DO model for RADIATION
 

Hallo,

I'm simulating car windows exposed to the rays of the sun. I know that the sun radiation is about 900[W/m2]. Using DO model for radiation, in the BC at wall I can set "External Radiation" giving temperature and emissivity. But using a "semi-trasparent" wall (for the glass) in the bottom of the BC panel, I have to set the direction of the sun rays and also the IRRADIATION!!!? So my question is : what's the difference between the values of "External Radiation" and "Irradiation"????

Thank you Davide