6,13) Since metals have relatively low thermal emissivity
values, absorber coatings are prepared mainly on metallic substrates (Al, Cu), which inherently have high thermal conductivity and good corrosion resistance.
Any material that redirects the sun's rays and reroutes heat to its surroundings can be classified as a cool roof by the Cool Roof Rating Council, as long as its solar reflectivity and thermal emissivity
values correspond to the climate.
The coating is called Low-E coating, or low thermal emissivity
0] is the surface thermal emissivity
On the relationship between thermal emissivity
and the normalized di_erence vegetation index for natural surfaces.
The Material and Coatings Laboratory of the Thermal Control Services of CNES-Toulouse, has developed a 'cold' coating, with low solar absorbance and high thermal emissivity
, which can be flexible or rigid, known under the trade name of FSR (Flexible Solar Reflector) or RSR (Rigid Solar Reflector).
The explanation lies in the surface property called thermal emissivity