Hello Mariëlle
Thank you for your quick answer.
1) For this question I do understand this in principle but I don't see how/when TRNSYS is considering it. By the way, what about the capacitance ? is the default value calculated by TRNSYS a good one ?
2) I understood I could do that, but it's calculated by default and I don't particularly know the solar absorbance of the material. So I was wondering if the calculation was alright ?
3) Thank you for that one : really helpful !
4) Anyone ?
5) Yes I'm adding a question here : for the ground definition, it is important to set the temperature of the earth below. By default it's 15°C. Does anybody know for which region of the world this is true ?
Thank you again.
Julie
Julie LESTRADE
Ingénieur d'études
CEDRE
Ophira 1, 1 Place Bermond
06560 SOPHIA-ANTIPOLIS
Tel : 04 92 96 03 77
Port : 06 45 68 07 53
Message original Re : RE: [TRNSYS-users] Wall definitionDe : Mariëlle Nuchelmans <M.Nuchelmans@chri.nl>
A : Julie Lestrade <lestrade.julie@cedre-sophia.com>, "trnsys-users@cae.wisc.edu" <trnsys-users@cae.wisc.edu>
Date : 2010-07-12 13:03:15
Hello Julie,
Some answers:
- If there is thermal mass, it is important (heat accumulation). In
your case, with isolation at the outside, you will have thermal mass. If
you add a wall to a zone, the inside of the wall is in your zone, the
outside not.
- In your wall definition screen, there you can add the solar
absorbance (characteristic of the material)
- If goesurf is set to zero, the incoming solar radiation is
distributed to all the walls in the zone. If you change geosurf (say 0,3
to one wall, and 0,7 to the others) Then the wall with geosurf 0,3 gets
30% of the incoming radiation.
Mariëlle Nuchelmans
Van: Julie Lestrade
[mailto:lestrade.julie@cedre-sophia.com]
Verzonden: maandag 12 juli 2010
13:53
Aan: trnsys-users@cae.wisc.edu
Onderwerp: [TRNSYS-users] Wall
definition
Dear Trnsys users,
I was wondering about some details in the wall definition.
1) Usually, the building I represent is insulated from the outside. When I
choose the layer that compose my wall I have an order (inside toward outside).
I was wondering if there was any importance in that ? Because it did not seem
to me that trnsys took into account the thermal bridges ? am I wrong ?
2) how can we choose the solar absorbance of the wall ? is it calculated ? if
yes how ? if not how is it determined ? how can we determine it ?
3) I read somewhere here that the geosurf should be set to 0. am I right ? if
yes why is that ? if not how do we choose the repartition ?
4) What about the wall gain parameter ? I notice it is set to 0 by default and
in my results, the solar gains are equal to zero if there is no windows. Is
that because my wall gain is zero ? To my mind it's not really representative
of the reality. Should I put a wall gain different from 0 ? if yes how do I
choose ?
Thank you for your feedbacks !
Julie
Julie
LESTRADE
Ingénieur d'études
CEDRE
Ophira 1, 1 Place
Bermond
06560 SOPHIA-ANTIPOLIS
Tel : 04 92 96 03 77
Port : 06 45 68 07 53
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