And what kind of heating system?

Geothermal energy provides cooling??? no no no...

But I think geothermal energy is very long-lasting... because if the inside of the earth no longer provides cold (which is heated by the heat pump), then there would be no more life on our planet, right?

Hello Florea,

no no no, you have completely misunderstood something - it’s called GeoTHERMAL energy, not Geo cooling :)

The earth inside - especially at a certain depth - is warmer than, for example, the outside temperature in winter.

A geothermal heat pump “taps” into this geothermal energy, this temperature difference to the outside temperature, and brings it into your house.

Please read here so you can see all the advantages and disadvantages:

A heat pump (geothermal heating) draws electricity from the grid and drives a compressor that extracts additional heat from the ground or groundwater. As a result, for one part of electricity, an additional 2 to 3 parts of free heat come from nature.

Advantages of geothermal heating

Low space requirement, no storage room necessary
(+) Absolutely safe operation
(+) Fully automatic, therefore very comfortable
(+) Low operating costs if the conditions are right
(+) Environmentally preferable to oil or often gas heating

Disadvantages of geothermal heating

(-) Economically viable only for well-insulated houses
(-) Investment costs are higher than other heating systems. Always make a total cost calculation.
(-) An electric heater is often additionally required in the bathroom to quickly heat it up
(-) An additional system is advantageous for hot water preparation, as the heat pump’s coefficient of performance significantly decreases when working at the higher temperature level needed for hot water. This causes additional costs.
(-) The ecological balance is worse than for pellet heating systems because in winter the electricity partly comes from fossil fuels
(-) Large garden area required (or expensive deep drilling)
(-) Maximum possible flow temperature is limited (approx. 60°C guideline). For radiator heating and poorly insulated buildings, this may be too low (so caution is advised when renewing heating systems without thermal renovation).
(-) Use of a heat pump as a hot water heat pump in addition to the existing (conventional) heating system: consider whether hot water production with the heating system (in winter) and a solar system (in summer) is more economical.

Conclusion: Expensive acquisition costs, only amortizes if the conditions are right for you, and you still have to add and pay for 1 part of electricity for every 2-3 parts of geothermal energy.

Also, no one guarantees that the spot drilled into the earth to extract heat will still be hot/warm enough in a few years to heat your house!

That means: it might need to be drilled again in a few years, which is very expensive, as you surely know.

Here is a link on the topic of heat pumps:
Heat pump, requirements for optimal operation

Here are the different types of heat pumps:
Heat pump, geothermal heating, heat sources

Here is an overview of different heating options, from oil to heat pump:
Energy carriers (geothermal, pellets, oil, natural gas, district heating,...)

All in all, for me personally - and also according to a specialist magazine from 2008 on heating, solar energy etc. - the combination of solar energy (for hot water preparation) with a stove that burns some kind of wood (firewood, wood chips or pellets, possibly also a combination stove pellets/wood chips) and can support not only heating but also hot water when solar is insufficient, is more economical for most people than the combo solar + heat pump.

Have both systems calculated for your individual house and energy needs. Because that varies depending on insulation and size of the house.

Weigh up pros and cons, such as running costs (including maintenance), and guarantee of durability (as mentioned, nobody guarantees that the geothermal source tapped remains as warm forever!), and how easy and expensive it is to repair a potentially broken part of the heating system you choose!

And what do you do if, as some do (for cost reasons), you live rather rurally or even in a city and there is another power outage? Then you can forget about your (quite electricity-demanding) heat pump and hopefully you have a large buffer tank to draw warm water from for a long time!

Or, as we plan, you have a mini combined heat and power plant for such emergencies that can produce emergency power.

For these deep drills, you usually also need permission from the city/municipality, which you might not always get due to groundwater or other reasons; if you want to use groundwater as a heat source, you especially need permission from them.

So, read everything thoroughly - the Austrian site is very informative anyway, so read it all :)

Best regards
Honigkuchen

That is all very interesting. We want to start building in the next few weeks and our architect is really pushing us to finally make a decision regarding the heating technology.

I have more or less concerns about all systems.

Geothermal heat pumps:
1. 150 to 200m deep drilling. If everyone does that, I don't know how good that is for our Earth.
2. It needs electricity

Heat pump:
Energy guzzler. 35 years ago, you were considered completely ridiculous if you heated with electricity.

Pellets:
Is wood really an endlessly renewable raw material? And then I wonder how pellet prices will develop in the future?

And last but not least: You need a cellar as big as the old oil cellars.

Sure, oil is a no-go. Maybe natural gas after all?

Thanks for your assessments.

Best regards

Simply making such a statement is difficult without knowing what kind of property you have, how the house is oriented, etc. Therefore, here are some basics about the options you mentioned. Please note that these systems partly influence your house planning and you may need to make changes accordingly.

Geothermal energy:

Basically, there are three ways to use geothermal energy: through geothermal probes, ground collectors, or energy baskets.
For the use of geothermal probes, it must be clarified in advance how many and how deep the drillings need to be; this is relevant for the costs.
Ground collectors or energy baskets are installed in your garden at about 1.2 meters depth. It is important that the garden is large enough and not shaded by buildings or planting. This means you can hardly afford more than a green lawn in your garden; a pond added later can be taboo.
Overall, the topic is relatively expensive; proper planning and quotes are mandatory to avoid the disaster of an apartment that does not get warm enough.
Sufficient space for the system technology and the buffer storage must be provided in the house.
Costs are difficult to estimate as they depend on the effort. Range: €10,000 – €20,000.

Solar:

Here it is important whether your house is properly oriented to use solar energy efficiently. A roof pitch of 45 degrees facing south is ideal; other constellations are less economical but can still provide a meaningful yield. A hot water and heating support system is conceivable; a complete coverage of the heating demand is not possible here.
Besides the required area on the roof, you also need a room for the system technology and the buffer storage, which you need with all systems.
Costs for a package for hot water preparation are around €4,000 for collectors, storage, and controls, e.g., from Viessmann, the Vitosol system.

Wood:

Certainly environmentally friendly, as wood is a renewable resource and climate-neutral. If you want to use wood in the form of pellets, this must be considered in the house planning. A chimney is required if you have not planned one yet. Furthermore, a sufficiently large storage room or an underground tank in the garden for the pellets as well as an appropriate space for the system technology must be considered. Costs are around €11,000 – €14,000 plus pellet tank and installation.
A wood stove is also possible but only suitable for supplementary heating. Chimney obligatory, but these are not approved everywhere due to the fine dust produced.

Gas:

Today, only modern gas condensing units are used, which do not require a chimney. Acquisition costs around €5,000, so super cheap compared to the other systems. The advantage of gas heating is the high supply quality, meaning if a lot of hot water is needed (guests) or the demand changes fundamentally (small children), this can be delivered reliably and cheaply.
A combination of gas heating with solar for hot water and heating support makes sense. Some manufacturers offer special combo solar systems for this, e.g., Buderus or Vaillant. Costs for Buderus or [B]Vaillant[/B] range from €7,000 – €14,000.

I recommend the website Initiative Erdgas pro Umwelt here. There you will find all the information and even a film explaining the technology to you.

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How can the specified primary energy limits be achieved in a larger house?

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Together with your planner (if he is able) or as a team with your planner and an energy consultant, you develop a concept for the house. In the first approach, the property is ideally insulated; in the second step, you then decide on a system concept based on user requirements. However, the main key figure is always the total available budget. From my point of view, it always applies here to rather make a decision against the expensive clinker, but a decision for the most economical heating system.

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In addition, we want to have an indoor pool. How should it be heated? Economic efficiency AND comfort factor are important to us?

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An own pool is of course a cost factor that is relevant and must be taken into account in a system concept. Especially against this background (I know many pools that were eventually shut down because of the costs), long-term management must be ensured. This can basically only be done by using solar energy. If the sun is absent or not sufficient, you ensure with gas that the pool is always warm. But even without an indoor pool, there are many reasons to choose a gas heating system with hot water preparation and heating assistance if you want to heat your house economically and comfortably.
Due to the pool, a larger buffer storage and a larger collector area are required. Because of the planned heating support, the required collector area then becomes quite large and must definitely be taken into account during planning.

Thank you for the great answer. I will pass this on to our paid professionals (architect, site manager, and structural engineer who handles the [Energieeinsparverordnung]). Let’s see what they say.

But such a technological approach was also what I estimated as best from many mosaic pieces.

Thank you

There are also water-bearing fireplaces that can support the hot water and heating......