The lower the heating flow temperatures, the more efficiently a heat pump can be operated. The temperature difference between the source temperature (air) and the sink temperature (heating system) is decisive for its efficiency. However, not only underfloor heating systems, but also radiators can be operated at a comparatively low temperature, provided that a few points are checked or adjusted in advance. In the simplest case, nothing is changed to the flow temperature, as this is already low enough and all rooms have been supplied with sufficient room heating. In this case, all existing radiators can continue to be used without any problems. However, if the flow temperature should be lowered in order to increase the efficiency of the heat pump, the existing radiators, with the lower flow temperature, must provide the same heating output in the respective room as before. This is important because if the temperature in a radiator drops, the output of the radiator also drops. The radiators must therefore be checked for their heat output. This is to ensure that the room is as warm afterwards as it was before when operating with a heat pump. Every degree less in the flow temperature increases efficiency by around 2.5%. If one or more radiators are too small, check how they can be replaced by other radiators (wider, higher, thicker). The time and costs involved are comparatively low and the radiators in living areas, such as living rooms, are always tested first. Conclusion: Heat pumps can also be operated with radiators. Well planned, installed and adjusted, a heat pump can also be used efficiently and without any problems in old buildings.

A heat pump in combination with underfloor heating tends to consume slightly less electricity, as the flow temperatures for underfloor heating systems are lower (e.g. 35°C) than for classic radiator systems (55°C). The difference in energy consumption here is around 18%. If the radiator temperatures can be reduced to a maximum of 45°C in the course of modernisation, the difference is just 8%. Generally speaking, the energy costs are higher overall in old buildings than in new buildings due to the higher energy requirements. In terms of efficiency, the lowest possible flow temperatures are generally advantageous, even with an AEROTOP® SPK heat pump, which can deliver up to 70°C. Nevertheless, a heat pump system can be operated efficiently with radiators. The advantage here lies in the comparatively low modernisation costs, as either existing radiators can be left in place or they are comparatively easy to replace. Conclusion: If planned correctly, heat pumps can also be operated efficiently without underfloor heating. Although the electricity costs are somewhat higher, the modernisation costs are lower with the AEROTOP® SPK in old buildings.

As outside temperatures fall, a heat pump has to provide more power and the required flow temperature increases. At the same time, the output of the air-to-water heat pumps decreases because the energy content in the air decreases. When and how much output is required is therefore a question of planning and determining the right appliance size. If the output of a heat pump decreases when outside temperatures fall, the integrated electric heating insert can provide support. In terms of planning, this should amount to a maximum of 2 % of the annual heating energy and thus prevent electricity costs from spiralling out of control. In addition, depending on the region, extremely low temperatures often only occur for a few hours or days a year. The AEROTOP® SPK is the first choice for these particularly cold days of the year, as it can deliver up to 60°C in the flow at -20°C outside temperature. Conclusion: A heat pump can reliably supply heating energy even at extreme temperatures of -20°C, whereby the AEROTOP® SPK can even achieve flow temperatures of up to 60°C. With the right planning, an electric heating insert is only required for a few hours a year. This is because the heat pump works for the most part (75-90% of the time, depending on the location) at moderate outside temperatures between -5°C and +15°C. A heat pump can therefore also supply an existing building with heat without an additional gas or oil boiler.

A heat pump utilises physical correlations in the form of an elaborate cooling circuit to avoid burning fossil fuels. In addition, it utilises electricity as drive energy and contributes to an overall reduction in global CO2 emissions. The investment costs for a heat pump are higher compared to gas or oil burners. In order to at least partially cover these additional costs, the state generally supports the installation of the heat pump in the form of subsidies. A heat pump is no more expensive to operate than other types of heating, although the total costs also depend on the respective prices for the operating energy (electricity, gas, oil). If a heat pump is combined with a photovoltaic system and a battery storage unit, a large part of the operating power can be covered by the photovoltaic system and the network supply costs can be massively reduced. Conclusion: The investment in heat pump technology is subsidised by the state and is no more expensive to operate than other types of heating. In combination with a photovoltaic system, the heating energy supplied can even be cheaper than with fossil fuels.

ELCO is your partner for maintenance, service and repair. We usually install our appliances and repair them ourselves if necessary. As a leading service provider, ELCO has the broadest network of its own service technicians, who are there for you every day around the clock. Maintenance contracts with a term of up to 10 years give you the security of always being able to rely on your heating system. Conclusion: If you want to be sure, you can rely on ELCO and our excellent 24-hour service.