English

Experiments were operated to determine the thermal stratification in a full-scale enclosure with natural ventilation driven by thermal source. Results provided by various predictive techniques were compared with experimental data. The salt-bath modelling technique and related mathematical model of Linden appear to be unappropriate for this type of air flow. CFD gives realistic predictions, especially when using a complete thermal radiation model.

That paper deals with the use of nondimensioanl graphs for designing the envelopes of naturally ventilated buildings. The graphs can be generated from theoretical models or from experimental data via a direct measurment of ventilation rates in a wind tunnel model.
Examples of graphs are given: they cover conventional design conditions and off-design conditions.

Experimental data for an impinging jet in a room are presented in this paper and non-dimensional expressions for the decay of maximum velocity over the floor are derived. The performance of that system is compared with the one of a wall displacement ventilation.

On account of Volatile Organic Compounds (VOCs), large proportions of workers suffer from eye and respiratory discomfort or headaches. In a small-scale painting process, efficient ventilation system must be provided for human health. In this study, ventilation characteristics of toluene have been analysed in a room of a small-scale painting process with various exit locations with different suction velocities at the exits.

The author explains that too tight building envelopes can cause bad operation of atmosperically vented combustion systems (e.g. gas water heaters) in case of of unintended depressurization of the building, for example with large exhaust fans and dirt filters. He considers that airtightness requirements of standards are often too severe. He proposes a building airtightness of 2 to 6 air changes per hour at 50 Pa for warm climates and 1.5 to 4 for cold climates, buildings with atmospherically vented combustion appliances being at the high end of the range or higher.

An analysis of recently published research results is provided, showing that if molds and the different compounds they produce can lead to some health effects (allergies, infections, potential toxicologic effects) when inhalated, these effects occur only for exposures at very high doses. The potential toxicity from indoor air exposures is therefore very low, which allows to consider the term 'toxic mold' as a misnomer.

This article presents how ventilation and air quality in smoking spaces are being treated by ANSI/ASHRAE standard 62, Ventilation for Acceptable Indoor Air Quality. Historical information is given about environmental tobacco smoke and ventilation requirements in the standard since its first issue in 1973. The status of the 31 addenda to the 1999 version of the standard, some of them being included in the 2001 version, others still being in discussion or in the process to be adopted, is explained. Among them are four smoking-related addenda : 62e, 62g, 62o and 62ag.

The article describes the different types of cold beams used to cool rooms from cold water. Passive cold beams mainly exchange through radiation and natural convection ; they include no fresh air introduction. Active cold beams are mainly based on forced convection, hot air from the room being induced by fresh air. Mix systems try to combine radiation and forced convection. Main characteristics and advantages of cold beams as well as system design rules are also briefly given.

Measurements of temperature and local heat flux were operated on a vertical surface, such as a window, equipped with louvers, such as those of a venetian blind, for different window temperatures, irradiation levels, louver to window spacings and louver angles. Results have been compared with calculations (see Airbase record # 14975). The comparison validates the numerical study.

This article presents the numerical study of the influence of louvers, such as those of a venetian blind, on heat transfer from an adjacent vertical surface, such as the indoor side of a window. The physical model used is described. Results show the influence on radiative and convective heat transfer, which were found as being of the same magnitude, of louver spacing, louver tip to window spacing, louver angle, window surface temperature and irradiation.