This paper discusses the use of trickle ventilators in the design for natural ventilation in dwellings. The discussion is based around the results of a field monitoring experiment where 17 out of 32 houses were fitted with trickle ventilators as a remedial measure to improve the distribution of ventilation and to reduce the occurrence of condensation. Reductions in condensation, effects on energy use, window opening and occupants views are considered. The paper concludes that trickle ventilators are a successful component part in the design of natural ventilation systems in dwellings.

During winter periods in four types of newly built terraced dwellings and in apartments of a flatbuilding,the daily behaviour and motivations of the inhabitants with respect to airing and ventilation have been studied. In total the information was obtained from 279 households. A combination of verbal interviews, diaries and technical measurements are used as methods of investigation. On basis of the findings,calculations can be made about air flows in occupied dwellings.

Within the framework of the International Energy flgency (IEA) Annex VIII , "Inhabitants Behaviour with Regard to Ventilation" an investigation has been carried out on the use of windows in an apartment building in Schiedam. The measurements have been done by the TNO Division of Technology for Society. They started in November 1984 and stopped in May 1986, Three inquiries and diaries have been set up in the tno heating seasons and the summer period to get additional information from the dwellers, In the 6th AIC conference [1] paper 20 dealt with the first heating season of this project.

A large inquiry campaign began in 1985 on 100 social housing estates and 2,334 families were visited. The housing estates were selected according to their age, location, type of building (dwelling/apartment) and heating system. The main purpose of this paper is to explore the data received concerning window use in order to find the effect of the inhabitants on the ventilation rate. The summertime and wintertime situation was analysed and differences between individual dwellings and apartments were also investigated.