This paper presents a way of ventilating a large room so that the room can be divided into different zones by temporary vertical walls (canvas, plastic sheets etc) and with no physical ceiling. Different activities, like welding, painting or mechanical assembly, can go on inside each of these zones, unaffected by each other, as long as pollutants are extracted through designated extract openings in the outer walls. These inner, temporary walls need only reach from say 3 - 4 metres above the floor and up to some metres above the pollutants' height of equilibrium.

In predicting the thermal environment of an indoor space affected seriously by the outdoor weather like an atrium using natural ventilation, it is essential to grasp the impact of the external outdoor weather precisely. This report describes the result of the analysis of the outdorr and indoor region including solar radiation analysis considering the date and hour, latitude and longitude taking the atrium under construction in Kyoto as an example.

For a large-scale building complex planned to be built in urban area, airflow around buildings and airflow inside a ventilated atrium of the building complex were estimated by CFO (Computational Fluid Dynamics) simulation, and wind and thermal environment were evaluated. The accuracy of CFO simulation was assessed by comparison with wind tunnel experiment. It was found that CFO tends to underestimate the air velocity near the ground surface compared with the results of wind tunnel experiment.

A large number of the studies have indicated that chemical indoor air pollution has become an important environmental factor which influences the population's health. Nitrogenmonoxide and nitrogen dioxide are mainly produced by combustion at high temperatures and are formed by reactions between nitrogen and oxygen. Both nitrogen in the fuel and nitrogen in the air participate in reaction, NO is further oxidized and transferred into N02 in the atmosphere. Nitrogen dioxide is the most toxic of the nitrogen oxides and is the most important from view-point of health.

Source/sink models of volatile organic compound (VOC) emissions from building materials are reviewed and a multi-zone ventilation model is developed to predict concentrations of contaminants in rooms. The source model based on the principles of mass transfer and fluid flow presented by Zhang et al. (1995, 1996) is integrated into the multi-zone ventilation model. The characteristics of the parameters related to voc concentration, i.e. Schmidt number, ventilation rate and air velocity at the free stream are investigated by the sensitivity analysis.

In many new buildings the indoor air quality is affected by emissions of volatile materials. The emission process may be controlled either by diffusion inside the material or evaporation from the surface but it always involves mass transfer across the boundary layer at the surface-air-interface. Experiments at different velocity levels were performed in a full-scale ventilated chamber to investigate the influence of local airflow on the evaporative emission fr-0m a surface.

CFD simulation of airflow and temperature field in a heated room has been described in the paper. The tracking of pollutant particle movement is also presented here. The comparisons between computation and experiment show good and acceptable agreement. It can be concluded that CFD prediction can capture the main features of convective flow and provide satisfactory results. It can be seen that the thermal wall jet created by radiator greatly influences airflow pattern, temperature and pollutant particle distribution in the heated room.

The results of various numerical simulations of wind induced flows through large openings in a room are presented. The study is parametric on the sizes and relative positions of the openings and the wind direction. Various grid densities have been used. Grid independency for the presented results is demonstrated. Validation of the numerical approach is performed using measurements on a test cell with a single opening. The influence of the inflow wind profile is studied. It is shown that different flow patterns are induced within the dwelling when different profiles are assumed.

Condensation on the surfaces of diffuser and cold air dumping are the two major concerns in the application of cold air distribution brought about by the high temperature difference between supply air and room air. Condensation will form if the surface temperature of the diffuser is lower than the dew point temperature of ambient air. The presence of surface condensation can promote growth of unhealthy and smelly mold, and produce unwelcome damage of a structural and/or aesthetic nature. Cold air dumping is a major factor that detracts from thermal comfort in an airconditioned room.