Sash Balance

Definition: A device for counter balancing a sash of a double hung window to hold it in an up position. There are four basic types: * Block & Tackle - Sometimes referred to as string balance. A type of balance that employs a block and tackle apparatus and coiled spring. This type balance allows the sash to be easily removed from the window frame. A block and tackle balance can normally carry a heavier load than a spiral or friction balance. * Spiral - A balance using a spirally-wound spring. * Spring - A balance using a spring for counter-balancing; introduced in the 1980?s. * Constant Force - A coiled steel tape under spring tension for balancing the sash, located in the head jamb of the window frame. * Counterweight - The most common type of balancing system in older homes, utilizing a weight held by a sash rope or chain over a pulley.