21. Careful attention to the placement and siting of the building has created natural ventilation system. 22. The system helped keep the interior cool by allowing natural ventilation as well as daylight. 23. They also impede natural ventilation , increasing climate control costs. 24. By using this system he combined energy saving and used natural ventilation and air conditioning. 25. Earthships have a natural ventilation system based on convection. 26. The construction of the grotto also utilized natural ventilation . 27. They are utilized for natural ventilation and temperature control. 28. Old buildings, with their natural ventilation , conserve energy. 29. The intentional introduction of outside air can be categorized as either mechanical ventilation, or natural ventilation . 30. Windows and overhangs are positioned to provide ambient lighting, and windows open to provide natural ventilation .
