CONTAM — The Complete Guide: Free Airflow, Contaminant and Smoke Modelling in Buildings
CONTAM is a multizone model of airflow and contaminant transport inside a building, developed at the US National Institute of Standards and Technology (NIST). Each room is a zone with uniform pressure and concentration, and the program computes flow between zones — through cracks, doors, shafts and ducts — driven by mechanical systems, wind and temperature differences.
CONTAM
NIST
Airflow and contaminant dispersion inside buildings — ventilation, pressures, smoke and CO2.
Get it from the vendorWhat you get
- Airflows — infiltration, exfiltration and flow between rooms and floors.
- Contaminants — dispersion of smoke, CO2, particles or a specific gas over time, including deposition and reactions.
- Exposure — estimating occupant exposure for risk assessment.
- Smoke management — checking stairwell pressurisation and smoke extract systems.
- Sketch interface — ContamW: draw the floor plan as a network of zones and flow paths.
What to know
CONTAM is US government public-domain software, completely free. The graphical interface runs on Windows only; the calculation engine also runs on Linux. Built-in data, such as leakage coefficients, are based on American sources, so adapt them to local construction practice. The model assumes each room is fully mixed, so it does not replace CFD.
Related tools
For detailed fire and smoke simulation inside a space — FDS. For building energy simulation — EnergyPlus. For general airflow CFD — OpenFOAM.
FDS and Smokeview
NIST
Fire and smoke movement simulation in buildings — the world standard in fire safety engineering.
Get it from the vendor
EnergyPlus
US Department of Energy
Annual building energy simulation — envelope, HVAC, thermal comfort and daylight. The US DOE engine.
Get it from the vendor
OpenFOAM
OpenFOAM Foundation
Comprehensive CFD solvers — flow, turbulence, heat transfer and multiphase. Text-file driven, no GUI.
Get it from the vendorOpenStudio
National Renewable Energy Laboratory
Graphical workflow on top of EnergyPlus — geometry, systems and scenario comparison.
Get it from the vendorThe bottom line
CONTAM is a fast, proven tool for whole-building questions of ventilation, pressures and smoke — free and maintained by NIST.