text: Cross ventilation works well in climates with hotter temperatures, where the system allows continual changes of the air within the building, refreshing it and reducing the temperature inside the structure and also when the window on the windward side of the building is not opened as much as the one on the leeward side. Cross ventilation will not be efficacious if the windows are more than 12m apart and if a window is behind a door that is regularly shut. 
  An opened window that faces a prevailing wind and is conjugated with another window on the opposite side of a building will supply natural ventilation for fresh air. A decent and effective cross ventilation will remove heat from the interior and keep indoor air temperatures approximately 1.5 °C (2.7°F) below the outdoor air temperatures, ensuring that there is a steady inflow and outflow of fresh air inside the building.
  Besides windows, other openings like brise soleils, doors, louvers or ventilation grills and ducts can also work as effective ventilation openings, though an awning window provides the least effectivity. The wind surrounding building structures is important when it comes to assessing the air quality and thermal comfort indoors since both air and heat exchange rely heavily on the wind pressure on the exterior of the building. For the best airflow, the windward windows of the occupied space should not be opened as much as those on the leeward side. Disadvantages of wind-driven ventilation include capricious wind speeds and directions (which may create a strong unpleasant draft), and the polluted air from the outside that may tarnish the indoor air quality.
  Cross ventilation is not recommended for use in disease prevention when air is being moved by the cross ventilation from an unclean area into a clean area.