Re: [TRNSYS-users] problem of windows and layers definitions

Dear Pauline,

I had a quick look at your questions.

also appeal to you about another problem I have with each project on TRNSYS.

When I define a set temperature at a specific time (eg 20 ° C at 7am), the temperature zones does not reach 20 ° C at 7am but an hour later.

It seems that, at 7 am, the temperature is rather than the average value between the past temperature and the set temperature.

Do you have an explanation and above all a solution to this?

è I assume you mean the heating of TRNbuild. If you define a heating set point of 20 °C at 7am ,this means that the temperature
at the end of the time step is 20 °C. If the temperature at the beginning of the time step ( 6 am if the tme step is 1h)
is 16 °C then the average temperature of the time step is 18 °C. This average temperature is the NTYPE 1 (output air temperature).
The temperature at the end of the time is only needed for the heating/Cooling of type 56 load calculation. Other calculations related
to energy over the time step are based the average temperature.

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.

Concerning values of layers, and especially insulation materials, it seems that the user library saves only two decimal places for conductivity. If we specify three digits, the value is rounded and if we add manually three decimal places in the file (opened by a notepad), only the first two are considered. How can we fix this?

è Thanks for insisting. Unfortunately, this has to be solved within the TRNbuild. It’s now on my list for the next update of TRNbuild.

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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