The heat transfer coefficient is defined as the temperature difference between the two sides of the surface in 1m (K, ℃),

in 1 second (1S), through the heat transfer area of 1 square meter, the unit is W / m ° (W / (m · K), where K can be replaced by ° C).

Thermal conductivity is only for the existence of heat transfer in the form of heat transfer when there are other forms,

such as radiation, convection and mass transfer and other forms of heat transfer when the composite heat transfer relationship,

the property is usually referred to as apparent heat Coefficient, explicit thermal conductivity or thermal transmissivity of material.

In addition, the thermal conductivity is for the homogeneous material, the actual situation, there are also porous,

multi-layer, multi-structure, anisotropic material, the thermal conductivity of this material is actually a comprehensive performance of thermal conductivity ,

Also known as the average thermal conductivity.