English

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.

In order to achieve a satisfactory level of hygiene and comfort in premises and to assess the pollutant transfers, it is necessary to control the air flow distribution. An intermediate approach between predictive numerical simulation and experimental determination of aerodynamic parameters characterizing air distribution in rooms, is the systemic approach. The paper presents the principles of this approach which is based on the residence times distribution (RTD) theory, commonly used in chemical engineering.

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.

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.

Zonal models have been proposed to bridge the gap between the whole-building macroscopic modeling methods of programs like CONTAM or COMIS and the more detailed microscopic modeling metho.ds based on solutions of the time-smoothed Navier-Stokes equations for room airflows. This paper identifies a critical shortcoming of conventional approaches to zonal modeling by introducing alternative approaches a) to formulate the key cell-to-cell flow relations upon which zonal models are based and b) to assemble the zonal system equations.

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.

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.

The protection of non-smoking persons against cigarette smoke is a very popular subject. In Germany the ,pro' and , contra' of non-smoking regulations especially in public accessible areas like restaurants, train stations or in governmental buildings is discussed in a more and more controversial way. Especially the discussion about passive smoking and negative health effects through passive smoking lead to the demand of an effective protection of nonsmokers.

The evolution of the temperature profile in a warm room driven by a natural ventilation flow which develops when the room is connected to a cold exterior by two openings at different vertical heights is explored. With the openings at the top and base of the room, we find the classical displacement ventilation regime provides a leading order description of the flow. With openings at the centre and top of the room, the ventilation is hybrid, with the lower part of the room being well-mixed, and the upper part being stratified by an upward displacement ventilation flow.

Large eddy simulations (LES) were performed for flows relevant to or incurred in ventilation air motions with and without thermal effects. The emphasis was placed on the discussion of the possibility and potential of LES for modelling indoor air flows. Some prospective views were given on the capability and implementation of the LES approach. LES is a potential tool for providing detailed and accurate solution of turbulent flow and heat transfer in analyses of indoor environment and building energy performance.