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Dear Karol, 1) You recommend to set
resistance of whole wall (include cold bridge) in “cold bridge
window” (hmK/kJ) or resistance of “massless wall” (hm^2K/kJ).
It doesn't matter which way will be chosen, dimension of element will be the
same and only units will change m<->m^2. No, you need the thermal
mass. The adjustment really depend on your wall construction. It is more adjusting the
u-value of layer (if poassible) and thereby of a wall. For a wall with
insulation I would increase the u-value for the insulation such that it
includes the loss of the cold bridge. Best regards, Marion Dipl.-Ing.
Geschäftsführer:
Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst,
Prof. Dipl.-Ing. Bleicher Von: Karol Bandurski
[mailto:karol.bandurski@put.poznan.pl] Dear Marion, Thank you very much for your
explanation! If I understand: 1) You recommend to set
resistance of whole wall (include cold bridge) in “cold bridge
window” (hmK/kJ) or resistance of “massless wall” (hm^2K/kJ).
It doesn't matter which way will be chosen, dimension of element will be the
same and only units will change m<->m^2. 2) In both case element will
be massless. So what can I do to account mass and heat capacity of wall and
cold bridge? Regards, Karol -----Original Message----- Dear Karol, If you define a "cold bridge" in TRNbuild the following
happens: - Instead of defining layers as for a wall you define a "thermal
resistance" (without mass effects) - Instead of setting an area as for a wall you define a lenght However, in the end this cold bridge is treated as "a massless
wall". If you use a detailed radiation mode, you can't add surfaces (and a
cold bridge would be surface somehow) in order to keep the geometry consistent.
It is not recommended to draw very small surfaces in T3d to represent
the cold bridge unless you need the inside surface temperature because very
small surfaces may cause trouble for matrix generation. Therefore, the recommendation is to integrate the losses of a cold
bridge into the wall by adjusting the u-value of a wall as previously mentioned
by Adrien. I hope this helps. Best regards, Marion Dipl.-Ing. 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: Karol Bandurski [mailto:karol.bandurski@put.poznan.pl]
Gesendet: Donnerstag, 12. Juli 2012 18:25 Betreff: [TRNSYS-users] cold bridge _______________________________________________ TRNSYS-users mailing list https://mailman.cae.wisc.edu/listinfo/trnsys-users |