Airtightness and ventilation of new Estonian apartments constructed 2001-2010

The performance of ventilation and airtightness of the building envelope was studied in field measurements in recently constructed Estonian apartment buildings. The buildings were selected with different building envelopes and ventilation systems. The mean air leakage rate at the pressure difference of 50 Pa in the database was 1.7 m3/(h·m2). The mean air change rate at the pressure difference of 50 Pa from the database was 2.3 h-1.
Ventilation airflows in apartments were low in general, resulting in bad indoor air quality. Only in a few apartments did the general airflow correspond to the requirements of indoor climate category II. Together with increasing air tightness of the building envelope, more attention should be paid to the performance of ventilation. The capacity of the ventilation system is not the only concern. Only increasing the ventilation airflow, without proper design (noise reduction, avoiding draft, energy performance, etc.), may not guarantee good results.