Gas-fired infrared radiant heaters are usually mounted overhead to direct infrared energy to the floor and objects, including people, at the working level of the building.
The infrared radiant energy is absorbed by the floor and the objects at the floor level, all of which become warm and, in turn, heat the air in the building. Moreover, the floor and objects continue to release heat to the air, even after cold air is introduced or the radiant heater is turned off.
Forced air convection heating, in sharp contrast, has two major drawbacks: the loss of heat during transmission; hot air rises to the ceiling, where it is not needed.