The most representative typology of residential buildings of Catalonia has been simulated in TRNSYS to evaluate the impact of both infiltration and natural ventilation. The typology is a block of apartments constructed during 1950-1980.
In this paper the methods used to characterize the infiltration and the natural ventilation are described. The infiltration model (UNE-EN 15242, 2007) considers the tightness of the construction and allows the use of measurement data obtained from experimental studies, as blower door tests. The natural ventilation of the building is single sided ventilation with courtyard effect. The model used (Gids and Phaff, 1982) depends on the indoor temperature, courtyard temperature, outdoor temperature and wind velocity. The control strategy defined for the natural ventilation is based on the results obtained in surveys of the building characterization study done in the framework of the MARIE project (www.marie-medstrategic.eu). The control strategy follows the assumption that the occupants use the natural ventilation to cool the households, and when it is not enough to have comfortable conditions, they use the cooling system.
The results are presented in terms of energy demand and thermal comfort. The evaluation of the comfort is based on the adaptive ASHRAE model (ASHRAE 55, 2004), which is applied in buildings without mechanical cooling systems. The comfort indices evaluated are the Long-term Percentage of Dissatisfied (Carlucci, 2013) and the hours of overheating. The typology has been evaluated in different situations: current building and refurbished building; with natural ventilation and without natural ventilation. The objective is to show the effect of the natural ventilation in different building configurations.