English

Mechanical ventilation of workrooms was formerly based mainly on the dilution principle. In recent years, however, 50% of new investments in industrial ventilation in Scandinavia have been spent on displacement ventilation. Very little data exist from industrial settings on the relative performance of displacement ventilation versus dilution ventilation as regards air quality and thermal comfort. The present study collected data on the indoor climate in a sewing plant before and after the ventilation was changed from dilution to displacement.

Domestic gas apparatus generate oxides of nitrogen (NOx), which have been classed in recent years as problem products in the context of indoor air quality (IAQ). These, together with carbon monoxide which may also be present in the products of gas combustion, mean that the formulation of regulations for health protection presents complex problems. The present work shows the importance of this matter and presents interesting case studies taken from the Basque Country and our area of influence. It also makes specific recommendations as to how existing regulations should be changed.

This paper provides a discussion on the use of the olf and the decipol. The validity of using these units to determine ventilation rates and compare pollution emission rates is discussed, in relation to their derivation and theoretical basis and the method of application. A procedure has been developed for testing buildings by using a trained panel of people to rate air quality directly in decipol units. This was used in nine European countries as part pf the 'European Audit Project'.

During the period August 1993-0ctober 1994 a study was undertaken throughout British Telecommunications pie to assess occupational exposure to radon. This paper is concerned only with that portion of the work concerned with underground structures. The results show that radon can build up to very high concentrations in manholes and implies a significant risk to those who need to work in them.

A major increase of complaints has been observed by the occupants of buildings, concerning health symptoms and comfort. In this study, the occupants' experience of symptoms as well as the occupants' sensation of the environmental parameters were estimated in six office buildings, where the indoor air quality was investigated. It was found that the percentage of building related symptoms experienced by the occupants of the buildings was high and it was strongly related to human comfort and human sensation concerning the environmental conditions.