Abstract
In many circumstances, natural ventilation is a costeffective
and efficient alternative to higher energy
consuming mechanical ventilation systems to provide
thermal comfort and good air quality. The aim of this
research is to investigate the performances of different
types of windows such as bottom hung, horizontal pivot
and top hung fanlight for single-sided natural ventilation
driven by buoyancy forces. CFD simulations, combining
RANS model and SST k-ω turbulence models, were used
to numerically evaluate the different window opening
styles for the weather conditions of South Tyrol, Italy. In
addition to the much-studied parameters of ventilation
effectiveness, thermal comfort parameters have been
considered based on standards such as EN ISO 7730 and
ASHRAE 55, for comparing the performances of these
selected windows. The results indicate that horizontal
pivot window performs the best among the 3 types,
because of its two-part structure ensuring better
segregation. It provides 23% higher incoming airflow rate
compared to bottom hung windows both in winter and
summer conditions, but a 11% higher draught risk in
winter.