Ventilation is increasingly a subject of concern due to its relation with health and energy loss. Environmental pollution and global warming demands energy conservation and a Airtight structures are being built to reduce the energy losses due to infiltration. Reduced air change rates may lead to accumulation of C02 and other toxic pollutants to undesirable levels. In view of such concerns tests are carried out here to study the influence of ventilation on indoor air quality and thermal conditions in a naturally ventilated building.

This paper presents the difference in the air quality between that perceived by the occupants (breathing zone) and that in the occupied zone as a whole. An environmental chamber with displacement ventilation system has been used to carry out the measurements with the presence of a heated mannequin and other heat sources. Measurements of the age of air distribution, the air exchange index and the ventilation effectiveness were carried out at different points in the chamber for different room loads.

This paper is based on a dual approach (experimental and numerical) in order to predict the indoor air quality for small ventilated enclosures. The experimental part employs a ventilated test room and a tracer gas technique (constant method as gas injection) to estimate the diffusion of a pollutant. The gas used is the sulphur hexafluoride (F6S). The numerical approach is a CFD simulation, adding a convection - diffusion equation (to determine the local mass fraction of the pollutant) to the equations normally used to solve a turbulent flow.

Gas cooking in the home can release high levels of nitrogen dioxide (N02) and carbon monoxide (CO). This study investigated the effect of various ventilation strategies to reduce personal exposure to these pollutants. It considered the effectiveness of windows, a kitchen extract fan and trickle ventilators for different dwellings, occupant behaviour, environmental conditions etc. Strategy selection was based on the need to minimise both personal exposure and energy loss. These strategies were simulated using BRE's BREEZE multi-zonal computer code.

The authors were asked to investigate the dynamic thermal performance of a winery building designed by Architects Freebairn-Smith & Crane. The objective was to evaluate the effect of the building fabric (particularly the strawbale wall construction) in moderating the impact of climatic variation on the internal environment in order to assess the need for auxiliary heating or cooling in the different areas of the building to achieve the thermal stability required particularly in the barrel storage room. A comparison is made with a fully serviced reference building.

This paper presents an innovative roof design. The roof is designed in response to the Tropical climate of Thailand with respect to human thermal comfort. It is composed of a combination of CPAC Monier concrete and transparent tiles on the outer side, air gap and another combination of gypsum with aluminum foil board and translucent sheets on the house side. It has two functions in operation: In daytime the roof acts as a solar chimney and induces natural ventilation. The transparent tile provides not only ,sufficient daylight for housing but also help in increasing the ventilation rate.

In many hot countries courtyard housing has evolved to help people achieve thermal comfort under hot conditions. Field studies have identified several thermal comfort adaptive actions that a person might take to achieve comfort. One of these actions is moving to a different thermal environment from the one causing the discomfort. The present paper examined how people adapt themselves thermally to achieve comfort in Iranian courtyard housing by moving between different spaces .in the house during the day.

Adequate ventilation and good air quality are essential for the comfort of occupants and productivity. Excessive ventilation however, may result in discomfort and high energy loss. A study was carried out to examine the influence of ventilation on indoor thermal conditions. The results show that ventilation has profound effect on lowering the indoor temperature, particularly the night time ventilation. Derived PMV is compared with actual votes (thermal sensation) and found that PMV is lower than actual votes.

For the academy Mont Cenis in Herne, Germany, a large microclimatic glass envelope (72m x 1.80m x 15m) with separate buildings inside the envelope, a concept for the natural ventilation was put up and a program for the control of the motor driven windows in the facades and in the roof was developed. To comprise the influence of wind speed, wind direction and the temperature difference between the envelope and the environment, numerous CFD-calculations were carried out on the base of a wind tunnel test and dynamic thermal calculations.

A computer model for predicting natural ventilation in buildings by solar chimney alone is presented. The simulations are based on the solution of the 3-D steady laminar conservation equations of mass, momentum and thermal energy with an appropriate set of boundary conditions. The equations are discretized using a finite difference formulation and solved by the Marker and Cell (MAC) scheme. Indoor airflow fields and temperature distributions are discussed with respect to human comfort at the living level, 1 m above floor.