The heat pump has become a standard heating system in recent years. Depending on the model and version, they can be used both in new-builds and in existing buildings for resource-saving heat generation. Large or small property, single-family house or multi-family house – which heat pump is the right one for your own construction or modernisation project depends above all on the conditions in and around the house. A few rough classifications and bits of basic data help in the selection process.
I have selected my plot, I know the development plan, and I have decided on the type of house. My planned house offers ideal conditions for operating a heat pump: It meets the KfW efficiency house standards with outer wall and roof insulation, windows with triple glazing, etc. I can plan space in the garden or cellar for the heat pump which allows for optimal installation conditions. However, my property is too small or unsuitable for deep drilling or large-scale installation measures in the ground to tap a heat source.
Heat source for air/water heat pump: An air/water heat pump uses the ambient or outside air to generate the desired heat. This heat source can be tapped almost anywhere with little effort. This makes an air/water heat pump universally applicable – so the technology can optionally be installed either indoors or outdoors. Particularly interesting for new-builds is the connection with a low-temperature heating system, such as underfloor or wall heating.
The heat, which is generated in a resource-saving way, must also be stored efficiently and brought into the rooms when needed. Additional energy can be saved if the corresponding components and the control technology of the entire system are precisely coordinated. These system components work well combined with the Kermi air/water heat pumps in new-builds:
I have selected my plot, I know the development plan, and I have decided on the type of house. My property offers enough space and the geological conditions for the large-scale installation of geothermal or surface collectors or for deep boreholes, for example to pump groundwater. The garden is also free of large plants and the area adjacent to the house is neither built on nor sealed.
Heat source of brine/water heat pump: A brine/water heat pump extracts energy from the ground. Geothermal collectors are installed for this purpose at approx. 1.2 to 1.5 metres deep or geothermal probes are installed vertically up to 100 metres deep. In both systems, a heat transfer fluid, what is known as brine, is circulating in the pipes and absorbs the geothermal energy and transfers it to the heat pump.
Heat source of water/water heat pump: A water/water heat pump extracts energy from the groundwater which has a temperature of between 10 and 15 degrees Celsius. This requires two wells that transport the water to the top and later release it back into the depths. A pump delivers groundwater from a suction well to the heat pump. Afterwards, the water is returned via an absorption well.
I would like to completely replace my existing heating system and use the heat pump in monovalent operating mode – i.e. as the only heat source in the house. This is also possible in existing buildings. However, in order for the heat pump to be able to cover all heating requirements, the house should have been modernised for energy efficiency beforehand: This includes that the heat exchangers (underfloor heating, steel panel radiators, bathroom and living room radiators) can be operated with a low-temperature heating system such as the heat pump. It is also important to properly insulate the roof, the exterior walls of the house and cellar, and the cellar ceiling, and to renovate the windows.
I would like to combine my existing heating system with a heat pump. This version is called bivalent operation. Here, too, it is generally beneficial if the building has been modernised for energy efficiency. There are two ways to add to the existing heating:
In the bivalent-alternative operating mode, the heat pump and the existing heating system alternate – depending on the outside temperature. In concrete terms, this means that the heat pump covers the entire heat demand up to a defined outside temperature, the so-called bivalence point. This is ideally between 2 °C and -6 °C. If the value falls below this, the existing heat source takes over the heating. Heat pump and existing heat source therefore do not operate simultaneously.
In the bivalent-parallel operating mode, both heat sources work together starting at a predefined outdoor temperature. It then looks like this: The heat pump takes over the heating load alone up to the defined bivalence value. Only when the outside temperature drops below this value does the second heat source switch on. The heat pump and the second heat source are designed in such a way that they cover the required heating load together during peak load.
I would like to use heat pump technology in my multi-family house and heat a total of 3–5 residential units with it. Is this possible and which heat pumps are suitable for an multi-family house?
Houses with several residential units have a greater heat demand and cooling demand than a single-family house Several heat pumps are needed to cover this higher demand. They can be connected together to form a common heating system (= cascading). Depending on the current requirements in the entire building, individual heat pumps can be switched on or off. This means that, all heat pumps are in operation during peak load, while fewer units operate when demand is lower.
The standard x-center x40 controller for Kermi heat pumps makes joint, coordinated control of several heat pumps together possible. At the same time, it sensibly integrates the corresponding heat storage units. The following heat pumps are suitable for cascade switching:
The topic of thermal comfort is really quite complicated and some of the terms used often need explaining. That is precisely when I can help you! As a real specialist, I am very familiar with all the system components and the way they work together, so I am able to explain these situations very clearly and in a way that is easy to understand.
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