1. Why does the heat pump technology belong to the most promising solutions in the thermal care, in particular for buildings?

The heat pump technology makes possible to multiplicate the used energy typically around factor from 4 to 5 (energy = heat).

2. How does the heat pump technology enable the duplication of the used energy?

The used energy serves for the impulse of a process (cold process) which makes it possibly heat at deep, useless temperature level to win and to deliver at higher useful temperature level usable.

For the production of the heat at deep temperature level there are two different heat source. The heat source under 1. limits itself in special cases, the heat source under 2. is always accessible:

  • Rejected heat, e.g. from further air (recuperative heat),
  • Renewable heat of the sun (regenerative heat) from earth close to surface (immediately) or outside air (indirectly).

The energy used for the heat pump (impulse energy) converts itself also into usable heat and is in adition available at the higher temperature level. From 1 kilowatt of used energy e.g. 4 kilowatts originate of usable energy.

3. Which energy type is required for the impulse?

The so-called compression heat pump (works in every fridge) need mechanical impulse energy for which only the electromotive impulse come into question.  All other are wishful thinking of the practical feasibility.

4. Where does the engine energy come for the heat pump technology?

The low required power for the engine of the heat pump can be taken without exception in every house from the electric low-voltage net.

5. How is the electric care to be valued ecologically?

The electricity economy, in particular their base, the electronical integrated network, has an overriding civilisation meaning in the modern times. A considerable deficit of information rules over the meaning of the electric integrated network.

The historical beginning of the electric care was in many cases the application of hydroelectric power plants which also make even today an overriding care contribution.

Memory power stations cares in additional for the cover of the peak load. They can dam energy, store and provide when required undelayed.

Only by the electric integrated network it has become generally possible to convert renewable energy in bigger extent water power, wind strength or from photovoltaics constructions can be fed and be taken again from a place far away.

The electricity industry provides about the integrated network for the fact that the strong variations of the "harvest" are adjusted in renewable energy, as well as the day-temporal load changes by highly complicated controls and are balanced by conventional power stations as well as international cooperation any time undisturbed.

However, the data network is a beneficial civilisation wonderwork of immense magnitude and immense significance for the use of renewable energy.

6. Is the economic advantage of the heat pump technology depreciated ecologically?

Fact is, the electric energy from the integrated network already contains considerable shares of renewable energy, from water power, wind energy etc., G = 14%, I = 25%, A = 55%, CH = 57%, N = 100% etc.

7. Does the gas calorific value technology outclass ecologically the heat pump technology?

As a reference for a comparison the energy source gas is suited best of all:

  • The heating with gas calorific value technology reaches 93% of efficienc the electric WP impulse from a gas power station reaches 58% (without possibility of the optimisation by "close warmth care")

The ecological equalization arises from it by the values 0.93: Equalization passes 0.58 = 1.6, i.e. by heat pumps working number of 1.6. Today every current heat pump technology reaches far more than the double working number and is with it of the gas heating ecologically far consider.

The heat pump heating can cool what becomes more and more important in summer, almost free of charge with geothermal energy use, by return cooling with warm spring outside air. The gas calorific value technology does not offer these possibilities yet!

8. Does the increased application of the heat pump technology for the enlargement of the power station park lead?

This is not to be expected because heat pumps may be separated during the appearing brief electric load points from the net. Also the local authority districts plans today already the time after the nuclear energy use the construction of the gas power stations which are suited basically also for the close heat use.

9. Does the heat pump technology is also suited for other areas of the thermal building care.

The heat pump technology offers of course also the possibility of the drinking water heating and the pool heating.

10. How does the heat pump system solution look in an own home new building?

The system solution encloses the floor surface heating in all rooms. Our surface heating permits the lowest preliminary heat temperature and thereby achieves the conceivably highest annual work number.
The regulation occurs depending on the outside temperature supplementally through a pilot's space feeler. This solution means „Heat without visible technology“ with the highest conceivable aerial hygiene.
All current floor documents are suitable. Ceramics, marble, granite and stuck parquet are especially recommendable.

The system solution also encloses the hygienic drinking water warming with memory volume from 250 l.

The system solution encloses the cooling in summer – the almost free natural cooling is possible with geothermal energy use (Cost originate only from the engine of the circulating pumps) or from return cooling with Wärmquelle outside air.

The heating of the summer pool about a Wärmeaustauscher in the filter circulation is possible also.

11. .Does the insertion of the heat pump technology also make sense with existing buildings?

Yes here an intensive consultation should occur in addition. Besides, the solution optimum for the isolated case or mode of operation – bivalent, monovalent, monoenergetisch must be determined.

12. How do heat pumps compare to wood-fired heating?

Any other type of heating is inferior to a professionally dimensioned heat pump system solution in relation to maintenance as well as fuel management. In the long run, energy prices will continue to climb, if only for the fact that the earth's population increases by almost 40 million per year and that everyone wants to participate in the prosperity offered by energy. Due to the performance factor, the gap continues to widen in the area of heat pump technology.

13. Does the installation of the heat pump technology calculate itself with existing buildings?

Based on a good building substance and sound fuel-powered heating, retrofitting a heat pump for "bivalent" operation is often the most cost-effective solution.

In case of a complete renovation, the focus is on additional external thermal insulation and window renewal. After that, it is only a small step to low temperature heating, which allows the optimal heat pump operation.

14. Here is a technical refreshment of basic knowledge.

The unit for heat = energy is:

          Watt hour = Wh
          Kilowatt hour = kWh

The electrical energy consumed is indicated by the counter in kWh.

An older unit - today still used for food - is the calorie, cal or kilocalorie, Kcal.

Please note: when "calorie" is indicated on the packaging, it always refers to kilocalorie; there is no explanation for this.

An adult needs approx. between 1,500 to 2,000 kilocalories per day!

          860 kilocalories equal one kilowatt hour

The calorie is easy to illustrate: it is the amount of heat needed to increase the temperature of 1 kg of water by 1 degree Celsius (precisely from 14.5 to 15.5 °C).

Example: To heat up 10 kg (litres) of water from 14 °C to the boiling point of 100 °C requires 860 kilocalories, or 1 kWh.

What is the unit for power?

Power is measured in W or kW.

In the past, HP was used: 1 HP = 0.736 kW or 1 kW = 1.36 HP.

HP can be illustrated as follows: One HP equals the power needed to raise 75 kg over a distance of 1 meter in one second = 75 mkg/s.

15. Who plans, delivers and install the WATERKOTTE heat pump?

The heat pump heating is a system solution.

System solutions are characterised by the fact that they are made up of system groups and system components, which must be perfectly matched to one another.

A well known example is the system solution of the automobile (Ital. Machina), comprising motor, transmission, wheels, steering, brakes, etc.

If a system solution is to function, it must be set into motion. This requires the corresponding preparations.

The "automobile" system can only be set into motion for example, when it has been filled with all foreseen "fluids", cooling water with anti-freeze, engine and transmission oil, fuel, etc.

The heat pump heating is a comparable system solution.

For this reason, the preparation of the "heat pump heating" system solution belongs without fail in the hands of a qualified, specialist fitter or in the case of a project, in the hands of an experienced, specialist planner.

In order to ensure a high degree of quality, the WATERKOTTE manufacturer's program is supplied directly (two-stage) via the trained WATERKOTTE partner fitter, who is in a position to deliver the system solution and handle it completely or in the case of a project, via the tender drawn up by the specialist planner.

The heat pump system solution (an invention of our company founder Klemens Oskar Waterkotte, which was first introduced in 1969) mainly comprises:

  • heat source system,
  • heat pump heating center,
  • heat utilisation system for
    • thermal supply of the building
    • heat/cold,
    • drinking water heating and possibly pool heating,
  • installation of the hydraulic, electrical supplies,
  • installation of the heat reservoir / heat exchanger,
  • implementation of the automation.

In other words, success requires comprehensive solutions. It is a proven fact that the path chosen to becoming an installer - training / support / partnership - produces the best results, with annual performance factors for heating mode clearly above "five" when using ground source heating.

In the project area, success is subject to commissioning an experienced professional planner who receives information about the possibilities of the WATERKOTTE product range by the WATERKOTTE back office or by the WATERKOTTE Automation department.

Project handling embraces the following services:

Specialist consultancy with the customer / client and drafting a concept that is consistent with their requirements.

Calculation of the manufacturing costs and submission of a binding quotation.
In the project area, preparing simulation and feasibility calculations if required and preparing and processing the tender as well as taking over construction/site management if necessary.

Finalising and confirming a complete and detailed service contract with the client, based on the WATERKOTTE know-how and WATERKOTTE range of products.

Order processing, taking into account all rules of technology for achieving the optimum result in terms of comfort, durability, operational safety and efficiency by way of an optimum system solution.

Carrying out operational preparations by way of filling, purging and bleeding all systems.

Commissioning and trial operation.

Note: After manufacturing, every WATERKOTTE compact heat pump is tested for tightness, electrical safety (in accordance with EN 60335, incl. documentation of measurement), started up and subjected to a thorough trial operation.

All test results are recorded and saved as "birth certificate" under the manufacturing number in the electronic archive (can be retrieved at any time under the corresponding manufacturing number in case of doubt).

Familiarising the user and carrying out a mutual acceptance test.

Offering a service contract.

Undertaking to carry out the first service.

Customer requests:

Contact for obtaining a quotation can be made via:

Internet for national and international customers or

field service distribution partner, see Internet.

16. How does the WATERKOTTE "COP Counter" work?

The "COP Counter" is integrated in all WATERKOTTE fluid-water heat pumps as useful addition to the "energy saving control". The promised characteristics can thus be verified at any time.

The "COP Counter" is not available for heat pumps with continuous power control!

First off, an explanation of some terms:

  •         COP = Coefficient of performance = efficiency rate of heat pump.
    The English version of "Wikipedia" explains the term correctly!
  •          It contains the following equation for the efficiency rate of the heat pump: COP = QH / W = Coefficient of performance = performance facto

      - QH = heat supplied - (e.g. in Wh or kWh),

     - W = work consumed by the heat pump - (e.g. in Wh or kWh).

     COP is dimensionless, dimensions cancel out!

The designation "WATERKOTTE COP Counter" is a "specific term", identical with the English term COP!

Measurement with the "COP Counter" functions as follows:

The "Counter" records the measured values in one-second intervals for:

  1. heating performance generated
  2. electrical performance used,
  3. COP value as ratio from 1 a. 2.

(the performance is always indicated in kWh on the display)

Detailed function of the "COP Counter":

  1.      For every individual consumer such as space heating, domestic hot water production and pool heating, the measurement and recording is performed separately: - heating energy generated, - electrical energy used, - the resulting COP value. The consumption of the "source" pump is included; for this purpose, its power input is entered once at startup.
  2.       The recording commences at commissioning and is stored as recognised result for the first time on 31 December at 24:00 o'clock.
  3.        On the following day, 1 January, the measurement and recording starts anew at 0:00 o'clock. This provides the option to query the current results as well as the recognised results of the previous year.
  4.       The recording is always completed on 31 December at 24:00 o'clock and recorded anew as recognised result of the previous year. As already described, the measurement and recording start anew for the new year.
  5.       All recognised results of the past 9 years can be retrieved and used for a comparison.


In the course of a performance measurement at the quality seal test center "Vienna Arsenal", the measurement results of the "COP Counter" were compared to the ones of the calibrated test bench - the deviations were below 2 %!

We hope you enjoy working with the WATERKOTTE "COP Counter"!