Assessing ventilation rates of Portuguese flats under different boundary conditions

Abstract

Indoor air quality is crucial for occupants health and wellbeing. In mild climates, natural ventilation (sometimes mixed) is the most common method to provide the required fresh air. However, in Portugal, commonly no specific inlet ventilation devices are used in construction and, therefore, ventilation success is strongly dependent on buildings airtightness and user behaviour. This paper reports the results of a field campaign where ventilation rates were measured in four typical Portuguese flats, each built on a different decade. Several set-ups were prepared in each flat, allowing for a complete characterization of their performance. Measurements were carried out separately in each room and with different boundary conditions (door open/closed, mechanical extraction on/off). The tracer gas method (decay technique) was used and 44 tests were made. Results are discussed. The standard target value was never achieved in the main compartments and an attempt to correlate ventilation rates with glazed area is made.