Editing Refrigerator (section)

=== Electric refrigerators ===
[[File:French Refrigerator Plant Increases its Productivity - DPLA - 95f3ac5808bd87d40bb4379003218b75.jpg|thumb|right|Production of refrigerators in France, ca. 1950s]]
In 1894, [[Science and technology in Hungary|Hungarian inventor]] and industrialist István Röck started to manufacture a large industrial ammonia refrigerator which was powered by electric compressors (together with the Esslingen Machine Works). Its electric compressors were manufactured by the [[Ganz Works]].  At the 1896 Millennium Exhibition, Röck and the Esslingen Machine Works presented a 6-tonne capacity artificial ice producing plant. In 1906, the first large Hungarian cold store (with a capacity of 3,000 tonnes, the largest in Europe) opened in Tóth Kálmán Street, Budapest, the machine was manufactured by the [[Ganz Works]]. Until nationalisation after the Second World War, large-scale industrial refrigerator production in Hungary was in the hands of Röck and Ganz Works.<ref>[https://web.archive.org/web/20220506202421/https://mek.oszk.hu/02100/02185/html/703.html The development and heyday of mechanical science] (Hungarian)</ref>

Commercial refrigerator and freezer units, which go by many other names, were in use for almost 40 years prior to the common home models. They used gas systems such as [[ammonia]] (R-717) or [[sulfur dioxide]] (R-764), which occasionally leaked, making them unsafe for home use. Practical household refrigerators were introduced in 1915 and gained wider acceptance in the United States in the 1930s as prices fell and non-toxic, non-flammable synthetic [[refrigerant]]s such as [[Dichlorodifluoromethane|Freon-12]] (R-12) were introduced.  However, R-12 proved to be damaging to the [[ozone layer]], causing governments to issue a ban on its use in new refrigerators and air-conditioning systems in 1994. The less harmful replacement for R-12, [[1,1,1,2-Tetrafluoroethane|R-134a]] (tetrafluoroethane), has been in common use since 1990, but R-12 is still found in many old systems.

Refrigeration, continually operated, typically consumes up to 50% of the energy used by a supermarket. Doors, made of glass to allow inspection of contents, improve efficiency significantly over open display cases, which use 1.3 times the energy.<ref>{{Cite conference|last1=Fricke |first1=Brian |last2=Becker |first2=Bryan |date=July 12–15, 2010 |title=Energy Use of Doored and Open Vertical Refrigerated Display Cases |url=https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2153&context=iracc |conference=International Refrigeration and Air Conditioning Conference|location=Purdue |via=Purdue e-Pubs}}</ref>