ASHRAE Journal - January 2010 - 42

These choices from ancient times influenced modern day Korea. During the 15th century, widespread adoption of the ondol occurred, conserving traditional floor lifestyles. Ancient Asia – Kang, Dikang, Ondol heated surfaces.5 It is during the time of the Zhou dynasty when Europe records its history of the hypocaust (see Part 2 in the next issue). Imperial China Archeological sites in Shenyang, China, show humans resided there as early as 7,200 years ago. There is evidence of “baked earth” floors in this region dating between 5300 to 4800 B.C., as well as in Xi’an, China, with “raised surfaces treated by fire,” dating to 4800 to 4300 B.C. This process of baking the earth is called zhi or zhidi and may be the process which gave birth to the dikang.5 Of anthropological interest from Alaska’s Aleutian Islands, is an archeological dig at Unalaska revealing remains of a heated floor system characterized by the Korean ondol with radiocarbon dating showing remains to be around 3,000 years old (see third photo on timeline). Pringle states: To stay warm, some families built subterranean stone-walled homes with energy-efficient heating systems consisting of a hearth, a stone chimney, and two subfloor channels…the subfloor channels funneled heat or possibly steam to warm the house floors…Such subfloor heating technology was previously unknown in the North American Arctic. But it resembles heated floors known as ondols that appeared in the Korean peninsula and in the Russian Far East during the same Neoglacier period….6 It is also known from early Chinese writings, excavated at Ningxia Hui (some dating back to 6000 B.C.), with references to heated floors or heated beds recorded over the centuries starting between 2852 and 2205 B.C. Literature from the Xia Dynasty (2070 to 1600 B.C.), Shang Dynasty (1600 to 1046 B.C.) and Zhou Dynasty (1122 to 256 B.C.) all refer to similar All through the Qin Dynasty (221 to 206 B.C.) when the Great Wall of China began; through the Han Dynasty (205 B.C. to 220 A.D.) in the communities of Xinjiang and Heilongiang, excavations have found remains of kang; into the Wu Shu and Wei periods (220 to 280 A.D.), Jin Dynasty (265 to 420 A.D.) where Ji’an excavations find remains of double-flue kangs during the; era of the 16 Kingdoms (304 to 439 A.D.); Southern and Northern Dynasties (420 to 589 A.D.); Sui Dynasty (581 to 619 A.D.); and Tang Dynasty (618 to 907 A.D.). It is the latter period when a large hall in the Guanji Temple was constructed for 1,000 monks with “heated floors affording students to study in cold winters.” As pointed out by Guo, “Monks were learned men, many from aristocratic classes” and it is likely they continued to innovate and improve on this type of heating.5 Certainly, through their travels they would influence others to use this type of system (see Part 2 with reference to America’s Civil War). It was also during the time that poet Meng Jiao writes, “No fuel to heat the floor to sleep, standing and crying in cold at midnight.”7 Literature and remains of surface heating are found from the Song Dynasty (960 to 1126 A.D.) where Yaozhou excavations of a Tang-Song pottery factory reveal remains of parallel-flue kangs; from the Yuan Dynasty (1271 to 1368 A.D.), Ming Dynasty (1368 to 1644 A.D.) into the Qing Dynasty (1644 to 1911 A.D.) where kang was enlarged to become a heated floor for the Manchu. L-type gudeul.9 Image credit: Kwang Woo Kim (left image) c. 1000 B.C., More than two hearths were used in one dwelling. One hearth located at the center was used for heating, the other, at the perimeter, was used for cooking throughout the year. This perimeter hearth is the initial form of the Budumak (meaning kitchen range), which composes combustion section of the traditional ondol in Korea. 42 c. 500 B.C. Greeks and later Romans scale up the use of conditioned surfaces (floors and walls) with the hypocausts. c. 200 B.C., The central hearth was developed into the gudeul (meaning heat releasing section of ondol), and a perimeter hearth for cooking became more developed. Budumak was almost established in Korea. c. 50 B.C., China, Korea and Roman Empire use kang, dikang/ondol and hypocaust, respectively. ASHRAE Journal ashrae.org January 2010

ASHRAE Journal - January 2010

Table of Contents for the Digital Edition of ASHRAE Journal - January 2010