Influence of the meteorological conditions on the inhabitants' behaviour in dwellings with mechanical 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. Data on all opening positions of all openable window sashs and door leaves were continuously recorded, thus providing exact time data for all opening positions to be stored on data carriers . All available data had to pass two plausibility tests, which resulted in 70 % of the main room data considered eligible for analysis. In evaluating the occupants' behaviour with regard to the different types of rooms, natural ventilation was found to be most frequent in bedrooms, followed, in decreasing frequency, by children's rooms and living rooms. For all rooms, ventilation habits distinctly correlated with outdoor air temperature and wind velocity. A function suited to describe these relations was derived. An alteration in occupants ' behaviour recorded during the period of measurements is probably accounted for by the initially higher content of trapped moisture (sweating) at the beginning of first occupation. When finally comparing the present results with studies on users' ventilation behaviour in flats with conventional window ventilation, it was found that in buildings with mechanical ventilation systems window ventilation duration i s reduced to a quarter of the corresponding values recorded for buildings with traditional ventilation .