Experiences with brine heat pump

Ring trench collector is an inexpensive alternative

Hi Lumpi, thanks for your answer. Unfortunately, none of the heating installers we asked have any experience with ring trench collectors, and we don’t have a very large plot of land. Doing it ourselves is hardly possible for us – we’re too clumsy and hardly have time due to work commitments. Or are there already specialized ring trench collector companies here?

@ It now depends on exactly what is being done / which material is used for the money (e.g. high conductivity of the filling). I would say, if high-quality material and a correspondingly deep drilling are involved, that it is not too expensive when comparing with my costs (further north), but from a few years ago.
I do not know what heat pump including installation means, but I would say the price is rather high here (the pump with storage costs half, so the question is what exactly installation means, what other services are included...)

Thank you Saruss for your initial assessment, here are some further details:

Erdsonde:
- factory-welded double U-probe(s) made of polyethylene PE-RC
- grouting of the annular space with marked frost and freeze-thaw resistant backfill material ascending from the probe base
- automatic monitoring of the sealing process in the borehole and documentation
- 10 years warranty on extraction performance, fully insured drilling, all from a single source, documentation, including expert and all earth and connection work (including basement core drilling)

Wärmepumpe:
Weishaupt WWP S 6 IDT-2, heating capacity 6.1kw, performance factor 4.8 with integrated 170l hot water storage tank. Also included in the offer: reference room controller, make-up unit, expansion vessels, valves/connection materials, labor time for installation and commissioning.

I will find out about the grouting material...

The price of a borehole is mainly determined by the drilling depth and the subsurface. These details are missing. The scope of services presented is also neither complete nor outstanding. Apparently, no improved grouting material is used, otherwise this would be stated. In an "all in" offer, I would also expect the disposal of the drilling sludge including container and fresh water consumption as well as the complete bureaucratic processing including the application for subsidies. The insurance, on the other hand, is nothing special and only requires a signature.

I know from personal experience that Nibe now works together with heating installers regarding the trench collector. They then completed the entire calculation for a friend of mine and also supervised the installation. With an excavator including a driver on an hourly basis, it was done in one Saturday. For a small plot, you will then need two days.

Otherwise, the only option is to obtain competing offers. I'm not very knowledgeable about heat pumps. It becomes problematic if the output is too high and it cannot modulate. You have a heating load of 4.8kw, but only at your standard outdoor temperature. Otherwise, it will be significantly lower. If the heat pump cannot modulate, it is constantly in on/off mode, which affects performance and durability.