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Mariëlle,<br>
In TRNSYS 16, the absorption for solar radiation can be set using the
wall type manager. The emissivity for the wall surface, however is
hardcoded inside Type56. You are correct that Type56 uses a star
network for radiation exchange. All surfaces radiate to the airnode and
the airnode radiates to all surfaces. There are no view factors. The
one control you have is the geosurf factor with which you can specify
the fraction of longwave radiation entering a zone that falls on a
particualr surface.<br>
<br>
In TRNSYS 17 you can define "radiation zones" which DO have view
factors provided that you have used the Trnsys3D plugin for Google
SketchUp to generate those view factors for your building's geometry.
You can also adjust the emissivity of the walls within TRNBuild.<br>
<br>
I am not as sure what to suggest for setting the temperature of the
wall. Inside (and outside) surface temperatures are calculated as part
of the zone energy balance. You might be able to use a thermostat and
the "wall gain" feature to control the inside surface temperature of
your warm wall.<br>
Best,<br>
David<br>
<br>
<br>
Mariëlle Nuchelmans wrote:
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<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB">Hello,<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB">I’m trying
to understand how trnsys deals with
long-wave radiation. I know that trnsys calculates it with the star
network
method from Seem (adjusted by Koschenz in 1997). I looked at the
method and I
wonder how the absorption factor between surfaces is determined. Seem
refers to
Gebhart, but this method uses view-factors and trnsys doesn’t know
them. So
how does trnsys determine this absorption factor?<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB">I also
wonder if it is possible to adjust (or make
variable) the mean average wall temperature (used to linearize the
long-wave
radiation exchange between surfaces between zones). In my project I
have one
wall which probably is a lot warmer than the other walls.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB"><o:p> </o:p></span></font></p>
<div>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB">Met
vriendelijke groet,<o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB"><o:p> </o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;" lang="EN-GB">Mariëlle
Nuchelmans<o:p></o:p></span></font></p>
</div>
<div class="MsoNormal"><font face="Arial" size="1"><span
style="font-size: 8pt; font-family: Arial;">
<hr style="width: 450pt;" id="Lijn" align="left" size="1" width="600"></span></font></div>
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alt="Cauberg-Huygen Raadgevende Ingenieurs BV" height="40" width="204"><br>
<b><span style="font-weight: bold;">M. Nuchelmans-van Wanum</span></b>
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Denk aan het milieu en print deze email alleen als het noodzakelijk is.</span></font><font
face="Arial" size="1"><span style="font-size: 8pt; font-family: Arial;"><o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Times New Roman" size="3"><span
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