Single hung windows have a lower operating sash for ventilation. They are commonly used in window openings that are taller than they are wide. Using hidden balance springs, the window sash can effortlessly be opened and closed. The sashes will self level at any location it is released at. This creates great incremental airflow for this window and since it does not open outwards, they are a perfect choice for high traffic areas such as decks and walkways. The screens are located on the outside of the sash and are easily removable from inside the home when desired.