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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:10.0pt;font-family:"Arial","sans-serif";color:blue'>Chris,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>Please see the responses below.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'><o:p> </o:p></span></p><div><div><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'>Gaurav Mehta, LEED® AP BD+C</span></b><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'><br>Sustainable Building Analyst<br>Stantec<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif";color:gray'>1932 First Avenue Suite 307<br>Seattle WA 98101<br>Ph: (206) 770-7779<br>Fx: (206) 770-5941<br>Gaurav.Mehta@stantec.com<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:13.0pt;font-family:"Arial Narrow","sans-serif";color:blue'><a href="http://www.stantec.com"><b><span style='color:#993333;text-decoration:none'>stantec</span></b><span style='color:#003F6E;text-decoration:none'>.com</span></a> <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'>The content of this email is the confidential property of Stantec and should not be copied, modified, retransmitted, or used for any purpose except with Stantec's written authorization. If you are not the intended recipient, please delete all copies and notify us immediately.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='font-size:13.5pt;font-family:Webdings;color:#008040'>ü</span><span style='color:blue'> </span><span style='font-size:10.0pt;font-family:"Arial Narrow","sans-serif";color:#008040'>Please consider the environment before printing this email.</span><span style='color:blue'> <o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'> </span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'><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";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> bldg-sim-bounces@lists.onebuilding.org [mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Chris Yates<br><b>Sent:</b> Wednesday, January 26, 2011 8:29 AM<br><b>To:</b> bldg-sim@lists.onebuilding.org<br><b>Subject:</b> [Bldg-sim] Is there a point to "virtual partitions"?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hello,<br><br><i>Virtual partition: a transparent partition with no mass and no thermal resistance. If the simulation employs an air flow network it may also be considered as a hole allowing air to pass through the partition. Usually used to define a perimeter zone. (BTW this isn't quoting any source, just what I understand!)</i><br><br>I feel I may be describing a cultural nuance of energy modelling in the UK. So I'd like to ask the following:<o:p></o:p></p><ul type=disc><li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1'>Do engineers in countries apart from the UK use "virtual partitions"?<o:p></o:p></li></ul><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>I use them all the time, especially when defining a large space (such as an open office or a gymnasium). I divide the zone into perimeter (~15 feet or approx. 5 m beyond external wall) and core zone. There is no actual partition but only a virtual partition which I have created. The reason for this division is that the perimeter zones experience external loads as well as internal loads, whereas the core zones experience only the internal loads.<o:p></o:p></span></p><ul type=disc><li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1'>What benefits do virtual partitions have over physical partitions?<o:p></o:p></li></ul><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'>The virtual partitions allow for heat transfer through convection between the perimeter and the adjacent core zone. If it is defined as an internal partition, then the heat transfer will be through conduction which is not true for the actual space as there is no actual partition. Additionally, if the internal partition is defined with thermal mass, it can add some thermal lag as well and the zone then might peak at a different time than it would without the lag. <o:p></o:p></span></p><p class=MsoNormal>Any other comments will be gratefully received.<br><br>Many thanks<o:p></o:p></p><div><p class=MsoNormal>-- <o:p></o:p></p><div><p>Chris Yates <span style='color:#4F6228'>C Eng MCIBSE</span><o:p></o:p></p><p><i>Building Physics Consultant</i><o:p></o:p></p><p>Tel: +447960731576<o:p></o:p></p><p>Email: <a href="mailto:chris.malcolm.yates@gmail.com">chris.malcolm.yates@gmail.com</a><o:p></o:p></p><p>Skype: <span class=spelle>christopher.m.yates</span><o:p></o:p></p></div></div></div></body></html>