On basis of several case studies into the ventilation behaviour in dwellings in the Netherlands, it is possible to answer the question whether the type of ventilation device influences the behaviour of the occupants during mild winter periods (5 Deg C).The dwellings are discerned in three types: * those with natural ventilation through passive stacks only; * those with mechanical exhaust ventilation provisions; * those with balanced mechanical ventilation provisions. By means of questionnaires in each of these dwellings characteristics of the households and the ventilation behaviour has been assessed. Consequences with respect to the air change rates will be discussed too.
