Ventilation, the balance between energy and well-being.

A survey is given of the sitution in The Netherlands with regard to ventilation and infiltration. Starting from a point of generally very leaky and hardly insulated buildings now the necessity is felt on the one side to make standards for the airtightness to prevent energy wastes by too high infiltration rates and on the other hand to define minimum ventilation rates to secure safe and hygienic conditions in well insulated and airtight buildings. This minimum ventilation rate is based on contaminants, caused by the occupants themselves, the so-called unavoidable sources. The emission of avoidable sources, like gases from building materials, should lead to concentrations at the given minimum ventilation rate, which are not harmful. This requires adequate regulations for these contaminants. Minimum ventilation can be obtained either by mechanical ventilation (cost aspect, especially for dwellings) or natural ventilation (requiring insight from occupants in ventilation parameters). The research activities are related to the mentioned developments: - ventilation/infiltration versus energy consumption - influence of contaminants from avoidable sources (building materials etc.) - mechanical ventilation in dwellings - ventilation instructions for occupants.