The three methods of air duct heater are:

The three types of high-temperature heating, medium-temperature heating and low-temperature heating are mainly used for heating through the air in the air duct; the three heating methods have similarities and differences.

The three heating methods are similar:

The three methods all use a steel plate to support the electric heating tube in the structure to reduce the vibration of the electric heating tube when the fan is stopped. The over-temperature control equipment is also installed in the junction box.