English

Sixteen countries world wide have participated to this international programme (IEA ECBCS Annx 35) running from 1998 to 2002 about "Hybrid ventilation in new and retrofitted office buildings" . All results of the project are published in a booklet and a CD ROM. They have also be published onthe AIVC CD (see AIRBASE recording number 14923).

A poor ventilation in buildings costs considerable amounts of money for hospitals and businesses.10 % of hospital acquired infections are directly due to an airborne route. The quantity and the quality of air supplied is important but also the way it is introduced into spaces. A change of the Wells Riley equation (establishing a link between the likelihood of infection, the infective agent production rate, the exposure time, the pulmonary and room ventilation rate) is proposed to take into account ventilation eefectiveness.

This paper deals with the case of a very important thermal discomfort due to wide open arcades and corridors beneath a building, especially under windy and rainy weather. Building thermal simulations (with ESP-r) and field measurements were operated for a building at Coimbra University (Portugal) to suggest architectural corrections (e.g. closing the arcades with windows and doors) in order to reduce discomfort outside and inside the building sand save energy.

Values for total dust concentration in indoor air in day-care centres, offices and schools with no reported problems are measured. These are: day-care centres 41 14 g/m3, offices 16 5 g/m3, schools 20 10 g/m3. In parallel the particle size distribution in six interval from 0.3 m - >20 m are reported. No seasonal variation in total dust concentration could be seen. Sudden increase in number of the particles in the smallest intervals are found at night for some systems when they are shut down or working on reduced speed.

This paper reports some findings from IEA ECBCS Annex 35 about wind driven flow through building openings. Wind tunnel studies have been performed on simplified buildings, in order to know if pressure distributions on sealed buildings can be used to predict airflow through facade openings. A new parameter, the catchment area, is introduced by author.

A large opening has first been defined as "an opening where the flow is not fully unidirectional". Then an experimental setup has been installed to conduct wind tunnel measurements on several models of a circular disk, in order to characterize the pressure distribution on simple objects provided both with and without openings.

This paper reports experiments carried out in a scale model, about possibilities to use buoyancy forces to distribute air and heat through horizontal openings. Water and saline water have been used as operating fluids. This study focuses on the effect of a staircase on the fluid exchange through the horizontal opening. This research is planned to be carried on in a full scale 2 storey-building.

One of the main objectives of this pilot study in a Swedish school was to evaluate the hybrid ventilation system with respect to ventilation, IAQ, thermal comfort, use of electricity for ventilation. The monitoring phase, lasting 2 years, included continuous measurements of outdoor environment, indoor environment, energy use. The monitoring system was integrated with the building energy management system. The reduction in energy use for space heating in the buildings was important and the reduction in use of electricity for ventilation too.

This paper presents the European Research project RESHYVENT with its structure (partners and different work packages) , and its objectives : to develop demand controlled hybrid ventilation systems, including the development of four prototypes of hybrid ventilation systems for specific climates.

The performance of various kinds of ventilation systems (mechanical supply, mechanical exhaust, mechanical supply and exhaust, crawl space supply and hybrid exhaust) was evaluated in a full-scale test house during heating period. The concentration method (SF6 tracer gas) was used to measure the ventilation air flow rates to each roomntilation. Results of experiments are presented, showing the air distribution between floors and rooms.