The transfer of heat through solid surfaces such as metal pipes or duct-work is called what?

The transfer of heat through solid surfaces, such as metal pipes or ductwork, is referred to as conduction. This process occurs when heat energy is passed from one molecule to another within a solid material. In solids, especially metals, the tightly packed particles allow for efficient energy transfer through direct contact. When one part of a solid becomes warm, the heat energy moves through the material to cooler areas, facilitating this heat transfer without the actual movement of the material itself.

Convection, on the other hand, pertains to heat transfer through fluids (liquids and gases) where hot fluid rises and cool fluid moves in to replace it, creating a circulation pattern. Radiation involves the transfer of heat in the form of electromagnetic waves, such as the warmth felt from sunlight, which does not require a medium to travel through. Insulation refers to materials designed to slow down heat transfer, thereby enhancing energy efficiency but is not a mode of heat transfer itself. Understanding these concepts is crucial in fire safety, as they influence how heat behaves in structures during a fire event.