Wissenswertes über die Kermi x-change Wärmepumpe

With an eye for what is important. Benefits of x-change heat pump.

In contrast to conventional heat pumps, most x-change heat pumps have an adjustable modulation width, i.e. their output can be set differently. The speeds of fans and charging pump can be also be controlled correspondingly. This means that in the partial load range which is often required, an optimal degree of efficiency can be attained. Modulation is managed by the heat pump manager.

  • The radial fan is extra large which means it can run more slowly. This reduces the drive noises and makes the x-change heat pump virtually silent.
  • Most x-change heat pumps are connected using the safe and secure plug & heat principle. Instead of simple terminals, coded connectors and defined connection sizes make installation easier. This virtually rules out incorrect installation and therefore the risk of hydraulic defects.
  • With the energy manager and the associated temperature module, the use of PV electricity you have produced yourself can be optimised with x-change heat pumps.

For the environment. And for the future.

The heat pump is currently the most future-oriented form or energy production. Based on the emission-free use of geothermal heat and solar energy, it firmly backs "Green energy". It is efficient and in the long term, impressively sustainable.

x-change heat pumps are optimally designed within the heating system to attain the maximum energy saving volume and that with maximum heat output! This means that x-change heat pumps guarantee the most comfortable climate and are also impressively good to the environment. The use of 3/4 air or geothermal heat (to generate heat energy) and 1/4 eco-electricity (to drive the pump) uses 100 % green, completely renewable energy with no ifs or buts.

Sustainable and efficient, the x-change heat pump is the key component of the "Kermi x-optimised system". Due to the perfect interaction of the individual components, this ensure better heat storage (x-buffer heat storage), more intelligent control (x-center) and more efficient transmission into the individual rooms through optimised panel heating (x-net) or steel panel radiators (therm-x2) respectively. And it is powerful enough to provide a comfortable feel-good warmth even with conventional radiators, convectors and design radiators.

Kermi x-change Wärmepumpen - Wohlfühlklima & gut zur Umwelt
Efficiency of Kermi heat pump - it only takes 1 kW of conventional electrical energy to generate 4 kW of heat output

Did you know that ...

… a heat pump only needs 1 kW of conventional electrical output to generate around 4 kW of heat output? This means that in comparison to conventional heating technologies, the heat pumps offer significant savings and the electricity used is converted much more efficiently. If the electricity used then also comes from regenerative energy or from cogeneration, then the CO2 emissions are reduced and the heat pumps takes full advantage of its ecological benefit! This is particularly interesting if the share of regenerative energies in the power mix continues to grow. By 2020, the declared objective of the Federal government is for this share to be 35 %; in 2030 even half of the electricity generated is to come from renewable sources. This means that the heat pump is a heating system which will become increasingly environmentally friendly in the long term.

Operating mode. That simple. And so clever.

The principle

A heat pump basically works in the same way as a refrigerator. While the refrigerator dissipates heat from the inside to the outside according to the heat and power principle, a heat pump extracts thermal energy from the earth, ground water or surrounding air and converts it into heating warmth, or in the case of a domestic water heat pump, into clean domestic hot water. This is based on a closed circuit made of the vaporiser, compressor, condenser and expansion valve.

In contrast to conventional heat pumps, most models in the x-change series have a wide modulation range, i.e. the output can be controlled. The speed of the fan and storage charging pump can be controlled to coordinate with this. Modulation ensures above all that the optimal degree of efficiency is reached in the partial load range which is often required.

Operating modes

To be able to ideally use a heat pump in practice, various operating modes are available:

The heat pump is the only heat source in a building.

Apart from the heat pump there is a second heat source. A distinction is made here between bivalent-parallel (from a predefined outside temperature both generators work) and bivalent alternative (heat pump and alternative generators operate alternately).

The heat pump works up to a predefined outside temperature, if the outside temperature is lower than this, an electric screw-in heater switches on as well. Both heat sources are operated with the same type of energy (electricity).


The heat pump takes the heat energy out of the air. It can be set up inside or outside the building.


There are two main methods of heat recovery from the earth: firstly using a panel collector and secondly, using a geothermal probe. For both systems, a heat transfer liquid is circulating in the pipes. The flowing medium absorbs the heat contained in the earth and transfers it to the heat pump.

Geothermal collectors

Heat recovery with geothermal collectors is also possible.

Geothermal probe

A geothermal probe extracts the heat energy stored in the earth.


The heat energy stored in the groundwater can be used with a heat pump.