What Is CONTAM Modeling? A Beginner's Guide to Better Smoke Control Systems

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Aric Aumond, P.E.


November 7, 2023

As fire safety awareness grows, the value of CONTAM modeling to predict smoke movement during emergencies and reduce associated risks becomes even more evident. It is a vital tool for assessing the performance of pressurization smoke control systems in modern high-rise buildings. In this guide, we'll explain the fundamentals of the CONTAM model, its importance in contemporary smoke control systems and its role in creating safer environments.

What Is CONTAM Modeling?

CONTAM modeling is a computer-based simulation tool that predicts and analyzes indoor air quality, airflow and contaminant transport in buildings. It’s commonly used during building design, particularly for assessing ventilation systems, smoke control and the distribution of airborne contaminants within structures.

CONTAM (short for contamination) models show how air moves through a building and how contaminants, such as smoke, can spread in the event of a fire. Using CONTAM modeling, fire protection engineers can simulate different scenarios and test different smoke control strategies to determine the most effective approach for controlling the spread of smoke in a particular building. Most often, CONTAM modeling is leveraged for the design of pressurization-based smoke control systems. 

How Does CONTAM Modeling Work?

CONTAM modeling represents an advanced computational method widely utilized in building ventilation and environmental engineering. It works by dividing the building into multiple zones, each with its own characteristics, such as temperature and pressure. Usually, each room of a building constitutes its own zone, depending on the objectives of the CONTAM modeling.

CONTAM is a product of the U.S. National Institute of Standards and Technology (NIST). Using mathematical equations and computational algorithms, CONTAM is used to demonstrate prescribed pressure differentials across various zones, which are the primary performance objectives of stair and elevator pressurization systems. It considers various factors, including:

  • Mechanical supply and exhaust systems and their interactions with each other
  • Building geometry and construction methods and materials
  • Environmental conditions such as extreme temperatures, wind, and elevation

By analyzing this data, fire protection engineers can optimize smoke control systems, including the placement of supply fans, exhaust fans, vents, and other elements of smoke control systems. This ensures the safe evacuation of occupants and minimizes the spread of smoke, ultimately enhancing fire safety in buildings.

What Are the Benefits of CONTAM Modeling?

CONTAM modeling’s ability to make sense of how contaminants, including smoke, move within a building provides a multitude of benefits:

  1. Quantitative analysis
  2. Optimizing ventilation strategies
  3. Compliance verification
  4. Design evaluation
  5. Emergency response planning
  6. Cost savings
  7. Customization
  8. Performance validation
  9. Data visualization

1. Quantitative Analysis

CONTAM helps in understanding how mechanical supply and exhaust systems impact static pressure differentials, which minimize the migration of smoke to different areas of the building.

2. Optimizing Ventilation Strategies

The software can be used to optimize the performance of the building's ventilation system during a fire, which can include evaluating the effectiveness of exhaust systems, pressurization and smoke control measures. Since CONTAM is a custom model unique for every building, the interaction between systems and airflow through walls and environmental factors are all considered to determine the most operationally efficient system.  

3. Compliance Verification

CONTAM modeling provides data to support compliance with building codes and fire safety standards by simulating smoke control system performance and predicting pressure differentials prescribed by codes.

4. Design Evaluation

CONTAM evaluates the effectiveness of different design choices related to smoke control, such as the location and capacity of smoke exhaust and supply points, the configuration of smoke barriers, and the impact of stack effect and other environmental factors leading to resilient system design.

5. Emergency Response Planning

CONTAM aids in providing an understanding of how smoke movement systems perform during fires, facilitating the development of effective evacuation plans and strategies.

6. Cost Savings

CONTAM modeling optimizes smoke control strategies. It's possible to make cost-effective design decisions and potentially avoid expensive modifications during commissioning and special inspections.

7. Customization

CONTAM can be customized for specific building configurations and scenarios, making it suitable for a wide range of building types and applications.

8. Performance Validation

After a building is constructed, system testing is required to validate the smoke control system performance. CONTAM modeling is used to validate the actual performance of the smoke control system against the design objectives before the building is constructed. This allows for seamless acceptance testing and minimal project delays. 

9. Data Visualization

The software provides visual representations of pressure differentials, making it easier to communicate results to stakeholders, including building owners, fire safety authorities and emergency responders.

With all of these advantages, CONTAM modeling has proven to be a powerful resource for building projects. But when is it necessary?

When Does a Building Need CONTAM Modeling?

CONTAM modeling is essential for buildings that require stairwell or elevator pressurization systems or zoned smoke control systems. It enables architects, engineers and building designers to optimize pressurization systems and enhance fire safety in these intricate environments.

For instance, many high-rises require pressurization smoke control systems, and CONTAM modeling aids in ensuring that code-prescribed pressure differentials are maintained.

When it comes to fire safety, CONTAM modeling becomes indispensable. It helps experts predict how smoke will spread during fire emergencies, allowing for the strategic placement of smoke control measures like exhaust fans and pressurization systems. This critical information ensures the safe evacuation of building occupants and minimizes the spread of smoke-related hazards.

Who Performs CONTAM Modeling?

Performing CONTAM modeling is a task that demands the expertise of qualified fire protection engineers who possess a comprehensive understanding of building design, ventilation systems and smoke control strategies. These professionals play a pivotal role in ensuring the safety and efficiency of building environments. To excel in this role, they must have a deep understanding of fire dynamics and fire department operations. Also, a deep knowledge of relevant building codes and standards is imperative. These codes dictate the regulations and requirements that establish specific design parameters, making them the foundation upon which sound modeling decisions are based.

The ability to interpret and comprehend the results of CONTAM modeling is equally crucial. After conducting simulations, FPEs must extract meaningful insights and actionable recommendations from the data generated. This involves understanding the dynamics of indoor airflow and pressure differentials, contaminant transport and smoke propagation, as well as being able to recommend appropriate adjustments to the building's design or smoke control systems to enhance safety and mitigate risks. 


CONTAM modeling is a versatile tool for designing buildings with optimal indoor air quality and safety. It allows designers to simulate different scenarios and evaluate the impact of design strategies on indoor air quality and smoke control.

While it requires specialized software expertise, the benefits of CONTAM modeling are worth the investment. Consider partnering with an experienced fire protection engineering firm to improve your building design and ensure the safety of its occupants.

Performance Based Fire Protection Engineering has the knowledge and technical expertise to perform CONTAM modeling for all types of buildings, including high-rises and warehouses. Contact us to discover how we can improve your building’s smoke control through CONTAM.