通风管道的摩擦阻力与空气在通风管道内的流动状态以及管壁的粗糙程度有关。一般情况下，高速风管的流动状态处于过渡区；薄钢板的通风管道的空气流动状态多处在紊流光滑区和粗糙区之间的过渡区；只有混凝土和砖的通风管道，在流速很高时，空气流动状态才是粗糙区。在工业通风系统中，当空气流过断面变化、流向变化和流量变化的管件时，都会产生局部阻力。局部阻力在工业通风系统中占有较大的比例，设计时应该注意，尽量减少局部阻力的产生 。
In industrial ventilation system, the friction resistance of ventilation duct is related to the flow state of air in the duct and the roughness of pipe wall. In general, the flow state of high-speed air duct is in the transition zone; the air flow state of thin steel plate ventilation duct is mostly in the transition zone between turbulent smooth area and rough area; only when the velocity of concrete and brick ventilation duct is very high, the air flow state is rough area. In the industrial ventilation system, local resistance will be produced when the air flows through the pipe fittings with section change, flow direction change and flow rate change. Local resistance accounts for a large proportion in the industrial ventilation system. Attention should be paid to reduce the local resistance as much as possible in the design.
工业通风设计过程中，涉及到的计算主要有通风管道内的空气流动阻力、通风管道内的压力分布、通风管道的水力计算、均匀送风管道的计算等。通过对工u型槽模具 井盖钢模具 保定雅思 一次性止血带 保定养老院  保定水处理设备 一次性止血带  业通风管道设计多年的工程应用研究和实践分析，在工业通风管道设计时应注意7个方面的问题。
In the process of industrial ventilation design, the calculation mainly involves the air flow resistance in the ventilation pipe, the pressure distribution in the ventilation pipe, the hydraulic calculation of the ventilation pipe, and the calculation of the uniform air supply pipe. Through the engineering application research and practice analysis of industrial ventilation duct design for many years, seven problems should be paid attention to in the industrial ventilation duct design.