冷风机通风管的规格一般采用假定流速法设计，主风管保持在8-10m/s，支风管6-8m/s,最末端风管保持4-6m/s。

The specifications of the ventilating duct of the cold fan are generally designed by the assumed velocity method. The main air pipe is kept at 8-10m/s, the branch pipe 6-8m/s and the terminal air duct 4-6m/s.

所设计的风管总体上要求既经济又能达到最低的风阻和噪声，使节能环保空调的送风量尽量达到最大值，风管弯曲半径一般不小于风管直径的两倍，以减少弯管通风阻力；送风管道的长度应根据不同型号的环保空调风压不同的特点进行设计；所设计的管道应尽量取直，避免不必要的拐弯和分支管，以减少管道局部阻力；从平面布置和经济角度上考虑，能不用风管的地方就不用风管，必须使用风管的地方，尽量把风管设计短些；

The design of the wind pipe in general requires both the economy and the minimum of the wind resistance and noise, so that the energy supply of the energy saving and environmental protection air conditioning can reach the maximum. The bending radius of the wind pipe is not less than two times of the pipe diameter to reduce the ventilation resistance of the pipe, and the length of the air supply pipe should be different according to the different types of environmental air conditioning air pressure. Design the characteristics of the design; the design of the pipe should be taken as far as possible to avoid unnecessary turning and branch pipe to reduce the local resistance of the pipe; from the plane layout and the economic point of view, the place where the pipe is not used, the wind pipe must be used, the wind pipe must be used, and the design of the pipe is shorter.

较长管道根据风量设计成多段不同规格的风管，采用变径管连接，变径管的设置不宜过多，一般整根不 超过四个，变径管长由“>2（D-d）”来确定；送风管道与环保空调主机出风口连接处应密封好；室外管道过长宜设计保温，室内管道一般不须保温；若在设计中存在支风管，则须在分支管上装设阀门或分风挡板以调节风量，使支管风量达到设计值。

The long pipe is designed to be a number of different specifications of wind pipe according to the air volume. The pipe is connected by variable diameter tube. The setting of the variable diameter pipe should not be too much, the whole root is not more than four. The diameter of the variable diameter pipe is determined by ">2 (D-d)"; the air supply pipe should be sealed well with the outlet of the air vent of the environmental protection air conditioner. Indoor pipes usually do not have to be insulated; if there is a branch pipe in the design, a valve or a split air baffle must be installed on the branch tube to adjust the air volume to achieve the design value of the pipe.