Listeria monocytogenes contamination pattern in pig slaughterhouses

Reprinted with permission from the Journal of Food Protection. Copyright held by the International Association for Food Protection, Des Moines, Iowa, U.S.A

Integral approach for adaptable indoor comfort; Building and occupants follow the sun

The focus on the needs and drives for adaptation of the building automatically leads to changing needs and demands of the occupants of the building. Building should really take care of its occupants and show adaptable behaviour and reaction to the changing outdoor environment during the day. Design for adaptability should start with the occupants needs for comfort and indoor air quality. These are partly influences by the changing environmental forces as wind and sun. Weather predictions and the aggegated voting of users about their thermal comfort, should be the leading parameters to adaptable comfort and the adaptable building

Design optimization study for an infrared heater using CFD and sensitivity analysis

Sensitivity analysis (SA) has become a very popular technique for various application areas. However, not many studies concern SA using CFD (computational fluid dynamics). The main problem appears to be the large number of model executions when using the Monte Carlo method of SA. The computing resources and time needed for such a SA in combination with CFD (in which one model execution could take several hours) can be enormous. Nevertheless, this paper describes an approach of using SA in such cases. The recommendations are obvious: simplifying the model as much as possible; considering just a key part of the model; and take more care about the speed of convergence. On this basis a case study on "Optimization of gas infrared heater radiation geometry" has been performed. The most interesting result is that the shape of the heater and the reflector material do not significantly influence the heat delivery to the occupied zone. The main conclusion is that Monte Carlo sensitivity analysis is not suitable for large CFD models with low level of abstraction. In order to obtain good results, we recommend to select a smaller part of the overall domain and/or to significantly simplify it

Ventilation of Dutch schools; an integral approach to improve design

Indoor Air Quality and thermal climate in schools is very important as it has a direct relation to the health and performance of the pupils. The status quo in the Netherlands is presented (e.g. average CO2 levels in schools, quality of ventilation). The goal of a first study was to evaluate the performance of exhaust-only ventilation systems. The performance was rather disappointed there were a lot of problems and insufficient situations found. During the next years different master students [1,2,3,4] together with the staff of Technische Universiteit Eindhoven were researching different aspects of the problem and trying to find solutions. In a following study, 6 schools with different ventilation systems were studied. Main conclusions from these studies were: IAQ in the evaluated schools did not meet the requirements and more ventilation was essential for better IAQ. A new integrated approach to design adequate solutions for ventilation of school buildings was developed. First design results are described in the paper

Assessment of the performance of the airflow in an operating theatre

Recently, a German draft standard that describes a method to assess the performance of an operating room ventilation system has been made available by the VDI [1]. To evaluate the VDI procedure and to assess practical problems, measurements have been performed in a full-scale mock-up of an operating theatre. In the design stage the VDI approach may also be useful for an objective design assessment. In that case the approach can be mimicked through the application of the Computational Fluid Dynamics (CFD) technique. In this paper the results of the full scale measurements and a comparison with numerical results will be presented. It is possible to use the VDI 2167 to evaluate the performance of a room in a reproducible manner. The CFD simulations underestimate the temperatures in the periphery of the room. A better prediction of these temperatures will lead to a better prediction of the particle concentration on the operating table