A ceramic heater is a type of space heater that generates heat using a heating element made of ceramic with a positive temperature coefficient (PTC) . 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. The ceramic elements are in contact with aluminum fins, which heat up when voltage is applied to the ceramic. A fan blowing across the fins heats the air, which is then distributed into the room. Ceramic heaters have thermostats that switch power to the PTC array on and off in response to the temperature of the room, like other types of heaters. Ceramic heaters are durable and should operate for many years without breaking down, provided they are routinely wiped free of dust and other particles. There are two types of ceramic heaters: radiant and convective. Radiant ceramic heaters warm up objects directly, while convective ceramic heaters warm up the air and circulate it around the room. Ceramic heaters are efficient because energy consumption is reduced as the temperature increases. They are also affordable to both buy and run.