Requirements for adequate and user-acceptable ventilation installations in dwellings.

After years of intensive studies on indoor air pollution sources, pollution levels, condensation effects, building airtightness, and air change rates, we are now at the point to discover that no solution whatsoever to the ventilation problem is possible if compatibility with user comfort and user habits are not properly taken into account. User compatibility of aventilation strategy under todays conditions in dwellings must in fact be understood as a requirement equivalent to the purely functional ones of pollutant removal and of economy. It is tried in this paper to summarise on the general requirements for user compatibility, the latter having been widely neglected so far. Features of improved systems are given.