2. There are no mechanical smoke prevention facilities in the smoke prevention stairwell and shared front room of high-rise buildings that do not have natural smoke exhaust conditions.

3. The stairwell and front room of a class of public buildings with a building height of more than 50m and residential buildings with a building height of more than 100m adopt natural smoke exhaust, but no mechanical smoke prevention facilities are provided.

4. The basement with mechanical smoke exhaust is not equipped with an air supply system with air supply volume not less than 50% of the smoke exhaust volume.

5. The smoke outlet and smoke outlet of mechanical smoke exhaust system in the basement cannot be switched in linkage.

6. When the smoke outlet and the air supply valve are opened, the fan cannot be linked to start.

7. The air duct of the ventilation and air-conditioning system passes through the partition walls and floors of fire-proof zones, ventilation and air-conditioning rooms and important or high-risk rooms, and there is no fire valve.

8, kitchen, bathroom, toilet and other vertical smoke exhaust pipes, did not take measures to prevent fire backflow, did not set fire dampers on the branch pipes.