Single-Hung/Double Hung In double-hung units, both sashes slide vertically. Only the bottom sash slides upward in a single-hung window. Ventilation area can vary from a small crack to an opening of one-half the total glass area. Screens can be placed on the exterior or interior of the window unit.
Casement Casement windows are hinged at the sides. Hinged windows such as casements generally have lower air leakage rates than sliding windows from the same manufacturer because the sash closes by pressing against the frame. Casement windows project outward, providing significantly better ventilation than sliders of equal size. Because the sash protrudes from the plane of the wall, it can be controlled to catch passing breezes, but screens must be placed on the interior side.
Awning Awning windows are hinged at the top and open outward. Hinged windows such as awnings 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 interior of the window unit.
Bay Window A bay window is made up of three or more windows. The side or flanker units project out from the building in 30, 45, or 90 degree angles. The center is parallel with building wall and is made up of one or more windows. All the units can be stationary, operating, or any combination thereof.
Bow Window A series of four or more adjoining window units, commonly five in number, installed on a radius from the wall of the building.
Fixed Frame Refers to windows that are non-venting or inoperable.
Skylight A window installed in a roof and assuming the same slope. Depending on which direction they face, skylights can bring in more light and heat than windows. For example, in the summer months, an unshaded south-facing skylight will bring in more direct sunlight and heat than a window. In a cold climate, a north-facing skylight gives almost five times more light than a north-facing window with almost the same amount of heat loss.
Slider Both sashes slide horizontally in a double-sliding window. Only one sash slides in a single-sliding window. Ventilation area can vary from a small crack to an opening of one-half the total glass area. Screens can be placed on the exterior or interior of the window unit.
Window Diagram 1. Head The main horizontal member forming the top of the window or door frame. 2. Jamb The main vertical members forming the sides of a window or door frame. 3. Frame The enclosure in which window sash or door panels are mounted. 4. Glazing Glass in a window or door; the act or process of fitting with glass. 5. Pane A framed sheet of glass within a window. 6. Sash A single assembly of stiles and rails made into a frame for holding glass. 7. Sill The main horizontal member forming the bottom of the frame of a window or door. 8. Muntin Bar Any small bar that divides a windows glass. Also called a grille, grids or windowpane divider.