Which of the following are types of radiant heat?

Radiant heat systems primarily rely on the transfer of heat through infrared radiation, directly warming objects and surfaces in a space rather than heating the air. The correct option highlights systems such as baseboards, wall panels, and ceiling panels that are designed specifically for radiant heating.

Baseboard heaters distribute heat horizontally along the perimeter of a room. Wall panels are mounted on surfaces and emit warmth through radiant heat transfer. Ceiling panels provide warmth from above, effectively heating people and objects in the room. The inflow refers to how these systems deliver heat, typically through conduction and direct radiation to the occupants.

In contrast, the other options include various types of heating and cooling systems that do not primarily function as radiant heating. For instance, fan coil units and air handlers typically rely on convection to circulate air, while ducts and vents distribute heated or cooled air throughout a space. Radiators can sometimes emit radiant heat, but they also work through convection. Therefore, the correct answer focuses on systems directly designed to utilize radiant heat as a primary mode of heating.