Radiant heating systems consist of electric wires or hot water tubes located beneath the floor that emanate thermal radiation through the floor and into furniture, fixtures and the bodies of humans and pets. Such systems keep the air temperature relatively even.
In addition to being quiet, unlike radiators and forced-air heating systems, radiant heating systems are more energy efficient than traditional systems. Although they cost more to install than other types of heating systems, they cost about 30 percent less to operate.
Radiant heating systems are also more consistent. Forced-air systems blow hot air, which then rises, leaving the lower part of a room cold and the upper part too hot. Ambient heat warms from the floor up, which eliminates cold floors and ensures a room's occupants are comfortably warm from their heads to their feet.
Some ambient heating systems include multiple heating zones, allowing homeowners to fine-tune the amount of heat being sent through tubing to different rooms. Others include outside reset controls that alter the amount of heated water flowing through tubing in response to fluctuating outdoor temperatures.
The first ambient heating systems were used by ancient Romans who heated rooms by placing flues from fires under raised marble floors. Slaves made sure the fires had plenty of wood during cold times.