The activation of the smoke control system would ensure that the smoke layer would not be lower than 1. The provision of a single door opening for this room is permitted provided the most remote part of the room is less than 8m from the door, and the equipment found inside this room, does not obstruct the throw of a water jet from a firefighting hose.
The above clause is mainly applicable to hotel building. Service areas such as laundries, stores and workshops that are restricted to staff only shall be compartmented. Each compartment shall be provided with smoke venting or smoke purging system. Adequate level of visibility and smoke dispersal shall be maintained for these areas to facilitate escape. A smoke vent in accordance with Cl. In lieu of smoke vents, a smoke purging system or an engineered smoke control system is permissible for car parks or other occupancies respectively.
Smoke ventilation shafts where extending through storeys above, shall be enclosed with imperforate walls having minimum 1-hr fire resistance. The positions of all smoke vent outlets and the basement level or areas they serve shall be suitably indicated on the external face of the building adjacent to such outlets. Smoke vents shall be adequately distributed along the perimeter of the space served, and its outlets shall be easily accessible during firefighting and rescue operations.
Smoke vents shall comply with the following requirements:. Smoke purging system, where permitted under this Code in buildings, shall conform to all of the following requirements:. The smoke purging system shall be independent of any other system serving other parts of the building.
The purging system shall be activated automatically by the building fire alarm system. In addition, a remote manual start-stop switch shall be located at the FCC, or at main fire alarm panel on first storey where there is no FCC in the building. Visual indication of the operation status of the smoke purging system shall also be provided with this remote control.
Supply air shall be drawn directly from the external space and its intake shall not be less than 5m from any exhaust discharge openings. Outlets for the supply air shall be adequately distributed over the area served. Where there is natural ventilation for the area served based upon evenly distributed openings equal to not less than 2. Supply air part of the smoke purging system is provided via opening to the external air.
The openings provided for supply air shall not be less than 2. Ramp openings, voids over car parking areas are considered acceptable openings for fresh air supply. Where a smoke purging system consists of a supply and exhaust , both of which shall be designed such that each can operate in two sections.
The capacity of each section shall be sufficient to provide half the air changes required. Each section of the smoke purging system shall so constructed that in the event of failure of one section exhaust part or supply part , the other section shall continue to operate.
This can prevent failure of the system caused by failure of one single fan. The exhaust and supply parts shall be electrically interlocked so that failure of any section of the exhaust part shall automatically shut down the corresponding section of the supply part, which can prevent total failure of the smoke purging system caused by the failure of one single fan. In the event that any exhaust fan fails to run or is shut down for maintenance, the corresponding supply fan should not run so as to prevent fresh air from being pumped into the basement.
The interlocking arrangement will not apply if smoke purging system consists of only the exhaust part. However, the exhaust system shall also be designed into two section as per the above.
Replacement air shall be provided and if it is supplied by a separate mechanical system, such a system shall be connected to a secondary power supply.
Exhaust ducts shall be fabricated from heavy gauge steel of at least 1. It is not intended for mechanised car park systems or other forms of car parking systems. Provision of sprinkler system. Zoning of car park. A commissioning test will be carried out using hot smoke to demonstrate that smoke can be contained within each zone and channelled to the extract fans.
The ducts shall be fabricated from heavy steel gauge steel of 1. Alternatively, sharing of the fresh air and exhaust air fans is permitted provided the fans, wiring and control panel are protected with at least 1-hr fire resistance rating. This requirement is also applicable for mechanised supply fan system, if it is used.
Jet fan system. The activation of the jet fan system shall be confined to the smoke control zone on fire and all its adjacent zones. A firefighter cut-off and activation override switch shall be provided at the FCC. As an alternative form of fan activation, the use of smoke detectors to activate the jet fan system is allowed, provided:. This is to minimise false alarms. The tested effective range of the jet fan shall be taken as the distance up to the point at 0. But if any of the exhaust fans is still in operation in a particular smoke control zone, all the jet fans in that zone shall continue to operate.
If the fans are manually restarted, both the exhaust fans and jet fans shall continue to run at high speed until they are set to low speed at the field control panel. The panels are also required to have the individual group of jet fans indication lights interlocked with the main exhaust fans in the respective smoke control zones. For example, if the operation of jet fan system in a particular smoke control zone is switched off by the firefighter during fire mode condition and the primary source of power fails, the subsequent operation of the secondary power supply shall be such that the jet fan system remains in the previous fire mode condition, i.
As such, information as to the viable approach route shall be displayed at the main fire alarm panel. This can be achieved by arranging the sprinkler control zone to correspond with that of the smoke control zone.
Wiring arrangement of jet fans. In the event of failure of one group of jet fans, the next corresponding group will be able to drive the smoke towards the exhaust location to be extracted see Diagram 7. Should one group of jet fans fail, all other groups shall still continue to run. This is to minimise the risk of a fire affecting all the control panels if they be spaced closely together, and thus rendering the ineffectiveness of the jet fan system.
Provision of supply air. Exhaust fan design. A lower air change not less than 9 air changes can be permitted provided the acceptance criteria stipulated in the Cl. The heat release rate of the fuel load for the hot smoke test shall be at least 1MW. The relevant PE or Fire Safety Engineer should decide on the fire location s that is are deemed most onerous with justification. In addition to the hot smoke test, Computational Fluid Dynamics CFD fire modelling will also be required in the following instances:.
The FSE is also required to put up a fire engineering report. These conditions shall commence at a distance of 5m from the fire location in the direction opposite to the induced bulk air flow induced by the jet fans. All other areas outside the smoke-logged area shall be kept substantially free from smoke i. Note: If hot smoke test is performed, assessment is to be made on the operation of the jet fans system, movement of smoke towards the extraction points and smoke spread.
The latter 2 aspects can be generally verified using the above visibility criterion. The temperature criterion need not be verified in view of the nature of the hot smoke test.
For general goods vehicle, the design fire size shall be based on at least 10MW steady state fire FSE is expected to provide justification for the bigger fire size other than the car fire.
The type of fire shall be flaming polyurethane. The data from the model shall be compared against physical test data. As such, the jet fan shall be tested for velocity profile by an accredited testing laboratory for comparison with the simulated velocity profile.
The test report is to be attached to the Fire Engineering Report. The duration of the fire simulation shall be at least 20 mins. Other than these zones, the grid size shall not be larger than mm X mm X mm. Alternatively, the relevant PE or FSE undertakes a grid resolution study to ascertain the appropriate grid size needed for the fire size and smoke flows modelled e.
This study is applicable to both fire modelling and hot smoke test. Notwithstanding the failure of 1 group of jet fans, the acceptance criteria must still be maintained. The above requirement is also applicable for mechanised supply fan systems, where used. Note: If there is sharing of the exhaust air fans, see Cl. Fire resistance of jet fan system. Operations and maintenance manual. An operations and maintenance manual shall be attached. The manual can also be used as a guide for future renovations and changes to the building.
Commissioning test. The Registered Inspector who carries out commissioning test of the jet fans system may make reference to Table 2 of BS - Part 7 as a guide. Reference may be made to AS on hot smoke test and PE is advised to make reference on how the test can be prepared and carried out in a proper manner. Acceptable design guidance.
Other acceptable standards such as NFPA 92A may be adopted, taking into consideration that the basic requirements of smoke control system in the Fire Code should be strictly complied with. The engineered smoke control system shall be in the form of a smoke ventilation system by natural or mechanical extraction designed in accordance with BR , BR , BR and other acceptable standards:.
Sprinkler system. The main reason that sprinkler system must be provided is to control the fire size. The sprinkler head spacing in respect of both hazard and classification determines the size of a fire, in area and perimeter. The activation of sprinkler heads would, besides controlling the fire size, help to reduce the build-up of heat and toxic gases, which can lead to flashover and smoke explosions.
Based on research, if the fire is not sprinkler controlled, the fire size would be unlimited and therefore, fire size could not be established.
This performance criterion is evaluated by calculating the smoke exhaust rate. The calculations used are based upon the location of the design fire and how the smoke plume will develop. The different configurations are an:. This is prescribed to ensure that the designer uses a reasonably sized fire. However, as part of an engineering analysis, a larger or smaller design fire can be justified and utilized. Heat release rate data for the fuel sources can be used to determine an appropriate design fire size.
The effect of sprinkler actuation on the design fire can also be factored in when determining a design fire size. There are many different factors that can be considered when selecting an appropriate design fire for a particular case, but it is critical that this process is well documented in the design report.
In addition to exhausting smoke from the smoke zone, the system needs to introduce makeup air into the smoke zone at a rate not exceeding fpm This is measured at the fire location.
It could be very difficult to get all makeup air at outlets to be below fpm. Makeup air should be introduced below the level of the smoke interface. Makeup air is required to balance the airflow in the smoke zone and prevent it from becoming a vacuum. The IBC does not prescribe a calculation method for determining the amount of makeup air, but it should be developed by the design team. Makeup air is comprised of air introduced into the building naturally or mechanically, and air coming from building leakage, the proportions of which are determined based on the tightness of the building construction.
An extensive amount of information needs to be considered. The report serves not only as a document to gain approval of the system design, but also as an operational guide to be maintained within the building by the owner. This requires a qualified engineer to prepare the design. To prepare an engineered smoke control design as required by the IBC, it is recommended that a fire protection engineer be part of the design team.
Most are intended to protect occupants while they are evacuating or being sheltered in place. The most common systems referenced in current codes are atrium smoke exhaust systems and stair-pressurization systems. In some specialized cases, zoned smoke control systems may be provided. These feature zones or floors that are either pressurized or exhausted to keep smoke from spreading.
The IBC contains mandatory provisions for smoke control systems. The manual controls required or provided for smoke control systems are a primary consideration for the fire service. These manual controls can override automatic controls that activate these systems. When fire department personnel arrive, they can assess whether the automatic modes are functioning as intended. Incident commanders may then use the manual controls to select a different mode or turn any given zone off.
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