Fire engineers have to understand more than just fire behavior; they also have to understand the occupant vulnerabilities, fire protection systems, building materials, and layout throughout the entire project lifecycle. Here are some of the duties a fire engineer has:

Fire Risk Assessment and Hazard Analysis

The first and foremost responsibility of a fire engineer is to conduct a comprehensive risk assessment that includes identifying sources of ignition, fuel loads, occupancy vulnerabilities, environmental and operational hazards using quantitative risk analysis models, historical incident data, and standards like NFPA 551 (Evaluation of Fire Risk Assessment). However, they need to be involved for a long time, even after the design, as risk assessment evolves with building use, occupancy, and changes in layout or building materials.

Designing Fire Detection, Suppression, and Control Systems

A fire protection system doesn’t only include sprinklers and alarms. There are other advanced suppression and detection systems that need proper design. Systems like water-based, clean agent, and foam systems need to be hydraulically calculated, compliant with codes like NFPA 13, NFPA 2001, NFPA 11, and designed based on the hazard, occupancy type, and property. Fire engineers are responsible for all these. They are the ones to model water demand, pressure losses, discharge time, and system activation sequence. They also make sure that when a suppression system activates, it doesn’t create new hazards like electrical failures or toxic gas spread by ensuring proper integration with alarm, ventilation, and power supply. 

Egress and Evacuation Modelling

Fire engineers also model human behavior using software like Pathfinder and EVACNET to simulate the occupant movement speed under smoke, their decision-making under the fire events, risks in stairwells and doorways, etc. They also design the egress path themselves, which includes the number and width of exits, emergency lighting, stair pressurization system, exit signage, etc.

Compliance with Codes

Interpreting and applying codes, like NFPA, IBC (International Building Code), IFC (International Fire Code), state and local regulations, while designing the fire safety system for the building might not sound too complex. However, if an architect wants to have a glass atrium with open staircases and it doesn’t comply with standard code, fire engineers are the ones to propose code alternatives through equivalency reports, fire modelling evidence, and risk-based analysis. 

Fire Dynamics and CFD Simulations

Fire prevention engineers have to use software like FDS (Fire Dynamics Simulator), Pyrosim, and SmokeView to model fire growth and spread, smoke movement and layering, heat transfer across compartments, and ventilation effects on fire dynamics. 

Performance-Based Design in Complex Structures

Complex structures like stadiums and skyscrapers need performance-based fire protection engineering because each one requires custom fire safety solutions based on goals like life safety and property conservation. Fire engineers need to combine CFD simulations, egress modelling, fire resistance calculations, detection response curves, and fire scenarios like sprinklered, unsprinklered, delayed response, etc.