正压送风作为楼梯间及前室或合用前室的防烟方式,在国内外建筑设计中已被广泛采用.在进行正压送风系统的设计计算时,首先遇到的问题是如何确定如火灾疏散时开启门的层数与数量、楼梯间与前室应保持的正压度、加压送风口的形式等与设计计算密切相关的一些因素.只有这些计算因素确定后,才能进行系统的设计计算.,[Abtract]positive pressure air supply is a smoke control way for stair and chamber or ante- chamber, It is widely accepted and used in the word . In the course of caculating , the question is first , how to know the design related factors, like the number of the opened doors and the nuber of layers、the positive degree of the stair and the ante chamber 、the type of the air opening. only we make sure these factors ,we can caculating and beginning design.