What is the term for the transfer of heat through circulation within a medium such as a gas or a liquid?

The transfer of heat through circulation within a medium, such as a gas or a liquid, is referred to as convection. This process occurs when warmer parts of a fluid rise while cooler parts sink, creating a cycle of circulation that facilitates heat transfer. In buildings, convection is significant during fire events as it can influence how heat spreads through the air and how smoke behaves, impacting firefighting strategies and evacuation routes.

Conduction, on the other hand, describes heat transfer through direct contact between materials, without the movement of the material itself. Radiation involves the transfer of heat in the form of electromagnetic waves, which can occur even in a vacuum and does not require a medium to take place. Autoignition refers to the spontaneous ignition of a substance without an external flame or spark, which is a different concept altogether. Understanding these distinctions is vital for comprehending heat transfer mechanisms in building construction and fire dynamics.