Which heat transfer method involves the circulation of a fluid?

Convection is the heat transfer method that involves the circulation of a fluid. In this process, warmer parts of the fluid rise due to decreased density, while cooler parts sink, creating a continuous flow. This motion efficiently transfers heat throughout the fluid, often observed in liquids and gases.

In practical terms, convection is commonly seen in heating systems where water is heated in a boiler and then circulated through radiators, efficiently warming a space. This method is particularly effective in transferring heat over larger distances compared to conduction and radiation, which are more localized in their effects.

Conduction relies on direct contact between materials to transfer heat, while radiation involves the transfer of heat through electromagnetic waves without needing a medium. Atmospheric transfer, while not a standard term in heat transfer, could imply heat exchange with the surrounding atmosphere, but it does not describe a method based solely on fluid circulation. Thus, convection specifically highlights the role of fluid dynamics in heat transfer.