When the air duct to transport the general gas, the black steel duct should be rust, brush anti-rust paint treatment, the dust can be sprayed with anti-wear protective layer, when the ambient air humidity is large, the air duct to be anti- Corrosion, rust treatment. For the transmission of high temperature, high humidity gas galvanized steel duct wall should be sprayed phosphating primer or other corrosion-resistant coating. In the duct to transport high temperature gas or low temperature air, the outer wall of the duct should be insulated (cold) treatment.

        The purpose of the high temperature gas duct is to prevent the heat loss from the air in the pipeline (in the winter air conditioning system); the other is to prevent the waste heat or high temperature gas to prevent the heat emitted to the room and the room temperature , But also to prevent people from exposure to air duct and burned. And in the summer often due to the temperature of the delivery gas is lower than the ambient air dew point temperature, the pipe wall will produce condensation phenomenon. This will focus on the air conditioning system air duct will increase the loss of cold, while condensation of water droplets will pollute the ceiling and wall, it should also be cold insulation treatment.