Defines the concept of VAV systems, traces their position in the hierarchy of all air systems, describes their classification, characteristics and application, and presents two examples.

• 提出了变风量系统的一种更为具体的定义，阐述了其在全空气系统族谱中的地位，系统的分类、特点和应用范围，简要描述了两个工程实例。