What is a insulated glass unit?
An insulated glass unit (IGU) is the sealed glass unit that is inside of the window frame, it consists of two panes with a spacer between and a seal. The vinyl frame has a track the IGU fits into. When the glass in a window breaks the old IGU can be removed from the frame and new one installed, it is not necessary to replace the frame if it has not been damaged. The window unit consist of the frame, the IGU and the screen.
