Pipes for a system of floor heating, before mounting the pavement.
In fact, the issuer could be for any other of the walls of the premises to be heated (walls or ceiling), but as warm air rises, it is more logical to use the floor. In any case, as heat is transferred by radiation, and human skin is a good absorber of radiation, the radiant ceiling heating is the problem of affecting the skin from head to those without hair (bald) giving pain head, so it is not advisable to use the roof.
This system has the advantage that the emission is by radiation, so that you can have living quarters in dry air at a temperature lower than with other heating systems, which means less heat loss through walls, ceilings or Soil in contact with the outside. In Spain, with normal minimum temperatures outside, saving the system is estimated between 15% and 20%, without reducing the benefits in terms of thermal comfort (wind chill).
The surface temperature of the soil should be moderate as the temperature of the water that runs well. This low temperature is offset by greater emission surface.
Water pipes (usually plastic) or electrical wires are distributed over the forged (see picture), interposing a thermal insulator to prevent heat from escaping into the lower floor. Pipe is placed on a layer of cement mortar and sand, then the flooring, which is recommended is a little heat-insulating material (stone, ceramic tile, hydraulic) and not wood or carpet. Some modern electrical systems are directly applicable and do not need the layer of cement mortar and sand.
If the building is well insulated is not necessary to cover the entire surface of the soil and may be left a narrow zone near the pipe walls without, to place furniture (bookcases, sideboards ,…) because the ground beneath them and not issue heat can spoil.