(by Adaquilio)
Set of components that can run simulations for infiltration, exfiltration, and room-to-room airflows in building systems, using Contam software (NIST)
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Pigeon can be used to simulate ventilation rates between building zones and outdoor environment given indoor and outdoor temperatures and wind pressure on facades. The plugin writes project files (.prj), runs simulation in Contam and re-imports results back into Grasshopper for visualization and data processing. Contam (developed by NIST)  is a multizone indoor air quality and ventilation analysis computer program. It can be used to determine infiltration, exfiltration, and room-to-room airflows in building systems driven by mechanical means, wind pressures acting on the exterior of the building, and buoyancy effects induced by the indoor and outdoor air temperature difference. You can read more about Contam at NIST website www.nist.gov/services-resources/software/contam


In order to run Pigeon and correctly re-import the results back into Grasshopper, you need to have installed the following:

1. Contam 3.2 on your C drive. You can downlaod Contam at: https://www.nist.gov/el/energy-and-environment-division-73200/nist-multizone-modeling/download-contam

2. SimRead3 in your Contam folder. SimRead3 is a utility provided to enable you to create text files from SIM files. You can downlaod it here. Please extract the content of the SimRead3 zip file into your Contam folder.

We would like to improve the Pigeon plugin, so please let the us know if you notice any mistake in the .prj input file, or if you have any other suggestion about the plugin's usability.

Weather files

For dynamic simulations Contam can use weather files (.wth format) in order to account for otudoor temperatures, wind directions and speed. It is possible to convert .epw weather files (EPW files can be found on the US Department of Energy's web site for Energy Plus) into .wth files by using the Contam weather file web application, available here.


The authors reserve the right to not be responsible for the performance and results of the plugin. The entire risk as to the quality and performance of the program is with you. Should the program prove defective, you assume the cost of all necessary servicing, repair or correction.


Pigeon plugin was developed by Rusne Sileryte and Antonio D'Aquilio as spin-off from a research project at TU Delft supervised by Michela Turrin and Eric van den Ham.