Current moisture analysis methods for walls ignore air leakage effects or are not directly applicable to multilayered walls. Mathematical equations were developed for water vapour flow, vapour pressures, and moisture accumulation under steady state conditions with homogeneous one dimensional air flow through a multilayered wall.

The determination of an acceptable range of humidity is complicated by the conflicting effects of an increase or decrease in humidity levels on the speed of chemical interactions and growth of biological organisms and pathogens that may affect human health and comfort.

This paper discusses the measurement of air infiltration rates and reports on measurements relating indoor and outdoor aerosol size distributions in the 0.01 to 1 micron size range. 

Outlines the foundations for calculating and designing natural ventilation: conditions for the building unit: technological prerequisites: components: sound insulation: calculation methods: fields of application: combination of mechanical and natural ventilation: and models for optimization of new buildings and for reconstructing factories.

The aim of the present study is to measure the possible health effects among tenants after certain characteristic energy conservation measures had been taken in their dwellings. Changes in comfort are also included. It is part of a number of projects on subjects such as indoor pollutant source control and changes in house dust mite populations related to moisture changes in retrofitted dwellings.

Since 1974 the french Authorities have insisted on energy being saved in all buildings. There was very strong pressure on manufacturers to obtain better sealed window frames . In practise less than two or three meters cubed per hour at a pressure of ten pascals penetrates. Also television campaigns have insisted on weather stripping all windows and window frames in all old buildings. The result of these campaigns is that all buildings with no or natural ventilation systems actually have indoor condensation problems.

The total energy consumption for five detached houses with air change rates of around 3 per hour right after construction, was measured and compared with estimated values, over a three-year period. Air change in the bedrooms was also measured. It was found that the recommended value was only obtained in very tight houses. If two windows are open, the ventilation system is partly short-circuited. A modified exhaust air ventilation system was designed to provide a sufficient air change in the bedroom with a reduced total air changein the house as a whole.

For optimum building design it is of importance to investigate the comfort and the energy conservation obtained with different types of ventilation systems and levels of airtightness of buildings. This could be achieved by aid of computer models based on full-scale and model measurements. In order to obtain experimental data as input data to such a computer model, an experimental, detached one-family house has been built near to Gothenburg on the Swedish west coast.

This paper discusses the potential for achieving an "energy-efficient" ventilation system by improving design procedures for natural ventilation. It considers ventilation requirements and the meaning of the term energy-efficient ventilation. Both of these topics are of fundamental importance to any design procedure. Natural and mechanical ventilation systems are discussed. This is done because natural ventilation is often compared unfavourably with purpose-built mechanical systems. It is argued that such comparisons can be misleading, unless all aspects are considered.

Measurements in a test room of 28.4 m3 located at the top of a 3-storey building have been made to determine ventilation rates of different natural ventilation systems. The systems under consideration were windows which are typical for residential buildings in Germany and various adjustable natural ventilation systems for installation in walls or window frames. The measurements take into account parameters such as inside/outside temperature differences, wind velocity and direction, opening position and location of thedifferent systems.