What is the difference between an enclosed stairwell and a smoke proof stairwell in a residential bu

Enclosed stairwells and smoke-proof stairwells in residential buildings are not a concept!

Closed stairwell: mainly refers to those stairwells that are separated by fire-resistant building components to prevent smoke and heat from entering, and generally closed stairwells are suitable for factories (warehouses), public buildings and residential buildings.

Smoke-proof stairwell: It mainly refers to a stairwell with smoke-proof front rooms, open balconies or alcoves (collectively referred to as front rooms) at the entrance of the stairwell, and the doors leading to the front room and stairwell are fire doors to prevent the smoke and heat of the fire from entering.

In fact, it can be seen from the definition that although both closed stairwells and smoke-proof stairwells have fireproof and smoke-proof functions, the construction and acceptance standards of the two are different.

Smoke-proof stairwell acceptance criteria.

In layman's terms, fireproof materials must be used when designing and constructing enclosed stairwells, while smoke-proof stairwells have no relevant regulations, mainly based on ventilation and smoke prevention, which is the main difference between the two. In addition, the most important thing is that the acceptance criteria of the two are also different.

Of course, if a closed stairwell has a front room, and its design and construction specifications meet the standards of smoke-proof stairwells, it can also be called a smoke-proof stairwell, not to mention that the two are originally used together before and after, which is no problem!

There is no antechamber in the enclosed stairwell, and the antechamber is a smoke-proof stairwell. The setting conditions of the closed stairwell and the smoke-proof stairwell are different, and from the form point of view, the simple understanding is that the stairwell is closed with one door and the smoke-proof stairwell has two doors.

Depending on the level of the stairwell, the requirements for the fire doors set up are also different. For stairwells of the first-class fire-resistant grade, the combustion performance and fire resistance limit of the building components are non-combustible, and a general fireproof door should be set up, and for the stairwells of the second-level fire-resistant grade, the building components are non-combustible bodies, and the door of the inner closed stairwell should be a two-way spring door.

However, the doors of closed stairwells in high-rise civil buildings, high-rise industrial buildings, densely populated public places, densely populated multi-storey Class C factories and other buildings should be Class B fire doors that open in the direction of evacuation.

1. Concept. Closed stairwell: refers to the stairwell separated by fire-resistant building components to prevent smoke and heat from entering, and the closed stairwell is suitable for places such as factories (warehouses), public buildings and residential buildings.

Smoke-proof stairwell: refers to a stairwell with facilities such as a smoke-proof front room, open balcony or alcove (collectively referred to as the front room) at the entrance of the stairwell, and the doors leading to the front room and the stairwell are fire doors to prevent the smoke and heat of the fire from entering.

2. Scope of application.

Enclosed stairwell:

1) Plant (warehouse):

1) High-rise factories and Class A, B and C multi-storey plants; (2) High-rise warehouse.

b) Public Buildings:

1) Medical buildings, hotels, buildings for the elderly and buildings with similar functions; (2) Buildings with singing and dancing entertainment, screenings, and amusement venues; (3) Shops, libraries, exhibition buildings, conference centers, and similar buildings; (4) Other buildings with 6 floors or more; (5) Podiums and second-class high-rise public buildings with a building height of no more than 32m.

c) Residential Buildings:

1) Residential buildings with a building height of no more than 21m adjacent to the evacuation staircase and elevator shaft; (2) Residential buildings with a building height greater than 21m and no more than 33m.

Smoke-proof stairwell:

High-rise factories with a height of more than 32m and more than 10 people on any floor; A class of high-rise civil buildings; Class II high-rise public buildings with a building height of more than 32m; A Class II high-rise residential building with a building height of more than 33m. When the number of underground floors is 3 or more, and the height difference between the ground and outdoor entrance and exit floors in the basement is greater than 10 meters.

3. Set requirements.

Enclosed stairwell:

1) The stairwell for evacuation shall comply with the following requirements:

1) The stairwell should be able to provide natural lighting and ventilation, and should be set up against the exterior wall; (2) There should be no boiling water room, combustible material storage room, and garbage chute in the stairwell; (3) There should be no protrusions or other obstacles in the stairwell that affect evacuation; (4) Class A, B and C liquid pipes should not be laid in the stairwell;

2) In addition to the above provisions, the enclosed stairwell shall also comply with the following provisions:

1) When natural lighting and natural ventilation are not available, a mechanical pressurized air supply system or smoke-proof stairwell should be installed; (2) The first floor of the stairwell can include the walkway and foyer in the stairwell to form an enlarged closed stairwell, but it should be separated from other walkways and rooms by measures such as Class B fire doors; (3) In addition to the door of the stairwell, there should be no other door and window openings on the inner wall of the stairwell;

Smoke-proof stairwell:

1) Smoke-proof stairwells and their front rooms should not be provided with roller shutters, and smoke-proof stairwells and their front rooms are forbidden to pass through or set up combustible gas pipelines;

2) Smoke-proof facilities should be set up;

3) The area of the front room, for public buildings, high-rise factories (warehouses), should not be less than 6, and the front room shared with the fire elevator should not be less than 10; For residential buildings should not be less than, the area of the front room shared with the fire elevator should not be less than 6; For civil air defense projects should not be less than 10;

An enclosed stairwell is a stairwell that is separated by fire-resistant building fittings to prevent smoke and heat from entering. So what is a closed stairwell? What is the difference between an enclosed stairwell and a smoke-proof stairwell? I'll answer it for you below!

What is a closed stairwell.

A closed stairwell is a stairwell that separates the staircase from the passage with building components, and is a stairwell that can prevent smoke and heat from entering, and simply put, it is a staircase made into a closed space with a wall or fire door.

What door to use to close the stairwell.

As long as it is a closed stairwell, it is necessary to use a Class B fire door.

Specifications for closed stairwells.

Code for fire protection design of high-rise civil buildings GB 50045-95 (2005 Edition): The evacuation staircase of each unit of the unit-type dwelling shall lead to the roof, and the setting of the evacuation stairwell shall comply with the following provisions:

1. The unit dwelling with 11 floors and below 11 floors may not have a closed stairwell, but the door opening to the stairwell shall be a Class B fire door, and the stairwell shall be against the external wall, and shall have direct natural lighting and natural ventilation.

2. Residential units on the 12th and 18th floors shall be provided with enclosed stairwells.

3. Units with 19 floors or more should be equipped with smoke-proof stairwells.

4. Tower-style houses should be equipped with smoke-proof stairwells.

Closed stairwell setting.

1) The stairwell for evacuation shall comply with the following requirements:

1) The stairwell should be able to provide natural lighting and ventilation, and should be set up against the exterior wall;

(2) There should be no boiling water room, combustible material storage room, and garbage chute in the stairwell;

(3) There should be no protrusions or other obstacles in the stairwell that affect evacuation;

(4) Class A, B and C liquid pipes should not be laid in the stairwell;

5. Combustible gas pipes should not be laid in the stairwells of public buildings;

6. Combustible gas pipes and combustible gas meters should not be laid in the stairwells of residential buildings. When it is necessary to install a residential building, protective measures such as metal casing and a device to cut off the air source should be used.

2) In addition to the above provisions, the enclosed stairwell shall also comply with the following provisions:

1. The stairwell should be close to the exterior wall, and should have direct natural lighting and natural ventilation, when natural lighting and natural ventilation can not be achieved, it should be set up according to the requirements of smoke-proof stairwells;

(2) The first floor of the stairwell can include the walkway and foyer in the stairwell to form an enlarged closed stairwell, but it should be separated from other walkways and rooms by measures such as Class B fire doors;

(3) In addition to the door of the stairwell, there should be no other door and window openings on the inner wall of the stairwell;

4. When a closed stairwell is set up in high-rise civil buildings, high-rise factories (warehouses), densely populated public buildings, and densely populated multi-storey Class C factories, the door leading to the stairwell shall be a Class B fire door and shall be opened in the direction of evacuation;

5 The door of the closed stairwell in other buildings can be a two-way spring door.

The difference between an enclosed stairwell and a smoke-proof stairwell.

Smoke-proof stairwells should have front rooms.

That's all for the knowledge of enclosed stairwells, I hope it will help you!

<>1. The structure is different: the closed type is to set the stairwell in the room, and open the doors and windows inside, and the door is the only passage connecting the staircase and the corridor. Smoke-proof stairwells are enclosed spaces on top of enclosed stairwells.

2. Different functions: the main function of the smoke-proof stairwell is to prevent fireworks from entering the stairwell, thereby alleviating the speed of fire spread, and the biggest role of the closed stairwell is to evacuate the crowd.

Smoke-proof stairwell:Refers to a stairwell that is equipped with facilities such as smoke-proof front rooms, open balconies or alcoves (collectively referred to as front rooms) at the entrance of stairwells, and the doors leading to the front rooms and stairwells are fire doors to prevent the smoke and heat of the fire from entering. When a fire breaks out in a high-rise building, its smoke-proof stairwell is the only vertical evacuation channel for internal personnel, and the fire elevator is the main vertical transportation tool for firefighters to put out fires. In order to meet the needs of safe evacuation and extinguishing, the smoke-proof stairwell and its antechamber, the antechamber of the fire elevator or the two combined antechambers, the mechanical pressurization mode is used to prevent the smoke from entering, and to create favorable conditions for safe evacuation and extinguishing activities, which has become the consensus of more and more designers, and has been increasingly applied in practical engineering.

The difference between a smoke-proof stairwell and an enclosed stairwell

1.The construction is different.

Smoke-proof and enclosed stairwells are compared with open stairwells, smoke-proof and enclosed are both enclosed, but they are still different in construction. The enclosed stairwell is generally set up in the room, and there will be doors and windows inside, and the door will be connected to the stairs or corridor, which is also the only passage; A smoke-proof stairwell is an enclosed space on top of a closed stairwell.

2.The features are different.

The smoke-proof stairwell needs to be equipped with fire doors, smoke-proof front rooms, evacuation signs, emergency lighting equipment, smoke exhaust equipment, positive pressure air supply equipment, etc., the main purpose of which is to prevent fireworks from entering the stairwell in time and alleviate the speed of fire spread; The enclosed stairwell is not equipped with more equipment, and its purpose is to evacuate the crowd.

3.The setup requirements differ.

There is also a difference between smoke-proof and closed stairwells, with smoke-proof stairwells having lower requirements for settings, but enclosed stairwells are more complex and have relatively higher requirements.

4.The applicable environment is different.

Smoke-proof stairwells are usually suitable for high-rise factories with a height of more than 32 meters and more than 10 people on each floor; tower dwellings; Class I high-rise buildings; Class II high-rise buildings with a height of more than 32 meters; Corridor-style residences with more than 11 floors. Enclosed stairwells are usually suitable for:

12 to 18 storey units; Corridor type houses with less than 10 floors.

ward buildings in hospitals and nursing homes; multi-storey hotels with air-conditioning systems; public buildings with more than five storeys; Class II high-rise buildings with a height of not more than 32 meters; Class A, B and C workshops and high-rise factories with a height of less than 32 meters.

Smoke-proof stairwell features:

The entrance to the stairwell needs to have a front room, balcony or alcove.

The area of the front room should not be less than 6 for public buildings, and the front room shared with the fire elevator should not be less than 10; For residential buildings, the area of the front room shared with the fire elevator shall not be less than 6; For civil air defense projects, it must not be less than 10.

Doors in the front room and stairwell need to be fitted with Class B fire doors and open in the direction of evacuation.

If there is no window, it is necessary to set up a pipe well to supply air under positive pressure. If it is a type of high-rise, there must be a pipeline positive pressure air supply.