color:#333333'>direct: </span><o:p></o:p></p></td><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'>954-418-4591</span><o:p></o:p></p></td></tr><tr><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal align=right style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-align:right'><span style='font-size:9.0pt;color:#333333'>website: </span><o:p></o:p></p></td><td valign=bottom style='padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'><a href="http://www.tlc-engineers.com">www.tlc-engineers.com</a></span><o:p></o:p></p></td></tr></table><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><a href="http://www.tlc-engineers.com/"><span style='text-decoration:none'><image002.gif></span></a><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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> [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>David Eldridge<br><b>Sent:</b> Wednesday, January 26, 2011 3:20 PM<br><b>To:</b> <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br><b>Subject:</b> Re: [Equest-users] What's in an Air Wall?</span><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'><span style='color:black'>Although “highly-conductive” you wouldn’t necessarily assume that the space temperatures end up being identical – there is still some resistance in your example, even if very small, and the area of interface is not infinite either.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'>Your last example with area/volume – the heat transfer will be limited by the size and thermal conductivity of this air wall. There are also radiant and storage effects from the other surfaces in the zone that might keep the two from being in equilibrium – that said your approach may be fine as you may not have widely differing temperatures/loads. One possible tweak might be to allocate your internal gains in these two modeled spaces to load the separately modeled HVAC systems along how you think they would actually perform in the real “two-system-one-zone” space. </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'>David</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'> </span><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><u><span style='color:black'> </span></u><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:8.0pt;color:black'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, HBDP</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='color:#244061'>Grumman/Butkus Associates</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><u><span style='color:black'> </span></u><o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:black'> </span><o:p></o:p></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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:[mailto:equest-users-bounces@lists.onebuilding.org]">[mailto:equest-users-bounces@lists.onebuilding.org]</a> <b>On Behalf Of </b>Nick Caton<br><b>Sent:</b> Wednesday, January 26, 2011 11:49 AM<br><b>To:</b> <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br><b>Subject:</b> [Equest-users] What's in an Air Wall?</span><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'>Hi everyone,<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'>A discussion on [bldg-sim] prompted me to bring up a topic that’s been bugging me in the “eQuest fundamentals” department… <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 have a general understanding that eQuest does not fundamentally model airflow (specifically, convection of internal loads) between zones.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>-<span style='font-size:7.0pt'> </span>The DOE-2 entry for INT-WALL-TYPE says an internal “air” partition “ …designates a non-physical interior surface with no mass (i.e., an opening between spaces) across which convection can take place.”<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>-<span style='font-size:7.0pt'> </span>A wizard-generated “air” internal partition has a construction with U-factor of 2.7… very conductive.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>-<span style='font-size:7.0pt'> </span> To draw a conclusion – two zones connected with an “air” partition are “connected” thermally. In practice, the internal loads in one are “combined” with the other.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>-<span style='font-size:7.0pt'> </span>This means heat in one zone should travel to the other in a rapid fashion during the hourly simulation, until the space temperatures are identical between the two.<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 hope my understanding thus far is correct, because from here I have some questions that dig at what’s going on under the hood:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>1.<span style='font-size:7.0pt'> </span>Imagine an air partition “connects” zones A and B. These zones have separate systems and separate thermostats with different setpoints. If zone A’s thermostat wants to be much warmer than zone B, is it possible the systems will “fight” each other and cause mutual unmet hours?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>2.<span style='font-size:7.0pt'> </span>In the same setup, if Zone A is identical in geometry to Zone B, but has 2x the internal/external loads, does it follow that the system for System A will handle 2x the internal loads as System B, or are they summed and applied equally to the two systems on an hourly basis? <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>3.<span style='font-size:7.0pt'> </span>Is the “distribution of loads behavior” affected if Systems A & B are specified with different capacities and/or airflows? <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in'>4.<span style='font-size:7.0pt'> </span>If one space is larger in area/volume than the other, does that affect how the collective loads are distributed to the corresponding systems?<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 have “exploited” air partition behavior in the past to get around the “one system per zone” rule (need two RTU’s serving that space? Just make an imaginary air wall!). However I want to be sure before I continue this practice or advise others to do the same that there aren’t any major potential pitfalls in how the loads/systems are distributed/affected…<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'>~Nick<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'><image001.jpg><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'> </span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'>NICK CATON, E.I.T.</span></b><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:7.5pt;color:#CC9900'>PROJECT ENGINEER</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>Smith & Boucher Engineers</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>25501 west valley parkway</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>olathe ks 66061</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>direct 913 344.0036</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;color:#2D4D5E'>fax 913 345.0617</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'><a href="www.smithboucher.com" title="blocked::www.smithboucher.com"><span style='font-size:10.0pt'>www.smithboucher.com</span></a></span><u><span style='font-size:10.0pt;color:blue'> </span></u><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></div></div></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal>_______________________________________________<br>Equest-users mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>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></p></div></blockquote></div></body></html>