An infrared heater, also known as a FIR (far infrared) heater, operates differently from a conventional space heater in that the infrared heat waves heat the body and objects of the room directly.  The heat stays evenly distributed and the room retains the heat longer.  Conventional heaters heat by first raising the temperature of the air within the room which in turn heats you.  The hot air rises and quickly dissipates out poorly insulated areas and cracks around doors and windows and results in uneven heat distribution, cold pockets and a greater concentration of heat near the ceiling rather than where you are down below.  The hot air is also very drying and irritating to the mucous membranes of the respiratory passages and the skin.

A conventional heater has to work much harder to maintain the room at the desired temperature and cannot heat as large an area as an infrared heater can.