English

Ventilation studies using small-scale water models have, especially in Norway gained new and important knowledge in industrial ventilation the last 15 years. The outcome has been twofold. First of all it has resulted inimportant experience

Sick building syndrome has up until recently been diagnosed from complaints by the users of the building. Specific causes of complaints symptoms usually have not been identified. Inspection methods have been limited. Frequency of sick buil

Analysis of five papers given at the Symposium on Sick Buildings. Conclusions are that the cause of sick building syndrome must be psychosocial, physical, chemical or biological. Symptoms are different from symptoms of mass psychogenic illne

Methods of controlling indoor air pollution include control, air cleaning and dilution with uncontaminated air. Assessment of the amount of ventilation necessary depends on the extent of pollution, which has increased as new pollutants are identified and new materials are used. This has lead to thereexamination of ventilation standards and their underlying rationale.

Methods of monitoring passive smoking vary in accuracy and expense. Annoyance is easily identified among smokers and non-smokers alike. Sensory irritation does occur, but the threshold is difficult to establish. Infections in children appear to be generally correlated with mother's smoking and by amount of smoking per day. The effect on children's lung function growth has been established, but amount varies. Passive smoking has a blunting effect on response to other irritants and asthmatics are more susceptible than others.

Indoor radon concentrations are approximately lognormally distributed, with the range of concentrations varying from a one in one thousand risk of contracting lung cancer to high one per cent risk. Source strength rather than ventilation rate seems to be the major factor causing the broad distribution in concentrations. There is general agreement that the most important mechanism for radon entry into homes is not diffusion but pressure driven flow of soil gas that carries radon from the soil into the homes.

Summary of conference discussions on formaldehyde, including character- ization, sources, measurement techniques, health effects, mitigation techniques and conclusions: 1. Elevated formaldehyde concentrations, higher than 100 ppb, are measured in many indoor environments. Formaldehyde concentrations relate positively with temperature and decrease with the age of the source. 2. Urea formaldehyde bonded products can be improved to such a degree that indoor levels can be reduced to ambient levels if the materials are properly installed and used. 3.

The report of the investigation into the possibilities for saving energy by closing (large) windows in good time after, for example, the so-called 'airing' of bedrooms, initiated by the Netherlands Ministry of Housing and Environment's Steeri

The session on measured air infiltration rates in residences showed that the situation has changed drastically since the first symposium on air infiltration in 1978. Whereas in 1978 little measured data or pressurization data, or both, exist. This session contained excellent papers that summarised the state of the existing data on air infiltration.

Large, multicelled and naturally ventilated buildings pose many problems for the measurement of overall infiltration rates using tracer gases. In this paper, a simple technique proposed earlier is explored further by reference toa computer model study as well as by field measurements in two in two naturally ventilated office buildings. Results show that using this technique, the overall infiltration rates of large, multicelled and naturally ventilated buildings can be obtained to a good approximation.