English

The SEF (system effect factor) causes loss of capacity of fan volume attributed to poorly designed and installed duct fittings at the inlet or outlet fan. It is the interaction of the air with obstructions such as elbows, guards, drive sheaves or dampers, that create SEF.
So SEF must be considered at the design stage of a fan system, it must be included as a separate item in the fan equipment schedule. Ignoring SEF has heavy cost implications.

In the first part of this paper, the techniques that allow the reduction of the radon exposure in buildings are presented. And in the second part, the authors present the results of studies that have shown the links between radon exposition and health. In conclusion, the authors assert that the risk of lung cancer due to a domestic exposure to radon is obvious.

Ashrae 52.1 and 52.2 test standards have been of great value in providing classification methods to compare and contrast filter performances. But they were criticized too, becauset the exposure of electrostatic filtration media to "real world" air results in a performance below the efficiency determined by the Ashrae 52.2. Test.

This paper describes the second step toward development of an affordable net zero energy house as part of the Department of Energy’s Building Technology Program. Building affordable houses that generate as much energy as they use is the long-term goal of

The French car group Peugeot-Citroen has been using for several years the perforated textile ducts at high induction Mix-ind for the heating of its industrial premises.That air diffusion technique uses the blowing air to start the moving of the ambient air at a very low speed.The ambient air inducted around the duct is mixed with the blowing air, so very quickly the temperature of the air inside the premises is homogenized.

Based on the advanced BIN-method, the annual energy use and the influence factors in an office building in NANJING are analyzed and presented in this paper.Under the climatic condition encountered in NANJING area, energy consumption of air-conditioning is the main energy use in office buildings.The general factors affecting the energy consumption of buildings include the inside design temperature, enclosure structure, people density, light condition, fresh air volume, the ratio of window to wall and shading coefficient.

This paper gives as a posthumous tribute to Walter Dittes, a summary of his thesis prepared at the University of Stuttgart (Germany) .It describes the various air diffusion patterns that can be used (mixing ventilation, displacement ventilation or use of both in different zones), and explains how thermal plumes are treated according to the chosen pattern.A zone model is then described for the prediction of air flows and pollutants transfers between zones within the indoor space.

This paper presents the requirements of the new European standard EN 13779 (2005) that replaced the German standard DIN 1946 Part 2 (1994). It has to be used in combination with the German recommendation VDI 6022 Blatt 1 for the design of ventilation systems fulfilling the requirements regarding indoor air quality.

Interdisciplinary research was based on simultaneous measurement of thermal environment and air quality, along with the survey of employees during their normal working activity. Statistical software and appropriate statistical methods were used to analyze the results of the questionnaire and to determine possible links with the indoor environment parameters.The results show the importance of psychological factors in subjective evaluations of the thermalenvironment.

The purpose of the present investigation was to study the indoor climate and the psychosocial work environment in different office environments.A cross-sectional questionnaire survey was performed in 11 naturally and 11 mechanically ventilated office buildings. Both buildings with cellular, multi-person and open-plan offices were studied.