Concept of underfloor heating system?

The full name of underfloor heating system is Radiant Floor Heating, which uses the entire floor as a radiator, uniformly heats the entire floor through the heat medium in the floor radiation layer, and conducts heat from bottom to top using the heat storage and upward radiation of the floor itself to achieve the purpose of heating. This technology is both ancient and innovative, dating back to the late Ming Dynasty in China. At that time, it was a heating method only available to the imperial palace and royal family. For example, in the existing Forbidden City, a chimney was built under the blue brick floor, and in winter, smoke was transmitted through the chimney for heating.