Which of the following is NOT a method of heat transfer?

Heat transfer occurs through three main mechanisms: conduction, convection, and radiation. Each of these methods involves the movement of heat energy in different ways.

Conduction involves direct contact between materials, where heat flows from a hotter object to a cooler one through molecular agitation. Convection refers to the transfer of heat through fluids (liquids or gases) by the movement of the fluid itself, often in currents. Radiation, on the other hand, is the transfer of heat through electromagnetic waves, which can occur even in a vacuum.

Expansion, as mentioned in the question, is not a method of heat transfer. Instead, it is a physical process that can occur as a result of heat transfer. When materials are heated, they typically expand due to increased kinetic energy among their particles, but this does not constitute a mechanism for transferring heat itself.

Understanding these different mechanisms is crucial, especially in the context of firefighting and safety, as it helps emergency services manage heat during firefighting efforts and assess fire behavior effectively.