Is it necessary to specifiy radiation boundary condition, if the material selection already defines the emissivity value?

[prikmushi]

In my simulation, the subject is cooling through radiation to vacuum. Since while selecting the materials, the emissivity value is already defined, is it necessary to define it again through radiation boundary condition? 

Won't this mean overlap, and emissvity values may end up being different than what it should be for a material?

[marwan_azzam · Accepted solution]

@prikmushi ,

If you want a surface to radiate to space you have to define a radiation boundary condition.

Emissivity value in material properties does not mean it will radiate.

Marwan