Characteristics of the PTC Heater Used in Automotive HVAC Systems

The present heating method which uses the cooling system of the internal combustion engine of the vehicle takes a lot of time to heat the interior air. In order to improve the heating process, auxiliary devices are required. The new innovative techniques propose as auxiliary heating device positive temperature coefficient heaters. For a better control of the temperature, the parameters of these devices should be known. This paper deals with a detailed description of the new types of positive temperature coefficient heaters used in automotive field. The test bench system developed for determining the parameters and characteristics of the positive temperature coefficient heater is described. The obtained data of the thermal resistance and voltage-current characteristics are used for controlling the temperature in order to design and control the positive temperature coefficient heaters properly.