ABSTRACT
The aim of ventilation is to maintain a comfortable and healthy indoor environment or even to cool buildings with minimum energy consumption. However, the consequences of ventilation might not be always beneficial, especially when fresh air is supplied from the urban environment. Because of specific urban characteristics, the potential of natural ventilation can be seriously diminished, mainly due to reduced wind speeds, variation in wind directions, high ambient temperatures and increased external pollutant and noise levels. Besides, the impact of ventilation on indoor air quality is a topic of major concern. Especially in urban buildings, indoor air quality is characterized with considerable interest since heavily polluted outdoor air penetrates the building shell and influences indoor air. Except for outdoor pollution, indoor sources and anthropogenic activities such as tobacco smoking may have a greater impact on personal exposure.
