English

Previous full scale experiments gave us a global and qualitative understanding of the gas circulation in a ventilated room in case of fire. In order to go thoroughly in the knowledge of these phenomena, we have built a scale model to perform more precise temperature measurements and more complete tracer gas experiments. The results show the existence of two zones when the air inlet is near the floor. At the opposite, when it is near the ceiling the room can be considered as a one single zone.

Microbial monitoring of the indoor environment can be performed in several ways and with the aid of different techniques. Knowing the limitations of the chosen system is of vital importance for the correct evaluation and interpretation of the results. The number of Colony Forming Units (CFU) detected by one method can not be directly compared with results from another method. The paper presents an evaluation of commonly used instruments for the collection and counting of airborne viable particles.

Displacement ventilation is acknowledged to be an efficient system for the removal of contaminants and excess heat from occupied zones of rooms, this system is aiming at supplying clean undiluted supply-air directly to the zone of occupation. Air flow rate, temperature and the design of the supply device strongly influence the parameters that determine thermal comfort. In the paper, one kind of displacement ventilation systems - ohair air supplying system is investigated.

The purpose of the work described in this paper is to develop a mathematical model of downdraft exhaust hoods in order that ways of improving these hoods efficiency can be examined. In this initial study the model developed is twodimensional. The flow has been assumed to be ideal and the complex potential considered. By use of conformal mappings the airflow in the vicinity of a bench, which is extracting air and also has air being blown down from above, is modelled. Various ratios of extraction to downdraft are considered in order to investigate the most efficient method of operation.

When a fume cupboard is placed in a room with a ventilation duct, the air movement inside and around the fume cupboard is fully three-dimensional turbulent flow. However, in order to understand the fluid flow away from the fume cupboard a much simpler model can be used. This leads to a steady 20 model, with the computational domain including only the sash of the fume cupboard, the room and the entrance into the ventilation duct. In this paper we have used both the k-E turbulence model and the wall function technique to calculate the steady 20 turbulent fluid flow.

This article describes a new and more efficient Vortex Air Distribution system for a soda recovery boiler house. Essentially th.e technology utilises directional air supply of up to 150 m3/s to compensate for beat gains of up to 2000 kW. Issues addressed include all stages of the design process from the Computational Fluid Dynamic (CFO) experiment and scale mock-up tests in the laboratory conditions to the field measurements after the system had been installed. The supply air is distributed into the building through specially designed air terminals.

A test room and measurement system were developed for the full-scale measurements of the active displacement air distribution. The room represents a 3-meter wide module of a larger hall. The requirements for the room included minimisation of the errors caused by air leaks, thermal conductance and flow obstacles. The measurement of the flow pattern is carried out with ultrasonic and thermal anemometers. Automated traversing system was built to move the sensors in the vertical symmetry plane of the room.