The air duct electric heater is mainly used to heat the air in the air ducting. It has three models of low tempt, medium tempt and high tempt. One common thing in terms of structure is that they adopt steel plate for supporting in order to reduce vibration of electric heating tubes when fan stops. Connection boxes are fitted with tempt controllers.

Of these models the low temperature heater can directly be installed on the duct as in fig 1. While the medium and high temperature heaters need certain insulation between the outer wall of the duct and the terminal connection box, as they are subjected to higher temperature and adopt a different structure.

As in fig 2 and fig 3. That way the heat diffusion of the entire ducting is reduced and on the other hand, temperature inside the terminal box is also reduced. That is why medium and high temperature heaters need a mounting frame to be set on the ducting as in fig 4.for their installation. Low and medium temperature heaters have wing shape heating elements and high temperature heater has tubular heating elements.