Numerical prediction of mixed turbulent airflow within a cavity using various turbulence models.

The overall objective of the present work is to evaluate the performance of three turbulence models, with a view to predicting characteristics of airflow within an anisothermic cavity. The standard K-c. model, the Renormalisation Group model (RNG) and the Reynolds stress model (RSM) are used in conjunction with the Fluent code. The accuracy and the relative performance of the three models are evaluated by comparing their numerical results with experimentally obtained data. This comparison is made for the constant flow rate of a twodimensional turbulent mixed convective airflow.

Heat transfer through facade element composed by double pane window and ventilated insulation screen.

Low energy buildings should satisfied two main tasks: to assure a low energy use and provide an excellent residence comfort. The building envelopment elements, especially the transparent one, have major influence on both tasks. The paper presents research results of heat transfer and fluid flows through double pane window with tight, opaque insulation screen. The insulation screen was installed in such a way, that a semi open air gap was formed. An air gap is connected with the building interior through an opening on the bottom and with exterior through siphon at the top.

Relative importance of temperature, draft, noise and window area in offices.

Achieving optimized partial improvements of the indoor climate may often be better than to know all optimal levels. The purpose of this study was to investigate the relative importance of temperature, noise, draft and window area. 30 heat-acclimatized subjects participated in 10 exposures in single person climate chambers. Each exposure lasted three hours. During an exposure, the subject was free to optimize the operative temperature at a link to either draft, noise or window area. For each pair of parameters, three linear links were tested.

Building acoustics and sick building syndrome.

The acoustic environment was examined in an office building with a high prevalence of symptoms typical of the sick building syndrome (SBS). Levels of ventilation noise exceeded 70 dB in many rooms. The peak was often found in the region below 20 Hz, which is the infrasound region and generally regarded as inaudible at these levels. Symptoms attributed to exposure to low frequencies include nausea, headache, choking, coughing, visual blurring and fatigue, which appear to overlap with some of the symptoms of SBS.

Numerical simulation of the air cooling by natural ventilation inside the "Maison ronde" of Botta.

The present study applies the N3S CFD code to the air cooling simulation on an "architectural reference object", namely the "Maison Ronde" of Mario Botta. The summer night situation is examined when natural ventilation creates indoor air motion and cools the building structure. The transient behavior of the walls is represented by a thermal model coupled with the CFD code. The simulation evaluates the unsteady temperatures of the outdoor and indoor air flow together with those of the wall surfaces.

Low-energy cooling conception in office buildings.

Air conditioning is widely used in the office building sector in the French Mediterranean region. Though often a «sine qua non» for renting office space, there is however a widespread feeling that operating and maintaining air-conditioning systems can be troublesome (unreliability, regulation and maintenance difficulties, non uniform comfort conditions, high prices are frequently lamented).

The effect of government grants on the uptake rates of home insulation measures in the UK.

This paper examines historical data on Government expenditure on grants for home energy efficiency improvements, and the effect that this had on the uptake of insulation measures. The analysis focuses on loft insulation, this being the main measure that has been targeted by grant schemes. The paper shows that variations in loft insulation uptake between 197 4 and 1996 were closely tied to changes to grant schemes. Furthermore, there is a clear correlation between the uptake rate achieved and the level of funding provided by the Government.

Atlas of natural cooling techniques in southern Europe: application to evaporative cooling systems.

This study is a contribution to European projects Pascool/Joule II and Altener/Sink that deal with the usability of passive cooling systems in Europe. The first phase of this work was to define design methodology in order to evaluate natural cooling potential according to the climatic quantification criteria of the site, the cooling needs of the building, the cooling system performances, and comfort criteria defined by the couple of temperature and relative humidity set points.

Calculation of air infiltration in buildings and the movement of the air inside buildings corrected by heat transfer.

The purpose of this work is to evaluate the air infiltration through the high buildings and in the same time to determine the exchange of the air between the rooms and the influence of the heat transmission for these exchanges. The method of approach for this problem is a network model. This is a grid system in which the nodes are the rooms or zones of the building and the connection between two nodes simulates a flow path of a given resistance. It was built a computer program for predicting the interactions between different zones which was applied for a given case of a building.

Road traffic pollution and its effect on the internal environment of buildings.

Indoor and outdoor concentrations of various pollutants were measured in a naturally ventilated building in the West End of Edinburgh during and after the period of the Commonwealth Heads of Government Meeting (CHOGM) to assess the effect upon indoor pollution levels of the closure of some streets in the city. The relationships between indoor and outdoor air qualities in respect of traffic-generated pollutants were studied and the building's relative attenuation of external pollution levels investigated.

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