A ceramic heater as a consumer product is a space heater that generates heat using a heating element of PTC (Positive Temperature Coefficient) ceramic. Ceramic heaters are usually portable and typically used for heating a room or small office, and are of similar utility to metal-element fan heaters.
PTC ceramic material is semi-conductive and when voltage is applied to it, the power decreases quickly as it reaches a certain temperature according to the particular composition of the ceramic. The ceramic elements are in contact with aluminium fins, thereby heating the fins up. A fan blowing across the fins heats the air.
Electric heating elements made of resistance wire also have a positive temperature coefficient of resistivity, but do not increase their resistance enough to be self-regulating; they are typically used with the wires red-hot. The ceramic, on the other hand, increases its resistance sharply at the Curie temperatures of the crystalline components, typically 120 degrees Celsius, and remains below 200 degrees Celsius, providing a significant safety advantage. Ceramic heaters have rheostats that are capable of sending voltage signals when the temperature of the room alters.