Influence of the number of sheds and the horizontal distance between them on the performance of natural ventilation

Abstract

Natural ventilation is an effective strategy for the passive thermal conditioning of buildings, and its potential is often connected with design decisions that differ from the conventional model. An example of that are sheds, which are openings in the roof that function as air extractors and collectors, depending on their location in relation to the prevailing winds. The aim of this paper is to evaluate the influence of the number of sheds and the distance between them on the performance of natural ventilation. The angles of incidence of the winds analysed were 0º, 45º, 135º and 180º. The methodology adopted was simulation by Computational Fluid Dynamics using the CFX software. The results indicate that increasing the number of sheds reduces the internal air renewal for the air extraction and collection. Increasing the distance between the sheds, increases the internal airflow for the air collector sheds. However, a reduction in renewal rates was observed in the air extractor sheds. This was due to the reduction of the air outlet total area, which influences the flow rate of the building. In the air collector sheds, the increase occurred because the sheds become more effective for air entrance despite the fact that an increased distance reduced the number of air inlet openings.

Keywords:
CFD simulation; Natural ventilation; Air extractors and collectors shed roofs; Distance between the sheds