Friday, November 6, 2009

A Brief History of Radiant Flooring

In the beginning, the Romans created the heavens and the earth. Well, not really, though they did do some pretty amazing things. Seriously, around 2000 years ago, the ancient Romans invented a system that utilized steam and hot air to warm a room. They built large public communal bathhouses with heating systems so that the men could bath and soak in warm water. A cold bath is not very relaxing or comfortable and could “give rise to” (or not) some embarrassing moments. So necessity being the mother of invention, radiant heating was born.The roman system was based on the hypocaust (see diagram), which is made of ducts that run under the floor and flues that were built into walls to carry the heat away. Hot air or steam from fires would circulate through this system, warming the floor and walls, with heat passing into the rooms.This turned out to be a fairly dangerous practice. Since the majority of the heat was created using fire, it is believed that carbon monoxide would creep into the rooms through cracks in the bricks. Today, we understand the effects of carbon monoxide poisoning, but in ancient roman times, it had the potential to be deadly.Moving forward to the 12th century, Muslim engineers improved this rudimentary heating system by directing the heat and smoke through pipes laid in the flooring instead of openly dispersing it below.Shortly after, the Romans adapted this newer heating methodology, and so did the Koreans. In Korea, they captured heat generated from cooking and called it an Ondol. An Ondol was made up of three parts: a stove or fireplace, a chimney, and horizontal flues under the flooring. On top of the flue system was a thick, flat stone called a Kudul and on top of the Kadul was flattened yellow soil topped with rice paper. And so, the Kadul became warm as a result of the heat passing through the flues under the flooring.In fact, this type of heating is still used in Korea today. When the country switched to the commonly used western forced heating system, many missed their traditional Ondol and returned to their ancient ways. Of course, there has been further advancement in floor heating, but we will get to that shortly.In the early 1900’s, Frank Lloyd Wright was visiting a Japanese nobleman with an Ondol. He liked the idea of radiant heating so much that he invented a new water based system – hydronic radiant heating. Instead of hot air blowing through flues, he routed hot water through pipes. This gave birth to a much safer radiant heating method, resulting in far fewer people being burned or dying from carbon monoxide poisoning.

Since then, the path of radiant heating has taken many turns, but currently, the most popular methods are hydronic and electric radiant heating. Both types are installed below the flooring and are safe. Both methods are superior to most any other heating system. However, hydronic typically is best for new construction when a whole house method of heating is desired, and electric is best for a specific room application. Most often, it is installed in a kitchen or bathroom remodel, or when putting an addition on your home, like a sunroom.

The article was taken directly from Flooring Now ( Also, visit out website at and

No comments:

Post a Comment