1 °C higher flow temperature => 2.5 % higher running costs.

Note: Low-temperature heating systems (underfloor and wall heating) are therefore the most energy efficient.

At first glance, the investment costs for a heat pump are higher than those for a traditional heating system. Realistic examination of equipment plus development (connection) costs, maintenance, etc. shows a completely different picture.

Air/water heat pumps can be installed both outdoors (garden) and indoors. Brine/water heat pumps and water/water heat pumps require a frost-free installation room. As houses are increasingly being built without a cellar and our units produce heat extremely quietly, they are being installed more and more in utility and storage rooms.

The heat demand of the building must be matched, taking into account the hot water requirements and the off-times of the local power supply company.

The average life of a heat pump with normal use is between 15 and 20 years. Many heat pump systems have already been running problem-free for over 25 years.

The energy expenditure factor of heat generation is the reciprocal of the seasonal performance factor and can be calculated to DIN 4701/10.

The output and size of the circulation pump must be designed for the pressure loss of the pipe system. Speed-controlled circulation pumps may not be used.

Environmental heat from the air, ground or water is fed to the evaporator. There the heat collected is transferred to the working fluid of the heat pump (with lower boiling point). The working fluid changes into its vapour state. This vapour is then compressed in the compressor and heats up as a result. The vapour in the condenser then transfers its heat the water circuit of the heating system. This causes the still pressurised working fluid to liquefy once more.

The pressure is dissipated at the expansion valve and the heat pump cycle begins again.

There's no off-the-cuff answer to this question, it depends on the local circumstances.

Buffer storage (aka accumulator storage or thermal store) should always be integrated to prevent the heat pump from switching on and off during the transition period. .

To provide defrosting energy for air/water heat pumps.

Environmentally-friendly modernisation with a heat pump is possible in general. Our H series with 65 °C flow temperature enables operation by means of radiators. To ensure maximum efficiency, however, precise analysis of the building is necessary. If possible, you should check what flow temperature is actually required. Ideally the heating curve of the existing boiler should be adjusted downwards as far as possible 1 year in advance.

At the same time, the thermostatic valves in the reference rooms must be turned up to the highest setting. In many properties it has been found as a result that 55 °C was also sufficient.

If flow temperatures higher than 65 °C are required the building envelope should be insulated. In exceptional cases a heat pump is not a viable option.


There are no nationwide grants and loans. The heat pump has managed to establish itself on the market without major government subsidy. Nonetheless, the installation of heat pumps is rewarded in some federal states, especially for the modernisation of old heating systems. Regional energy supply companies too provide financial incentives for the installation of heat pumps. The KfW Bank (German government development bank) offers financial support in the form of low-interest loans.






There are no nationwide grants and subsidies. The federal states each have different schemes. Please ask your respective state (Land) government or your local tax office.


www.eva.ac.at (Austrian Energy Agency)


There are no nationwide grants and subsidies. The cantons each have different schemes. Please ask the environmental agency in your canton.

Sources: www.energie-schweiz.ch

There are two rough calculation methods:

  • one is DIN 4701/10
  • the other VDI Guidelines 4650


Yes, for an air/water heat pump

No, for brine/water & water/water heat pumps

At any time. A heat pump can be combined with all heat generators. The only question is whether it makes sense in energy terms. What is important is that it is integrated in the hydraulics to our specifications.

No. The air flow rate required for the heat pump is too high.

No. It's not necessary to add antifreeze to the system.

The heat pump controller has a frost monitoring function.

There is sufficient energy even in minus temperatures. The heat pump pumps this environmental energy to a higher temperature level so that it can be used for heating purposes.

Our air/water heat pump operates at an outdoor air temperature of as low as - 20 °C.

Borehole heat exchanger (vertical collector): approx. 30-50 euros / metre

(Horizontal) ground collector: approx. 15-20 euro / m2 (ready filled), subject to regional differences

Wells: approx. 100-150 euro / m

Air: least expensive option

Comparatively quiet compared to other heating systems. The new generation of Alpha-InnoTec heat pumps operate ultra-quietly due to innovative sound insulation. This predestines our heat pumps for installation on the living level too (utility or storage room).

Heat pumps draw 2/3 of the energy they need from the environment and have the greatest CO2 savings potential of all heating systems. If the electricity required to operate the compressor were to be supplied from renewable sources only (e.g. hydropower), the result would in principle be "zero emissions heating".