French

The study, carried out in an atmospheric wind tunnel (reproduction of natural wind conditions, particularly turbulence), quantifies wind flows around built-up obstacles in their realistic location context, and the associated pressure fields. For various types of buildings (detached house, block of flats), the article presents in illustrated form the chart of these flows and pressures in general (mean values, standard deviations, extreme values), but deals more specifically with the wind resistance of solar collectors.

States that although controlled mechanical ventilation is becoming more widespread, the installations and their application are capable of improvement. Illustrates diagrammatically and explains methods of improving the components, their installation and operation. Considers ways of improving the air tightness of the buildings. Concludes by describing methods of simulating the performance of controlled mechanical systems, which facilitates the evaluation of measures aimed at improving their operation.

The development and construction of portable test equipment to determine air leakage has made it possible to carry out measurements on a large number of dwellings built using different construction technologies. The recording and analysis of the data collected is presented in this paper. This makes it possible to propose a method for taking sealing defects into account in the calculation of air infiltration of dwellings.

The distribution and level of pressures due to the wind on the external faces of buildings condition the working of ventilation systems and hence the thermal losses. This article presents the results of wind-tunnel experiments imitating natural wind, in the form of a "mapping" of the mean pressure coefficients exerted on the ordinary forms of dwelling. Attention is also given to the local effects on extraction outlets on flat roofs.

The aerodynamic forces affecting wind and rain penetration of roofs are described. They are: 1 the wind and its turbulent nature, 2 the induced pressure field, 3 the air flows in contact with the roof and 4 the characteristics of the roof (internal pressure, permeability, structure, etc).

Discusses levels of radon commonly found, the limits fixed by Sweden for buildings, and the health effects of these levels. The three main sources of radon are domestic water, building materials and the ground, with the ground being the most important element. Radon values for different soils in Sweden are given as illustration. COSTIC is planning to study the most susceptible zones of France, and to follow this with recommendations, including minimumair change rates.

In newly built well insulated houses, a wind of 4 m/s will produce an air change rate of almost 0.3 h-1. However it is considered necessary to obtain air change rates of 0.7 h-1. 

Roof space ventilation is necessary to evacuate water vapour to avoid condensation and to conserve the wooden roof supports. It has been affected by 1. increased insulation, 2. snow screens fitted under the roof, 3. increased humidity due to

Describes three research programmes measuring tightness of components, of specific areas of a building and of complete buildings. Defines the Belgian standards currently applicable. For air tightness, the area or building is depressurized by 5 to 100 Pa and the flow of air that enters is measured. Thenthe components are made air tight one by one, and each time the new flow rate is measured to give values for the different components. The specific area alone can be depressurized, the specific area plus the whole building or just the whole building.

Treats the causes of deterioration in buildings, thermal bridges, the indoor climate, data for the design and execution of buildings and living conditions in rooms. Section headings are The formation of moulds, Humidity in buildings, The temperature factor, tau, as a criterion of the thermal quality of thestructural elements, Conditions of occupation of buildings, Thermal bridges, Natural ventilation of buildings, Conclusions, Advice.