The air flow rate of a ventilation duct is calculated by the formula T=R*S*3600, where T stands for cubic meters per hour, R is the cross-sectional area of the duct, and S is the velocity of airflow in the duct in meters per second. This formula is applicable to various types of ventilation ducts, such as purified air conditioning, central air conditioning, environmental control and industrial ventilation systems, as well as special occasions such as mining ducts.
The choice of duct material varies according to the specific area of application. For example, purification air-conditioning systems tend to use galvanized sheet metal and stainless steel, to avoid dust source contamination of glass fiber reinforced plastic (FRP) and composite materials; while the central air-conditioning and environmental control systems can be selected FRP, composite materials and so on. Industrial ventilation systems usually choose steel and galvanized sheet, but in special requirements, such as fire prevention or anti-static, may need to limit the type of material.
Ventilation ducts are used in a wide range of industrial and architectural applications, including purification systems in electronics factories, aseptic workshops for medical and food products, air conditioning systems in hotels and office buildings, as well as dust removal, fume extraction, and exhaust ventilation in industry. In special cases, they may also be used in the design of escape routes in movie and television productions.
During the construction process, designers and engineers need to coordinate the various trades to ensure that the piping layout is reasonable, following the principle of "small pipes give way to large pipes, and pressure gives way to no pressure". Before the construction, need to draw a detailed plan, in order to find and resolve potential elevation conflicts. In order to save space and cost, some pipes can be considered through the beam laying.
The above information is taken from the Baidu encyclopedia's entry on Ventilation Ducts, which is an important reference for airflow calculations and duct design.