Heat-conductivity
The heat-conductivity is decisive for the heat insulation quality of the insulation material. It shows, which heat-energy (W) by a temperature difference of 1 Kelvin flows through a component per meter (m). The unit of measurement is W/mK and will be abbreviated to λ. The smaller this value, the better is the heat insulation quality of the insulation material.
Heat-conductivity coefficient
The heat conductivity coefficient shows the heat quantity in joule per second (j/s) which passes through 1 m² of a substance with a specific thickness (d), if the temperature difference of both surfaces is 1 Kelvin. The calculation results from the thermal conductance of the substance (heat-conductivity) λ, which will be divided through the coat thickness of the material.
h=λ/d - The unit of measurement therefore is W/(m²xK)
Thermal resistance
A material can be calculated also covered to its resistance against the heat conductivity. The calculation is mathematically the reciprocal of the heat-conductivity coefficient. The commensurability between material thickness and heat conductivity explains therefore the heat resistance.
R=d/λ
The unit of measurement therefore is (m²xK)/W