Dimension a wall heater

Wall heating is enjoying increasing popularity. It's not just a fad. In fact, wall heating offers very special advantages. However, it is always important that the wall heating is dimensioned correctly. It depends on various factors. You can find out how to dimension a wall heating system here.

Wall heating versus conventional heating (convection heating)

A major advantage of wall heating is the fact that radiant heat is used here. Conventional heating works on the principle of convection heat. This means that the air must be heated to the temperature that is also felt. With radiant heat, the air is as good as not heated, but objects and bodies that are illuminated.

  • Also read - wall heating or underfloor heating?
  • Also read - Installing a wall heater
  • Also read - installing a wall heater

In a room with convection heating, the room air must be 21 degrees Celsius in order to be perceived that way. In a room with radiant heating, 18 degrees is enough to also achieve the feeling of 21 degrees of warmth. Keep in mind that the additional energy expenditure for each degree of heat is more energy than six to seven percent more energy, here quickly reveals a significant potential for savings.

Similar to the underfloor heating

It is not yet considered that this heat itself is perceived as a pleasant. The principle according to the wall heater is similar to a underfloor heating to look at. Only that even opposite the underfloor heating, the heat of the wall heating is also perceived as much more pleasant.

The wall heater is a surface heating


From the principle of radiant heat is already derived that it must be a large-area heating. In principle, the DIN EN 1264 part 2 and DIN EN 12831 can be added to dimension a wall heater suitable. However, numerous factors have an impact on heat output:

  • Insulation of the wall
  • Flow temperature
  • Density of the heating pipes
  • Window area
  • later cladding of the wall


what has to be considered when dimensioning

The insulation of the wall is a fundamental factor. This significantly influences the required flow temperature. This in turn should in any case be below 45 degrees (between 30 and 45 degrees). In an old building without adequate thermal insulation to the outside, wall heating is problematic because too much heat is radiated to the outside. This increases the required flow temperature significantly.

As with underfloor heating, it is also important how close the heating pipes are to one another. Therefore, the usual dimensions also help with wall heating. In addition, the outer wall should always be provided with the wall heater. Otherwise there may be negative peculiarities such as a cold pull on the feet.

Rule of thumb: 20 to 30 percent of the living space for wall heating

Since the wall surface of the outer wall is preferably provided, the surface of the window naturally plays an equally important role. If all these factors have been clarified, it can be assumed under normal to optimal circumstances that the wall heating should be dimensioned with a size of 20 to 30 percent of the living space (of the room in question).

Tips & Tricks In the meantime, providers and manufacturers of wall heating systems also offer small programs for calculating on the Internet. For a serious calculation, however, data such as the U-value for the wall in question are also a decisive factor for correct dimensioning.