GB 51251-2017 Technical Standard for Smoke Control and Exhaust Systems in Buildings

General Provisions

• 第 1.0.2 条This standard applies to the design, construction, acceptance and maintenance management of smoke control and…
• 第 1.0.3 条The design of building smoke control and exhaust systems shall incorporate the building's characteristics and…
• 第 1.0.4 条For building smoke control and exhaust systems, natural ventilation should be adopted as a priority. When nat…
• 第 1.0.5 条The design, construction, acceptance, and maintenance management of building smoke control and smoke exhaust …

Terminology

• 第 2.1.1 条Smoke control system : A system that prevents smoke from entering evacuation routes through mechanical pressu…
• 第 2.1.2 条Smoke exhaust system : Mechanical or natural smoke exhaust is used to discharge smoke generated by a fire in …
• 第 2.1.3 条Natural smoke exhaust : Uses the buoyancy of hot smoke generated by a fire or outdoor wind pressure to discha…
• 第 2.1.4 条Mechanical smoke exhaust : Forced smoke exhaust via smoke exhaust fans, ducts and other equipment. Applicable…
• 第 2.1.5 条Smoke control zone : A space within a building divided by smoke curtains, partition walls, or beams projectin…
• 第 2.1.6 条Smoke curtain : A facility made of non combustible material, installed vertically below the building ceiling …
• 第 2.1.7 条Clear height : The vertical distance between the lower edge of the smoke layer and the floor during a fire, t…
• 第 2.1.8 条Smoke exhaust outlet : An opening installed within a smoke control zone for discharging smoke. In hotels, the…
• 第 2.1.9 条Fixed window : Installed in spaces equipped with mechanical smoke control and exhaust systems, for use by fir…
• 第 2.1.10 条Operable exterior window : A window designed for natural ventilation or smoke exhaust, with manual or automat…

Smoke control system design

• 第 3.1.2 条For public buildings (including hotels) with a building height greater than 50 m, the smoke proof stairwells,…
• 第 3.1.3 条For public buildings (including hotels) with a building height of 50 m or less, natural ventilation or a mech…
• 第 3.1.5 条The mechanical pressurization air supply system for smoke proof stairwells and their vestibules shall comply …
• 第 3.1.6 条Enclosed stairwells (enclosed stairwells within the hotel that are not on both sides of an evacuation corrido…
• 第 3.2.1 条For enclosed stairwells and smoke proof stairwells using natural ventilation, openable exterior windows or op…
• 第 3.2.2 条When a vestibule (the vestibule on a hotel guest room floor) adopts natural ventilation, the area of openable…
• 第 3.3.1 条For hotel buildings with a building height greater than 100 m, the mechanical pressurization air supply syste…
• 第 3.3.5 条Mechanical pressurization supply fans should use axial fans or medium low pressure centrifugal fans , and the…
• 第 3.3.7 条The mechanical pressurization air supply system shall use ducts for air supply and shall not use built in civ…
• 第 3.4.1 条The design air volume of a mechanical pressurization air supply system shall not be less than 1.2 times the c…
• 第 3.4.2 条The air volume calculation for mechanical pressurization air supply systems in smoke proof stairwells, indepe…
• 第 3.3.1条 条If the hotel building height exceeds 100m, special attention must also be paid to the sectional configuration…

Smoke exhaust system design

• 第 4.1.3 条For public buildings (including hotels) and industrial buildings with a building height greater than 50 m, th…
• 第 4.2.1 条In hotel buildings, the smoke exhaust system design for corridors, rooms and other areas shall clearly define…
• 第 4.2.4 条In spaces within the hotel such as lobbies and ballrooms with a clear height greater than 6 m , the maximum a…
• 第 4.3.2 条In hotel buildings, the smoke exhaust outlets or smoke exhaust valves of rooms (such as guest rooms and meeti…
• 第 4.4.1 条In large space areas of hotel buildings such as atria , lobbies , and ballrooms , when mechanical smoke exhau…
• 第 4.4.2 条Corridors , windowless rooms , or rooms larger than 50㎡ with frequent occupancy (such as guest rooms and offi…
• 第 4.4.12 条In hotel buildings, smoke exhaust outlets should be located within the smoke reservoir . When mechanical smok…
• 第 4.5.1 条In hotel buildings, when a mechanical smoke exhaust system is installed, a make up air system shall also be p…
• 第 4.5.2 条For underground or above ground windowless corridors and rooms in hotel buildings, the makeup air system shou…
• 第 4.6.1 条In hotel buildings, the design airflow rate of the smoke exhaust system shall not be less than 1.2 times the …
• 第 4.6.3 条In hotel buildings, the smoke exhaust volume for corridors shall be calculated at 60m³/(h·㎡) and shall not be…
• 第 4.6.4 条In hotel buildings, the smoke exhaust volume for rooms (such as guest rooms and meeting rooms) shall be calcu…
• 第 4.6.5 条In hotel buildings, the smoke exhaust volume of an atrium shall be calculated at 4 air changes per hour , and…

Smoke control system equipment

• 第 9.1.1 条Equipment for smoke control and smoke exhaust systems shall be products that comply with current national sta…
• 第 9.2.1 条Smoke exhaust fans shall be capable of continuous operation for 30 min at 280°C. In hotel buildings, smoke ex…
• 第 9.2.2 条Smoke control fans (pressurization supply fans) shall be capable of continuous operation for 30 min at 280℃. …
• 第 9.2.3 条Fans shall be installed in dedicated fan rooms, and the fan rooms shall be separated from other areas by part…
• 第 9.2.4 条A 280°C smoke exhaust fire damper shall be installed at the fan inlet and interlocked to shut down with the f…
• 第 9.3.1 条The smoke exhaust fire damper shall have the function of automatically closing at 280℃ and shall be capable o…
• 第 9.3.2 条Smoke exhaust valves (outlets) shall have both manual and electric opening functions, and upon opening shall …
• 第 9.3.3 条Normally closed smoke exhaust valves (outlets) shall have a reset function and shall be able to open again af…
• 第 9.4.1 条Smoke exhaust outlets shall be installed within the smoke reservoir, and the distance from combustibles shall…
• 第 9.4.3 条Air vents shall be made of non combustible materials. In hotel buildings, all smoke control and exhaust air v…
• 第 9.5.1 条Smoke exhaust ducts shall be made of non combustible materials with smooth inner walls. In hotel buildings, s…
• 第 9.6.1 条Smoke control and smoke exhaust systems shall be capable of automatic startup in the event of a fire and shal…
• 第 9.6.2 条Smoke exhaust fans and make up air fans shall be capable of automatic shutdown at 280℃ and feed back signals …
• 第 9.6.3 条The smoke control system (positive pressure air supply) shall be capable of automatically opening the supply …

Smoke control and exhaust system equipment

• 第 9.1.2 条Equipment for smoke control and smoke exhaust systems shall have a reliable power supply capable of normal op…
• 第 9.4.2 条Supply air outlets (pressurization supply outlets) shall be installed in the vestibule and stairwell, and sha…
• 第 9.5.3 条Pipes of smoke control and smoke exhaust systems shall be provided with independent supports and hangers and …

Smoke control and smoke exhaust system equipment

• 第 9.5.2 条Fire dampers shall be installed where smoke exhaust ducts penetrate fire compartments, equipment room partiti…

System control

• 第 5.1.2 条Linkage control requirements : After the fire alarm is triggered, the smoke control system (pressurization ai…
• 第 5.1.3 条Smoke exhaust system activation : After a fire is confirmed, the smoke exhaust system should, via the fire li…
• 第 5.2.1 条Smoke exhaust fan control : The smoke exhaust fan shall be capable of manual direct start/stop control from t…
• 第 5.2.2 条Make up air system interlock : The make up air system shall be interlocked with the smoke exhaust system; whe…
• 第 5.2.3 条Smoke exhaust outlet control : The smoke exhaust outlet (or smoke exhaust valve) shall be capable of automati…
• 第 5.2.4 条Signal feedback : The open/close status signals of equipment such as supply air outlets, smoke exhaust outlet…
• 第 5.2.5 条Manual control : A manual control panel shall be provided in the fire control room for direct start/stop cont…
• 第 5.1.2条 条In hotel buildings, the smoke control system (pressurized air supply) for vestibules, shared vestibules, and …
• 第 5.1.3条 条Smoke exhaust system control for large spaces or corridors such as guest room areas, banquet halls, and meeti…

Construction and Commissioning

• 第 9.1.1 条Before construction of the smoke control and smoke exhaust systems, construction drawings, design specificati…
• 第 9.2.1 条Air ducts (including smoke exhaust ducts and pressurized supply air ducts) shall be made of non combustible m…
• 第 9.2.2 条When smoke exhaust ducts, pressurized supply air ducts and other ducts penetrate fire compartments, fire wall…
• 第 9.3.1 条Smoke exhaust valves, smoke exhaust outlets, supply air outlets, fire dampers, etc. shall be installed secure…
• 第 9.3.2 条Smoke exhaust outlets (including normally closed smoke exhaust outlets) shall be located within the smoke res…
• 第 9.3.3 条Smoke exhaust fans shall be installed in a dedicated machine room, and the machine room shall be separated fr…
• 第 9.3.4 条The pressurization supply fan shall be installed in a dedicated machine room (or a safe outdoor location), an…
• 第 9.4.1 条System commissioning shall include standalone equipment commissioning and interlock commissioning. Standalone…
• 第 9.4.2 条During integrated commissioning, fire signals should be simulated to test the actuation logic of the smoke co…
• 第 9.4.4 条During integrated commissioning, the linkage control function between the automatic fire alarm system and the…
• 第 9.4.5 条After system commissioning is completed, commissioning records shall be filled in and a commissioning report …

Construction and commissioning

• 第 9.4.3 条During commissioning, the air velocity and air volume at each supply air outlet and smoke exhaust outlet shal…

System Acceptance

• 第 9.0.1 条After system completion, project acceptance inspection shall be conducted; if the inspection fails, the syste…
• 第 9.0.2 条Acceptance shall be organized by the construction unit, with the design, construction, supervision and other …
• 第 9.0.3 条Before acceptance, check whether construction quality, commissioning reports, as built drawings and other doc…
• 第 9.0.4 条During acceptance of smoke control systems (e.g., pressurized air supply systems for stairwells and vestibule…
• 第 9.0.6 条During acceptance of natural smoke exhaust facilities (such as hotel exterior windows and roof skylights), ch…
• 第 9.0.7 条The linkage commissioning of the mechanical pressurization air supply system and the mechanical smoke exhaust…
• 第 9.0.8 条During system acceptance, check whether the fire control room can remotely manually start/stop fans, motorize…
• 第 9.0.9 条During acceptance of the makeup air system (e.g., hotel basement or inner zone corridors), the air velocity a…

System acceptance

• 第 9.0.5 条During acceptance of smoke exhaust systems (e.g., corridors, windowless guest rooms, atriums), the air veloci…

Engineering reference only — verify against project conditions and the latest codes.