The PTC characteristics of the main parts of the PTC heater and the thermal design of the heater are extremely important, especially for the high-power PTC heater. Within a certain range, the same PTC element, high heating power and high surface temperature of the heater depend greatly on the thermal resistance of the heater. According to the following formula, the thermal resistance of the heater:
In the formula, T1 is the temperature in the center of PTC element; T2 is the surface temperature of heat transfer plate of heater; P is the heating power of heater. According to the formula, low Q value means low △ t value and high heating power. For PTC element, low T1 and high P value are corresponding. The heating resistance of heater depends on the structure of heater itself: