because they draw around three quarters of their energy from the environment and only about one quarter – drive energy – is supplied by electricity.
Heat pumps primarily use energy sources with almost unlimited availability: heat from ambient air, groundwater or the ground. In addition, there are further heat sources such as waste heat from other processes, from sewage and many more besides. For detached and two-family houses, air, ground and groundwater are of primary interest. Extract air from the building is also suitable for DHW heat pumps . There are other heat sources which can be tapped, above all in industry, commerce and the residential housing sector. Which heat source is suitable in any specific case depends on the energy standard of the building, its geographical location and the site. In case of doubt, consult an expert, such as an OCHSNER system partner. More information can be found in the sections on Groundwater heat pumps, Ground source heat pumps and Air source heat pumps.
just in reverse. The basic principle governing heat pumps is always the same.
They generally operate just like a refrigerator. One end of the heat pump process generates cooling, the other end generates heat. This is very obvious in the case of a refrigerator. As the interior is cooled, heat is generated behind the refrigerator which is transferred to the ambient air. In a thermodynamic process, heat pumps make use of the fact that the temperature of certain refrigerants changes when they are put under pressure or allowed to expand. If pressure increases, the temperature rises as well. If the pressure decreases, it drops. Within the heat pump circuit, the refrigerant draws heat from the ground, groundwater or air until it has warmed to approximately the same temperature as these media. The liquid is then compressed in a compressor, which raises its temperature. At the other end of the process, this higher temperature is transferred to the heating system water or domestic hot water via heat exchangers. This causes the temperature of the compressed refrigerant to drop. The liquid is then relaxed, whereby the temperature falls further an dramatically – to a temperature significantly lower than the initial temperature. The decompressed, cooled liquid is then returned to the heat source – ground, groundwater or air – where it is heated, and the heat pump cycle of compression, heat transfer, decompression and cooling can start all over again.
In the heat pump process, external energy in the form of electricity is only required to operate the compressor and the circulation pumps for the refrigerant.
The ratio of electricity input to heat generated is around 4:1. This means that from one watt of electricity, 4 watts of heat are generated through environmental energy. The ratio of electricity to heat basically determines the efficiency of the heat pump. The key factors are the temperature of the heat source, the temperature differential between the heat source and the required heating temperature, the efficiency of heat transfer from the heat source to the refrigerant, and the efficiency of the heat pump process.
Constant heat source temperature level. As heat sources, groundwater and the ground generally achieve the best results, since they maintain a very constant temperature level.
Air as a heat source, however, is subject to stronger fluctuations, so that the level of efficiency can fall on cold days. On the one hand, the time and effort, and therefore costs, invested in drilling and pipework for ground and groundwater heat pumps are initially greater. On the other hand, a heat pump with air as the heat source is, by comparison, quick and simple to install, providing in many cases a very good, practicable alternative.
Small temperature differential between heat source and heating temperature
The temperature differential between heat source and the required heating temperature also has an influence on efficiency. The smaller the differential, the greater the system efficiency. Low temperature heating systems, such as underfloor or wall-embedded area heating systems, are therefore generally more favourable than radiators. Today, high efficiency OCHSNER heat pumps can generate flow temperatures for standard radiators or for domestic hot water at a very reasonable cost.
The transfer of heat from an environmental energy medium to the refrigerant should be effected with as little loss as possible.
With air as a heat source in particular, good results are achieved by modulating systems with variable speed fans. It is also important to be aware of noise emissions. More basic heat pumps can cause problems in residential areas. OCHSNER's R&D department is continually working on a whole host of detailed optimisations, upon which the efficiency of the heat pump process itself depends. The fact that OCHSNER heat pumps regularly achieve best results at the heat pump centre in Buchs, Switzerland, shows that the time spent on such developments really pays off. All of these factors, combined, are expressed in the important coefficient of performance (COP).
For almost 40 years, OCHSNER has been concentrating exclusively on the development and manufacture of highly efficient high end heat pumps. Every OCHSNER heating heat pump is manufactured specifically to your requirements using only high grade components. As part of commissioning, your system is adapted to suit your individual circumstances and conditions. To safeguard your investment in the long term, we recommend your heat pump is serviced regularly. This assures you of permanently low running costs, it extends the service life of your system and prevents possible faults.
On the safe side
In many respects you'll be on the safe side with OCHSNER. Heat pumps use free environmental energy – a heat source that never fails.
Furthermore, OCHSNER heat pumps are built to a high quality standard and are designed for a long service life. Not only is close attention paid during quality control at the factory, the correct installation of the entire system, which is carried out by our system partners, is also of critical value to us. Consequently, our quality control procedures also include the documentation of all system data. This data also forms the basis for OCHSNER's efficient customer service.
Benefit from our expertise and experience gained through decades of research, development and production at our site in Austria, and proven in over 130,000 installed systems.
Heat pumps are suitable for new build as well as modernisation projects. Regardless of whether your building has underfloor heating, wall-embedded heating or radiators – OCHSNER was the first manufacturer, many years ago, to launch a range of heat pumps with flow temperatures of up to 65 °C, now extended to 68 °C through the latest developments. Operation of existing heating systems with conventional radiators is now possible.
The efficiency values of an OCHSNER heat pump will help you to reduce the total outlay of building and system technology right now. Using OCHSNER high efficiency heat pumps, you will have no problem meeting applicable standards and building regulations (EnEV, KfW Haus [German reconstruction credit institute], energy performance certificate, etc.). And this with no investment in thermal insulation or system technology. Savings achieved in the reference building according to DIN 18599 amount to several thousand euros, for example. The significantly better performance data achieved by OCHSNER, compared to standard values, also provide a basis for improving energy performance certificate values (CO2 reduction and primary energy demand).