Emissions due to chicken farming should be minimised because they increase the greenhouse effect on the one hand and odours lead to annoyance. This paper sums up the investigations conducted in various chicken houses to analyse the effect of drying the chicken manure. The emissions streams were measured in different sites with tracer gas (SF6 or Krypton 85). Thanks to suitable ventilation systems the manure can be dried and thus ammonia and odour emissions streams can be purposefully reduced.

A validated CFD model was used to generate concentration distribution data for CO2, radon and moisture in a Hong Kong workshop with displacement ventilation.Contaminant concentration distribution depends on the contaminant source type and location. A low concentration may be obtained in the occupied zone when the contaminant source is associated to a heat source whose thermal plume is sufficiently strong to reach the upper zone.

The objective of this paper was to illustrate the potential of the CFD technique to compare the effectiveness of different general ventilation systems in reducing the workers' exposure to styrene vapour in a workroom. . Thanks to the CFD technique predicted airflow velocities and styrene distribution are shown for the 3 different ventilation arrangements at identical planes across the room. And predicted values of styrene concentration at workers'position are given.

2 examples of extract systems are presented in this paper : the first one concerns dust removal in a public waste plant and the second smoke separation in a smoker/non-smoker zone with no visual impact (i.e. no walls).Thanks to the CFD simulation, proper exhaust systems for dust and smoke have been successfully designed and optimised for each case with simulation results. The proposed solutions were then realized and with few minor modifications led to excellent working conditions on the one hand and excellent smoke caption on the other hand.

The second part of the paper deals with the measurements of the indoor thermal environment and the ventilation performance of a commercial kitchen.Measurements were made with a tracer gas (SF6) which is non-toxic and odorless.A smoke machine (ROSCO) was placed on the floor of the middle of the kitchen while operating the ventilated ceiling system. Air inlets near the floor or at the lower parts of the walls brought fresh air in the lower part of the kitchen and pushed the smoke upward.The results almost agreed with the results of the previous numerical simulation ( in part 1).

The first part of this paper deals with the performance of a ventilated ceiling system. Field measurements were made in a kitchen of a dietitics school in Kyoto practising mass cooking. The kitchen was half equipped with air canopy hoods to compare with the ventilated ceiling system.
A numerical simulation was conducted with CFD in order to understand the trends of the indoor thermal environment of the kitchen.

This paper deals with measurement of the capture efficiency of REEXS (Reinforced Exhaust System). For the experiment a local exhaust hood was designed with the possibility of working either as a traditional circular exhaust hood or as a REEXS. Experimental measurements were done both for the traditional hood and the REEXS, with the same exhaust flow rate. The results were then compared.The results proved that the main weaknesses of the traditional local exhaust hood can be improved by using REEXS hood.

One way to prevent cold air from entering through the doorway into a building is to use an air curtain. It is a stream of air blown across the doorway that acts as a thermal barrier.

This paper aims at showing the difference between the two approaches used to evaluate the capture efficiency of a local ventilation system : an experimental research using the tracer gas method ( CO2) and the numerical modelling using CFD code ( STAR-CD). Comparison between the two methods show that the CFD modelling can provide results in good agreement with the experiment.

The aim of that study was to measure the performance of local ventilation for various parameter settings (nozzles and slots REEXS) and to demonstrate the benefit for real working situations.A test cabin was built, to measure the capture efficiency under reproducible cross draughts. Optimised REEXS hoods were used for the experiment : they proved to have a larger capture range compared to the conventional flanged hood. The results were so encouraging that an exhaust installation for 6 welding working places was completed.