Ventilation plays an important role in the RT 2000 regulation. The ventilation system is of course taken into account, but also the building envelope airtigthness on which this paper focuses.

We investigate the airtightness of 12 French non-residential buildings, by means of experimental fan-depressurization tests. For this study, 12 recent large (volume > 500 m 3 ) buildings have been chosen according to the construction structure and the activity. Four categories of buildings have been selected : hotels, schools, offices and polyvalent halls. We assessed the air leakage rate of each building, with a fan-depressurization equipment, following the recommendations of the international norm project ISO 9972.

Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of envelope air-tightness is critical to determining how much energy is being lost through infiltration and how much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a Blower Door. Tens of thousands of unique fan pressurization measurements have been made of U.S.

This paper illustrates the airtightness and ventilation performance of a recently built ecological house in Helsinki, Finland. The wood frame house, which is built with no plastic vapour retarder, has a satisfactory air tightness (3 ach at 50 Pa). The ventilation measurements show that the outdoor ventilation rate provided by the natural ventilation system tended to be lacking (i.e., less than the required value of 0.5 ach) even though the measured CO2 concentrations were generally satisfactory (i.e., below 1000 ppm) when the bedroom doors were open.

For over 20 years, the AIVC has been a key player in developments in technical knowledge on ventilation and related issues, and has always been very active in the dissemination of information. Since its creation in 1979, there has been a substantial change in the users' expectations of how information on ventilation knowledge should be disseminated. The AIVC has always tried to adapt its strategies to these evolving needs. In the first part of this paper, a brief historic overview is made. It is followed by a more extensive discussion of our envisaged new approach.

Passive cooling techniques driven purely by natural wind forces present a highly attractive environmental solution in the perspective of low energy architecture. The physics governing passive cooling are well understood and have been extensively discussed in the literature. Indeed the necessary design details that must be incorporated to achieve the full potential of the technique, such as exposed thermal massive and good internal and solar gain control, are also well understood.

This paper presents a passive design strategy where thermal comfort is achieved by engaging the occupants to define their own comfort condition and vary the quality of the space according to their needs. Two naturally ventilated houses in South Australia designed with this approach were tested and their actual performance documented. The results showed that most of the time the houses were always comfortable without any assistance from active systems.

The measurement and simulation of energy consumption and comfort is undertaken for a primary school in Melbourne, Australia. Four classrooms are measured providing data sets of air temperature, humidity, heating and lighting energy consumption in conjunction with external weather measurements over a full year. The primary investigation is to assess two different heating systems: electric radiant ceiling panels versus gas convective air heating.

We made a series of subjective experiments to grasp individual behaviours and thermal sensation of the occupants in as actual environmental conditions as possible by observation using video cameras. The use of video cameras allows us to have the time-series of scenes of the occupants participating in the experiment; it also allows us to avoid disturbing their natural behaviours and sensations.

Wind access/protection in cities can be affected by the morphological characteristics of the built environment. Town-planning legislation, building codes and city plan regulations influence those characteristics. Substantial climate-responsive changes of such laws and by-laws as well as simplified environmental performance evaluation tools can contribute to the reduction of mechanical ventilation and air conditioning energy loads through natural ventilation-proned urban design.