About Heat Pumps

Air / water heat pumps

Heat pumps do not cause air pollution due to nitrogen oxides (NOX), fine dust, and carbon monoxide and dioxides. They are the most environmentally-friendly alternative to the combustion of gas or oil. The installation effort of a heat pump is usually much lower than with a gas or oil heater, the latter with tank bearings.
Heat pumps remove energy from outside air and, in simple terms, convert these into hot water. This conversion process takes place under the use of electrical energy, whereby from 20% electrical energy expenditure 100% heat energy can arise. This is documented with high COP values ​​(e.g., COP 5.1 = 1 kW effort for 5.1 kW yield), but these are only valid under this one climatic condition, in Summer temperatures in which a heating up to the production of hot process water is unnecessary.
The energy gain is dependent on the temperature of the outside air, i. the higher the outside temperature, the higher the energy gain. If the air temperature drops, and this is the case in winter, the energy gain decreases, which means that for 100% heat energy gain, the electrical energy consumption increases quite considerably. At -10 ° C air temperature is no longer a COP of 5.1 sometimes only 1.2. depend to the heat pump installed technic.
Since the period of relatively low outdoor temperatures in the winter months is narrowly limited in Central European latitudes, air / water heat pumps still operate on average with good energy-saving values, especially when solar radiators can provide additional heat energy on sunny days.
If a storage tank is used, the production of hot process water is also included.
Room heating by means of floor radiators (floor heating) with a heat pump is particularly recommended because of the low water temperatures, but cooling with cold water is only possible to a limited extent because of the risk of condensation, possibly with water temperatures above 17 ° C. It should be noted that cold air is heavier and convection from the ground hardly takes place.
For reasons of high heat pump performance, it is not recommended to install the heat pump in a closed place outside the building.
In recent years, the technical development has tried to counteract this situation with new ideas, components and energy sources in the machine itself and to increase the efficiency of the heat pump, so that even in cold temperature periods of the year there is sufficient energy gain.
Another problem is and was the achievable water temperature necessary for heat transfer of radiator heaters in order to make the heat pump compliant with fossil fuel heaters for this application. Achievable water temperatures of 60 ° C. at most 65 ° C. were the previous limit and this is still at an unsatisfactory efficiency energy expenditure.
The new HRC 70 is capable of generating a water temperature of 70 ° C for the first time in heat pumps and thus exceeds the economic viability of previous energy generators with fossil fuels in terms of energy consumption.

Reversible air / water heat pumps

With a suitably technical device, a heat pump - as reversible - can produce both hot water and cold water. This means HOT WATER for heating in winter and COLD WATER for cooling in the hot summer months. However, it is not possible to transfer both these together with conventional radiators, since the operation with cold water leads to the condensation of the atmosphere and the radiotransporters. On the other hand, cold air is heavier and is not distributed in the room. For this purpose, fan coil units can be used which can be used both for heating and cooling. An electronic control ensures a constant room temperature. Condensate during cooling is collected in a container and discharged via a hose line.
Reversible air / water heat pumps have a technically complex additional installation and can produce both hot and cold water. This makes the process in the machine reversible so that the outside air is additionally heated, which is available on the water side as cold water. The economic limit in this case is an outside air temperature of plus 45 ° C. In this case, the effort and the yield are indicated as 1: 1,2 - 1: 1,5 as an EER value in the technical data of the machine. High COP or EER values ​​are therefore always related to quite favorable outside temperature values. It is recommended to observe the reference temperatures of the air.
The heat pump supplies hot water up to 60 ° C for heating and the installation of a suitable storage tank allows the preparation of hot drinking water, unless an existing tank already exists in an existing installation. If the heat pump is operated parallel to an existing boiler, both heating circuits must be fitted with a non-return valve in order to prevent the boiler from receiving hot water from the heat pump circuit or vice versa.
In the cooling mode, the heat pump delivers cold water of 7 ° C with an outside temperature of + 32 ° C. Standard radiators are not suitable for this because of dehumidification and lack of air circulation. Instead of this, it is best to use fan coil units with electronic room temperature control, which can also be used for heating in any case.


Water (brine) / water heat pumps

Are basically monoblock devices and evacuate energy from the water of a deep-water fountain or a geothermal heat exchanger. The available water temperature of the deep-water fountain or of a geothermal heat exchanger is usually the same, so these systems work with a high efficiency, ie. low electrical energy expenditure but high thermal energy gain. The disadvantage is the high cost-intensive installation work of the water circuit, which is usually dispensed with as a result of the long amortization period. Deep well bores are usually notifiable and are rarely allowed, also because the drainage of the waste water from the heat pump into the sewage system to the sewage treatment plant is not permissible.

Water / water heat pumps can also be reversible if they have an additional installation.