[TRNSYS-users] Persistent questioning about window definition in WINDOW6

Tue Sep 10 04:57:35 PDT 2013

How is defining the frame as wall going to correctly account for  
thermal bridging effects? That is the whole point of using a FEM  
program like Therm together with Window6 to get a representitive  
assembly componant. Does the higher frame surface temperature create  
such an error if it is not represented?

Mit freundlichen Grüßen- Sent from my iPhone (excuse the brevity)

i. A.
Jean Marais
b.i.g. bechtold
Tel.   +49 30 6706662-23

On 10.09.2013, at 12:36, Marion Hiller <Hiller at Transsolar.com> wrote:

> Pauline Gelin,
>
> the resulting u-value is dependent on the boundary conditions. Type  
> 56 take the current boundary conditions (actual temperatures etc.)
> whereas WINDOW takes fixed conditions according to the selected  
> standard. This means in order to have the same values you need
> to have the same boundary conditions.
>
> The u-values displayed in the window type manager are read from the  
> footer lines which are added to the WINDOW report file.
> If you create a new glazing you have to add these values manually.
>
> Without looking at your project it is impossible to give further  
> advice. B4_QT is a zone output for all surfaces of a zone.
> I have no clear view on how you use this output for calculating the  
> u-value of a window.
>
> However, the following explains the calculation principles of Type  
> 56 a little.
>
>
> Type56 – glazing modeling
>
> In the window type manager you can select 5 options for calculating  
> the spacer:
> If you select ID-Spacer = 0 it uses the data from the WINDOW report  
> (this includes the height and width of the glazing).
> Otherwise, it uses the selected space condition of no spacer.
>
> Type 56 divides the glazing area into glazing and edge area. The “ed 
> ge area” is defined as
> 63.5mm wide band at glass periphery. The region inside this is what  
> is called "center of glass".
> The height and width of the glazing defined the window type manager  
> and  the WINDOW report file, respectively.
>
> Type 56 calculates the area weighted conduction values for the total  
> glazing based on temperature dependent
> u-values for edge and  center of glass under the current conditions.
>
> Type 56 - FRAME modeling
> TRNSYS doesn’t use the frame data from the WINDOW report file.
>
> In principle there are two ways of simulating the frame:
>
> 1.)     Define the frame as a wall
> This is the precise way to do it because the frame has it’s own surf 
> ace temperature (independent from the window)
> in the solving processing in Type 56. However, it is more effort to  
> define it.
>
> Define frame properties like frame fraction, solar absorption,  
> emissivity, conduction (1/Rcond) in window type
> Type 56 calculates a temperature depending resulting for the glazing  
> (including edge effect and shading)
> and then applies a simple area weighting to the conduction:
>
>
> Best regards,
>
> Marion
>
>
>
>
>
> Dipl.-Ing. Marion Hiller
>
> Transsolar Energietechnik GmbH
> Curiestraße 2
> 70563 Stuttgart
> Telefon: +49 711 67976-0
> http://www.trnsys.de
>
> Transsolar: KlimaEngineering- Technologien für energieeffizientes Ba 
> uen und Nutzerkomfort in Gebäuden
> Stuttgart – München – New York – Paris
> Geschäftsführer :Diplom-Ingenieur Matthias Schuler, Diplom-Ingenieur 
>  Thomas Auer, Diplom-Physiker Stefan Holst, Diplom-Betriebswirt Diet 
> er Schnelle
> Eingetragen beim Amtsgericht Stuttgart HRB 23347,
> Steuernummer: 99073/00911,USt-IdNr.: DE 152272639
>
> Von: trnsys-users-bounces at cae.wisc.edu [mailto:trnsys-users- 
> bounces at cae.wisc.edu] Im Auftrag von Pauline GELIN
> Gesendet: Freitag, 6. September 2013 13:29
> An: trnsys-users
> Betreff: [TRNSYS-users] Persistent questioning about window  
> definition in WINDOW6
>
> Hi,
>
> When I use a glass that I had created from WINDOW6 software, it  
> turned out that the Uwindow value, deduced from the B4_QT output  
> doesn’t correspond to what I expected, when I calculated it with the 
>  Ug value shown in the database TRNBUILD, the percentage frame and U 
> frame filled in TRNBUILD.
>
> After many tests, it appears that the Uwindow calculated differs if  
> I take a glazing created in WINDOW6 (for which I didn’t give any inf 
> ormation of spacer in order to change this in the TRNBUILD project)  
> 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?
>
>
> Then, also with a  test of 100% glazing window, if I use a glass  
> type I created with WINDOW 6 without frame and spacer (because I  
> want to choose after the spacer and the frame in TRNBUILD), which is  
> shown in WINID with a indicative Ug of 1.07 W/m²K, correct value for 
>  this type, when I look the outputs Uwin and B4_QT, these ones give  
> me a Uglass of only 0.57 W/m²K !
> Could you explain to me what I did wrong? And more especially, how  
> TRNSYS could calculate this value?
>
>
> Thanks a lot in advance for all your answers.
>
> Best regards,
>
> Pauline GELIN
> Ingénieur Conception environnementale
>
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>
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> 69120 VAULX EN VELIN
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>
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>
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