[TRNSYS-users] heat flux through a wall

[Pablo Díaz Núñez]

Dear trnsys users,

I want to get the heat flux through the walls in a building using type 56. I
don´t think there is an NType that gives that data but looking at the
mathematical description I find some outputs that I think I can use. These
are the following:

NTYPE 19: QCOMI energy from inside surf. incl. conv. to air and longwave
radiation to other surfaces. [kJ/hr]

NTYPE 20: QCOMO energy to outside surf. incl. conv. to air and longwave
radiation to other surfaces or Tsky. [kJ/hr]

NTYPE 21: QABSI radiation absorbed (or transmitted) at inside surf. [kJ/hr]
(includes solar gains, radiative heat, internal radiative gains and
wallgains, except longwave radiation exchange with other walls)

NTYPE 22: QABSO radiation absorbed at outside surf. [kJ/hr] (includes solar
gains, radiative heat, internal radiative gains and wallgains, except
longwave radiation exchange with other walls or Tsky)

NTYPE 82: QWG wall gain on inside surface of wall or window [kJ/hr]

As I said, looking at the mathematical description, I think I can obtain the
heat flux through a wall by adding those outputs for the external or
internal surface respectively. The problem is that the results I get with
the inside and outside surfaces are very different. I also tried getting the
temperatures of the surfaces and calculating the flux with the U-values but
the results are still different.

So finally my question is, am I doing it allright with the outputs? Maybe
there's something I'm forgetting or something I'm not understanding.

I would be very grateful if someone knew how to get that data :)

Thanks in advance.

Pablo.
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