Experiences with brine heat pump

So much do we two need in the summer just for hot water, if I extrapolate. A miracle how you do it.

The miracle is more likely how YOU do it. What is your consumption behavior like?

In fact, our hot water energy demand is also higher than what is reported in other experience reports. We do not get below 100 kWh of electricity per month in the summer, just for hot water. It is probably due to the rather wasteful lawyer shower, which nebulizes very finely and is therefore turned up quite warm. Hot water storage temperature 46 degrees as target, normally 2 cycles for hot water per day.

We have hot water at 50 degrees, circulation 8 hours a day. I am not really interested in consumption, comfort is the main thing.

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

Ground probe:
- factory-welded double-U probe(s) made of polyethylene PE-RC
- sealing 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, everything from a single source, documentation, including expert and all earth and connection work (including cellar core drilling)

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

Maybe you should get another offer from this company. Our boys were very satisfied anyway. But I don’t know if they drive to your area.

The price of a borehole mainly depends on the drilling depth and the substrate. This information is missing.

The scope of services shown is also not complete or outstanding. Apparently, no improved grouting material is used, otherwise this would be listed. 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.

Thanks for your hints, that already helps me a lot!: Attached are the further info: - Drilling sludge disposal, if not possible via sewer (flat rate +500 euros) - Backfill material is standard with a thermal conductivity of about 1 watt :-( - Bureaucratic processing etc. is all included.

As said: about 15,000 euros for 4.8kW (guaranteed). What do you think? I will definitely get more offers.

I still have another question regarding the design (I am really still a beginner on the topic, hope it’s not too stupid): 1. Topic heating load vs. probe size: Does the power of the probe have to exactly match the calculated heating load? Or slightly below? Or above? Do I have to add domestic hot water to the DIN heating load? 2. Concretely, we have a calculated heating load (DinEN 12831) of 5.1kW. Here, all basement rooms have already been deducted – but we want to heat 2 rooms. If I include these, I get 6.3kW. Additionally, we have a controlled ventilation system with heat recovery. If I apply 80% recovery of the ventilation heat losses here, I gain about 1.3kW. In total this is then 6.3kW - 1.3kW = 5kW heating load. If this is correct, my probe with a guaranteed 4.8kW output is somewhat undersized, right? (Gap of 0.2kW) 3. Would improved grouting material help me here? I read in a forum that this can achieve up to 10-15% more performance – then I would be safe? 4. The 6.1kW heat pump from Weishaupt (WWP S 6IDT-2) then fits well with this system, right? 5. Friends told me that an expert must additionally be paid who supervises the drilling – is that always the case?

So, for me, a flat rate for disposal (without sewer use) and better backfill material was included; I also predetermined the depth of the drilling (for a guaranteed performance it would be too vague for me – depending on how you calculate what the ground would allow, someone could also sell you a drilling that’s too short). I had it drilled a bit deeper, but the extra meters weren’t even that expensive overall. Now it seems a bit more expensive to me.

Sorry, I am now a bit confused myself: Regarding above: 4.8kW is the guaranteed cooling capacity - is this then also the total performance of the probe?
Regarding 5. it has been clarified: The expert is already included in the offer.