Underground Heated Flooring
Nowadays, many homeowners prefer hard-surface flooring to carpet as it tends to be easy to maintain and clean. Unfortunately, many of the harder surfaces, such as stone and tile flooring, can get very cold during the fall and winter seasons. Without socks, slippers or shoes to keep your feet warm, you may find yourself turning up your room heating in order to compensate.
Thanks to the ingenuity of present-day flooring, there is a solution to this problem. Now a variety of floors can be heated from underneath. These include tile, wood, vinyl, stone and carpet.
While contemporary manufacturers have managed to streamline underground heating, it was actually the Romans who first invented it. Roman floor heating systems involved a raised floor on piled bricks (called a hypocaust), flues built into the wall, and ducts running underneath the floor. All of this was attached to a hidden furnace that required the constant addition of wood and removal of ashes.
Unfortunately, Roman innovation for heated flooring far surpassed the resources they had available. In fact, their heated floor systems often resulted in fire and smoke inhalation.
Modern underground floor heating can be carried out in several different ways. The most common types are either electric systems or hot water systems:
• Electric heating systems are typically easier to install than warm water systems, and are therefore often available for a lower cost. During installation, heated cables are arranged directly on the subfloor (preferably concrete), and the flooring is laid on top of the cables. Some electric systems are installed onto an insulated underlayment* which helps reduce the amount of heat lost in the subfloor.
*Underlayment is a layer of material installed between the subfloor and new flooring.
• Hot water heating systems use a variety of pipes (tubes) which are laid onto the subfloor and directly underneath the floor being installed. Warm water is carried through the network of pipes, generating heat which goes up through the flooring. Some hot water heating systems use a thermosiphon, a method of heat exchange that operates through natural convection*. Since thermosiphons do not rely on a conventional pump, they are generally cheaper to buy.
*Convection, or heat transfer, is the passage of heat from a hot object or fluid to a cold one.
The geothermal heat pump (GHP), also known as GeoExchange system, is a popular favorite with environmental advocates as it uses natural thermal energy stored below the earth's surface. Pipes filled with water are buried underneath the ground and exchange heat directly with the earth. While a GHP can be pricey, the cost for maintenance and operation is often significantly less than other heating systems.
You may not have been aware that actually heating your floors was an option. But hats off to the Romans for coming up with a great idea that is now a staple of the modern world.