Air pump more efficient than ground pump, noise disturbance?

Since I assumed that the technical terminology is correctly applied in this forum, here again is the definition of the term "heat demand" (not "energy"): heat demand (Qa in kW) = living area: A (in sqm) * specific heat demand QH (in kW/sqm) = kW (since today, however, as noted by Mr. €, it applies = heat (?) in kWh). To calculate the annual performance factor, it is advisable to calculate it using the COP of the refrigeration system; here, however, the wheat is separated from the chaff. With this, I say goodbye to this conversation with a smile, knowing that when it comes to repairing the refrigeration circuit of the heat pump, after all, a "layman" (refrigeration technician) will be called in to fix the system ... because he knows how to do it.

Since I assumed that the technical terminology is correctly applied in this forum, here again the definition of the term "Wärmebedarf" (not "energy"): Wärmebedarf (Qa in kW) = living area: A (in sqm) * specific heat demand QH (in kW/sqm) = kW

A professional should by now be aware that the incorrect term "Wärmebedarf" (DIN 4701) has been replaced for years by the precise term "Normheizlast" = power (DIN 12831) ;-)

best regards

Hello, regarding the additional price of 15,000 EUR you mentioned for a geothermal heat pump, that is quite within the range we have also been quoted by construction companies.
1. If you calculate with a demand of 15,000 kWh, for the geothermal heat pump at 600 EUR at 15 cents per kWh, an annual performance factor of 3.75 would result and for the air heat pump 3.125. Basically not far from any reality. However, I would expect a geothermal heat pump with probes to be significantly higher. Also, this electricity price assumes existing heat pump tariffs. Here with us, heat pump electricity would cost over 17 cents plus about 55 EUR additional basic charge per year and is absolutely not green.
2. In the municipality where we are buying our plot (the house is still in planning), you cannot just put an air heat pump anywhere. It is also about how much the noise could disturb the neighbors.
3. No. An air heat pump is completely inefficient at -20 °C outside temperature. In addition, with a heat pump with probes, the temperature is the same all year round in the depth from which the "temperature is extracted." In Berlin, this area is at about 20 to 30 meters depth. From here on, with every meter you drill deeper, the temperature is the same year-round and increases with depth. So it is relatively irrelevant to the geothermal heat pump whether it is -20 °C or +20 °C "above."
4. Basically, he is not advising incorrectly when he says there is shale; he does not recommend probes. Drilling would be very expensive here. According to the conversations we have had so far, an air heat pump costs more than 10,000 EUR less compared to geothermal with drilling. Since the drilling was not planned here, the 2,000 EUR can be within range. I really cannot judge.
Depending on the region you live in (we want to build near Berlin), I would never install an air heat pump because they become extremely inefficient at subzero temperatures and that is exactly when you need them (who heats in summer anyway).
But even the geothermal heat pump relativizes itself for us in the current planning again. We want to build sustainably and ecologically, but that should not come at the cost of living quality. In other words, if we spend tons of money on ecology, there will be no money left afterwards for, for example, a nice kitchen. We are not that "eco" after all.
Let’s assume the quoted 600 EUR for the geothermal heat pump compared to 1,200 EUR for gas would be correct. Then, with additional costs of 15,000 EUR, a simplified payback period of 25 years results! That, again simplified, assumes that gas and electricity prices rise at the same rate. But electricity prices (electricity is what the heat pump works with and the condensing boiler only needs a little) have risen significantly more. You can also be eco-friendly with gas; after all, there are biogas providers like sand by the sea (just like green electricity providers). Our current consideration therefore goes in the direction of a condensing boiler for support and a large solar system with a very large storage tank.
P.S. Why do I only refer to drilling above? In my opinion, investing in a geothermal heat pump only makes sense if you can also drill deep because otherwise the advantages are lost and the investment costs are still much higher than for an air heat pump. At a depth of 6 meters, it is simply colder in winter and therefore the heat pump is not as efficient as it could be.

Hello,

....Regarding 1. If you calculate with a demand of 15,000 kWh, the annual performance factor for the geothermal heat pump would be 3.75 at 600 EUR at 15 cents per kWh, and for the air heat pump 3.125.

The achievable annual performance factors for heat pumps result from the boundary parameters of the individual construction project, not from one’s own wished-for needs ;-)

....Regarding 3. No. An air heat pump is completely inefficient at -20 °C outside temperature.

A very one-sided view. The heating element share of well-planned air heat pump systems accounts for just 0.2 to max 2% of the annual heating work. Mostly trivial compared to the remaining 99.8 or 98%! ;-)

....In addition, with a heat pump using probes, the temperature "taken from" the depth remains the same all year round.

In milder climate locations, near-surface trench collectors are advantageous because they benefit more from solar radiation effects than one (or several) expensive vertical drillings, which can hardly or only very slightly participate in this.

...Depending on the region where you live (we want to build near Berlin), I would never install an air heat pump because they become extremely inefficient at subzero temperatures and that's exactly when you need them (who heats in summer?).

A misconception, as long as the annual balance is completely ignored!

... Our current idea therefore goes towards a condensing boiler as support and a large solar system with a very large storage.

If condensing gas boiler is set, I would forgo the solar thermal system (15% rule).
A solar thermal system is actually hardly economically viable for a "normal" single-family house. If you disagree, have a heat meter installed and compare the "actual harvest" with the additional investment for it – report here about the "success" of the measure! ;-)

... In my opinion, investing in a geothermal heat pump only makes sense if you can drill deep, ...

Completely wrong! Narrow or wider trench collectors are inexpensive (high self-performance ratio possible) and feasible.
Possibly lower efficiency is usually more than compensated by significantly lower investments.

Best regards,

NB: Tendency: The higher the actual demand for heating/hot water, the greater the requirements for the efficiency of the technical solution!

More factors must be considered with trench collectors than just the mere cost savings compared to deep drilling when it comes to the pure investment costs for installation. First of all, you need a sufficiently large plot of land. Large plots are logically more expensive, and you certainly wouldn't buy a larger plot just because of a shallow collector (exorbitant additional costs). If you have a large plot, it first needs to be free of trees. You cannot lay a collector under roots. Cutting down trees costs money, replanting costs money. An air heat pump, on the other hand, can be planned as well as possible, but you cannot plan for sub-zero temperatures, unless you massively oversize the air heat pump so that it can still operate at temperatures below zero. A 100% solar coverage is practically impossible; you are absolutely right about that. However, for half the additional investment of a geothermal heat pump, you can already achieve 40-50% (I am basing this on price quotes from providers). Gas, on the other hand, is significantly cheaper than electricity (which the heat pump requires) and is subject to less severe price increases. In addition, due to climate warming, it is actually becoming colder in northern Germany! This means air heat pumps will become even more inefficient in the future (how fast climate warming progresses cannot be predicted with certainty), and the same applies to geothermal energy to some extent. Solar systems, on the other hand, only need sun and even operate significantly more efficiently at low temperatures.

With trench collectors, more has to be considered than just the pure cost savings compared to deep drilling regarding the actual investment costs for installation. You first need a sufficiently large plot of land.

How big exactly?

...An air heat pump, on the other hand, can be perfectly planned, but you cannot plan for subzero temperatures,...

No, not against, but you plan in the respective climate parameters (AT curve)! ;-)

A 100% solar coverage is practically excluded, you are absolutely right about that. But for half the additional investment of a geothermal heat pump, you can already achieve 40-50% (I am referring here to the price quotes from the providers).

40...50% of what? Marketing hype or actual contract content? Then pin down the respective representatives to a definite kWh/a yield, that will hardly succeed for you due to well-known circumstances :-)

...Solar systems, on the other hand, only need sun and even work significantly more efficiently at low temperatures.

Which ones? Solar thermal system or photovoltaic? To what reliable results does this insight lead you?

Best regards.