How Did Persians Make Ice in the Desert? (Yakhchal)

Yakhchal, often called the 'ancient Persian refrigerator': how people on Iran's desert plateau made real ice on winter nights and kept it until summer. A shallow pool, a giant shade wall and the clear night sky could freeze the water even when the air was above freezing; a deep pit, straw and a thick mud-brick dome kept it. Eyewitnesses Fryer, Chardin and Tavernier describe the ice, the night festivals and the free iced water. And the truth about the '400 BC' date, the egg-white mortar and the wind towers. Would you have given up half your bread for a cold drink? Tell us in the comments. Watch next: How the Mongol Composite Bow Was Made (and How Far It Shot)    • How the Mongol Composite Bow Was Made (and...   Chapters 0:00 Half a Penny for Snow 0:41 The Ice Pit 1:10 The Night Shift 1:52 Ice From the Sky 2:43 A Party in the Pit 3:22 Winter in a Box 4:02 Ice for Everyone 4:45 The 400 BC Myth 5:39 Melting Sources John Fryer, A New Account of East-India and Persia (London, 1698), Letter V; ed. W. Crooke (Hakluyt Society, 1909-15), vols. 2-3 Sir John Chardin, Travels in Persia, tr. E. Lloyd (London, 1720), vol. 2, pp. 233-236; Voyages du chevalier Chardin en Perse, ed. L. Langles (Paris, 1811), vol. 4 J.-B. Tavernier, The Six Voyages (London, 1677), The Persian Travels, Book IV Thomas Herbert, Some Years Travels into Divers Parts of Africa and Asia the Great (London, 1677) Adam Olearius, The Voyages and Travells of the Ambassadors, tr. J. Davies (London, 1669), Books V-VI C. J. Wills, In the Land of the Lion and Sun, or Modern Persia (London, 1891), ch. XXII H. Jorgensen, 'Yakcal', Encyclopaedia Iranica (2012) C. Bromberger, 'Bannai (construction)', Encyclopaedia Iranica III (1988) B. Hosseini and A. Namazian, 'An Overview of Iranian Ice Repositories', METU Journal of the Faculty of Architecture 29:2 (2012) 223-234 M. Mahdavinejad and K. Javanrudi, 'Assessment of Ancient Fridges', Asian Culture and History 4:2 (2012) 133-139 J. Pochee, P. Gunstone and C. Wilton, 'New insight on passive ice making and seasonal storage of the Iranian Yakhchal', PLEA 2017, Edinburgh M. Martin and P. Berdahl, 'Characteristics of infrared sky radiation in the United States', Solar Energy (1984) A. P. Raman et al., 'Passive radiative cooling below ambient air temperature under direct sunlight', Nature 515 (2014) 540-544 D. S. Parker, 'Theoretical Evaluation of the NightCool Nocturnal Radiation Cooling Concept', FSEC-CR-1502-05 (2005) Sir Robert Barker, 'The Process of Making Ice in the East Indies', Philosophical Transactions 65 (1775) Zimri-Lim ice-house inscription, CDLI P448586 (RIME 4.06.12.03); O. Rouault, Terqa Preliminary Reports 7 (1979) Fakhr al-Din al-Razi, Mafatih al-Ghayb, on Quran 103:1 Wikipedia, 'Yakhchal', revision 28088369 (12 November 2005), where the '400 BC' sentence first appears Photo credits Yakh-chal in Yazd province - Iran (cropped), reibai, CC, via Wikimedia Commons 20110102 Ice House (exterior) Meybod Iran, User:Ggia, CC, via Wikimedia Commons 20110102 Ice House (interior) Meybod Iran, User:Ggia, CC, via Wikimedia Commons Zarisf Yakhchāl-Kerman-ID3510- یخچال زریسف-کرمان, Mhsheikholeslami, CC, via Wikimedia Commons Yakhchal meybod, Soheil46, CC, via Wikimedia Commons Yakhchal Agha, Shahab P., CC, via Wikimedia Commons Water reservoir windcatchers (21016524126), s1ingshot from Berlin, Germany, CC, via Wikimedia Commons Yakhchal Langar 1, Mehdi yazdan1983, CC, via Wikimedia Commons Maps: Natural Earth (public domain). Elevation: Copernicus DEM GLO-90, (c) DLR e.V. 2010-2014 and (c) Airbus Defence and Space GmbH 2014-2018, provided under COPERNICUS by the European Union and ESA. Script researched from the sources above. #Yakhchal #AncientTechnology #Persia