Multizone Air Flow Modelling

Completed (1990 - 1996)


The objective of this annex is to study physical phenomena causing air flow and pollutant transport (e.g. moisture) in multizone buildings and to develop modules to be integrated in a multizone air flow modelling system. The system itself shall be user-friendly and structured to be incorporable in thermal building simulation models. Furthermore, special emphasis shall be given to provide data necessary to use the system (e.g. wind pressure distribution, default values for leakage of building components, material properties like absorption and desorption). The comparison between results from the model and from in-situ tests is an important part of this annex.

To reach these objectives the project is structured in three parallel subtasks:

  • System development (subtask 1)
  • Data acquisition (subtask 2)
  • System evaluation (subtask 3)

Results of these subtasks are addressed to researchers and consultants and will promote an energy efficient design. The participants will undertake a task sharing project involving model development, data acquisition and analytical studies. Expected results are:

  • Hardware-independent multizone air flow modelling system
  • User Guide for the modelling system
  • Data base of reference cases for evaluation purposes
  • Data base of default input values for use of air flow models
  • Document on evaluation exercise
  • Report on sensitivity analysis.

IISiBat can be translated from French as "Intelligent Interface for the Simulation of Buildings" and is a general simulation environment program which has been adapted to house the COMIS simulation software. Because of the flexible nature, many powerful tools and utility programs can be housed within the IISiBat shell. In this way a complete simulation package, from simulation engine and graphical connection programs to plotting and spreadsheet software can be incorporated into one environment program; making it easier to learn and use. For more information about IIsiBat please contact CSTB email:

Operating Agent

Dr. Helmut Feustel
Lawrence Berkeley Laboratory


Belgium, Canada, France, Greece, Italy, Japan, Netherlands, Switzerland, USA