[TRNSYS-users] Wall definition

[Mariëlle Nuchelmans]

Hello Julie,

Some answers:


 1.  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.


 1.  In your wall definition screen, there you can add the solar absorbance (characteristic of the material)


 1.  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.


Kind regards,

Mariëlle Nuchelmans

Van: Julie Lestrade [mailto:lestrade.julie at cedre-sophia.com]
Verzonden: maandag 12 juli 2010 13:53
Aan: trnsys-users at 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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