You may be aware that a radiant floor heating system is a modern, efficient and healthy method to heat your home, but do you know its history?
Radiant heated floors may seem like a relatively recent innovation to most. It’s true that it rose to prominence as a common and sought-after feature in North-American and European homes in the 1980s, but the practice of heating living spaces through heat radiating through the floor goes back centuries.
Ancient China and Korea
Many have credited the Romans with first utilizing this system, however, archaeologist have discovered evidence that it was used in China and Korea around 5,000 B.C. The Chinese kang (meaning to dry or, later heated bed) or dikang (meaning heated floor) was a raised heated surface used for living and sleeping. The hot gases emanating from a fireplace were sent through flues constructed in the earth or masonry below the kang or dikang. The heat of the gases was conducted to the surface and radiated into the room.
Similarly, Koreans developed a heated floor system called ondol (meaning warm stone). This system uses the heat from a fire hole in the kitchen stove, drawing it through flues before venting it through a chimney. The warm air heats flat stones placed above the flues and radiates into the room above.
The use of kangs continued for centuries well into imperial China. During the Tang Dynasty (618 to 907 A.D.) a large hall for 1,000 monks was built in the Guanji Temple with heated floors to allow students to study during the cold winter months. The popularity of heated floors never waned, remaining the most popular heating choice in Korea and Northern China to this day.
As the technology continued to be refined and developed in Asia, the Romans introduced the hypocaust around the third century B.C. to heat baths, houses and other buildings. The floors, made of a layer of tile, concrete and another layer of tile, were raised above the ground by pillars. Gaps were left in the walls allowing smoke and hot air to be vented through the roof. Rooms requiring more heat were placed closest to the furnace. Following the fall of the Roman Empire, hypocausts fell into disuse in Europe in favor of central heating sources.
Heated Floors in Europe
Heated floors did not reappear in Europe until the late 17th century, when they began being used to heat greenhouses. The hot water boiler was introduced soon thereafter. Sir John Stone was believed to be the first to introduce a system of pipes carrying hot water as a heating method, installing such a system in the Bank of England in 1790. A better scientific understanding of the principles of radiant heat transfer also arose out of this period.
In 1839 and 1841, two important patents that were forerunners to modern fluid based heating systems were issued to Angier March Perkins relating to the use of circulating hot water to transmit heat and as a source of heat.
Heated Floors in America
During the civil war, a rudimentary form of heated flooring, reminiscent of the dikangs of China, was used in hospital tents. A fire pit was dug next to the tent with a trench running through the tent leading to a chimney on the opposite side. The trench was covered by sheet iron that would become heated by the fire in the pit.
In 1907, a British professor named Arthur H. Baker, discovered that small hot water pipes embedded in concrete or plaster worked well as a heating system. Following the civil war era, more sub-floor heating systems began being used in the U.S. In 1909, a small school in Indiana was constructed with steam pipes suspended between the floor joists below conventional flood boards.
Perhaps no figure was more important in popularizing radiant floor heat than celebrated architect Frank Lloyd Wright. He employed radiant floor heating in many of his projects going as far back as Buffalo’s Larkin Administration Building designed in 1904, the Johnson Wax Building and the Jacobs Residence (1937).
Since that time, radiant floor heating systems have continued to gain popularity in the U.S., with the development of electric radiant heat options. Recent surveys indicate the use of radiant heated floors is more likely when informed homeowners take an active role in the heating and cooling choices for their homes.
Warm Your Floor is a specialized retailer of electric radiant floor heating systems. We work with brands like Nuheat, SunTouch, WarmWire, DITRA Heat. If you want to learn more about floor heating options you have check our website or call us with your questions! This article could also help see what systems are out there and costs for typical projects.