Source: Magnific
Singapore’s fire safety regulations set minimum requirements for building design based on common building types and standard scenarios. However, they cannot account for how smoke and heat will actually spread in a specific space, as they do not follow code categories. They respond to the structure of a building: where beams interrupt airflow, how ceiling height varies across a floor plate, and how ventilation systems interact under fire conditions.
Computational fluid dynamics, or CFD, allows engineers to test these conditions in a digital model before a building is constructed or modified. The results can support fire safety assessments by showing how smoke, heat, and gases are likely to behave within the building’s specific geometry and ventilation setup.
What is CFD Analysis in Fire Safety?
CFD analysis uses mathematical equations to model the movement of air and gases through a space, as well as heat transfer. In fire safety, it can simulate how smoke, hot gases, toxic combustion products, and heat move through a building during a fire.
Unlike standard airflow or comfort ventilation analysis, the purpose of fire safety CFD is to model conditions created by a fire. It produces a detailed picture of factors such as temperature, gas concentrations, smoke movement, and airflow at different locations and stages of the simulated fire.
The simulation does not predict the exact course of a future fire. Instead, it tests how a building and its fire safety systems may respond under defined fire scenarios.
What can CFD Analysis Show During a Fire?
CFD provides detailed insights into how fire conditions may develop within a building, helping engineers assess key safety factors before a building is built or altered. The key outputs include:
- Smoke Movement: Shows how smoke spreads, where it may collect, and whether it reaches escape routes or adjoining spaces.
- Fire Suppression System Evaluation: Shows how sprinklers, fire curtains, and mechanical ventilation affect smoke and fire conditions within the specific building layout.
- Visibility: Estimates how quickly visibility may fall as smoke develops within the building, including along evacuation routes.
- Temperature: Tracks heat levels at different heights and locations, including along evacuation routes, to show how fire conditions may affect occupants and building elements.
- Performance-Based Code Compliance: Provides numerical results that can be used to demonstrate whether a fire engineering design meets the required safety objectives where standard prescriptive code provisions cannot be directly applied.
Where is CFD Analysis Used in Fire Safety?
CFD analysis is useful for buildings and spaces with complex layouts, ventilation systems, or smoke-control requirements that require detailed assessment of fire and smoke behavior:
- Enclosed Car Parks: CFD analysis models airflow, carbon monoxide concentration, and smoke movement under both normal ventilation and fire conditions. This helps determine whether the ventilation and smoke-control systems can maintain safe conditions and direct smoke towards the designated extraction points.
- High-Rise Buildings: A fire on a lower floor can affect escape routes and pressurized stairwells across multiple levels. CFD analysis maps smoke and hot-gas movement through floors, corridors, and other connected spaces to assess conditions along evacuation routes.
- Atrium Spaces: Large open volumes in commercial, hotel, and mixed-use buildings can allow smoke to rise, accumulate near the top, or spread into occupied areas. Analysis accounts for building geometry, ventilation, and smoke exhaust systems to assess how these factors influence smoke movement.
- Underground and Complex Spaces: Basement areas, interconnected spaces, and other enclosed environments can present complex smoke movement patterns. CFD simulation helps assess smoke spread and the effectiveness of proposed ventilation and smoke-control systems.
- Buildings Undergoing Modifications: Changes such as new walls, ceilings, services, or altered layouts can affect an existing smoke-control strategy. CFD analysis helps determine whether the system continues to perform as intended after these modifications.
When is CFD Required for Car Parks in Singapore?
Two separate regulatory documents require CFD analysis for car parks in Singapore.
1. BCA/ACES/IES Joint Circular 2022
The Joint BCA/ACES/IES Circular 2022 (1 December 2022) requires a Professional Engineer in the branch of Mechanical Engineering (PE(Mech)) to carry out CFD simulations when proposing jet fans as an Alternative Solution in lieu of ductwork under SS553.
The report is submitted to the Commissioner of Building Control. The acceptance criterion is no carbon monoxide hotspot exceeding 25ppm at 0.5m and 1.7m height under steady-state conditions.
2. SCDF Fire Code 2023
SCDF Fire Code 2023, Clause 7.4.4g(1)(a), additionally requires CFD fire modeling alongside a hot smoke test when any of the following apply:
- Air changes per hour during a fire fall below 12
- Jet fans are spaced more than two-thirds of their tested effective range apart
- Replacement air comes from a combination of natural and mechanical ventilation
- The car park accommodates large goods vehicles or coaches, where the design fire size exceeds 4MW
Accepted software includes FDS, Swift-AVL, Fluent, and Pheonics. The study must be endorsed by a Fire Safety Engineer.
How Soteria Carries Out CFD Analysis for Car Parks
Soteria carries out all CFD analysis in-house with no outsourcing. A registered PE is directly involved at every stage, from initial modeling to final submission. The process includes:
- 3D Modeling: A detailed 3D model of the car park is built to simulate how air, carbon monoxide, and smoke behave under both normal ventilation and emergency fire conditions.
- System Optimization: Fan positions, thrust levels, and activation sequences are adjusted to achieve efficient airflow and effective smoke purging while minimizing energy use and equipment costs.
- Integrated Fire Safety Design: Smoke control is designed as part of the building’s overall fire safety design, with consideration given to evacuation routes, compartmentation, and detection systems.
- PE-Endorsed Submissions: All submission drawings and calculation reports are endorsed by a registered PE and prepared to meet SCDF and BCA approval requirements.
Ensure Fire Safety Compliance with Soteria’s CFD Analysis
Source: Magnific
Accurate CFD simulation supports the plan approval process and is a prerequisite for demonstrating regulatory compliance at the design stage. For buildings with non-standard designs, approved plans are required before progressing toward the SCDF Fire Safety Certificate needed to occupy or operate the building.
For car park projects specifically, CFD modeling is required for a compliant ductless jet fan design. Without it, the submission cannot demonstrate that the system meets SCDF and BCA acceptance criteria. This makes choosing an experienced CFD specialist essential.
With over 20 years of experience working with the SCDF Fire Code, SS 553, and BCA submission processes, Soteria builds every CFD submission around Singapore’s specific regulatory requirements from the start.
Contact Soteria today for expert CFD analysis and fire safety engineering support.
