Ventilation research in Hungary.

After the oil crisis in the seventies the main aims of ventilation research changed. Many energy saving measures had been taken by the authorities, among them the reduction of infiltration heat losses. The Ministry of Building and Urban Development ordered the production and installation of better quality airtight windows, and the draughtproofing of existing window assemblies. Since about 1980 the wide use of these window structures has led to a variety of difficulties with indoor air quality, and recent ventilation research in Hungary has been aimed at providing solutions to these problems.