(by Jialei Shen)
Multizone indoor air quality (IAQ) and ventilation analysis plug-in built on CONTAM
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ANT is a multizone indoor air quality (IAQ) and ventilation analysis plug-in on Grasshopper. ANT integrates the functions of programs in CONTAM family, including CONTAMW, CONTAM Weather File Creator, CONTAM Particle Distribution Calculator, FaTIMA, ContamFactorial, CONTAM Results Viewer, and CONTAM Results Export Tool, which allows ANT to perform analyses of

  • multizone airflow and contaminant transport,
  • occupant exposure to indoor contaminants,
  • estimation of transmission and infection risk of respiratory diseases, and
  • visualization of contaminant and exposure modellings.

CONTAM is a program (family) developed by NIST to accomplish multizone IAQ and ventilation analyses. ContamP and ContamX APIs were used in ANT to develop GH components to create CONTAM project elements (such as zones, paths, air handling system, and occupancy), generate project files (.prj) and run simulations. The original CONTAM and associated tools can be found on NIST website and a Python wrapper for ContamX (CONTAM simulation engine) is available on PyPI.

The name "ANT" originates from "contaminant" (or "contam-in-ant"). It implies the link between CONTAM and ANT, and also embodies the mission of ANT. Besides the regular functions of CONTAM, the highlighted features of ANT mainly include

  • capability of establishing 3D building models for CONTAM analyses (compared to the conventional way of drawing 2D sketches on CONTAMW),
  • simplified approaches on creating CONTAM zones and paths,
  • access to U.S. EPA's Air Quality System (AQS) database to generate ambient contaminant files (.ctm) for typical atmospheric contaminants in U.S. cities,
  • capability of parametric analysis,
  • estimation of contaminant exposures and disability-adjusted life years (DALYs),
  • calculation of multizone airborne transmission and infection estimation for respiratory diseases (e.g. COVID-19), and
  • visualization of contaminant and exposure calculations through plots, contours, and animations.


  1. Download and unzip ANT.
  2. Place the entire ANT folder (including .gha and other dependencies) under Grasshopper's Components Folder (via Grasshopper - File - Special Folders).
  3. Unblock files in ANT folder (how to unblock files?)
  4. Restart Rhino/Grasshopper and enjoy.


The latest version of ANT is 0.2.2. The version number of ANT is aligned with the 3.5 version of CONTAM APIs and simulation engine (contamx3.exe). The revision history of ANT is provided in ANT Revision History.

Tutorials & Examples

  • Link (Examples are only compatible with the latest version of ANT. Please update your ANT before you run the example files.)

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License Cost:
For instructions on installing Grasshopper Add-Ons, please see FAQ for details.
ANT 0.2.2
Grasshopper for Rhino 7 for Win
ANT 0.2.1
Grasshopper for Rhino 7 for Win
ANT 0.2.0
Grasshopper for Rhino 7 for Win
ANT 0.1.2
Grasshopper for Rhino 7 for Win
ANT 0.1.1
Grasshopper for Rhino 7 for Win
ANT 0.1.0
Grasshopper for Rhino 7 for Win
ANT 0.0.3
Grasshopper for Rhino 7 for Win