Compared to the conventional heating coil technology (B) the shorter heat-up times are not the only distinguishing feature of Trotec fan heaters with PTC ceramic heating elements (A). There are also substantial process-related differences in the response behaviour of the heating elements.

Although both devices maintain the preselected target temperature (orange) in a similar manner by means of thermostat control, the respective temperature adaptation takes place at a significantly reduced speed and with greater deviations from the desired target temperature in case of devices with heating wires. The reason for this is the different conductivity behaviour of the heating elements: if current flows through the heating coils or wires, they will always retain the same temperature once they have heated up. For controlling the desired room temperature, the power supply is first interrupted, causing the coil/wire to cool down, and then re-activated by the thermostat so that the coil/wire heats up again completely before it is switched back off upon reaching the set target temperature.

This "on/off process" causes greater temperature fluctuations than with ceramic heating elements, for the material of the latter provides an integrated temperature self-regulation. The hotter PTCs get, the higher is their electrical resistivity, resulting in less current flowing through the heating element and in a reduced heating capacity, and thus in significantly lower temperature fluctuations and less switch-on and switch-off processes in thermostat-controlled operation. For this reason, ceramic fan heaters are able to create more even room temperatures for a pleasant indoor climate.