烟道是住宅通风系统中的一个重要部分，建设部1999年颁布的《住宅设计规范》对烟道设计作出了规范。但不少楼盘还是存在无烟道设计的问题，小区住宅倒烟、串味、交叉污染情况严重。
Flue is an important part of residential ventilation system. The code for design of residential buildings issued by the Ministry of construction in 1999 regulates the design of flue. However, many buildings still have the problem of smoke-free road design, and the residential areas are seriously polluted by smoke, odor and cross pollution.
一、烟道排烟不畅原因
1、 Causes of poor smoke exhaust in flue
《民用建筑设计通则》规定，烟道伸出屋面高度不低于0.6米。但有些地方对此规定的执行情况不一。一些建了烟道的住宅设计的烟道类型单一，容易造成油烟倒灌、串味。另外，一些楼盘为了增大厨房面积，缩小了竖向烟道的横截面积，并且没有机械排烟装置，以至排烟系统流量很小，造成排烟不畅。
According to the general rules for design of civil buildings, the height of the flue extending out of the roof shall not be less than 0.6m. However, the implementation of this provision is different in some places. Some houses with flue are designed with single type of flue, which is easy to cause oil fume backflow and odor. In addition, in order to increase the kitchen area, some buildings have reduced the cross-sectional area of the vertical flue, and there is no mechanical smoke exhaust device, so that the flow of the smoke exhaust system is very small, resulting in poor smoke exhaust.
二、了解住宅烟道的分类
2、 Understand the classification of residential flue
当前的住宅烟道一般分为：单烟道式、主次式、变压式、止逆阀式。
The current residential flue is generally divided into: single flue type, primary and secondary type, variable pressure type, check valve type.
单烟道式：由一个简单的矩形烟管构成，垂直穿越各层住宅，在每层住宅中留有一个连接抽油烟机的进风口，底层由一个补风口补气。其原理是各层烟气在抽油烟机的推动下，将油烟排入烟道中，由于烟气温度的作用，在烟道中产生上升浮力，从出屋面的出风口将烟气排出。
Single flue type: it is composed of a simple rectangular smoke pipe, which passes through each floor of the house vertically. There is an air inlet connecting the range hood in each floor of the house, and the bottom floor is supplied with air by a make-up air outlet. The principle is that each layer of flue gas is pushed by the range hood to discharge into the flue. Due to the effect of flue gas temperature, the rising buoyancy is generated in the flue, and the flue gas is discharged from the air outlet of the roof.