English

In that study, Volatile Organic Compounds levels found in two tropical office buildings are analysed. The concentrations have been measured under different conditions of ventilation (normal occupancy with ventilating system working, and with the ventilation system shut down).

A CFD model that incorporates fan-performance characteristics was applied to investigate and compare the air-recirculation performance of the two general designs of unidirectional-flow cleanrooms. For the simulation, typical flow-resistance models of the various components in the air path were used.

In this paper, the airflow characteristics in the outlet region of a generic vortex diffuser are experimentally and numerically investigated. A specific arrangement of tetrahedral and hexahedral cells was used in grid generation: it has been found ideal for the analysis of the room air movement due to an air diffuser.
Corresponding airflow measurements were conducted by using a three dimensional ultrasonic anemometer.

A supervisory control scheme for a sensor based demand-controlled ventilation system is described in this paper. The strategy based on neural network models is used to diagnose the measurement faults of outdoor and supply air flow sensors, and makes the fault-tolerant control of outdoor air flow when faults occur. Tests using that dynamic system simulation have been conducted to validate the strategy.

Starting from models library, a zonal model of an entire building can be constructed by assembling the appropriate modules. A model-generating tool called GenSPARK makes the process automatic. This paper describes how that tool works and give examples of configurations that can be analyzed.

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.