Centrally controlled mechanical exhaust air ventilation systems in residential buildings can satisfactorily serve only a few of the inhabitants. As the need for ventilation in each apartment varies both temporally and locally, the exhaust air ventilation system should operate accordingly. On the basis of a new cascade-control method a selfcontained constant flow exhaust air terminal device was constructed. With the device the user can, according to his own needs, increase temporarily his own exhaust air ventilation.

Each occupant in a room should be able to control his own indoor environment. Individual control can be achieved in many ways: from simple window-opening to automatically arranged personal mini-environment. Individual control is not utilized effectively today. This is partly caused by lack of proper information, and partly by the fact that builders pay more attention to construction than to use and operation. Even technically complicated systems can be easy to operate - what is needed is sufficient, but not too difficult user information.

The need for reduced energy consumption has led to an overall decrease of air infiltration rates in buildings. particularly in dwellings. Unfortunately. this has given rise to a significant number of problems involving condensation. with resulting damage to the structure and contents of affected buildings. Various means of condensation control are available. The use of a passive ventilation system to achieve this aim has several attractions. not the least of which is that the occupants of houses fitted with such a system need little. if any, knowledge of the principles involved.

Occupants can significantly influence both the heating energy requirements and the indoor air quality of a building by opening and closing doors and windows. If the effects of these actions are to be accurately estimated, both the quantity and character of these exchange flows must be determined. In this paper, data on gravity-driven exchange rates through open doors obtained from field experiments at the Alberta Home Heating Research Facility are compared with laboratory model simulations and theoretical predictions.

In order to save energy, i.e. ventilation heat losses, the fresh air change rate should be adapted to the prevailing need. Even though it is a fact that reducing the fresh air change rate will result in a ventilation heat gain, the fresh air flow rate should not be kept too low, so that pollutants, humidity and body odour can accumulate. The results of measurements in a climatic chamber and in a lecture theatre show a significant relationship between the concentration of carbon dioxide and body odour of the indoor air under nonsmoking conditions.

One of the most important reasons for ventilation of dwellings is moisture control. Ventilation strategies differ. The article deals with 1) Ventilation as a measure for moisture control in dwellings: comfort aspects, durability aspects, air humidity and ventilation: 2) Principles for risk analyses; surface phenomena, moisture conditions within buildings components; 3) Ventilation requirements in different climates; climatic data for different climatic zones, principles for moisture- ventilation analysis, and analyses of the examples.

This research attempts to offer partial answers as to how and why inhabitants of a rented apartment building behave as they do in aeration. The authors adopted a two-fold approach : first, by using computerised data recording of outdoor and indoor temperatures per room, the number of hours of sunshine, the surface temperature of radiators and the opening of the windows in each room;second, through interviews with the tenants, sometimes filmed, in order to ascertain their behaviour patterns and underlying motivations in ventilation.

Within the framework of the national research project "Ventilationin Housing Construction", studies on occupants ' ventilation behaviour were conducted in a demonstration building in Duisburg- Neumuhl (Federal Rep. of Germany) which also formed part of the project . Analyses were based on values measured from Jan, 1 - Dec. 31, 1984 in 24 flats with identical ground plans, all of which were equipped with mechanical ventilation systems.

SINTEF, The Foundation for Scienti f ic and Industrial Research at the Norwegian Institute of Technology, has monitored a number of experimental low-energy houses, and also undertaken measurements in some other houses to establish the energy consumption, air tightness, ventilation rates etc. Some of the experimental houses are extremely air tight. In connection with these measurements we have made some observations on the occupants behavior related to ventilation, and their satisfaction with the ventilation system.

A group of 18 identical well-insulated experimental houses in Sweden, utilizing a user controlled exhaust fan ventilation system, was monitored during 1985- 1986. The ventilation rate can be controlled by the user by adjusting the fan speed with a conveniently located three-way switch. No heat recovery is provided for, the idea being that the average ventilation rate will be low, thereby saving energy. The houses are described. The results from measurements of ventilation efficiency, ventilation rates. run time of fan speeds and energy consumption are presented.