English

For the building team, the design of library, archives and museum facilities brings with it special responsibilities. Archive and conservation facilities require the highest levels of preservation and maintenance of the building environment. Understanding how to maintain and preserve vulnerable materials is a key component to developing a successful design solution.

In recent years, poor indoor climate has caused health problems for building occupants. Sometimes these problems have been so serious that these buildings have, quite rightly, been labelled sick buildings.Today, there is good evidence in some areas as to why such problems arise. Unhealthy substances given off by various building materials, the existence of mould and general air pollution are the main causes. Another important factor is the high level of humidity in buildings and indoor air.In general, the most important way to remedy the problem is to improve ventilation.

This is a personal set of comments giving the author's impressions of the papers presented at the conference. A great concern of him is the difference between building scientists and health scientists as indoor air quality issues are investigated.

Carbon-dioxide (CO2) based demand controlled ventilation (DCV) offers the potential for moreenergy efficient building ventilation compared with constant ventilation rates based on designoccupancy. A number of questions related to CO2 DCV exist regarding energy benefits, optimalcontrol strategies, and indoor air quality impacts for contaminants with source strengths that areindependent of the number of occupants. In order to obtain insight into these issues, a simulationstudy was performed in six commercial and institutional building spaces.

There is research acknowledging that the home environment may be responsible for worsening respiratory conditions, especially for children. The indoor environment is a substantial source of exposure to pollutants e.g. environmental tobacco smoke. Apart from conducting specialised, costly and complex studies a method was needed to understand and assess indoor environments in the UK and how people could be encouraged to improve their indoor environment.

Twenty homes were tested and monitored in Houston, Texas, U.S.A. to evaluate humidity controlperformance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Fourteen houses had one of the six integrated dehumidification and ventilation systems and also met a high standard of energy efficiency criteria.

In January 2002 the EU RESHYVENT project started, a three-year project within the EU Fifth Framework Programme on the investigation and development of demand controlled hybrid ventilation systems in residential buildings. The project is a clustering of four industrial consortia with a multi-disciplinary scientific consortium. Each of these industrial consortia will develop a working prototype of a hybrid ventilation system for a specific climate.

The airtightness of a building envelope impacts upon the magnitude of uncontrolled air leakage and associated ventilation energy losses. A building's airtightness can be assessed using a steady state fan pressurisation technique. This paper describes a study on the largest building in the UK ever to have had its airtightness tested. Power law regression analysis revealed a good correlation between flow rate into the building and observed pressure differentials.

For historical and demographical reasons, in many European countries, an important part of educational building must be retrofitted. These retrofitting must be carried out in a context of reduction of greenhouse emissions and energy consumption.Among different targets for retrofitting, there are the improvement of indoor environment. In fact, educational buildings are particularly vulnerable to indoor environment problems. Studies have indicated a correlation between the way educational buildings are designed, or retrofitted, and student performance.

To better quantify the impact of different window opening models in comparison to ventilation techniques a multizone ventilation model, incorporating the CO2-production of the inhabitants, was developed, using Comis-Transys. The reference model represents a free-standing dwelling in which infiltration is the only source of fresh air. Through a series of simulations natural ventilation systems (standard, user controlled or CO2-based demandcontrolled), air-tightness techniques and/or window opening models (deterministic or stochastic) are added.