Heat and energy transport in membranes

12 Outside view of the furniture store near Stuttgart. 

2 Basic physics of thermal transmission general comments 

During exact analysis three modes of transmission of energy can be distinguished through closed envelopes  

The dominating physical laws are the first and second Pick s Law. This kind of energy transport is relatively slow as the excitation spreads slowly through the continuum. 

The radiation from the sun is in general aligned vertically to the surface of the sun. With very good approximation, on earth it can be seen as parallel radiation. Through diffusion and deflection this parallel radiation is diverted by the geometrical irregularities of the earth s surface, so that there the so-called diffuse fractions are detectable, whose direction is spread statistically. The diffuse fractions also depend on the season and the geometrical position of the place of impact on the earth s surface, on the width, and so on. 

---