Geothermal heat pump trench collector or ground probe

Hello,
I have already received great help here in the forum and am currently a bit overwhelmed.
To the basic data. Kfw55 house with 130 sqm living space, 1.5 floors.
The property has a south/west orientation with 599 sqm. 22.8m x 26m.
Ht (transmission) = 0.2345, A (envelope area) = 381, Ve (heated volume) = 471.
4-person household.
My calculated heating load should be about 4300 kWh, the data from the heating company are not yet available to me.

Soil survey topsoil up to 0.3m, silty fine sand SU 3-4 up to 0.6m and glacial moraine SU 4, UL, very moist at 7m.

Planned was a geothermal heat pump with brine probe. The builder now says that 2 drillings of 60m each are necessary. These are additional costs, whereas surface collectors would be free instead.
For me, probably only trench collectors would be an option, since I would like to have 2-3 trees and a vegetable garden. According to neighbors, a hedge is mandatory in the area.

1. Now I have heard that the deep probe is no longer considered so good and a surface collector, trench collector is more efficient because it does not require a circulation pump.

2. Are 2 drillings of 60m each necessary?

3. Can you recommend a heat pump manufacturer? The construction company probably wants a Vaillant flexoCompat, etc. I tend to Nibe F1155.

4. If collectors, is a tree with 2m distance okay or is a hedge directly above possible?

Thank you very much in advance for your help
Best regards David

P.s. A rough sketch from me with trench collectors as an example.

We spoke with the builder today. Unfortunately, since we are tied to the builder, he gives us no room for negotiation. We can either choose a Vaillant ground source heat pump with 2 boreholes of 50-60m each for €12,000 more or an air-to-water heat pump. The builder wanted to impose a Rotex on us, but we were able to persuade him to accept a few alternatives, such as Nibe, Vaillant, etc. We most likely will not be able to get the Panasonic Geisha. We are somewhat frustrated that we are so dependent on the builder. We would be grateful for suggestions regarding the air-to-water heat pump.

We spoke with the developer today. Unfortunately, since we are bound to the developer, they leave us no room for maneuver. We can either take a Vaillant brine/heat pump with 2 boreholes of 50-60m each for €12,000 more or an air/water heat pump. The developer wanted to force a Rotex on us, but we managed to persuade him to accept a few proposals such as Nibe, Vaillant, etc. We will most likely not be able to get the Panasonic Geisha.

We are a bit frustrated that we are so dependent on the developer. We would be grateful for suggestions regarding the air/water heat pump.

Hi, how did it turn out for you – I am also still looking for information on this as well as specifically on the trench collector.

I have a 90m borehole, which is dimensioned for 4kW cooling capacity (45W/m).

Your actual heating load should be below 4kW, even if you assume 4.3kW, you are at a cooling capacity of ~3.4kW, which is still oversized for a 90m borehole.

2x 60m boreholes is brainless, unless you are not allowed to go deeper than 60m.
For the heating load, as you already mentioned, the Nibe F1x55-6 would fit.

(In the next few weeks, the F1255-6PC will be installed at my place)

My heating load according to DIN EN 12831 is 3.2kW + domestic hot water (0.4kW) = 3.6kW. The planner said the actual heating load would rather be below 3kW, but because of the heating load calculation according to DIN, he comes up with an Ht of 0.2 due to some general surcharges.

According to the energy certificate (with detailed thermal bridge calculation), my Ht is 0.185.
Ve = 722m³
A = 504m²
An = 231m²
KfW40

We talked to the builder today. Unfortunately, since we are bound to the builder, they do not give us any leeway.

Why ???

1. Now I heard that the deep probe is no longer supposed to be that good and a surface collector, trench collector is more efficient, because it doesn’t need a circulation pump.

I don’t know where you got that information from, but why should the horizontal trench collector not need a circulation pump?
It needs it just like a deep borehole.
The near-surface collector is more effective for domestic hot water in summer, but in deep winter not as effective as a borehole.

For these reasons, I didn’t want a collector:
-no own work possible, thus no savings
-design freedom / conflict with other pipes

Therefore, I spent a one-time 5000€ and have practically lost nothing in the garden and hopefully have peace and constant temperatures for the next 40 years.