[TRNSYS-users] Zeroing inside and outside longwave radiation of window surfaces

[hotline]

Dear Oselen,

you are right with your idea, if you set the longwave radiation mode to simple and set the combined heat transfer coefficient equal to the convective part, the longwave radiation is effectively zeroed. One thing to keep in mind is that this is then the case for all surfaces in the room.
If you want to consider the longwave radiation for all surfaces but the window, you can use the same method you did for the outside case. You can select longwave radiation detailed mode for the zone and set the back emissivity of the glazing + the frame to 0, too. In this case the window will behave like a longwave radiation-mirror so to speak and the longwave radiation exchange will still be calculated using view factors between the other surfaces in the zone.

[cid:image001.png at 01D7D7BD.BC1718A0]

Best regards,
Christina

__________________________________________________________________________________________________


Transsolar KlimaEngineering

Stuttgart  | München | Paris | New York


https://www.trnsys.de<https://www.trnsys.de/>
https://transsolar.com/de



Transsolar Energietechnik GmbH | Curiestraße 2 | 70563 Stuttgart

Geschäftsführer: Matthias Schuler, Thomas Auer, Stefan Holst, Dieter Schnelle

Registered at Amtsgericht Stuttgart HRB 23347 | USt-IdNr.: DE 152272639

The simulation project you have sent will be stored on the local servers of Transsolar Energietechnik GmbH for the duration of the project support. Our employees are obliged by us to confidentiality. After this period, all project-related data is deleted.

The storage of your personal e-mail and other contact information is based on the mutual interest in the execution of this traffic and on a mutual business contact. If you have any questions, please contact our data protection officer at privacy at transsolar.com<mailto:privacy at transsolar.com>. Our privacy policy can be found here<http://www.trnsys.de/docs/userservice/userservice_dataprivacy_en.htm>.
________________________________
Von: TRNSYS-users <trnsys-users-bounces at lists.onebuilding.org> im Auftrag von Oselen Imafidon via TRNSYS-users <trnsys-users at lists.onebuilding.org>
Gesendet: Freitag, 29. Oktober 2021 15:21
An: trnsys-users at lists.onebuilding.org <trnsys-users at lists.onebuilding.org>
Cc: Oselen Imafidon <josephoselen at yahoo.com>
Betreff: [TRNSYS-users] Zeroing inside and outside longwave radiation of window surfaces


Hello,



To zero the inside longwave radiation of the window I used the simple model longwave radiation exchange within a zone.



To zero outside longwave radiation of the window, I modified both the window frame emissivity to zero and the front emissivity of the first window glazing in the building input description file (BIU) to zero.



I used hand calculation to verify the simulation results using the following equations for heat fluxes to the outside and inside surface and the results were same. . The result shows inside and outside longwave radiation of window surfaces are zeroed.



Is this the right way of zeroing inside and outside longwave radiation of window surfaces?



Thank you.



Regards,

Oselen I



Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20211112/27cefd29/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 70167 bytes
Desc: image001.png
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20211112/27cefd29/attachment-0001.png>