Health effects caused by aerosol air pollutants in the breathing air is a main target for occupational health investigations. The effects of aerosol particles on health usually depend on the dose of particulate matter (PM:) retained at various locations of the respiratory tract. Displacement ventilation has been proved to be an effective ventilation system for the removal of passive pollutants in many buildings. The question is often asked about the performance of non-passive particle removal in a room ventilated by displacement ventilation.

Forced air circulation in a storage room either with freezing/cooling or controlled atmosphere is usually turbulent because a high air change rate is generally required. The interaction between the turbulent air flow and the product layers plays an important role in the performance of the storage room. In this paper, a homogenous model based on the Brinkman-Forchheimer-extended Darcy equation for both fluid and porous layer is described, in association with the standard k-e turbulence model.

The heat sources in a room with upward air supply, can be ideally decomposed into some basic models. Based on searching of the solution of the basic models, then solving the varieties of practical problems, a simplified method for predicting vertical temperature distribution of room air is submitted in this paper. Calculated values of some practical examples agree satisfactorily with experiment results.

Information on thermal plume characteristics is essential for designing ventilation systems with displacement air supply. Empirical, analytical and computational fluid dynamics are the commonly used approaches to evaluate air temperatures, velocities and airflow rates in thermal plumes above different heat sources. However, only limited information is available on the behavior of thermal plumes in rooms with a temperature gradient along the room height.

The aim of this study was to ascertain the validity of using computational fluid dynamics (CFD) techniques to predict the behaviour of three dimensional gravity induced natural convection buoyant plumes from a vertical heated cylinder in a large quiescent enclosure. The calculated velocity distributions and turbulence quantities over the cylinder were compared to a wide range of experimental measurements. The laminar boundary layer on an isothermal vertical plate was also modelled. The CFX4.

The paper presents the results of the research on application of the equation describing the increase in the air volume flux in buoyant plume above a point heat source to calculate plumes in rooms with displacement ventilation.The tests carried out in test room have given information about practical defining of the distance from the origin, assuming entrainment coefficient values and possibilities of assuming equal widths of temperature and velocity profiles in order to determine the origin distance.

This study is a part of a research project named 'Convective Flows and Vertical Temperature Gradient within Active Displacement Air Distribution'. The project was started in 1996 in order to determine guidelines for air flow rate dimensioning of the system. Aim of this study was to determine the characteristics of the thermal plumes of the heat sources used in the project. The characteristics were determined in order to apply the results to different kinds of plumes, which may occur with active displacement air distribution system.

No longer relegated to the garage or the workshop, the search for more power is taking over the kitchen, as commercial-sized kitchen fans invade the home. The problem is, residential kitchens aren't regulated the way commercial kitchens are. This causes potential hazards when these huge fans are turned on.

This report characterizes ventilation in residential suites located in ten buildings in major metropolitan areas of Canada. All buildings were between six (6) and thirty-two (32) stories high and were built between 1990 and 1995.
Ventilation in mid- and high-rise residential buildings is a particularly complex issue to investigate and to discuss in a report.
This report answers three key questions: