The purpose of this work – connected with overheating process occurring in buildings – was to investigate the intensity of natural air exchange when a value of thermal resistant for outside walls is being increased together with the increase of the window’s surface. To obtain higher thermal resistant the outside partition were covered with insulating material subsequently from 3 to 30 cm. Window surface to wall surface ratio (wwr) was changing from 5% to 50%. The window’s test surface was facing east, south and west in turn while the wwr of the remaining orientations was kept at a constant 1/10 of the wall. The intensity of the buoyancy flux was analyzed as well. Three forms of ventilation airflow were considered – with assisting and opposing winds and no wind appearance. The process was examined in a single zone building, naturally ventilated, fitted with heat accumulating mass.

The purpose of this work – connected with overheating process occurring in buildings – was to investigate the intensity of natural air exchange when a value of thermal resistant for outside walls is being increased together with the increase of the window’s surface. To obtain higher thermal resistant the outside partition were covered with insulating material subsequently from 3 to 30 cm. Window surface to wall surface ratio (wwr) was changing from 5% to 50%. The window’s test surface was facing east, south and west in turn while the wwr of the remaining orientations was kept at a constant 1/10 of the wall. The intensity of the buoyancy flux was analyzed as well. Three forms of ventilation airflow were considered – with assisting and opposing winds and no wind appearance. The process was examined in a single zone building, naturally ventilated, fitted with heat accumulating mass.