Similarities and differences between the three heating methods of duct heaters

The three most common types of duct heaters used in industrial production are high-temperature heating, medium-temperature heating, and low-temperature heating. These methods primarily heat the air in the duct. These three heating methods share similarities and differences.

Similarities:

All three types utilize steel plates to support the heating tubes to reduce vibration when the fan is stopped. They also feature over-temperature control devices in the junction box.

Differences:

In terms of control, in addition to over-temperature protection, an interoperability device is installed between the fan and heater to ensure that the electric heater starts only after the fan. A differential pressure device is installed before and after the heater to prevent fan failure. The low-temperature model can be installed directly in the air duct. However, due to structural differences, the medium- and high-temperature models have 100mm thick insulation material sandwiched between the duct outer wall and the heater terminal box. This is primarily to reduce heat dissipation from the entire duct and the temperature within the terminal compartment. The gas pressure heated by the duct heater should generally not exceed 0.3 kg/cm². If pressures exceeding this limit are required, a circulating electric heater should be used. The maximum gas temperature of the low-temperature heater does not exceed 160°C; the medium-temperature model does not exceed 260°C; and the high-temperature model does not exceed 500°C.

Applications:

Duct heaters are used in industrial ducts, air conditioning ducts, and various other industries to heat the air and increase the output temperature. They are generally inserted into the lateral opening of the duct. According to the working temperature of the air duct, it can be divided into low temperature, medium temperature and high temperature; according to the wind speed in the air duct, it can be divided into low wind speed, medium wind speed and high wind speed. Therefore, buyers should choose according to their actual situation.