Crystal Hopper Windows

Crystal Hopper windows, commonly referred to as basement windows, are hinged at the bottom and open inward. Hinged windows such as hoppers generally have lower air leakage rates than sliding windows from the same manufacturer because the sash closes by pressing against the frame. Screens are placed on the exterior of the window unit. Similar to casements, the entire window area can be opened, while sliders are limited to less than half of the window area.