Natural ventilation is a key element of Bioclimatic design; saving energy by reducing demand for air conditioning.
Night cooling by ventilation lowers the temperature of a building at night, significantly reducing temperature from the daytime peak (typically by 2/3 degrees). Night cooling can only be achieved if windows are automated and controlled. This can also improve air quality by evacuating fouled air which has built up during the day.
Usually a building is unoccupied when night cooling takes place. This is why only an automated system with timer settings, can ensure that windows are opened and closed reaching the maximum performance level expected from the building.