Kang bed-stove

The kang (Chinese: ; pinyin: kàng; Manchu: nahan, Kazakh: кән) is a traditional long (2 metres or more) platform for general living, working, entertaining and sleeping used in northern part of China, where there is cold climate in winter. It is made of bricks or other forms of fired clay and more recently of concrete in some locations.

Its interior cavity, leading to a (often) convoluted flue system, channels the hot exhaust from a firewood/coal fireplace, usually the cooking fire from an adjacent room that serves as a kitchen, sometimes from a stove set below floor level. This allows a longer contact time between the exhaust (which still contains much heat from the combustion source) and (indirectly) the inside of the room, hence more heat transfer/recycling back into the room, effectively making it a ducted heating system similar to the hypocaust system used by ancient Romans. A separate stove may be used for controlling the amount of smoke circulating through the kang, maintaining comfort in warmer weather. Typically, a kang occupies one-third to one half the area the room, and is used for sleeping at night and for other activities during the day. A kang which covers the entire floor is called a dikang (Chinese: 地炕; pinyin: dì kàng; literally: "ground kang").

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