The wet installation
There are two fundamentally different systems for installing water-bearing wall heating systems, which differ in their construction and handling and which are optimized for the respective area of application. Both systems can, however, be combined with one another and thus enable effective work on large areas and in nooks and crannies.
The classic design is the so-called wet installation. This is the optimal construction method in old buildings and when redesigning an existing building stock. The loose heating pipes are bent and laid on the wall as required. Adaptation to the structural conditions is therefore extremely flexible, as it is not necessary to level the subsurface beforehand. The pipe lies just as well on crooked walls as it does on a perfect level. In order to ensure a reliable hold, holding rails are attached to clip the pipes to the subsurface.
Prefabricated wall heating elements, in which the pipe is bent in a loop and fixed, can also be integrated flat into the plastered wall heating construction.
You can bend the aluminum composite pipes with what is known as a spiral spring, which you can use to bend the pipes in an arc-shaped manner without kinking or damage. Pipe kinks damage the inner coating of the pipe, the water corrodes the metal and can even lead to leaks and subsequent moisture damage to the wall in the long term.
Three work steps
The flexibility of the design enables the exact planning of each heating circuit, even in tight corners or otherwise inaccessible corners, but the flow resistance should be set equally via the hydraulic balance to ensure even heat distribution throughout the house.
After laying the heating pipe, three more plastering operations follow. First of all, the space between the pipes is filled with a clay plaster up to their apex. After this layer has dried, a sub-plaster with embedded mesh follows, which completely covers the pipes. As a conclusion, a topcoat or fine-finish plaster is applied. To do this in three work steps has proven itself, and is important insofar as insufficient drying of the individual layers can lead to cracking or warping of the plaster. In particular, the bottom layer, where there is a lot of mass between the pipes, has to dry out thoroughly. Otherwise distortion or even cracks will form over the pipes.
The connection to the heating system is made via a heating circuit distributor for each heating circuit. It is also possible to connect several heating circuits per room, which can be controlled via a room thermostat. This thermostat measures the room temperature and initiates the opening or closing of a valve (the so-called servomotor) in the heating circuit distributor. When connecting several heating circuits for a room, the servomotors are controlled in parallel, they open or close evenly.