English

This paper asks questions about what is the right tightness and a warns against too tight tightness guidelines.The author gives advice :- A tight building envelope should reduce average natural infiltration (due to wind and temperature) to 0.05 to 0.1 air change per hour.- A tight building envelope should contain the desired air pressure field.- A building envelope should not be too tight because of the unbalanced airflows that can create excessive levels of depressurization.

The investigation was made in a Finnish building built for people with respiratory diseases. During 3 years the main indoor air parameters were measured. In parallel a questionnaire to evaluate symptoms of the occupants and their satisfaction was conducted.The experiment proved that the use of low emitting building materials, along with a high quality control of the building practices during the contruction phases, gave full satisfaction to the occupants (decrease of their symptoms during the 3 year-occupancy).With low additional costs a high IAQ can be obtained.

This article aims at precising the difference between Underfloor air distribution (UFAD) and Displacement Ventilation (DV) systems, though they both use supply air delivered into a room or space from an access floor.This article presents each system with its different way of working in applications for commercial buildings.

The purpose of that study was to quantify the effect of the variables (previously identified during the first phase of that study conducted from 1999 to 2002) concerning smoking room performance under controlled laboratory conditions.In a test chamber simulating a smoking room, 27 experiments were conducted.

DVC is a new energy saving technology, buildings that use a DVC strategy use CO2 sensors that measure and regulate the amount of outdoor air supplied to the space.Standards and local building codes have been slow to adopt it.Available data suggests that DVC reduces ventilation, heating and cooling load by 10 to 30 %.

It is a basic biological truth that people bring different levels of responsiveness to irritant stimuli to work. No one reacts to the same levels with the same intensity (symptoms are different)What are the stress factors that lead people to complain? Poor work organization, inadequate communication or pollutants ? The author suggests that priority should be given to the problems of work organisation before looking for problems of indoor air pollution, air-handling, or heating.Systematic approaches to stress management have shown to have major benefits.

The impact of the concentration of pollutants in the air on emissions from building materials is the subject of that study.Different building materials were studied in ventilated small-scale test chambers. The experiment allowed the changing of the dilution factor or the changing of the area factor.The results showed that more ventilation in a given space may increase the emissions from the inner surfaces.

A methodology for assessing the potential for a CO2 retrofit on an existing building is presented in this paper. A case study is described, the subject building is an Energy Star rated building that has a Direct Digital Control (DDC) system. The complexity of a CO2 ventilation control retrofit is related to the type of building control system currently in place. Significant energy savings are possible through the application of a well-conceived executed ventilation control strategy.

The model estimations aimed at identifying the most important parameters that determine air change rate along with predicting the indoor radon concentration to be expected in new Dutch dwellings under different ventilation conditions.Measurements were compared to the model estimations. To increase infiltration and thus to decrease radon concentation, opening the air inlets and inside doors proved to be efficient.

A good indoor air quality is necessary to minimize exposure to airborne pollutants. The main source of those pollutants is often outdoor air. Ventilation and air filtration are the main solutions to reduce them.The aim of that study was to investigate the effects of air ventilation and filtration on submicrometer particle concentrations indoors thanks to a simple one zone mathematical model that simulates the time evolution of particle concentrations indoors.