A jalousie window or louvre window (UK) is a window which consists of parallel glass, acrylic, or wooden louver

Louver

A louver or louvre , from the French l'ouvert; "the open one") is a window, blind or shutter with horizontal slats that are angled to admit light and air, but to keep out rain, direct sunshine, and noise...

s set in a frame. The louvers are locked together onto a track, so that they may be tilted open and shut in unison, to control airflow through the window. They are usually controlled by a crank mechanism.

A patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

 for a louvered window was applied for in the US in 1900 and patented Nov. 26, 1901. Patent # 687705 by Joseph W. Walker, of Malden, Massachusetts

Malden, Massachusetts

Malden is a suburban city in Middlesex County, Massachusetts, United States. The population was 59,450 at the 2010 census. In 2009 Malden was ranked as the "Best Place to Raise Your Kids" in Massachusetts by Bloomberg Businessweek Magazine.-History:...

.

Jalousie windows are best-suited for porches that are not climate-controlled and are located in mild-winter climates, and thus were very common on mid-20th-century homes in Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

, southern California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, the deep South

Deep South

The Deep South is a descriptive category of the cultural and geographic subregions in the American South. Historically, it is differentiated from the "Upper South" as being the states which were most dependent on plantation type agriculture during the pre-Civil War period...

, and Latin America. They can remain open during heavy rains and (because the glass louvers protrude outward) keep most of the rain from entering in through the windows. It is impossible to achieve a good seal between panes. It is also very hard to secure this design, as the slats are easily and silently removed.

They were also widely used in mobile home

Mobile home

Mobile homes or static caravans are prefabricated homes built in factories, rather than on site, and then taken to the place where they will be occupied...

s during the 1950s and 1960s before most mobile home manufacturers began switching to sliding and sash window

Sash window

A sash window or hung sash window is made of one or more movable panels or "sashes" that form a frame to hold panes of glass, which are often separated from other panes by narrow muntins...

s in the 1970s and '80s.

They are also called louver/slated/glass crankout windows in certain legal circles; jalousie windows with extremely wide louvered panels (e.g. over six inches) are frequently called awning windows.

See also

• Van Ellis Huff
  Van Ellis Huff
  Van Ellis Huff has been credited as the inventor of the jalousie window. Supposedly he was inspired by homemade wooden slat windows in houses he saw in the Bahamas. Actually the first patent for the jalousie window was applied for in 1900, when Huff was only six years old, by Joseph W....
  
   (1894–1987), has been widely credited as the inventor of the jalousie window, but no patents have been found in his name. He was only 6 years old when the first patent for the jalousie window was applied for by Joseph W. Walker (see above).
• Louver
  Louver
  A louver or louvre , from the French l'ouvert; "the open one") is a window, blind or shutter with horizontal slats that are angled to admit light and air, but to keep out rain, direct sunshine, and noise...
  
  
• Window blind
  Window blind
  A window blind is a type of window coverings. There are many different kinds of window blinds, using different systems and materials. A typical window blind is made with slats of fabric, wood, plastic or metal that adjust by rotating from an open position to a closed position by allowing slats to...