<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: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:D="DAV:" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" 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:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" 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:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.apple-style-span
{mso-style-name:apple-style-span;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple style='word-wrap: break-word;
-webkit-nbsp-mode: space;-webkit-line-break: after-white-space'>
<div class=Section1>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Hi All – again<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'>When I created my long post on the Daylighting models I
self-edited because it was looking like going on forever. For example, I
stopped short of listing the full range of software that has been subject to
validation exercises, and stuck to just those that have been validated against
measured data. There is for example the validation suite created by the CIE to
be an equivalent for lighting of the IEA BESTEST / ASHRAE 140 validation
process for thermal simulation programs. To my knowledge, AGI 32 and the
Integra software from Japan have undergone this validation process. <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'>This most recent post returns our focus to energy simulation. I
have over the past six months of a sabbatical at the Lawrence Lab in Berkeley
CA come to know and appreciate the COMFEN program which is targeted at
providing the power of the EnergyPlus program, very early in the design of a
building. Programs like EnergyPlus have inbuilt engines for calculating
light distributions due to daylight. The COMFEN (<a
href="http://windows.lbl.gov/software/comfen/2/index.html">http://windows.lbl.gov/software/comfen/2/index.html</a>
) program from LBNL makes some of the daylight calculations within EnergyPlus accessible
in these very early phases of the design process. This is fully integrated. <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'>Clearly an add-on for daylighting to a thermal simulation
program will not be the best lighting program. However, it should be
sufficiently accurate for many purposes where thermal and daylight performance
are combined. <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'>Rob, you are correct about the su2rad/OpenStudio plugins for
SketchUp. Because the OpenStudio plugin from DOE/NREL will read EnergyPlus
input (idf) files, SketchUp is the potential integrator of COMFEN/EnergyPlus
and Radiance. It works well here because of the elegance of the underlying
template for the COMFEN EnergyPlus model. But even here it has limitations. The
thermal simulation model representation of a wall is a set of 3D coordinates
locating a surface in space and its orientation to the sun. The thickness and
thermal properties are represented mathematically. Reading an EnergyPlus ‘.idf’
file into SketchUp reveals windows with no frame and reveals with no depth –
anathema to the good daylight modeler. If one creates buildings with depth for
daylighting in SketchUp, one needs to specify thermal zones within the model
before exporting to EnergyPlus. <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'>The single BIM model that links to all analytical programs but
is independent of them all is an ideal that has been worked on since the days
of the COMBINE project in Europe 20 or so years ago. Many are working still on
it. Logic suggests it is the most elegant solution to the dilemma of exchange
of information between many different analytical programs. But this simple illustration
suggests to me that the Building Information Model is not SketchUp. It is
merely one on a long line of geometry creation tools. It is unusual in that it can
be used to create lighting, acoustic or thermal models. But it merely creates a
common starting point for these separate analytical tools. <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'>M<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'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span style='color:#1F497D'>Michael
Donn
<br>
Director Centre for Building Performance Research<br>
School of Architecture</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:black'> </span><span style='color:#1F497D'><br>
Victoria University +64 4 463 6221 work<br>
PO Box
600
+64 21 611 280 mobile<br>
Wellington
+64 4 463 6204 work fax<br>
New
Zealand
+64 21 611 594 </span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:black'>mobilefax</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:black'><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 0cm 0cm 0cm'>
<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"'>
bldg-sim-bounces@lists.onebuilding.org
[mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Rob
Guglielmetti<br>
<b>Sent:</b> Thursday, 12 March 2009 4:12 PM<br>
<b>To:</b> Ross Harding<br>
<b>Cc:</b> bldg-sim@lists.onebuilding.org<br>
<b>Subject:</b> Re: [Bldg-sim] One model<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<div>
<div>
<p class=MsoNormal>On Mar 11, 2009, at 6:09 PM, Ross Harding wrote:<o:p></o:p></p>
</div>
<p class=MsoNormal><br>
<br>
<o:p></o:p></p>
<div>
<div>
<div>
<p class=MsoNormal><span class=apple-style-span><span lang=EN-AU
style='font-size:9.0pt;color:#144FAE'>The ultimate goal for us would be to use
one model for daylight and energy models, but I haven’t found that quite
that simple as most software requires varying drawing techniques.</span></span><span
lang=EN-AU style='color:black'><o:p></o:p></span></p>
</div>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal>Amen brother! Another issue is that while the energy
model has to include the total building -- all spaces and systems -- to be a
complete picture of the energy use, a Radiance-based daylight model does not
necessarily require all the spaces to be modeled simultaneously. Indeed,
the accuracy of the ambient calculation is directly affected by the maximum
size of the scene, and so conducting a simultaneous daylight simulation of an
entire building at an acceptably rigorous ambient resolution can be -- is
generally -- time-prohibitive.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal>As mentioned in a recent thread on this list, Thomas
Bleicher's "su2rad" plugin for SketchUp can export a SU model to
Radiance format and there is also an E+ plugin to allow one to use the same SU
model for E+ analysis; in theory, these three components (SketchUp, su2rad and
the E+ plugin) allow for a "single model" approach to energy and
daylight modeling. However, because the su2rad exporter wants to take the
entire model and create a single Radiance scene description, that creates the
aforementioned problem of the ambient calculation getting out of hand fairly
quickly. I suppose through intelligent layering and model structuring,
one could create a model that could be exported to Radiance in "space
components", but I'm not sure if this is compatible with the E+ plugin's
layering/model organization requirements.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal>- Rob Guglielmetti<o:p></o:p></p>
</div>
</div>
</body>
</html>