History of the Double Hung Window If you notice the old stand alone farm house in the country, you will see tall trees around the house to provide shade. This has a cooling effect for the house and the surrounding area. These older homes also had a lot of windows that were tall and narrow. The tall windows would project light deep inside the house. This was particularly helpful before electricity when lighting was poor. In order to get this cool air from outside of the house to inside the hot house is where the Double Hung Window comes in. By lowering the top sash this allows the rising hot air to flow out and by raising the lower sash a little, allowed cool air from outside to flow in creating a convection effect. That is the old fashion air conditioning. Double Hung Window Now we know why the Double Hung Window was created back in the day! ...