How it works at a glance
The basic principle of a heat pump is based on a closed refrigeration circuit with an evaporator, compressor, condenser and expansion valve. In the evaporator, the liquid refrigerant absorbs heat from the environment and evaporates. The evaporation process occurs at low temperature. The compressor then increases the pressure and thus the temperature of the gaseous refrigerant. In the condenser, the hot gas gives off its heat to the heating system and condenses back into a liquid before it is expanded and cooled and fed back to the evaporator through the expansion valve.
The efficiency of a heat pump is often described by the annual performance factor or seasonal performance factor, which reflects the ratio of heating energy delivered to electrical energy used over a longer period of time. This key figure depends heavily on the difference between the source and system temperature, on the control and the design of the system.
Types of heat pumps
There are different types that differ depending on the heat source used: air-water heat pumps extract energy from the outside air, ground-water heat pumps use geothermal probes or Surface collectors and water-water heat pumps rely on groundwater. Each design has specific advantages and disadvantages in terms of installation effort, costs, efficiency and space requirements.
Air-water systems are often cheaper to purchase and easier to retrofit, but have lower performance figures at very low outside temperatures. Ground and water-based systems tend to be more efficient and stable in their output, but require more extensive earthworks or access to groundwater as well as appropriate permits.
Areas of application and possible combinations
Heat pumps are suitable for residential buildings, multi-family houses, office and commercial properties as well as for industrial applications for process heat, provided the temperature requirements are suitable. Heat pumps harmonize particularly well with low-temperature heating surfaces such as underfloor or wall heating and, together with photovoltaics, offer a sustainable and cost-efficient energy supply.
To increase flexibility, heat pumps can be combined with additional heat storage, hybrid solutions with existing gas or oil boilers and intelligent controls. Such hybrid systems enable optimized use of various energy sources and can contribute to grid stability by shifting load peaks.
Advantages of heat pumps
Heat pumps offer high levels of efficiency and can significantly reduce CO2 emissions, especially if the electricity used comes from renewable sources. They work on site with zero emissions, require less fossil fuels and reduce heating costs in the long term if planned and operated sensibly. In addition, modern heat pumps often also offer a cooling function, which provides additional comfort in warmer months.
Other advantages include low maintenance requirements compared to combustion systems, the possibility of combining with solar power and the often available support programs that reduce investment costs. Thanks to advances in control technology, many systems are very user-friendly and can be integrated into smart home environments.
Disadvantages and limitations
Despite many advantages, there are also limitations: The initial investment can be higher than for classic boilers, and the economic viability depends on local conditions, electricity prices and government subsidies.Air-water heat pumps can be less efficient at very low outside temperatures and may require additions or special designs of the heating surfaces.
In addition, excavation work for underground systems involves additional effort, and water-water systems require hydrogeological tests and permits. In old buildings with high flow temperatures, additional measures such as improving the building envelope or larger heating surfaces are often necessary to ensure the efficiency of a heat pump.
Economy, costs and funding options
The costs for a heat pump consist of the system price, installation, possible earthworks, hydraulic integration and control technology. In the long term, the system pays for itself through lower operating costs, especially if the electricity mix contains renewable sources or if your own photovoltaic systems supply electricity. Relevant factors are the annual performance factor, the running times and the local price development for electricity and fossil fuels.
In many regions there are government support programs, low-interest loans or grants that make the investment significantly more attractive. These subsidies are often linked to efficiency requirements, integration into a renovation concept or to specific CO2 reduction targets. Careful advice and examination of the funding conditions saves costs and ensures optimal use of funds.
Sizing and planning
Professional dimensioning is crucial for the efficiency and longevity of a heat pump. The heat requirements of the building, the desired flow temperatures, the type of heat source and the operating times are taken into account. Oversizing leads to frequent cycles and lower efficiency, undersizing leads to loss of comfort and additional operation of reserve heaters.
When planning, thermal storage, hydraulic switches, suitable buffer storage and the integration of hot water storage should be taken into account. In addition, the local conditions such as the area of land for collectors, the condition of the soil or the availability of groundwater are important key points that significantly influence the selection and design.
Installation and commissioning
The installation of a heat pump requires qualified specialist companies who have mastered both cooling and heating technology. In addition to setting up the heat pump generation and connecting it to the heating system, the tasks include laying geothermal collectors, drilling holes for probes, connecting to groundwater extraction points and setting up the control and safety devices. A professional electrical connection and hydraulic installation ensures safe and efficient operation.
Commissioning includes pressure and leak tests, filling the refrigeration circuit, adjusting the hydraulic components and fine-tuning the control system. It is advisable to give the building owner detailed instructions on operation and maintenance in order to optimize operation and identify possible faults at an early stage.
Maintenance and service life
Regular maintenance extends the service life and maintains the efficiency of a heat pump. Typical maintenance work includes checking the refrigeration circuit, cleaning air or geothermal components, checking pumps, valves and electrical connections, and adapting the control to changing needs. Service intervals should be adhered to according to the manufacturer's instructions.
The average lifespan of modern heat pumps is 15 to 25 years for well-planned systems, and often even longer with good maintenance.Replacement of wear parts, updates to the control software and occasional refills or repairs are part of the usual maintenance cycle and are often cheaper than constantly replacing a combustion heater.
Comfort, control and smart home integration
Modern heat pumps come with sophisticated controls that efficiently control room temperatures, hot water preparation and operating times. Comfort functions such as weather forecast-based control, time programs, remote diagnostics and automatic modes increase energy efficiency and user comfort. Many systems offer interfaces to smart home platforms and enable intelligent load control for the use of self-generated electricity.
Through networking, heat pumps can be integrated into energy management systems that optimize energy flows, avoid load peaks and maximize the self-consumption of photovoltaic systems. Such control approaches contribute to reducing operating costs and stabilizing the power grid through flexible load control.
Environmental aspects and sustainability
Heat pumps contribute to the reduction of local CO2 emissions because they do not have any combustion processes at the place of use. However, the ecological balance depends heavily on the electricity mix used: If the heat pump is operated with electricity from renewable energies, the climate impact is particularly favorable. Furthermore, the selection of environmentally friendly refrigerants and proper disposal are important aspects for sustainability.
When assessing the environmental impact, the entire chain must also be considered, i.e. production, transport, operation and disposal. Efficient planning, the use of renewable energies and a long service life of the system are central factors in maximizing the ecological advantage compared to fossil heating systems.
Purchasing advice and selection criteria
When buying a heat pump, you should pay attention to tested performance data, the annual performance factor, references from the manufacturer, warranty conditions and the quality of customer service. Independent energy advice on site helps to select the right system according to the heat requirement, the heating system and the local conditions. Compare offers not only based on purchase price, but also based on expected operating costs and funding opportunities.
It is also important to select an experienced installation company who will take care of the entire system integration and provide detailed documentation. Good advice takes future developments into account, such as possible retrofitting with photovoltaics or expansion into a neighborhood concept, and ensures the long-term profitability of the investment.
Frequently asked questions and answers
Many interested parties ask about noise emissions, funding options, compatibility with old buildings and repayment times. In principle, modern devices have become quieter, especially units installed indoors; Nevertheless, the choice of location and noise insulation should be taken into account when planning. Funding programs are regularly adjusted, so it's worth getting up-to-date advice. In old buildings, measures to reduce flow temperatures can be useful in order to improve efficiency.
There is no general answer to amortization, as it depends on individual factors. A practical approach is to simulate various scenarios with current energy prices, subsidies and planned usage behavior. Specialist companies and energy consultants provide support with reliable calculations and concrete recommendations.
