The process of air exchange can be described through both planar and spatial network system. It depends on a few random variables (those related to climate) and also on controlled variables (i.e. those like arrangement, etc.). Consequently, the air exchange problems are solved only approximately. In order to avoid that, a neural model was applied as well as estimation in the so-called learning process with simultaneous weight correction. On the basis of comparison with experimental data it can be claimed that solutions presented in the paper demonstrate high result congruence.

This paper introduces the infrastructure of Microflo CFO modelling system in conjunction with the virtual simulation environment. The theoretical basis is described and particularly the graphical user interfaces for pre and post processing are described in detail. Features of the Microflo system are further demonstrated through its application in the design projects.

Improvement in methods of air flow pattern scale modelling in large enclosure requires above all, précising the conditions necessary in the model in order to maintain Reynolds number independence of the mean flow, as well as defining ways in which the flow turbulent structure could be simulated. The paper presents the results of experimental analyses of air velocity fields in scale models in the range of Reynolds number 1850 to 98000. The field maps of air velocity mean value were tested.

Cheap 3D models for visualization of room ventilation applications are now available. VRML (Virtual Reality Modelling Language) is found to be a good format to describe buildings, rooms and furniture. A 3D model in VRML can be placed on an World Wide Web www page and others can see the model in "Walk Through" mode. Use of VRML is described with examples as for instance in planning of measurements and as a basis for geometry in CFD calculations. The advantage of 3D and VRML is that it is much easier to see, find and correct problems than using traditional drawings.

Previous full scale experiments gave us a global and qualitative understanding of the gas circulation in a ventilated room in case of fire. In order to go thoroughly in the knowledge of these phenomena, we have built a scale model to perform more precise temperature measurements and more complete tracer gas experiments. The results show the existence of two zones when the air inlet is near the floor. At the opposite, when it is near the ceiling the room can be considered as a one single zone.

Displacement ventilation is acknowledged to be an efficient system for the removal of contaminants and excess heat from occupied zones of rooms, this system is aiming at supplying clean undiluted supply-air directly to the zone of occupation. Air flow rate, temperature and the design of the supply device strongly influence the parameters that determine thermal comfort. In the paper, one kind of displacement ventilation systems - ohair air supplying system is investigated.

Task-ambient air conditioning system is one of the systems developed to achieve quality indoor thermal environment and energy conservation simultaneously. The purpose of this study is to find the optimum supply air conditions of floor air outlet required to make thermally comfortable environment in the task area without cold draft. To achieve the purpose were carried out the experiments with subjects, who were allowed to control the supply air volume and the direction of inclined jet according to their tastes.

The concept of air exchange efficiency of ventilation, a quantity entirely determined by the spatial distribution of the local mean age of air, is discussed. A divergence-type conservation equation for the local mean age of air is derived. This equation is solved numerically for a room ventilated by the desk displacement ventilation concept, using a CFO-routine. The CFO-calculated mean-age-of-air pattern is compared with mean age results from tracer experiments in a corresponding laboratory configuration.