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Fire Growth and Smoke Transport Modeling with CFAST

The Consolidated Model of Fire and Smoke Transport, CFAST, is a computer program that fire investigators, safety officials, engineers, architects and builders can use to simulate the impact of past or potential fires and smoke in a specific building environment. CFAST is a two-zone fire model used to calculate the evolving distribution of smoke, fire gases and temperature throughout compartments of a building during a fire.

The latest version of the software is designed to work with Windows and has been tested with Windows XP and Windows 7. The CFAST package includes NIST’s Smokeview program, which visualizes with colored, three-dimensional animations the results of the CFAST simulation of a specific fire’s temperatures, various gas concentrations and growth and movement of smoke layers across multi-room structures.

Obtaining CFAST

The latest version of the software is version 6.2.0. The software and documentation is available for download.

  • Install CFAST 6.2.0 (11.1 MB) - This software requires the Microsoft .NET framework version 4 or later. More information on the Microsoft .NET framework is available here:
  • CFAST User's Guide - The User's Guide for CFAST describes how to install the model, verify its correct installation, create input data in an appropriate form, and analyze of the output of a simulation.
  • CFAST Technical Reference Manual - The Technical Reference Manual for CFAST presents the underlying physical principles, provides a comparison with other models and experimental data, and includes a description of the limitations of the model. 
  • CFAST Software Development and Model Evaluation Guide – The Software Development and Model Evaluation Guide includes documentation of the software quality assurance processes used in the development of CFAST and a broad range of validation tests of the current version of the model.
  • Documentation for Smokeview - CFAST Version 6 includes NIST's Smokeview program for visualization. 
  • Development Version – Source code and installation software for the latest development version of the model is available on the CFAST development site.
  • Version History - A version history of CFAST is available.
  • Archive - Older versions of the model are also available. 



We are interested in hearing your comments and suggestions. Many of the improvements to date in both CFAST and Smokeview are a result of feedback we have already received from users of the software.

  • Please go to the Discussion Group, for general questions and/or to provide feedback related to your experience using CFAST, Smokeview, the documentation, the web sites, etc. Often this will resolve your issue without reporting a specific bug to the developers.
  • FAQs - Frequently asked questions for CFAST. CFAST Examples - Some typical examples of commonly encountered scenarios. Version History - A version history of CFAST is available.  
  • Report to the Support Issue Tracker specific bugs or problems that you encounter with either CFAST or Smokeview.
  • See the Support page for more options.


What's New in CFAST

See the roadmap for thoughts on future developments being considered for CFAST.

The most recent version of CFAST is version 6.2.0. New to this version: 

  • Added plume centerline temperature calculation from work of McCaffrey, Heskestad, and Evans. This is used for the surrounding gas temperature for target calculations. Note that at this point, it only impacts targets directly over a fire source.
  • Updated spreadsheet column headings to be more readable and useful, including units. This also added the option for a net heat flux output (now the default) for all target heat flux outputs.
  • Added cylindrical targets largely aimed at improving calculation of heat flux to and temperature of wire and cable targets.
  • Corrected an error in the calculation of layer absorbtivity. Calculation was using wrong species concentration for water vapor. Corrected version typically will produce slightly lower gas temperatures than previous versions.
  • General code cleanup, verification, and validation. This included removal of numerous unused variables that were left over from earlier features long since removed from the model. Code logic analysis with Forcheck to ensure call and variable consistency, additional and repeated validation tests.
  • Added detailed discussion of CFAST's fire chemistry and target calculations to Technical Reference Guide. Updated User's Guide and Validation Guide for latest version.

CFAST is developed by the National Institute of Standards and Technology (NIST) of the United States Department of Commerce. CFAST is free software developed through the National Institute of Standards and Technology (NIST) by employees of the Federal Government in the course of their official duties. Pursuant to Title 17, Section 105 of the United States Code, this work is not subject to copyright protection and is in the Public Domain.  

NIST assumes no responsibility whatsoever for use by other parties of its source code, documentation or compiled executables, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic. See the Disclaimer page for additional information.