Heat pumps for the energy-conscious

If you want to make yourself independent of expensive oil and gas, you are well off with a heat pump.

Heat pumps are a very interesting alternative to conventional heating systems. They make you relatively independent of the large energy suppliers and save a lot of energy costs.

The environmentally friendly heat pumps use the heat from the ambient air, the groundwater or the ground and provide hot water for heating and consumption all year round.

The principle of a heat pump is as simple as it is ingenious and also works at outside temperatures of down to -20 ° C.

The principle of a heat pump

Regardless of whether the heat pump uses the medium air, water or ground, it first extracts the heat stored there with the help of a heat exchanger system and raises the temperature to a usable level via a heat pump circuit. This makes use of the environmental energy that is available free of charge.

But electricity is also necessary to get the pump running. You should therefore expect around 25% external energy. If you want to produce this electricity in an environmentally friendly way, you can combine the heat pump wonderfully with a solar system and heat for absolutely free.

The physical principle used by the heat pump is called the Joule-Thomson effect. It is also used – exactly the other way around – in the refrigerator. But a heat pump can also be used for cooling with the appropriate equipment. More on that later. Now let’s first take a look at the different types of heat pumps.

Heat pump white

Three types of heat pumps

Depending on the medium used, there are air heat pumps, geothermal heat pumps and water heat pumps. The geothermal heat pumps from Stiebel Eltron are characterized, for example, by the fact that they use the heat stored in the ground through vertical or horizontal probes. In the case of horizontal use, the probes are distributed over a large area and twisted around the property, similar to underfloor heating.

Of course, this requires a correspondingly large property. The work required for this can also be done by hobby craftsmen themselves. If the plot size is insufficient, vertical probes have to be drilled deep into the ground. This usually requires a permit and an experienced specialist company.

This looks similar when using a water heat pump. Two wells have to be drilled here and permits have to be obtained. The groundwater has a temperature of 10 to 12 ° C all year round and is therefore an ideal source of energy. Even if the water heat pumps are among the most effective, they are not that widespread, as it must first be checked whether there is enough groundwater.

In contrast, air source heat pumps do not require any probes or wells. They simply suck in the ambient air, but they also generate a certain level of noise. The fan also requires some space and is not – like the other probes – hidden underground.

Using heat pumps effectively

In order to be able to use the heat pumps effectively, the home should be well insulated. This is the only way to avoid unnecessary heat losses. Since it can happen in particularly cold winters that a heat pump alone does not generate enough heat, a combination with other heating systems is beneficial.

Particularly interesting is a combination with solar thermal systems, which – unlike photovoltaic systems – are particularly cheap and can be easily installed on the roof.

A heat pump is usually sufficient for passive or zero-energy houses. An air-to-air heat pump can also be used here. It does not use a refrigerant to transfer the heat, but realizes the heat exchange from one air circuit directly to another.

In this way, the exhaust air heats the new fresh air and in buildings with controlled living space ventilation, hot water can even be heated in this way.

As mentioned, heat pumps can also be used for cooling in summer. With passive cooling, the cooler groundwater and soil are used, while active cooling simply reverses the process in the heat pump. Passive cooling can lower the temperature by around two to three degrees.

With active cooling, however, significantly more. However, this is also associated with considerable additional costs. In any case, the existing heating surfaces are used as cooling surfaces and thus lower the room temperature.

Heat pumps for the energy-conscious