Window

From Freepedia

For other uses, see Window (disambiguation).
Image:JapaneseWindow.jpg
Image:TeaHouseWindowInuYama.jpg
Image:Window in stone wall.jpg

A window is an opening in an otherwise solid, opaque surface through which light and sometimes air can pass. For example, a window in the wall of a house, or a window in a scientific measurement device that permits reading of certain wavelengths.

Window is also used metaphorically to refer to a time period during which something can occur and outside of which the thing cannot occur, as in a window of opportunity to launch a rocket to the moon on the most efficient trajectory.

The word Window dates back to Old Norse "Wind Eye"; opening to the air.

Contents

Opening in wall

A window is an opening in the wall of a building that allows light and air to enter a room and people to see out. At previous times in history they were merely small oval or square holes in the walls.

Very early windows were shielded with hide or cloth stretched over the opening or with wooden shutters. Later, three types of windows were invented that allowed light but not weather to pass into a building: mullioned glass windows, which joined multiple small pieces of glass with leading, paper windows, and windows made of plates of thinly sliced marble. Mullioned glass windows were the windows of choice among European well-to-do, whereas paper windows were economical and widely used in ancient China and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century. Modern-style floor-to-ceiling windows became possible only after the industrial glass-making process was perfected. Evidence of glass window panes in Italy dates back nearly 3000 years.

Modern windows are customarily large glassed-in rectangles or squares. Churches traditionally have stained glass windows.

Today a window can be made in practically any shape and size desired.

Window styles

Modern domestic windows come in many styles. The choice of design varies thoughout the world, and is largely dictated by the prevailing weather conditions. Coastal climates tend to have smaller outward-opening windows due to the stronger winds experienced - eg England. Continental climates tend to have larger windows, many of which open inwards - eg France and Germany. Styles available include:

  • Double-hung sash window: The traditional style of window in the USA, and many other places that were formerly colonized by the UK, with two parts (sashes) that overlap slightly and slide up and down inside the frame. The two parts are not necessarily the same size. Nowadays, most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes either side of the window were used. These were and are attached to the sashes using pulleys of either braided cord or, later, purpose-made chain. Double-hung sash windows were traditionally often fitted with shutters. Sash windows may be fitted with simplex hinges which allow the window to be locked into hinges on one side, while the rope on the other site is detached, allowing the window to be opened for escape or cleaning.
  • Single-hung sash window: one sash is movable and the other fixed. This is the earlier form of sliding sash window, and is obviously also cheaper.
  • Horizontal Sliding sash window: has two or more sashes that overlap slightly but slide horizontally within the frame. In the UK, these are often called Yorkshire sash windows, presumably because of their traditional use in that county.
  • Casement window: An outward-opening window comprising either a side-hung, top-hung, or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash. In the USA these are usually opened using a crank, but in Europe they tend to use projection friction stays and espagnolette locking. Formerly, plain hinges were used with a casement stay.
  • Tilt and slide: a window where the sash tilts inwards at the top and then slides horizontally behind a fixed pane.
  • Tilt and turn: a window which can either tilt inwards at the top, or can open inwards hinged at the side.
  • Jalousie window: A window comprising many slats of glass that open and close like a Venetian blind, usually using a crank. A Jalousie door is a door with a Jalousie window.
  • Clerestory window: A vertical window set in a roof structure or high in a wall, used for daylighting.
  • Skylight: A flat or sloped window built into a roof structure for daylighting
  • Bay window: A multipanel window, with at least three panels set at different angles to create a protrusion from the wall line.
  • Oriel window
  • Fixed window: A window that cannot be opened. A non-opening window is often called a "light" , particularly as its function is limited to allowing light to enter without any outside air. However, etymologically speaking, any window can be called a "light". Clerestory windows are often fixed.
  • Picture window: A very large fixed window in a wall, intended to provide an unimpeded view as if framing a picture.

Technical terms

In the USA, the term replacement window means a framed window designed to slip inside the original window frame from the inside after the old sashes are removed. In Europe, however, it usually means a complete window including a replacement outer frame.

The USA term new construction window means a window with a nailing fin designed to be inserted into a rough opening from the outside before applying siding and inside trim In Europe, many 'new build' windows are used as templates, and bricks are laid up to the frame.

Window materials

Modern windows typically have insulated glazing, called insulated glass when made from glass, which for insulated glazing is usually double paned but might be triple paned.

Modern windows are made from large sheets of glass while windows in the past were made from multiple panes held together by a grille within the sash. Such a grille is called "glazing bars", "astragals", "muntins", "muntin bars" or "mullions". Today, decorative muntin bars tend to be attached to the surface of the glazing or sandwiched between the panes of the insulated glazing. In the UK, the term glazing bars is currently most popular term. Most companies in the USA use the term grille for a set of decorative muntin bars within a sash. In the UK, the term "grille" tends to be used when there are bars on only within the glazing unit, and not stuck to the outsides of it.

Frames and sashes were traditionally made of wood, but metal, vinyl, and composites are also common. Solid metal frames and sashes are inefficient because metals conduct heat quickly. Some frames are made of vinyl-clad or aluminum-clad wood. Modern metal window parts typically consist of two halves separated by insulating spacer material.

The terms "single-light", "double-light" etc refer to the number of glass panes in a window.

A beam over the top of a window is known as the lintel or transom.

Many windows have movable window coverings to keep out light, provide additional insulation, or ensure privacy.

See also

External links

Retrieved from "http://en.freepedia.org/Window.html"


Views
Personal tools
In other languages
Similar Links