Bonjour,
Voilà je suis actuellement entrain de calculer une toiture terrasse et j'aurais voulu savoir si on devais cocher le bilan explicite de rayonnement ??
D'avance merci pour votre réponse
Toiture plate terrasse
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Mathieu.nicolay
- WUFI User
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Christian Bludau
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Re: Toiture plate terrasse
Dear Mathieu,
I´m working on a model about simulating a roof terrace in hygrothermal building software. A first idea, which is also using a reduction of the absorptivity and emissivity is published here, but at the moment thats only available in German:
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Bludau, Ch., Kölsch, Ph.: Verschattung von Holzflachdächern - Holz-Flachdächer: Neue Forschungsergebnisse zu Dachterrassen und Verschattung durch PV-Module. 5. Internationaler Holz[Bau]Physik-Kongress 20.–21.03.2014, Leipzig
http://www.hoki.ibp.fraunhofer.de/ibp/p ... Bludau.pdf
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For the calculation I did not model the terrace itself, outside i started with the roofing felt. For modelling the shading I reduced the existing absorption value of the wooden surface the following way:
shaded absorption = absorption of roofing felt * 0,6
and
shaded emission = unchanged
So for a grayed wood (bankirai) that would be:
abs_shaded = 0,74 * 0,6 = 0,44
em_shaded = 0,9
In this calculations you should use the explicit radiation balance in WUFI.
Christian
I´m working on a model about simulating a roof terrace in hygrothermal building software. A first idea, which is also using a reduction of the absorptivity and emissivity is published here, but at the moment thats only available in German:
---
Bludau, Ch., Kölsch, Ph.: Verschattung von Holzflachdächern - Holz-Flachdächer: Neue Forschungsergebnisse zu Dachterrassen und Verschattung durch PV-Module. 5. Internationaler Holz[Bau]Physik-Kongress 20.–21.03.2014, Leipzig
http://www.hoki.ibp.fraunhofer.de/ibp/p ... Bludau.pdf
---
For the calculation I did not model the terrace itself, outside i started with the roofing felt. For modelling the shading I reduced the existing absorption value of the wooden surface the following way:
shaded absorption = absorption of roofing felt * 0,6
and
shaded emission = unchanged
So for a grayed wood (bankirai) that would be:
abs_shaded = 0,74 * 0,6 = 0,44
em_shaded = 0,9
In this calculations you should use the explicit radiation balance in WUFI.
Christian