<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:m="http://schemas.microsoft.com/office/2004/12/omml" 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:Verdana;
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:11.0pt;
font-family:"Calibri","sans-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.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Verdana","sans-serif";
color:windowtext;
font-weight:normal;
font-style:normal;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 70.85pt 70.85pt;}
div.WordSection1
{page:WordSection1;}
--></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=FR link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>Dear users<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>I am really puzzled by Werner’s post hereunder.<o:p></o:p></span></p><p class=MsoNormal><a href="http://sel.me.wisc.edu/trnsys/mailinglist/archive2003/msg00297.html"><span lang=EN-US>http://sel.me.wisc.edu/trnsys/mailinglist/archive2003/msg00297.html</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>If I understand it well, characteristics for internal glazing systems should be specified regarding external glazing systems characteristics. For instance internal transmittance should be different than normalized value if spectrally selective transmission is performed by external glazing systems. The reason invoked being that the same wavelength cannot be absorbed twice. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>However when I think about it, I rather understand transmission coefficient (thermal or visible) as a probability of transmission averaged on a wavelength interval. Therefore I would intuitively conclude that each glazing system transmits radiation as expected regarding its normalized characteristics.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>When I simulate a fictive 2 * double glazing system in WINDOW with a very wide middle air gap I get the following results.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'> SHGC Tvis<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>Initial double glazing 0.54 0.78<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>2*double glazing simulated 0.41 0.62<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>Characteristics of initial glazing**2 0.29 0.61<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>So Tvis resulting from WINDOW calculation is close to the square of initial Tvis value but SHGC is in-between. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>I would need help to conclude. How should internal glazing systems be specified in Trnbuild?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>Also if Radiance users are amongst you I would be very interested to know how they handle this issue when specifying transmissivity values for internal glass materials.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif"'>Best regards<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#404040'>--<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#404040'>Antoine Gautier<br>Solam</span><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#70B221'>en</span><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#404040'> SAS</span><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:black'><br></span><span lang=EN-US style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#404040'>+33 6 58 24 02 60<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:#404040'><a href="mailto:antoine.gautier@solamen.fr"><span lang=EN-US style='color:blue'>antoine</span><span style='color:blue'>.gautier@solamen.fr</span></a></span><span style='font-size:8.0pt;font-family:"Verdana","sans-serif";color:black'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>