Ventilation ducts - Materials and dimensions - Basic requirements

First, the ventilation duct material

1 Sheet metal:
Ordinary thin steel plate: a good processing performance and structural strength, but easy to rust;
Galvanized sheet steel: the surface of galvanized, anti-rust effect, generally used to produce acid-free role in the humid environment;
Aluminum and aluminum alloy plate: good processing performance, corrosion resistance, friction is not easy to produce sparks, explosion-proof requirements are commonly used in the ventilation system;
Stainless steel plate: It has the ability of resisting rust and acid resistance. It is commonly used in the production of cold and damp, shabby exhaust pipe and chemical environment to be corrosion-resistant ventilation system;
Plastic composite steel plate: In the ordinary thin steel plate surface sprayed with a layer of 0.2-0.4mm thick plastic layer, commonly used in dustproof high air-conditioning systems and -10 degrees -70 degrees temperature corrosion-resistant duct system;
2 Non-metallic materials:
Rigid polyvinyl chloride plastic board: It is suitable for ventilation system with acid corrosion. It has the advantages of smooth surface and convenient manufacture. But it can not bear high temperature and not cold. It is only suitable for air environment of 0-60 degree Celsius. Easy to crack;
FRP: with light, high strength, non-flammable, corrosion-resistant, high temperature, anti-cold melt and other characteristics.
Second, the basic requirements of ventilation duct size
Ventilation, air conditioning systems, air duct, should adopt a round or long, short side ratio of not more than 4 rectangular cross-section, the maximum length and short side ratio should not exceed 10. The cross-section size of the duct shall be implemented according to the provisions in the national standard "Construction Quality Acceptance of Ventilation and Air-conditioning Engineering" (GB 50243). The diameter of metal air duct shall be outside diameter or outside length; Should be inside diameter or inside length.