Faster air heating – more uniform room temperature
Trotec’s fan heaters with PTC ceramic heating elements (A) not only differ from conventional heating coil technology (B) in terms of their shorter heat-up times. There are also process-related differences in the response behaviour of the heating elements.
Although both devices maintain the preselected target temperature (orange) by means of thermostat control using a two-position controller, the respective temperature adaptation takes place significantly more slowly and with greater deviations from the desired target temperature in case of devices with heating coils. The reason for this is the different conductivity behaviour of the heating elements:
if current flows through the heating coils, the coils will always have the same temperature once they have heated up. For controlling the desired room temperature, the power supply is first interrupted, making the coil cool down, and then re-activated by the thermostat so that the coil heats up again completely before it is switched off again when the set target temperature is reached.
This "on/off process" causes significantly 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 temperature-sensitive manufacturing processes as well as a pleasant working climate.