In order to protect cleanrooms from contamination from adjacent less clean spaces, the cleanroom must be built air tight and maintain an (over) pressure of sufficient magnitude and deviation. For this magnitude there are guidelines. However, there is a lack of guidelines for the required deviation of the pressure. As a result, an unstable pressure could result in an undefined air direction and increase the risk of contamination. This unstable pressure occurs especially during entering the cleanroom with an air tight cleanroom. In this paper the pressure and the entrance of the cleanroom are modeled in the SimuLink modeling environment. The model is verified and validated. The main problem addressed here is that the air tightness and the deviation of the pressure are in conflict with each other. It is concluded that the new proposed adjustment decreases the deviation of the pressure in the cleanroom and enhances the precision of control.

The paper presents an overview of Multiphysics applications using a Multiphysics modeling package for building physical constructions simulation. The overview includes three main basic transport phenomena for building physical constructions: (1) heat transfer, (2) heat and moisture transfer and (3) heat, air and moisture (HAM) transfer. It is concluded that full 3D transient coupled HAM models for building physical constructions can be build using a Multiphysics modeling package. Regarding the heat transport, neither difficulties nor limitations are expected. Concerning the combined heat and moisture transport the main difficulties are related with the material properties but this seems to be no limitation. Regarding the HAM modeling inside solid constructions, there is at least one limitation: the validation is almost impossible due to limitation of measuring ultra low air velocities of order µm/s.

This paper presents an overview of the development and evaluation of integrated heat, air and moisture modeling using the SimuLink/COMSOL simulation environment for simulating dynamic heat, air and moisture processes in buildings and systems. Most of the models are successfully verified (by analytical solutions or by comparison with other simulation results) and/or validated (by experimental data). Overall it is concluded that the SimuLink/COMSOL simulation environment is capable of solving a large range of integrated heat, air and moisture problems. Furthermore, it seems promising in accurately solving modeling problems that are caused by the presence of different time scales and/or lumped/distributed parameters.