However, variableairvolumesystem itself is strongly coupled and nonlinear, the traditional PID controller is usually difficult to achieve satisfactory control effect.
但由于变风量空调系统本身的强耦合、非线性等特点，传统PID控制往往难以达到满意的控制效果。
2
As air distributor in a variableairvolumesystem, the performance of slot diffuser is the best one, but the type of diffuser is too expensive, so at home many firms try to choose square diffuser.