heat pumps (8,898 offers*)

A heat pump takes heat from the ground, groundwater or air and transfers it to a heating system. The heat is absorbed either by a refrigerant that circulates in the heat source system or by fans that draw in warm outside air.
The refrigerant is evaporated with the help of the heat obtained in this way. This vapour is compressed in a compressor, which increases its temperature. A downstream heat exchanger, also known as a heat exchanger, extracts the heat back from the compressed vapour and transfers it to a storage system that supplies the heating or hot water system.
Some heat pumps can also reverse this process and draw heat from the rooms of the house, thus functioning as cooling or air conditioning.

Heat pumps are already very popular in new buildings, but the installation of a heat pump heating system is also possible in many old buildings, even with minor adjustments.
The decisive factor is that the heating system is designed for a low flow temperature so that a heating system modernisation using a heat pump is really worthwhile. Underfloor heating systems and heating systems such as radiators or radiators designed for a low flow temperature are particularly suitable for this purpose. In addition, the building must have good thermal insulation.
In general, geothermal or groundwater heat pumps are rarely installed in old buildings because they require expensive drilling. Air-to-water heat pumps, on the other hand, can be installed almost anywhere or integrated in a hybrid system with photovoltaics, a solar thermal system or a gas condensing boiler, for example, without having to carry out any renovation work.
A heat pump is particularly worthwhile in terms of its environmental friendliness and climate protection, as it emits little to no CO2 and also requires no flue gas system. Heat pumps require little maintenance and are very cost-effective to run. In this way, they help to make massive savings on heating costs.

The following table gives you an overview of heat pumps and the energies they use:
Type of heat pump
Primary energy source
Hot water heat pump
Indoor air
Air-to-water heat pump
Outside air and exhaust air
Ice energy storage
Air and geothermal heat
Brine-water heat pump (geothermal heat pump)
Heat from the ground (geothermal energy)
Water / water heat pump
Groundwater
Split air / water heat pump
Ambient air
You can find more information on this under "Different energy sources".

Air source heat pumps are not only ideal for use in detached houses, but also for apartment buildings. For these houses, you should calculate the hot water requirement precisely by adding 200 watts to the maximum number of people per household.
Depending on the residential building, living space and number of occupied apartments, the scalable output of the heat pump must be adjusted. In many cases it makes sense to install a cascade system, in which two or more heat generators are connected in parallel or in series. The advantage of a cascade is that optimum adaptation to the heat demand is guaranteed over the entire output range. In addition, a cascade solution leads to a high level of operational reliability, as in the event of a fault, each heating appliance in the circuit can take over the function of another.
In many apartment buildings, the total system output is often designed too large, which can lead to expensive follow-up costs. Therefore, a heat pump system must always be designed precisely to the actual heat requirement.

Since many suppliers offer technically almost identical solutions, it is worth comparing the prices for heat pumps on a kilowatt (kW) basis. There are therefore differences for each pool size.
Before you buy, you should know how large the pool heat pump needs to be in order to heat a certain volume of water or to generate the desired temperature efficiently. To calculate how big the pool heat pump needs to be to heat the water, you should know approximately how much heating work is required due to the weather and night-time cooling.
As a general rule, a pool heat pump should heat the pool water by about 0.20 to 0.25 degrees Celsius per hour. For a medium-sized pool with a capacity of 50 cubic metres (m³), the effective heating output is around 13 kilowatts (kW), which requires an operating time of around four to five hours per day. If a significantly lower operating time is required, the heating capacity of the pool heat pump would have to be correspondingly larger.

There is no rule of thumb for calculating the electricity costs, because several factors, some of which are variable and unpredictable, influence the actual consumption. It depends on how good the thermal insulation of the property is, how many people live in the household and what the personal heating behaviour is like. In addition, the type of heat pump system used and the climatic conditions and weather also play a role.
In operation, heat pumps generally impress with their extremely low energy consumption and therefore low costs - significantly less than the heating costs of a fossil fuel system. In addition, there are special heat pump electricity tariffs. The device can be excellently combined with photovoltaics, so that you can achieve even lower operating costs through the self-produced electricity and thus optimally benefit from the utilisation of solar thermal or solar energy.

The volume of a heat pump varies between 30 and 60 decibels (dB). On average, heat pumps produce noise of around 50 decibels, which is only slightly louder than refrigerators.
By way of comparison, 40 dB is equivalent to birdsong and a normal conversation volume is around 60 dB. So you don't have to worry about the heat pump emitting too loud a noise that could disturb you.

Outdoor installation is particularly popular for air-to-water heat pumps. So-called monobloc heat pumps are usually used for outdoor installation only.
With outdoor installation, there is a risk that the cold air that the heat pump blows outside after releasing the generated heat in the house is sucked back in. This effect reduces the efficiency of a heat pump, which is why you should make sure that the main wind direction does not blow in the direction of the discharge opening.
Also, the blower vents should be at a minimum distance from sidewalks and the patio, as the resulting draft can affect your comfort when in close proximity to the heat pump. As a general rule, the distance from the house should be kept as short as possible, because every additional metre increases heat losses via the heat pump's outdoor pipes. Otherwise, you can install your heat pump indoors in the traditional way in a utility room, cellar or similar.

You connect the heat pump to the hot and cold water pipes, so make sure you install the pump close to the connections.
The main components of a heat pump are the evaporator, compressor, condenser and expansion valve. These assemblies are connected to each other through piping and are also connected to the hot and cold water connections. In addition, a water drain is required for the condensation water so that no damage occurs as a result of moisture. Before commissioning, you must connect the heat pump to a 230-volt mains supply.
It is best to install the heat pump in cooperation with an expert, so that there are no unpleasant consequences and the device works properly in heat generation.

When the heat pump is installed, the installer sets the heating curve using a controller. In practice, however, this presetting must be adjusted during operation to the real heating and usage conditions in order to always generate only as much heat as the outside temperature requires. However, this is highly dependent on the building and the heating distribution system.
Basically, when adjusting the heat pump heating curve, you should try to set it as flat and low as possible. This is limited by the heating curve setting at which the heat provided by the heat pump is just sufficient to heat the house. In practice, you should take these tips to heart:
Individual changes to the heating curve should only ever deviate from the previous setting by a maximum of ten percent.
Select a mostly cold reference room to measure temperature changes in.
You should change the setting on cold days without intense sunlight.
Open the thermostatic valves in the reference room so that they do not throttle any heat surplus of the heat pump and falsify the measurement result.