1. Boiler induced draft fan and induced draft fan shall be configured for single boiler. When centralized configuration is required, air and flue doors with good sealing performance shall be set at the connection between the air and flue of each boiler and the main air and flue.

2. When a single boiler is equipped with a fan, the air volume of the layer furnace shall be 10%, and the air pressure shall be 20%.

3. When the fans are centrally configured, there shall be at least two fans and induced draft fans, one of which is for standby, and the fans can operate in parallel. After parallel operation, the fan air volume and air pressure abundance are the same as those of single boiler configuration.

4. Fans with high efficiency, energy saving and low noise shall be selected.

5. The fan shall be in a high efficiency range during perennial operation.

6. The design of boiler smoke exhaust and air duct shall meet the following requirements:

(1) The smoke exhaust duct shall be straight, with good air tightness, few accessories and low resistance;

(2) When multiple boilers share a chimney or flue, the wind force of each boiler shall be balanced;

(3) The flue shall be used on the ground (tree bird education HVAC design) and shall be set at an appropriate location to clean the flue into holes;

(4) The influence of thermal expansion of flue and hot air pipe shall be considered;

(5) Set necessary measuring points and meet the technical requirements of testing instruments and measuring points.