The process of heat transfer can occur through which of the following methods?

Heat transfer can occur through three primary methods: convection, conduction, and radiation.

Conduction is the transfer of heat through a solid material, where heat moves from the warmer part to the cooler part via direct contact between molecules. For example, when one end of a metal rod is heated, the heat travels to the other end through the rod due to molecular interactions.

Convection involves the movement of heat through fluids (liquids and gases). It occurs when warmer parts of a fluid rise and cooler parts sink, creating a circulation pattern. This is why a room warms up more quickly when a heater is used—hot air rises, spreading heat throughout the space.

Radiation is the transfer of energy through electromagnetic waves and does not require a medium to occur. An example of this is the warmth felt from sunlight, where heat is transferred through the vacuum of space.

Understanding these three processes is crucial in applied structural drying, as they directly relate to how moisture evaporates and moves in a structure. The other methods listed in the other choices, such as evaporation and condensation, are primarily phase changes; compression and expansion are related to gas laws and pressures, while reflection, refraction, and absorption deal more with light and electromagnetic radiation than with the transfer