English

A systematic process that analyses the relationship between building layouts and the efficiency of natural ventilation in and around high-rise apartment is demonstrated in that paper. Strategies to improve the quality of indoor/outdoor air environment are suggested.

In that paper , the presentation of a simplified control strategy for naturally ventilated buildings is made. The concept of the "ventilation function" has been introduced. The procedure applied to derive it was illustrated. It is a non dimensional graph that is proposed to perform quick and reliable estimates of the air-change rates provided by natural ventilation for any space.

Developing a device that has indoor ventilation performance through solar heating is the aim of that study. A device using solar radiation as the driving power is proposed , it is composed of shoji paper, a Japanese paper used traditionally in construction (in summer , it is used for ventilation and in winter it heats a cold room by directing the solar heat into it). Thermal insulation and ventilation performance of that device were confirmed by the experiments.

An experimental study was carried out to articulate the relationship between indoor thermal radiant environment and comfort in naturally ventilated room space is presented. Two identical-shaped wooden buildings were used for the experiment : one with external shading and the other more conventional with lower levels of thermal insulation, heat capacity and solar control. There was a significant difference in the comfort sensation votes. Measurements were made, using the measured data, the authors found a relationship between the radiant exergies and the votes of thermal comfort.

The aim of that study was to determine the best technical method for the measurement of ventilation rate in naturally ventilated buildings. First, a literary survey was performed on the current methods : traditional tracer gas method appears the most reliable technique, but the accuracy of the method could be increased by a better understanding of the mixing within the whole system. For that reason the whole volume has been divided into fictitious zones and the interaction between them has been considered.

Three new efficiency measures are defined based on the buoyancy distribution with the space. The first one is a time-averaged efficiency for a space considered as a whole. The second is an instantaneous measure for the whole space. And the third one is a local time-averaged measure with an efficiency profile.

That numerical study confirms the high efficiency of that new device for ventilation and cooling application : the air-jet device with moving parts. It is of great interest in so far its geometry generates a self oscillating flow that provides a uniform distribution of air. A wide range of velocities and geometry parameters is studied that provide information for its design.

In 2000, two similar blocks of flats with clean and effective ventilation system and low emitting building materials were built for people with respiratory illnesses. They have centralized supply and exhaust air system, either demand or user controlled. During four years they have been tested, the results show the benefits of demand controlled ventilation compared with user controlled one.

The ventilation of underground car parks is essential to avoid health problems. The aim of that study is to assess the impact of the use of axial ventilators (jet fans) suspended under the car park ceilings. That CFD analysis should be validated with experimental measurements.

For that work, a numerical study is carried out to define the optimum airside system design of tomb air ventilation systems, that will provide the best comfort and healthiest conditions with optimum energy use. A CFD software, FLUENT, was used. It appears that adding air outlets to serve the side rooms at the end of Ramses IV tomb axis, helps in lowering the relative humidity to acceptable limits.