should I uncheck "Simulation takes into account" and defining proper short-wave absorptivity? what about "additional diffusion resistance" and heat transfer coefficient?
I would recommend leaving the aluminium panel itself out of the assembly and instead accounting for its vapour diffusion resistance through an additional diffusion resistance (sd-value) in the surface transfer conditions.
For the exterior surface properties, use the short-wave absorptivity and long-wave emissivity of the actual aluminium finish. I would also recommend enabling radiative overcooling, especially if the emissivity is significantly lower than the default value of 0.9.
The heat transfer coefficient can generally be left at the standard exterior value unless you have specific measurements or project requirements that justify a different setting.
