Optimization of air duct heater

Preferably, the outer surface of the housing is provided with the same amount of terminals as the heating tube, one end of the terminal penetrates the outer surface of the housing and is connected to the heating tube, and the other end of the terminal is connected to the electrical box provided on the outer surface of the housing.

Preferably, the electrical box is provided on the outer surface of the side end of the housing, a plurality of heating tubes are laterally provided in the housing, and the terminals of the heating tube are connected to the end of the terminal post away from the electrical box.