The installation of air ducts should comply with the following provisions:

1) The specifications, installation position, elevation and direction of the air duct shall meet the design requirements, and the installation of the air duct on site shall not reduce the effective section of the interface.

2) The connection of the air pipe interface should be strict and firm, the thickness of the gasket should not be less than 3mm, and it should not be convex into the pipe and outside the flange; Smoke exhaust duct flange gaskets should be non-combustible materials, thin steel plate flange duct should be bolted.

3) The installation of air duct cranes and supports shall be carried out in accordance with the relevant provisions of GB 50243, the current national standard "Code for Acceptance of Construction Quality of Ventilation and Air Conditioning Engineering".

4) The connection of air duct and fan should be flange connection, or flexible short pipe connection of non-combustible material. When the fan is only used for smoke prevention and exhaust, it is not suitable to adopt flexible connection.

5) If there is a bend in the connection between the air duct and the fan, the guide blade should be installed to ensure smooth air flow.

6) When the air duct passes through the partition wall or floor, the gap between the air duct and the partition wall should be tightly packed with non-flammable materials such as cement mortar.

7) The smoke exhaust pipe in the ceiling shall be insulated with non-combustible material, and shall be kept at a distance of no less than 150mm from combustible materials.