Which of the following best describes conduction in HVAC?

Conduction in HVAC refers to the transfer of heat through direct contact between materials. This process occurs when two objects at different temperatures come into contact, allowing thermal energy to flow from the hotter object to the cooler one until thermal equilibrium is reached.

In the context of HVAC systems, understanding conduction is essential for effective insulation and heat transfer calculations. For instance, the materials used in ducts, walls, and other components should be selected to minimize unwanted heat loss or gain through conduction. This is particularly important in maintaining energy efficiency and comfort within a building.

The other options describe different heat transfer processes. The movement of air or fluid is associated with convection, while absorption of heat from a surface refers to a specific thermal interaction, and heat loss through radiation pertains to heat transfer via electromagnetic waves.