Abstract: Traditional outdoor unit of air conditioner which uses the axial fan system to generate large air flowrate to ensure heat capacity, but it is so bad in overcoming static pressure. When the resistance of a pipe network or environment increases, the heat capacity of the whole machine decreases, which seriously affects the comfort and energy-saving effects. In order to solve the current problem, this paper uses a new-type duct system in outdoor unit of the air conditioner, which changes the axial duct system in the traditional air-conditioner to a centrifugal duct system. The verification shows that the air distribution on the heat-exchanger's surface of the new duct system is more uniform, and the capacity to overcome static pressure is increased by 150% which compares with the original duct system, and the capacity to interfere with external static pressure is better.

Key words: Duct system, Static pressure, Air distribution