What is heat transfer by direct contact called?

Heat transfer by direct contact is known as conduction. This process occurs when two objects at different temperatures come into contact with each other, allowing thermal energy to flow from the hotter object to the cooler one. The transfer continues until both objects reach thermal equilibrium, meaning they attain the same temperature.

In conduction, the movement of heat happens through the vibration and interaction of the molecules within a solid or between solids. An everyday example would be touching a metal spoon that has been left in a hot soup; the heat from the soup is conducted through the spoon, heating it up.

Understanding this concept is crucial for fire investigators, as it plays a critical role in how fires spread through materials and structures. In contrast, convection involves the transfer of heat through fluid motion, radiation requires energy transfer through electromagnetic waves, and evaporation refers to the change of state from liquid to gas, none of which pertain to direct contact heat transfer.