How does radiant heating primarily transfer heat?

Radiant heating primarily transfers heat through radiation, which is the correct choice. This method relies on the emission of infrared radiation from a hot surface, such as radiant floor heating systems or ceiling panels, directly to the objects and people in the room. Unlike convection, which requires a medium (like air) to transfer heat through movement, or conduction, which requires direct contact between materials for heat transfer, radiation allows heat to travel through space without the need for a physical medium. Consequently, this kind of heating can efficiently warm up a room by directly affecting the occupants and objects within it, enhancing comfort levels without needing to heat the air first.

In contrast, ventilation involves moving air to distribute heat but does not inherently raise the temperature of surfaces through direct heating. Thus, while convection and ventilation are important concepts in HVAC systems, they do not accurately describe the primary method of heat transfer involved in radiant heating.