1, and the area is calculated by expansion method; The perimeter times the length equals the area, for example, 500*400 long1000 mm (0.5+0.4) * 2 *1=1.8 m2. Reducing pipe is usually calculated as one end with larger diameter.
2. The length of air duct shall be subject to the length of the center line, but excluding the length of parts.
3. The air duct deflector is calculated according to the area of the illustrated blade.
4. The hose is calculated in square meters according to the size shown in the figure.
The extended data duct is mainly used in industrial and architectural engineering, and its application fields mainly involve: cleaning system of clean workshop in electronic industry, cleaning system of sterile workshop for medicine and food, central air conditioning system in hotels, shopping malls, hospitals, factories and office buildings, exhaust duct for dust removal, smoke exhaust and oil absorption in industrial pollution control, exhaust duct for industrial environment or post comfort, gas drainage system for coal mine gas drainage, return air system for coal mine environmental management, etc. PS: It is often developed into a special escape and stealth route in movies and comics.
Distinguish by purpose
1. air duct for air conditioning system: galvanized sheet and stainless steel; (It is forbidden to use glass fiber reinforced plastics and composite materials that may cause dust pollution)
2. Air duct of central air conditioning system: galvanized sheet and color steel insulation board; (FRP and composite materials can be used)
3. Air duct of environmental control system: galvanized sheet and stainless steel; (Plastic, FRP and composite materials can be used)
4. Air ducts for industrial ventilation systems: steel plates and galvanized plates; (Ladbrokes ventilation duct. Plastic, FRP and composite materials can be used)
Note: FRP air ducts are divided into organic and inorganic types. According to the design specification, the use of organic materials for fire prevention is prohibited.
5. Air ducts for special use occasions: mine coated air ducts and mine plastic ventilation air ducts; (Mine safety features requiring flame retardancy and antistatic property)
Baidu encyclopedia-ventilation pipeline