To investigate the effect of ventilation on indoor radon (222Rn), simultaneous measurements of radon concentrations and air change rates were made in 117 Danish naturally ventilated slab-on-grade houses built during the period 1984-1989. Radon measurements (based on CR-39 alpha-track detectors) and air change rate measurements (based on the perfluorocarbon tracer technique; PFT) were in the ranges 12-620 Bq m-3 and 0.16--0.96 h-1, respectively. Estimates of radon entry rates on the basis of such time-averaged results are presented and the associated uncertainty is discussed.
Thermal comfort in a naturally ventilated test room is investigated. The test room is a lightweight portable cabin located in a sheltered area at Loughborough University, UK. Thermal comfort simulations were carried out for various sizes of openings and glazing. Medium and high thermal mass were added to the test room and their effects on thermal comfort were investigated. The results suggested that thermal mass has significant effect on thermal comfort parameters. Adding a 200 mm thick layer of medium-density concrete to the walls improved the thermal comfort over the summer by 40%.
When talking about air-conditioning systems in buildings people argue with high energy consumption of those systems. They do not take into account that it is not possible in many climates to realise several indoor thermal conditions by merely opening windows.Within the framework of the research project SANIREV, sponsored by BMBF and ROM, the Hermann-Rietschel-lnstitute make tests about the use of window ventilation. For different roomloads and out-door-conditions the room conditions are determined. Now we got the first results.
The design of natural ventilation devices in industrial buildings is complicated by the nonlinear interaction between the air flow rate and the indoor air temperature. Designs are therefore usually based on relatively simple calculations of the areas of ventilation openings to provide a specified flow rate at a given indoor/outdoor air temperature difference. However, the practical performance testing required for acceptance of the ventilator design still remains a difficult and dubious task.
This study presents a new method of interior air motion assessment using artificial neural networks. The air motion inside a building depends not only on the external wind velocity, but also to a great extent on most of architectural parameters such as position and orientation of building, size and configuration of windows, roof geometry, whether the building is stilted or not, etc ..
Ventilative cooling represents one of the heat dissipation techniques in the building design process. In this paper, we identify the driving forces of natural ventilation and their implications within the building. We focus on the various strategies to enhance the air circulation and exhibit the limits of this cooling technique. Design guidelines for architects based on existing knowledge are suggested. Finally, perspectives in terms of future research actions are exposed
Over 90% of office workers would rather be served by natural ventilation systems, so why is it not normal practice?
Many architects and consultants argue that serious technical difficulties make it impossible to implement.
This paper presents the state of the art on the natural cooling techniques. The development on the evaporative, radiative and earth contact cooling techniques and components is discussed. A classification of the existing systems and techniques is attempted and tbe knowledge on the more important of them is presented. Advantages and disadvantages of the classified systems are evaluated and their suitability for European climates is discussed. The luck of information as well as the existing scientific gaps on the subject are identified.
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