What is Conduction?

Conduction is the process of heat transfer from one body to another by direct contact. The more rapidly moving particles collide with slower ones, and transfer some of their energy. This happens until there is a balance between the hot and cold objects. The rate of conduction is proportional to the difference in temperature (the thermal gradient) and the area of contact between the two objects.

In metals, this process is relatively easy because their atoms are free to move around, and they have a large number of them so collisions are frequent. In other materials like glass or wood, the molecules are held together by strong bonds which make it difficult for them to move and thus conduct heat less well. The thermal conductivity of a material is a measure of how well it conducts heat. It is usually given in units of Watts per meter per Kelvin (W/m·K). The lower the thermal conductivity, the better the insulator.