Jump to content

Window: Difference between revisions

Edit links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
m Reverting possible vandalism by Kevin12345678911111111 to version by Keith D. False positive? Report it. Thanks, ClueBot NG. (1898096) (Bot)
←Replaced content with ''''Windows''' is a computer line ==Line of Windows computers== *Windows 1 *Windows 2 *Windows 3 *Windows 4 *Windows 95 *Windows 98...'
Line 1: Line 1:
'''Windows''' is a computer line
{{About|the part of a building|the Microsoft operating system|Microsoft Windows|other uses|Window (disambiguation)|and|Windows (disambiguation)}}
{{pp-move-indef}}
{{Refimprove|date=December 2010}}[[File:Window Porto Covo August 2013-2.jpg|250px|thumb|Window of traditional design in [[Porto Covo]], [[Portugal]]]]


==Line of Windows computers==
A '''window''' is an opening in a [[wall]], [[door]], [[roof]] or [[vehicle]] that allows the passage of light and, if not closed or sealed, air and sound.<ref name="Window">{{cite web| url= http://www.thefreedictionary.com/window /|title=Window |publisher=The Free Dictionary By Farlex|accessdate=2012-05-19}}</ref> Modern windows are usually [[glazing (window)|glazed]] or covered in some other [[transparency (optics)|transparent]] or translucent material. Windows are held in place by frames.<ref name="britannica.com"/> Many glazed windows may be opened, to allow ventilation, or closed, to exclude inclement weather.<ref>{{cite web| url= http://www.cmhc-schl.gc.ca/en/co/renoho/refash/refash_022.cfm|title=Understanding Window Terminology
*[[Windows 1]]
|publisher=Canada Mortgage and Housing Corporation|accessdate=2012-05-19}}</ref> Windows often have a latch or similar mechanism to lock the window shut.
*[[Windows 2]]

*[[Windows 3]]
Types include the eyebrow window, fixed windows, single-hung and double-hung sash windows, horizontal sliding [[sash window]]s, casement windows, awning windows, hopper windows, tilt and slide windows (often door-sized), tilt and turn windows, transom windows, sidelight windows,
*[[Windows 4]]
jalousie or [[louver]]ed windows, clerestory windows, skylights, roof windows, roof lanterns, bay windows,
*[[Windows 95]]
oriel windows, thermal, or Diocletian, windows, picture windows, emergency exit windows, [[stained glass window]]s, French windows, and double- and triple paned windows.
*[[Windows 98]]

*[[Windows XP]]
The Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt&mdash;In Alexandria ca. 100 AD. Paper windows were economical and widely used in ancient [[China]], [[Korea]] and [[Japan]]. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. Modern-style floor-to-ceiling windows became possible only after the industrial [[plate glass|plate]] [[Glass production|glass making]] processes were perfected.
*[[Windows Vista]]

*[[Windows 7]]
== Etymology ==
*[[Windows 8]]
The word ''window'' originates from the [[Old Norse language|Old Norse]] 'vindauga', from 'vindr – wind' and 'auga – eye', i.e., ''wind eye''. In [[Norwegian Language|Norwegian]] [[Nynorsk]] and [[Icelandic Language|Icelandic]] the Old Norse form has survived to this day (in Icelandic only as a less used synonym to ''gluggi''), in [[Swedish language|Swedish]] the word ''vindöga'' remains as a term for a hole through the roof of a hut, and in the Danish language 'vindue' and Norwegian [[Bokmål]] 'vindu', the direct link to 'eye' is lost, just like for 'window'. The Danish (but not the Bokmål) word is pronounced fairly similarly to ''window''.

'' Window'' is first recorded in the early 13th century, and originally referred to an unglazed hole in a roof. ''Window'' replaced the [[Old English language|Old English]] ''eagþyrl'', which literally means 'eye-hole,' and 'eagduru' 'eye-door'. Many Germanic languages however adopted the Latin word 'fenestra' to describe a window with glass, such as [[Standard language|standard]] [[Swedish language|Swedish]] 'fönster', or [[German language|German]] 'Fenster'. The use of ''window'' in English is probably because of the Scandinavian influence on the English language by means of [[loanwords]] during the [[Viking Age]]. In English the word ''fenester'' was used as a parallel until the mid-18th century and ''fenestration'' is still used to describe the arrangement of windows within a [[façade]]. Also, words such as "defenestration" are in use, meaning to throw something out of a window.

From Webster's 1828 Dictionary: ''Window'', n. [G. The vulgar pronunciation is windor, as if from the Welsh gwyntdor, wind-door.]<ref>{{cite web |url=http://www.1828-dictionary.com/d/search/word,window |title=1828 Webster |accessdate=2010-05-02 |date=October 16, 2009 |work= |publisher=1828-dictionary.com}}</ref>

== History ==
[[File:Roman window glass.jpg|thumb|200px|Fragment of a Roman window glass plate dated to 1st to 4th century A.D.<br/>Note the obvious curvature, this is not a flat pane.]]
[[File:MorellaSantaMariaWindow.jpg|thumb|200px|[[Alabaster]] 'mullion' divided decorative windows in Santa Maria La Major church ([[Morella, Castellón|Morella]], Spain).]]
The earliest windows were just holes in a wall. Later, windows were covered with animal hide, cloth, or wood. [[Window shutter|Shutters]] that could be opened and closed came next. Over time, windows were built that both protected the inhabitants from the elements and transmitted light: [[mullioned glass]] windows, which joined multiple small pieces of glass with [[lead]]ing, [[paper]] windows, flattened pieces of translucent animal horn, and plates of thinly sliced [[marble]]. In the Far East, paper was used to fill windows.<ref name="britannica.com">{{cite web| url= http://www.britannica.com/EBchecked/topic/645175/window |title=Window
|publisher=Britannica|accessdate=2012-05-19}}</ref>
The Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt&mdash;In Alexandria ca. 100 AD, cast glass windows, albeit with poor optical properties, began to appear&mdash;but these were small thick productions, little more than [[glass blowing|blown glass]] jars (cylindrical shapes) flattened out into sheets with circular striation patterns throughout. It would be over a millennium before a window glass became transparent enough to see through clearly, as we think of it now.
Over the centuries techniques were developed to shear through one side of a blown glass [[Cylinder (geometry)|cylinder]] and produce thinner rectangular window
panes from the same amount of glass material. This gave rise to tall narrow windows, usually separated by a vertical support called a mullion. [[Mullion]]ed glass windows were the windows of choice among [[Europe]]an well-to-do, whereas paper windows were economical and widely used in ancient [[China]], [[Korea]] and [[Japan]]. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century.<ref>{{cite book|last=Langley|first=Andrew|title=Medieval Life|series=Eyewitness|year=2011|publisher=Dorling Kindersley|isbn=1-4053-4545-4|page=16}}</ref> Noted science historian, author and television show host/producer [[James Burke (science historian)|James Burke]] attributes the rapid deforestation of Great Britain in the late 1500s to the uptick in production of glazed windows as well as iron cannon production (1st Cast in 1547). He writes further this gave rise to coal for fuel, which spurred iron production, requiring more coal, and more iron, then steam engine pumps, canals... and more iron; all because windows became a middle class commodity in the latter days of the [[little ice age]], one large factor among several leading to the deforesting English woodlands, and the switch over to a coal economy.

Modern-style floor-to-ceiling windows became possible only after the industrial [[plate glass|plate]] [[Glass production|glass making]] processes were perfected. Modern windows are usually filled with glass, although a few are transparent plastic.<ref name="britannica.com"/>

==Types==

===Eyebrow===
The term eyebrow window is used in two ways: a curved top window in a wall or in an eyebrow [[dormer]]; and a row of small windows usually under the front eaves such as the [[James-Lorah House]] in Pennsylvania.<ref>Harris, Cyril M.. ''American architecture: an illustrated encyclopedia''. New York: W.W. Norton, 1998. Print.</ref>

===Fixed===
A window that cannot be opened, whose function is limited to allowing light to enter (unlike an unfixed window, which can open and close). Clerestory windows are often fixed. Transom windows may be fixed or operable. This type of window is used in situations where light or vision alone is needed as no ventilation is possible windows without the use of trickle vents or overglass vents.

===Single-hung sash===
One sash is movable (usually the bottom one) and the other fixed. This is the earlier form of sliding sash window, and is also cheaper.<ref name="britannica.com"/>

===Double-hung sash===
A [[sash window]] is the traditional style of window in the United Kingdom, 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. Currently most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes on 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. Three types of spring balances are called a tape or clock spring balance; channel or block-and-tackle balance; and a spiral or tube balance.

Double-hung sash windows were traditionally often fitted with [[Window shutter|shutters]]. Sash windows can be fitted with simplex hinges that let the window be locked into hinges on one side, while the rope on the other side is detached—so the window can be opened for fire escape or cleaning.

===Horizontal sliding sash===
Has two or more sashes that overlap slightly but slide horizontally within the frame. In the UK, these are sometimes called ''[[Yorkshire]]'' sash windows, presumably because of their traditional use in that county.

===Casement===
[[File:Gordijnen aan venster.JPG|thumb|right|200px|[[Casement window]]]]
{{main|Casement window}}

A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung (also called "awning window"; see below), or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash.<ref name="Window"/> In the USA, these are usually opened using a [[Crank (mechanism)|crank]], but in parts of Europe they tend to use projection friction stays and [[espagnolette]] locking. Formerly, plain hinges were used with a [[casement stay]]. [[Handing]] applies to casement windows to determine direction of swing; a casement window may be left-handed, right-handed, or double. The casement window is the dominant type now found in the UK and parts of Europe.

====Awning====
An awning window is a casement window that is hung horizontally, [[hinge]]d on top, so that it swings outward like an [[awning]]. Emilie Poisson designed this window.{{citation needed|date=November 2013}}

====Hopper====
A hopper window is a bottom-pivoting casement window that opens by tilting vertically, typically to the inside.<ref>{{cite book|last1=Allen|first1=Edward|last2=Thallon|first2=Rob|title=Fundamentals of Residential Construction|edition=3|year=2011|publisher=Wiley|location=Hoboken, NJ|isbn=978-0-470-54083-1|page=654}}</ref>
(Mostly used for schools)

===Tilt and slide===
A window (more usually a door-sized window) where the sash tilts inwards at the top and then slides horizontally behind the fixed pane.

====Tilt and turn====
A ''tilt and turn'' window can both tilt inwards at the top or open inwards from hinges at the side. This is the most common type of window in Germany, its country of origin. It is also widespread in many other European countries.<ref>{{cite web|url=http://www.windowanddoor.com/article/products/will-tilt-and-turn-windows-gain-market-share-north-america?page=0%2C1 |title=Will Tilt-and-Turn Windows Gain Market Share in North America? &#124; Window & Door |publisher=Windowanddoor.com |date=2010-03-29 |accessdate=2012-02-11}}</ref>

===Transom===
A window above a door; in an exterior door the [[Transom (architectural)|''transom]] window is often fixed, in an interior door it can open either by hinges at top or bottom, or rotate on hinges. It provided ventilation before forced air heating and cooling. A fan-shaped transom is known as a fanlight, especially in the British Isles.

===Side light===
Windows beside a door or window are called ''side''-, ''wing''-, and ''margen-lights'' and ''flanking windows''.<ref>Curl, James Stevens. "Flanking window". ''A dictionary of architecture and landscape architecture''. 2nd ed. Oxford England: Oxford University Press, 2006. 285. Print.</ref>

===Jalousie Window===
[[File:Jalousie2.jpg|thumb|200px|Jalousie or [[louver]]ed window]]
[[File:LouvreRoofWindow.jpg|thumb|200px|A roof window at the [[Musée du Louvre]] ([[Paris]])]]

Also known as a [[louver]]ed window, the [[jalousie window]] consists of parallel slats of glass or [[Poly(methyl methacrylate)|acrylic]] that open and close like a [[Venetian blind]], usually using a crank or a lever. They are used extensively in tropical architecture. A jalousie door is a door with a jalousie window.

[[File:Cathedrale d'Amiens - Grandes verrieres et voutes de la nef.jpg|thumb|150px|right|[[Clerestory]] window]]

===Clerestory===
{{main|Clerestory}}
A window set in a [[roof]] structure or high in a wall, used for [[daylighting]].

===Skylight===
{{main|Daylighting}}
[[File:BurlingtonHousePavementWindow.jpg|thumbnail|Sidewalk skylight (also named 'pavement light') made of [[Glass brick]] in [[Burlington House]], [[London]]]]
A flat or slope window used for daylighting, built into a roof structure that is out of reach.<ref>{{cite web| url= http://www.roofingnetworks.com/info/types-of-skylights/|title=Types of Skylights – All You Need to Know
|publisher=Networx|accessdate=2012-05-19}}</ref>

===Roof===
A sloped window used for [[daylighting]], built into a roof structure. It is one of the few windows that could be used as an exit. Larger [[roof window]]s meet building codes for emergency evacuation.

===Roof lantern===
{{main|Cupola}}
A roof lantern is a multi-paned glass structure, resembling a small building, built on a roof for day or moon light. Sometimes includes an additional [[clerestory]]. May also be called a [[cupola]].

[[File:The Real Estate Associates (TREA) House.JPG|thumb|150px|right|Bay window in [[San Francisco]]]]

===Bay===
{{main|Bay window}}
A multi-panel window, with at least three panels set at different angles to create a protrusion from the wall line.<ref name="Window"/>

====Oriel====
{{main|Oriel window}}
This form of bay window most often appears in Tudor-style houses and monasteries. It projects from the wall and does not extend to the ground. Originally a form of porch, they are often supported by brackets or corbels.

===Thermal===
Thermal, or Diocletian, windows are large semicircular windows (or niches) which are usually divided into three lights (window compartments) by two mullions. The central compartment is often wider than the two side lights on either side of it.

===Picture===
A picture window is a large fixed window in a wall, typically without glazing bars, or glazed with only perfunctory glazing bars near the edge of the window. Picture windows provide an unimpeded view, as if framing a picture.<ref>{{cite web| url= http://www.thefreedictionary.com/picture+window |title=Picture window |publisher=The Free Dictionary By Farlex|accessdate=2012-05-19}}</ref>

===Multi-lit===
A window glazed with small panes of glass separated by wooden or lead ''glazing bars'', or ''[[muntins]]'', arranged in a decorative ''glazing pattern'' often dictated by the building's architectural style. Due to the historic unavailability of large panes of glass, the multi-lit (or ''lattice window'') was the most common window style until the beginning of the 20th century, and is still used in traditional architecture.

===Emergency exit/egress===
A window big enough and low enough so that occupants can escape through the opening in an emergency, such as a [[fire]]. In many countries, exact specifications for emergency windows in bedrooms are given in many [[building codes]]. Specifications for such windows may also allow for the entrance of emergency rescuers. Vehicles, such as [[bus]]es and [[aircraft]], frequently have emergency exit windows as well.<ref>{{cite web|url=http://www.fmcsa.dot.gov/documents/outreach/bus/PreTrip-SafetyBrochure-Pull.pdf |title=U.S. Dept. of Transportation: Safety information for bus/motorcoach passengers |format=PDF |date= |accessdate=2012-02-11}}</ref>

===Stained glass===
[[File:GlassWindow.jpg|thumb|right|225px|A [[stained glass]] panel depicting [[Bible|Biblical]] scenes at a historic [[Church (building)|church]] in Scotland]]
[[File:Vitrail roccella k.JPG|thumb|right|225px|A contemporary [[stained glass]] window in France]]
{{main|stained glass}}

A window composed of pieces of colored glass, [[transparency (optics)|transparent, translucent]] or [[Opacity (optics)|opaque]], frequently portraying persons or scenes. Typically the glass in these windows is separated by lead glazing bars. Stained glass windows were popular in [[Victorian era|Victorian]] houses and some [[Frank Lloyd Wright|Wrightian]] houses, and are especially common in [[Church (building)|churches]].<ref>{{cite web| url= http://www.thefreedictionary.com/stained+glass+window|title=Stained glass |publisher=The Free Dictionary By Farlex|accessdate=2012-05-19}}</ref>

===French===
A French window (when hinged ''French door'') is a large door-sized lattice light, typically set in pairs or multiples thereof. Known as ''porte-fenêtre'' in France and ''portafinestra'' in Italy, they often overlook a [[Terrace (building)|terrace]] and are commonly used in modern houses
<ref>{{cite web| url= http://www.thefreedictionary.com/French+window|title=French Window |publisher=The Free Dictionary By Farlex|accessdate=2012-05-19}}</ref>

===Double paned ===
Double paned windows have two parallel panes (slabs of glass) with a separation of typically about 1&nbsp;cm; this space is permanently sealed and filled at the time of manufacture with dry air or other dry nonreactive gas. Such windows provide a marked improvement in thermal insulation (and usually in acoustic insulation as well) and are resistant to fogging and frosting caused by temperature differential. They are widely used for residential and commercial construction in intemperate climates. Triple-paned windows have been commercially manufactured and marketed with claims of additional benefit but have not become common.

== Terms ==
EN 12519 is the European norm that describes windows terms officially used in EU Member States.
The main terms are:
[[File:Casement (PSF).jpg|thumb|Casement window, with [[Latticework|latticed]] lights]]
*'''Light''' is the area between the outer parts of a window ([[Transom (architectural)|transom]], sill and jambs), usually filled with a glass pane. Multiple panes are divided by mullions when load-bearing, muntins when not.<ref>{{cite book |last=Brett |first=Peter |year=2004 |title=Carpentry and Joinery |edition=2, illustrated |publisher=Nelson Thornes |isbn=9780748785025 |page=[http://books.google.com/books?id=iVthU6rPGK8C&pg=PA225#v=onepage&q&f=false 255]}}</ref>

*'''Lattice light''' is a compound window pane madeup of small pieces of glass held together in a [[Latticework|lattice]].

*'''Fixed window''' is a unit of one non-moving lite. The terms ''single-light'', ''double-light'', etc., refer to the number of these glass panes in a window.

*'''Sash unit''' is a window consisting of at least one sliding glass component, typically composed of two lites (known as a ''double-light'').

*'''Replacement window''' in the United States means a framed window designed to slip inside the original window frame from the inside after the old sashes are removed. In Europe it usually means a complete window including a replacement outer frame.

*'''New construction window''', in the US, means a window with a nailing fin that is inserted into a rough opening from the outside before applying siding and inside trim. A nailing fin is a projection on the outer frame of the window in the same plane as the [[glazing in architecture|glazing]], which overlaps the prepared opening, and can thus be 'nailed' into place.

:In the UK and mainland Europe, windows in new-build houses are usually fixed with long screws into expanding plastic plugs in the brickwork. A gap of up to 13 mm is left around all four sides, and filled with expanding polyurethane foam. This makes the window fixing weatherproof but allows for expansion due to heat.

*'''[[Lintel]]''' is a beam over the top of a window, also known as a [[transom (architectural)|transom]].

*'''window-sill''' is the bottom piece in a window frame. Window [[wikt:sill|sills]] slant outward to drain water away from the inside of the building.

*'''Secondary Glazing''' is an additional frame applied to the inside of an existing frame, usually used on protected or listed buildings to achieve higher levels of thermal and sound insulation without compromising the look of the building

*'''[[Millwork (building material)|Decorative millwork]] is the moulding, cornices and lintels often decorating the surrounding edges of the window.

===Labeling===
The United States [[National Fenestration Rating Council|NFRC]] Window Label lists the following terms:
* [[Thermal conductivity|Thermal transmittance (U-factor)]], best values are around U-0.15 (equal to 0.8 W/m2/K)
* [[Solar heat gain coefficient]] (SHGC), ratio of solar heat (infrared) passing through the glass to incident solar heat
* [[Visible transmittance]] (VT), ratio of transmitted visible light divided by incident visible light
* [[airflow|Air leakage]] (AL), measured in cubic foot per minute per linear foot of crack between sash and frame
* [[Damp (structural)#Condensation|Condensation resistance]] (CR), measured between 1 and 100 (the higher the number, the higher the resistance of the formation of condensation)<ref>[http://www.nfrc.org/documents/WindowsandHeatLoss.pdf Windows and Heat Loss], [[NFRC]] Heat Loss Fact Sheet</ref>

The European harmonised standard hEN 14351-1, which deals with doors and windows, defines 23 characteristics (divided into ''essential'' and ''non ''essential''. Two other, preliminary European Norms that are under development deal with internal pedestrian doors (prEN 14351-2), smoke and fire resisting doors, and openable windows (prEN 16034).<ref>[http://www.alueurope.eu/wp-content/uploads/2012/12/CPR_guideline_Dec_2012_ver-1.pdf CPR guideline]</ref>

== Construction ==
[[File:5-chamber plastic window profile.JPG|thumb|225px|5-chamber plastic window profile]]
[[File:Passivhaus Fenster Beispiele.png|thumb|225px|Examples of modern plastic and wooden window profiles with [[insulated glazing]]]]
[[File:WaterMill Window LymeRegis.jpg|thumb|right|225px|Modern wooden framed window fitted in the 14th century [[Lyme Regis]] [[watermill]], [[UK]].]]

Windows can be a significant source of heat transfer.<ref name="Window Systems">Carmody, J., Selkowitz, S., Lee, E. S., Arasteh, D., & Willmert, T. (2004). ''Window Systems for High-Performance Buildings''. New York, NY: W. W. Norton & Company, Inc.</ref> Therefore, [[Insulated glazing|insulated glazing units]] consist of two or more panes to reduce the transfer of heat.

=== Grids or muntins ===

These are the pieces of framing that separate a larger window into smaller panes. In older windows, large panes of glass were quite expensive, so muntins let smaller panes fill a larger space. In modern windows, light-colored muntins still provide a useful function by reflecting some of the light going through the window, making the window itself a source of diffuse light (instead of just the surfaces and objects illuminated within the room). By increasing the indirect illumination of surfaces near the window, muntins tend to brighten the area immediately around a window and reduce the contrast of shadows within the room.

=== Frame and sash construction ===

Frames and sashes can be made of the following materials:
{| class="wikitable"
|-
! Material
! [[thermal resistance]]
! Durability
! Maintenance
! Cost
! Recycled content
! Comment
|-
| [[Wood]]
| very good
| variable
| high
| high
| low
| shrinks and swells with humidity changes
|-
| [[Polyvinyl chloride|PVC ("vinyl")]]
| very good
| good*
| low
| low
| very low
|
|-
| [[Aluminum]]
| bad**
| good
| very low
| low
| typically >&nbsp;95%
| used in most large structures
|-
| [[Steel]]
| medium
| superior
| very low
| high
| >&nbsp;98%
| typically welded at corner joints
|-
| [[Fiberglass]]
| very good
| very good*
| very low
| high
| medium
|
|}

<nowiki>*</nowiki> PVC and fiberglass frames perform well in accelerated weathering tests. Because PVC is not as strong as other materials, some PVC frames are reinforced with metal or composite materials to improve their structural strength.

<nowiki>**</nowiki> Modern aluminium window frames are typically separated by a [[thermal break]] made of a polyamide. This greatly increases thermal resistance, while retaining virtually all of the structural strength.

[[composite material|Composites]] may combine materials to obtain aesthetics of one material with the functional benefits of another.
[[File:Bleekman zimmer.jpg|thumb|right|225px|A typical installation of insulated glazing windows with uPVC window frames.]]
A special class of PVC window frames, uPVC window frames, became widespread since the late 20th century, particularly in Europe: there were 83.5 million installed by 1998<ref>{{cite book|last1=Pritchard|first1=Geoffrey|title=Novel and Traditional Fillers for Plastics: Technology and Market Developments|year=1999|publisher=iSmithers Rapra Publishing|isbn=9781859571835|page=95|url=http://books.google.com/books?id=U3GWoyuMEckC&pg=PA95}}</ref> with numbers still growing as of 2012.<ref>{{cite web|url=http://www.prweb.com/releases/Vinyl_doors_market/vinyl_windows_market/prweb9415523.htm|title=Global Vinyl Windows Market to Reach 163 Million Units by 2017, According to a New Report by Global Industry Analysts, Inc. |publisher=PRWeb|date=April 18, 2012|accessdate=2012-02-11}}</ref>

=== Glazing and filling ===

[[Low-emissivity]] coated panes reduce heat transfer by [[radiation]], which, depending on which surface is coated, helps prevent heat loss (in cold climates) or heat gains (in warm climates).

High thermal resistance can be obtained by evacuating or filling the insulated glazing units with gases such as [[argon]] or [[krypton]], which reduces [[Heat conduction|conductive]] heat transfer due to their low thermal conductivity. Performance of such units depends on good window seals and meticulous frame construction to prevent entry of air and loss of efficiency.

Modern double-pane and triple-pane windows often include one or more low-e coatings to reduce the window's U-factor (its insulation value, specifically its rate of heat loss). In general, soft-coat low-e coatings tend to result in a lower solar heat gain coefficient (SHGC) than hard-coat low-e coatings.

Modern windows are usually glazed with one large sheet of glass per sash, while windows in the past were glazed with multiple panes separated by ''glazing bars'', or ''muntins'', due to the unavailability of large sheets of glass. Today, glazing bars tend to be decorative, separating windows into small panes of glass even though larger panes of glass are available, generally in a pattern dictated by the architectural style at use. Glazing bars are typically wooden, but occasionally lead glazing bars soldered in place are used for more intricate glazing patterns.

=== Other construction details ===

Many windows have movable [[window covering]]s such as [[blinds]] or [[curtain]]s to keep out light, provide additional insulation, or ensure privacy.
Windows allow natural light to enter, but too much can have negative effects such as glare and heat gain. Additionally, while windows let the user see outside, there must be a way to maintain privacy on in the inside.<ref name="Design Evaluation Project">Howell, Sandra C. (1976). ''Designing for the Elderly; Windows''. Massachusetts Institute of Technology. Department of Architecture. Design Evaluation Project.</ref> Window coverings are practical accommodations for these issues.

== Windows and the sun ==
{{main|Daylighting}}

===Sun incidence angle===

Historically, windows are designed with surfaces parallel to vertical building walls. Such a design allows considerable solar light and heat penetration due to the most commonly occurring incidence of sun angles. In [[passive solar building design]], an extended [[eave]] is typically used to control the amount of solar light and heat entering the window(s).

An alternate method is to calculate an optimum window mounting angle that accounts for summer sun load minimization, with consideration of actual latitude of the building. This process has been implemented, for example, in the [[Dakin Building]] in [[Brisbane, California]]—in which most of the fenestration is designed to reflect summer heat load and help prevent summer interior [[over-illumination]] and glare, by canting windows to nearly a 45 degree angle.

=== Solar window ===
{{Main|Photovoltaics}}

Photovoltaic windows not only provide a clear view and illuminate rooms, but also convert sunlight to electricity for the building.<ref>{{cite web|url=http://web.mit.edu/newsoffice/2008/solarcells-0710.html |title=MIT opens new 'window' on solar energy |publisher=Web.mit.edu |date=2008-07-10 |accessdate=2012-02-11}}</ref> In most cases, translucent photovoltaic cells are used.

===Passive solar===

Passive solar windows allow light and solar energy into a building while minimizing air leakage and heat loss. Properly positioning these windows in relation to sun, wind, and landscape—while properly shading them to limit excess heat gain in summer and shoulder seasons, and providing thermal mass to absorb energy during the day and release it when temperatures cool at night—increases comfort and energy efficiency. Properly designed in climates with adequate solar gain, these can even be a building's primary heating system.

===Window coverings===

A [[window covering]] is a shade or screen that provides multiple functions. For example, some window coverings control solar heat gain and glare. There are external shading devices and internal shading devices.<ref name="Windows">Beckett, H. E., & Godfrey, J. A. (1974). ''Windows: Performance, design and installation''. New York, NY: Van Nostrand Reinhold Company.</ref> Low-e [[window film]] is a low-cost alternative to window replacement to transform existing poorly-insulating windows into energy-efficient windows. For high-rise buildings, [[smart glass]] can provide an alternative.

==Gallery==
<gallery>
File:TeaHouseWindowInuYama.jpg|Woven [[bamboo]] window in [[Japan]]
File:Obereisesheim Mauritiuskirche03.JPG|Church window
File:Berlin-Köpenick - Spindlerwerke 6.jpg|Factory site in Berlin-Spindlersfeld: window with letter S for Spindler
File:Lan Su Chinese Garden, Portland, OR 2012 - window.JPG|Classical Chinese window in [[Lan Su Chinese Garden]]
File:Doubled window.jpg|Arab-style windows in [[Jerusalem]]
File:Arles-abadia-3.jpg|[[Romanesque architecture|Romanesque]]/[[Gothic architecture|Gothic]] window from Abbey of St. Maria d'Arles
File:Desay madu jhya.jpg|[[Desay Madu Jhya (window)|Desay Madu Jhya]] traditional carved wooden window in [[Kathmandu]], [[Nepal]]
File:Half Glazed Window 17th Century.jpg|A half-glazed window of the 17th century from [[Scotland]]
File:Washington DC windows.jpg|Windows of a brick building in Washington DC
File:Villa Majorelle fenètre 02 by Line1.jpg|Window, [[Villa Majorelle]], France
</gallery>

== See also ==
{{colbegin|2}}
* [[Airflow window]]
* [[G-value]]
* [[Glass mullion system]]
* [[Insulated glazing]]
* [[Porthole]]
* [[Rose window]]
* [[Shop window]]
* [[Trickle vent]]
* [[Window film]]
* [[Window tax]]
* [[Window treatment]]
* [[Witch window]]
{{colend}}

==References==
{{reflist|35em}}

==External links==
{{commons category|Windows}}
*[http://www.alueurope.eu/publications-building/ European Aluminium Association's publications dedicated to Buildings]
* [http://www.nfrc.org National Fenestration Rating Council] (NFRC), a non-profit organization, administers an independent, uniform rating and labeling system for the energy performance of fenestration products. NFRC is the "engine" that drives virtually every window energy efficiency program in the country including ENERGY STAR (the U.S Government Sponsored Initiative).
* [http://www.metmuseum.org/toah/hd/rgls/hd_rgls.htm Roman Glass from Metropolitan Museum of Art]

[[Category:Windows| ]]
[[Category:Architectural elements]]
[[Category:Glass]]

Revision as of 17:06, 11 July 2014

Windows is a computer line

Line of Windows computers

Retrieved from "https://en.wikipedia.org/w/index.php?title=Window&oldid=616548495"