the U-Values you get out of the program Window are depending to the standard you use in window. The standards are typically assuming a fix temperature range in order to determine the static U-Value. If you are using TRNSYS to calculate the U-Value then this is considering that e.g. the temperature of the outside is changing and so you get different U-Values depending to the time.
Regards
Christian
Gesendet: Montag, 27. Mai 2013 14:43
Bis: trnsys-users
Betreff: [TRNSYS-users] Persistent questioning about window definition
Hello,
Sorry to insist but I am really blocked by these questions of data. I am not at all sure of the TRNSYS simulations.
Are there no one else who has met these misunderstandings?
Pauline GELIN
Ingénieur Conception environnementale
10 avenue des canuts
69120 VAULX EN VELIN
T : 04.37.45.33.33
Ligne directe : 04.37.45.33.47
De : Pauline GELIN
Envoyé : jeudi 23 mai 2013 09:49
À : trnsys-users
Objet : Persistent questioning about window definition
Hi,
Then I used a glass that I had created from WINDOW6 software, it turned out that the Uwin value, given output by TRNBUILD and used in the simulations, did not correspond to what I expected, result due to the Ug value from database and percentage frame and Uframe filled in TRNBUILD.
After many tests, it appears that the calculated Uwin TRNBUILD differs if I take a glazing created in WINDOW6, for which I have not information of spacer and, or a glazing initially given in the TRNBUILD database.
While Uframe percentage and spacer values indicated in my database windows are the same.
Does anyone know where does this difference come from?
What values of Uframe, and percentage frame and spacer, does TRNBUILD consider : those entries in the database glazings or those filled in the database window that is created for each project?
This misunderstanding about the values considered by TRNBUILD is not at all reassuring.
Especially when I tested a window created with WINDOW6 and one from the initial TRNBUILD database with 100% glass (so without frame).
And in the first case I found a Uwin value equal to 0.3 instead of Ug equal to 1.07.
And in the second case I found a Uwin value of 1.22 for the same value of Ug equal to 1.07.
Thanks a lot in advance for all your answers.
Best regards,
Pauline GELIN
Ingénieur Conception environnementale
10 avenue des canuts
69120 VAULX EN VELIN
T : 04.37.45.33.33
Ligne directe : 04.37.45.33.47
De : Marion Hiller [mailto:hiller@transsolar.com]
Envoyé : vendredi 18 mai 2012 08:49
À : Pauline GELIN
Cc : trnsys-users
Objet : AW: Re: [TRNSYS-users] problem of windows and layers definitions
Dear Pauline,
I had a quick look at your questions.
Concerning the definition of a window, we would like to know if Ug presented in the library already includes convective heat transfer coefficients (if so what value?) and the standard to which it is calculated ?
è
The Ug values presented in the German library related to products are the values you can find in the catalog.
This means including including convective + radiative heat transfer coefficients and are in general measuered under test condition
acc. to a standard. The values are shown such that the user can select a glass according to published properties.
These values are NOT used during the simulation! Type 56 uses the pane, gap properties as well as the pacer and frame properties
AND the real temperature conditions to calculate heat transfer through the window.
Best,
Marion
Dipl.-Ing. Marion Hiller
TRANSSOLAR: KlimaEngineering - Technologien für energieeffizientes Bauen und Nutzerkomfort in Gebäude
Munich - New York - Stuttgart + 49.711.67976.0
Transsolar Energietechnik GmbH, Curiestrasse 2, 70563 Stuttgart
Amtsgericht Stuttgart - HRB 23347, Steuernummer 99073/00911, USt-IdNr.: DE152272639
Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst, Prof. Dipl.-Ing. Bleicher
-----Ursprüngliche Nachricht-----
Von: Pauline GELIN [mailto:p.gelin@katene.fr]
Gesendet: Mittwoch, 16. Mai 2012 16:38
An: David BRADLEY; Matt Duffy <duffy@tess-inc.com> (duffy@tess-inc.com); trnsys-users (trnsys-users@cae.wisc.edu)
Cc: Vincent MORELLE; Amélie MARILLER
Betreff: Re: [TRNSYS-users] problem of windows and layers definitions
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