Modern inlet devices applied in the field of ventilation of rooms are getting more complex in terms of geometry in order to fulfil the demand for thermal comfort of the occupants in the room and in order to decrease the energy consumption This expresses the need for more precise calculation of the flow jield. In order to apply CFD for this purpose it is essential to be able to model the inlet conditions precisely and effectively, in a way which is comprehensible to the manufacturer of inlet devices and in a way which can be coped by the computer resources.

Numerical modelling is performed to predict air movement, thermal comfort level and contamination distribution within an open office space. The office located in the building interior has a concentrated thermal load at its center and is conditioned by cool air delivered from a ceiling-mounted linear diffuser. the air velocity and temperature distributions and contaminant dispersion in the office are calculated for three different cooling loads and air exchange rates with a three-dimensional turbulent finite difference model.

Results of 3-D computational fluid dynamic simulations of the air flows, temperature distribution and contaminant remove efficiencies for typical workstation configurations which include the option for localized supply of outdoor air will be presented. A typical office configuration including desks, partitions, localized heat and contaminant sources will be modelled. The results will be compared to similar simulations the same workstation environment using ceiling supply and return plenum configurations.

The airflow pattern and thermal comfort in a naturally ventilated classroom were predicted using CFD techniques. The CFD model for turbulent flow consists of equations for the conservation of mass, momentum and thermal energy and the equations for the k-E turbulence model, taking account of the effects of buoyancy and obstacles in the room. The thermal comfort was assessed according to the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD).

A mathematical model has been developed which will facilitate the prediction of infiltration rates within multi-zone buildings. The aim was to cater for: (i) significantly different temperatures in different parts of the building; (ii) flow paths at any height, including vertical connections between zones; and (iii) flow paths extending over large vertical distances. These aims led to the requirement in the associated computer program that the variation of pressure with height be accounted for independently within each zone of the building.

The concentrations of indoor pollutants should be maintained below recommended values at all occupied locations at any time. A design method based on minimal air change rates may not be satisfactory, since the ventilation effectiveness is determined not only by the nominal air exchange rate but also many other factors, such as the airflow pattern the space, location of contaminant sources, and properties of the contaminants. It is the objective of the present study to investigate numerically the effect of airflow patterns due to the various factors of ventilation effectiveness.

The evaluation of a code can be done by investigating two items: solving the correct equations and solving equations correctly and eficiently. An indoor airflow code VentAirI has been developed and is evaluated here. An evaluating procedure is suggested. The code is characterized by the standard high-Reynolds-number k-E model with wall function, the two-band radiation model and the SIMPLE algorithm. Test examples are: 1. A three-dimensional forced convection problem (Re=5000), 2. A natural convection problem (Ra=5 *10^10), 3.

The computer programs published so far have enabled the calculation of airflows at constant temperatures or of air temperatures at constant airflows. The first version of a new microcomputer program has now been developed in which the airflows and temperatures are calculated simultaneously. The time dependency of temperatures, airflows and contaminant concentrations is considered in the calculation method. The source strength of contaminants, outdoor air temperature, wind velocity and direction, convection and radiation loads can all be freely scheduled.

Simulation models basing on 2-dimensional finite-difference approach were developed for the steady-state and dynamic analyses of the thermal coupling of leakage airflows and building components. The considered types of leakage flows were crack flow and filtration through porous materials.

Combined ventilation and heating systems in floors demand extensive investigations about the heat transfer before they could be installed in residential buildings. For basic investigation about the heat transfer two experimental plants with different duct geometries are build in a laboratory of the University of Essen. Especially the measurements of temperature on different places of the plants are taken to determine the heat transfer at the two floors.