Dear Loïc I have to confess that this is a little confusing. I would have loved to remove the surface category “internal” completely. However, due to backwards compatibility it remained. I recommend to use
category 'boundary' and the boundary condition 'identical' because there it is more clear what is calculated. Please find my comments below: I noticed that the first option implies to consider the total exposed surface (both sides) for the area parameter, unlike the second one. I guess that in (a) the middle of the wall is assumed adiabatic in order to model only a half wall
but with an area 2 times higher. If this is correct, it is implicitly assumed that the internal wall composition is symetric. By the way, I found that the wall balance is not null otherwise. Is the (a) modelling really only concern symetric composition? Nonetheless, when I compare (a) with a 2*S area and (b) with a S area, for a symetric composition, the results are not exactly the same. I succeed having same results by setting the composition of (a) with only the half of it (from a face
to the middle). => For having (a) and (b) giving similar results you have to use for (b) the same exposed area to the airnode/zone as for (a) (area =2*S). So, the (a) modelling need half composition? => No, (b) requires double area (see above).
Regards, Marion -----------------------------------------------------------------------------------------------------------------------------------------------------------
Dipl.-Ing. Marion Hiller t:
+49.711.67976.0 f:
+49.711.67976.11 www.transsolar.com/ Amtsgericht Stuttgart - HRB 23347
/ Steuernummer: 99073/00911 / USt-IdNr.: DE 152272639 Von: TRNSYS-users <trnsys-users-bounces@lists.onebuilding.org>
Im Auftrag von Loïc Frayssinet via TRNSYS-users Dear all, I was wondering if it is similar to model an internal wall as a wall : (a) with the category 'internal' or I noticed that the first option implies to consider the total exposed surface (both sides) for the area parameter, unlike the second one. I guess that in (a) the middle of the wall is assumed adiabatic in order to model only a half wall but with an area
2 times higher. If this is correct, it is implicitly assumed that the internal wall composition is symetric. By the way, I found that the wall balance is not null otherwise. Is the (a) modelling really only concern symetric composition? Nonetheless, when I compare (a) with a 2*S area and (b) with a S area, for a symetric composition, the results are not exactly the same. I succeed having same results by setting the composition of (a) with only the half of it (from a face to the middle). So, the (a) modelling need half composition? If yes, why non-symetric compositions causes balance divergences? Regards, -- |