The aim of this study was to unravel the occupational exposure to radon among underground workers. The possibility for radon mitigation by improving ventilation or by sealing was also investigated. 65 workrooms in 19 workplaces has been investigated in the ground floor, in basements and in underground spaces in southern Finland and in middle Finland. Radon concentration varied from 15 to 1636 Bq/m³du ring working hours resulting in annual dose of 0.09 to 10.3 mSv.

In certain parts of the United Kingdom where radon gas seeps from the ground into the basement of domestic housing, normal methods of removing this gas by using under floor extract ventilation is not appropriate. In this situation the radon gas enters the basement through the side walls of the cellar and hence into the house. Using mechanical ventilation to either pressurise or de-pressurise the cellar may be an appropriate solution to this problem, however before installing such a system in a house a ventilation strategy must be established.

The paper presents some selected results of evaluation of improvement effectiveness of thermal insulation and tightness of multifamily dwelling houses located in the region of Silesia. The effect of the modernization work on heat consumption (to heat the buildings) and ventilation performance is discussed. Attention is paid mainly to the sensations of the flat users connected with air flows and change. Prospects of effective implementation of thermorenovation of buildings are evaluated in the conclusions when taking into account predominating role of ventilation.

In recent years plants have increasingly become an integral part of building interior design. Greened office space and large enclosures can provide a better human environment not only because of psychological reasons. Due to photosynthesis, plants interact with the "aerial" environment. Water evaporation aflects room air humidity and temperature. Water uptake rates offive common plants in typical indoor climate conditions have been studied. Water evaporation of these plants can now be predicted in architectural design studies.

A kitchen is one of the major moisture producing areas in a dwelling. In order to prevent condensation and mould growth the relative humidity should not be too high. This paper describes a set of experiments comparing methods of kitchen ventilation and their effectiveness at moisture removal. The three methods of extract ventilation were: 1. A mechanical extract fan of extract rate 60 l/s 2. A passive stack ventilation system 3.

Multifamily buildings with natural ventilation are still being built and exploited. Such buildings are often equipped with individual gas-fired water heaters located in windowless bathrooms. It implicates the possibilities of improper gas exhaust as a result of the decrease of infiltration, what could be sometimes even harmful for the occupants' health. Based on the numerical simulations, analysis of ventilating air flows in typicalmultifamily dwelling house will be carried out.

Computational fluid dynamics has been used for assessing the thermal comfort and air quality in an office ventilated with a displacement system for a range of supply air conditions. Thermal comfort is predicted by incorporating Fanger's comfort equations in the airflow model. Indoor air quality is assessed according to the predicted contaminant concentration and local mean age of air. The performance of the displacement ventilation system is then evaluated based on the predicted thermal comfort and indoor air quality.

The present case study refers to a larger office building in Sweden. The employees in this building, which was built in 1982, began to complain about the indoor environment around 1985-86. A preliminary examination of the building started in 1989. The preliminary investigation showed that the concrete framed floors were levelled off with self levelling compound containing casein and that there were relatively high concentrations of ammonia under the PVC-flooring.

The acquisition of temperatures and velocities is a permanent recurrent task for the investigation of air flow in ventilated rooms. On the one hand it is important to measure the temperature and velocity field with a high spatial resolution. On the other hand, in general, varying outdoor conditions prevent from reaching a steady state and an additonal demand consists in short measuring times. Sometimes, the obtained measuring results are used both to supply appropriate boundary conditions for numerical computations and to verify the CFD-codes used.

The reason for the present project is the need for more reliable information about the actual ventilation conditions in naturally ventilated, detached houses. The aim has been to quantify the ventilation and humidity conditions and to establish a better basis for elaborating directions and guidelines on proper ventilation of detached houses. A national questionnaire survey covering more than 2100 households has been carried out, together with detailed investigations in about 150 houses.