Radient Heat

Efficient Heating for Your Home

Radiant Heating takes place when a hot surface warms the air or other objects around it. This process is much more efficient than other ways of heating the air in a building and is currently believed to be the perfect type of heating system. Under-floor radiant heat is the most common type of radiant heating found in homes and other buildings. However, wall and overhead radiant heating systems are also being used. Radiant heating can even be used to heat outdoor areas such as patios and porches. Contrary to what one might think, radiant heat is not a new idea at all, but has a long, illustrious history of use in many very old buildings.


Both the Romans and the Koreans used radiant heat. The Romans were first to use under-floor radiant heating systems. Their systems were based on “hypocausts” which used warm air for heat. The floor was built on top of brick piles which allowed space for hot air and steam produced by an accompanying furnace to pass underneath the floor. However, these unique systems were very expensive both to build and maintain. Consequently, they were affordable by only the wealthy. In Korea, radiant heating has been in use for approximately 2000 years. “Ondol”, meaning “warm stone”, is a process by which stones and underground ducts are used to help move warm air from the kitchen to other rooms in a building. Many homes and buildings in Korea still use this unique, age old process. However, today, many Koreans also use modern hot water and electric systems as well. One of our most famous American architects, Frank Lloyd Wright, discovered the Korean “ondol” radiant heating process in the early 1900s and used it in many of his buildings. Importantly, it was Frank Lloyd Wright that also invented hot water, under-floor systems.


There are three types of under-floor heating:

  • Hot air systems use hot air to heat the floor. These radiant heating systems are similar to the Romans’ systems. However, since air does not hold heat very well, these systems are not recommended for residential use.
  • Hot water systems are the most popular and cost-effective radiant heating systems for cold climates. These systems heat water by use of a boiler and pump it through pipes laid underneath the floor system. Such Hot water systems can also be used in combination with solar thermal energy to make them more environmentally friendly… since solar thermal energy uses sunlight to heat the water which can in turn be used in the under-floor heating system. Hot water systems can also be run in reverse by running cold water through the system`s pipes to provide cooling to the building. However, currently, this technology is difficult to use properly and can result in condensation on the floor causing hazardous conditions which can ruin hardwood floors and carpets, as well as creating slippery conditions that could cause serious accidents.


Currently, The Joinery Company is investing in research of a new technology that might eventually master the undesirable characteristics of using hot water systems in reverse. If a way can be found to master the potential occurrence of condensation problems created by running hot water systems in reverse, then of course, our world would have the perfect heating and cooling system… in one.

  • Electric systems are created by laying electric cables underneath the floor. These cables are then heated by electricity. This type of system can be switched on and off much faster than a hot water system. However, that speed comes at a cost. Due to the high prices of electricity, these systems are usually more expensive than hot water systems, especially if the hot water system is being used in combination with solar thermal energy. Electric systems are far less environmentally friendly since electricity is most often produced by burning fossil fuels, which increases carbon emissions.


Under-floor radiant heating systems can be installed in two ways, either as wet systems or as dry systems.

  • Wet systems are laid in place and then concrete is poured over them. Concrete floors hold heat well, but they can take a long time to absorb the heat. On the other hand,
  • Dry systems run in the open air space between the foundation and the floor system. These systems can be slightly less efficient because they have to heat the air as well. However, dry systems are much easier to get to for maintenance if the system should become damaged or leak. To many, that seems to be a good trade off. The Joinery Company agrees.


Any kind of flooring can be used with under-floor heating. Ceramic tiles are one of the most popular flooring materials because they transfer and store heat well. However, even though wood floors, carpet, and linoleum may decrease the heat transfer from the under-floor system a small amount, requiring that the system be set slightly higher, they are also very popular.


The Joinery Company believes that radiant heating is the perfect heating system for all wood floors…and especially for reclaimed wood floors. We have several reasons for that emphatic statement:

  • Radiant heat is time tested! It has been used for centuries and has proven itself superior. There can be no better way to test anything.
  • Radiant heat is the friendliest of all environmental alternatives. It does not require the use of fossil fuels or anything potentially unhealthy.
  • Wood is an excellent conductor of heat. It is easy for heat to travel through wood and into the surrounding space, warming the air.
  • Wood is an excellent distributor of heat. As the warm air leaves the surface of the wood floor, it is distributed evenly in all directions.
  • Wood is an excellent retainer of heat. It will retain warmth, even if temperature drops in the system, or the system is turned off.
  • Radiant heat is far healthier for wood than other types of heating systems because heat is evenly distributed at low temperature throughout the floor. Therefore, each board experiences the same amount of heat and is not subjected to the stress of uneven drying.


With regard to reclaimed woods, the radiant heating process is actually very similar to the natural conditions that reclaimed wood was exposed to, often for decades, during its previous life of service. During the time that reclaimed timbers and planks were being used structurally in houses, barns, and textile mills, they were regularly exposed to small increases and decreases in temperature and moisture. The low temperatures and even heat distribution that their respective reclaimed flooring planks experience today, while in use over radiant heating systems, is indeed much the same.