Mattieu,
I think that the wall type manager is where the incorrect units are
displayed. My understanding is that a coldbridge does not have any
thickness but it does have a length. For example, if you want to make a
coldbridge to represent the lack of insulation where two exterior walls
are joined, you would define a coldbridge that has the length of the
joint. The resistance you enter should be in kJ/h.m.K (where the length
is the length of the bridge). The error in TRNBuild is that the wall
type manager should change the units of u-value when a coldbridge wall
is displayed. Note that since the u-value displayed in the wall type
manager is not actually used in calculation, that this error should not
affect your results.
Kind regards,
David
matthieu duclos wrote:
Dear Trnsys Users,
I have a problem about a bug for thermal bridge, I find an answer in
the archives but ...:
Hi Nicola,
nicola wrote:
> Dear all,
> I'm modelling a wall wit a thermal bridge effect.
> I found a bug in TRNBuilt :
> 1. If I put the value of resistence equal to xxx (hmK/kJ) in the
layer
> manager, the program create a wall with a U-value expressed in
kJ/h
> m^2K and a resistence equal to xxx in hm^2k/kJ!!!
Thanks for finding this bug. I think it is only a problem of displaying
the units. The resistance should be entered in h m^2K /kJ, and not h m
K /kJ. When you check on the 'Layer type manager', the resistance is
shown in h m^2K /kJ.
> 2. the u-value of a wall with thermal bridge effect is lower than
the
> same wall without thermal bridge effect.
The u-value displayed in the 'Wall type manager' is calculated by
adding
two reference heat transfer coefficients to the wall (7.7 and 25 W/m^2
K).
Best regards,
Diego
... in "Walls" when I choose a coldbridge I can put the value for
length in m , not a surface in m^2.
What is the solution?
If the solution is all in m^2, how can I change a linear thermal bridge
to surface thermal bridge?
Thanks in advance,
Matt
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