A potential conflict may exist between energy saving and good indoor climate. The present project is phase 2 of a 5-year research programme consisting of four phases, the objective of which was to develop energy efficient ventilation strategies that will provide both healthy and comfortable indoor climate and reduced energy consumption when compared to present standard.

DCV systems have proved to be energy saving with correct IAQ in previous studies. In order to achieve correct performance, these systems must be properly designed and tested. The purpose of this study is to identify the possibility of using presence sensors based on movement detection to evaluate the number of people present in a room, and also gather some more information about the real occupation rate of meeting rooms. For that, an experiment in several kinds of meeting rooms, located in different buildings and having different uses has been run.

The NEN 5128 "Energy performance of dwellings and residential buildings- Determination method" [1] describes a procedure to calculate the energy performance coefficient EPC. The requirements are given in the Dutch Building Decree [2]. The energy performance is expressed as an Energy Performance Characteristic (EPC). In this EPC procedure ventilation and air tightness play an important role. This paper describes the role of ventilation and air tightness in the Energy Performance Standard. Moreover it gives the alternative way of the so called equivalence principle.

The airtightness performances of buildings and ventilation systems can have a major impact on the indoor climate (IAQ, thermal comfort,...) and on the energy performance. Measurement results for Belgian buildings clearly show that the airtightness is often moderate to very poor. As part of the proposed energy performance legislation for the Flemish Region, it is envisaged to pay attention to the airtightness of buildings and ductwork. In the first part of the paper, results found for Belgian buildings and systems are briefly presented and discussed.

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.