Istis normally assumed by designers that all pollutants in a displacement ventilation system follow the buoyant air flow into an upper zone, where they are evacuated. But studies have shown that it is not always true and that concentrations of pollutant particles can be found in the breathing zone. This study aims at designing a ventilation system that will minimize the respirable airborne particle in that breathing zone.
People that work in office buildings have new needs in terms of comfort within their work place. We suggest to develop a multicriteria office cell façade, allowing to control luminous, thermal and airflow parameters. It will be controlled to offer global
For a long time, scientific research has tried to establish the relationships between jet momentum and room velocities. The final breakthrough is still to come. One approach is to use a kinetic energy balance, which was initially suggested by Elterman (1980). This paper presents a thorough kinetic energy analysis. Based on the analysis, a new method is developed for calculating the average room velocity. The calculation method is evaluated with the experimental date from laboratory experiments with three different air distribution methods.
This paper is the investigation of two approaches for describing the details of air-flow in large indoor spaces. One approach is the zonal method, and the second one uses a CFD model.Results swow that when airflows details are necessary, coarse-grid CFD is a better method for predicting airflow in large indoor spaces than the zonal methods.
The experimental investigation of airflow performance in a ceiling slot-ventilated enclosure under an isothermal condition was the aim of that study. Air-flow characteristics have been analyzed via experimental data then compared to literature theoretical expressions.
The results will be used in design guidelines of ventilation system for controlling indoor environment.
In this study, the air flow in a small scale industrial hall is simulated numerically using two different computing codes, the commercial flow solver with a high-Reyholds number turbulence model and a university code with a low-Reynolds number turbulence model. The results are compared with measurements. Two different air supply arrangements with grille or nozzle types of air terminal devices are studied, both with isothermal and non-isothermal boundary conditions.
The new model of the COMIS program has been modified, it allows individual rooms to be divided into smaller zones. This new program has been evaluated and the results have been compared to those from other zonal and CFD models.
Natural convection, which arises around an occupant by his own metabolic heat, plays an important role in convection heat dissipation of the body in a room environment. The present research aimed at to know how local airflow penetrates through the natural convection layer, how it is perceived at a body surface, and finally causes sensations of warmth and air motion. As a basic study of it, horizontal local airflow was directed at the representative two locations on subjects surfaces, which are the back of the neck and the left side of the ankle.
The aim of this study was to find out the effectiveness of equipment used to prevent cold air flows in the wind boxes of commercial buildings and super markets. Measurements were carried out in 14 buildings at the total of 42 work sites. The effectiveness of the equipment used to prevent cold air flows in wind boxes was insufficient. The measurements showed that temperature changes and air flows can reach even beyond than 10 m from the wind box and create serious local draft at work sites.
Laser Doppler anemometry was applied to an axial fan. Results give access to a detailed knowledge of air flows, useful for optimizing the fan geometry.
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