The aim of this report is to provide information and advice to policy and decision makers, researchers, architects, designers, and manufacturers on strategies for achieving a good balance between good indoor air quality (IAQ) and the rational use of energy in buildings, available guidelines and assessment techniques on energy and IAQ, significant trends for the future with implications for IAQ and the use of energy in buildings; and an indication of current research issues.
Ventilation plays a crucial role in relation to the indoor pollution levels but it is also of importance in relation to the management of outdoor pollution levels. The complex role of ventilation in the various pollution related processes is discussed in chapter 2.
During recent years, increased attention is given to the identification of the appropriate conditions for a sustainable built environment, including sustainable energy systems. This, in combination with the fact that an increased number of people live in cities and the increased importance of urbanisation has a clear impact on the potential of ventilation and the related
challenges.Various aspects of this complex issue are discussed in chapter 3.
An important challenge for the buildings stock is to achieve appropriate indoor climate conditions. This means that certain needs are met in relation to the indoor air quality, the thermal, visual and acoustical comfort.This is discussed in chapter 4, whereby on the one hand the present knowledge is described as to IAQ and its links with other environmental factors as well as the remaining uncertainties with respect to the human demands on IAQ. From this analysis, it is clear that there are uncertainties in the needs for all the indoor climate parameters whereby the uncertainty in the indoor air quality is probably the largest.
Achieving appropriate indoor climate conditions, including good IAQ, requires in most cases the use of energy. In chapter 5, an indication of the energy use induced by the various indoor climate aspects is given. Moreover, the remaining uncertainties in the loads and needs (as discussed in §4) are translated into variations of the energy use. It appears that in modern buildings the energy use related specifically to ventilation is becoming more and more important.
In chapter 6, there is a discussion about the reasons for ventilation and of the role of standards and regulations. Specific attention is given to various aspects regarding ventilation and IAQ control. Also the European context (directives and CEN standards) is discussed.
Once ventilation requirements are specified in national standards and regulations, one could expect that these specifications are more or less met by daily practice. However, this is not always the case. In chapter 7, various field studies are reported and analysed. Moreover, information concerning the correlation between the reported air flow rates in field studies and health related characteristics is given.
Chapter 8 is focused on strategies that allow to achieve at the same time an appropriate IAQ and energy efficiency.This includes design, loads control and ventilation strategies.
The implementation of ventilation strategies for achieving appropriate indoor air quality conditions are in practice translated into the need for certain investments. The information given in chapter 9 highlights the consequences of inappropriate indoor air quality:They do not only regard health and comfort but also has major economic implications.
Based on the information given in the various chapters, an indication of priorities for actions is given in chapter 10, whereby also an indication is given about the requested efforts for carrying out such priorities and the chances for success.