The heat source in the element consists of a PTC element – a semi-conductor that adapts its output to the ambient temperature.
The PTC element has a high starting current and provides full output almost immediately. The current then falls quickly and the element is thereafter self-regulating, meaning that the warmer the surroundings, the less output produced by the element.
Thanks to the chimney effect, meaning that the colder air is drawn into the element's bottom and discharged at the top, good self-circulation is achieved for the heated air.
The heating element is best installed in smaller cabinets so as avoid condensation or that the temperature falls beneath the minimum level.