Continuous development of software and boundary value descriptions in connection with computer simulation of air flows in rooms, including inlet devices, use of transport equation for particles, turbulence models, models for personal exposure, models for diffusion in materials, models for emission from surfaces and models for furnishing in the occupation zone are being developed continuously. The research activity in the project also focuses on quality assurance of the numerical predictions. Furthermore, great expertise has been achieved with the applicability of the design model through practical project work in a number of projects made in cooperation with consulting engineering firms. The work is performed under REHBA, among others. Previously, The Technical University of Denmark, Chalmers Institute of Technology in Sweden, and Air Flow Cnsulting AG participated in the project.