Feedback on heat pump / offer requested!

Hello everyone,

I would like to get your feedback on our offer for the heat pump and also on the groundwater heat pump in general.

Currently, we are planning to use groundwater as a heat source and have received the following offer, which includes the complete installation of the underfloor heating, connection of the heat pump... Only the drilling for the two wells would be additional.

Water Water Heat Pump Ochsner GMWW 11 plus
Ochsner separation tank PU800
Ochsner fresh water module
230 sqm underfloor heating including insulation
various small parts such as room thermostats etc.

The price is gross €30,100

What do you think, good offer? Groundwater heat pump sensible??

Google [ringgrabenkollektor].

Unfortunately, there is not enough space on our property for that. Only about 180 sqm of garden remain, and part of it will also not be built over.

Groundwater heat pump is the most efficient thing you can do.

Are you sure this is approvable with you? Do you have an idea how deep drilling needs to be?

What kind of building is this supposed to be? Any special features regarding the hot water demand? The system would be rather oversized for a single-family house new build with 230 sqm. Is there a heating load calculation?

What is the 800l storage tank for? Is someone trying to hook up solar thermal to a heat pump? That would be crazy. Ochsner states on the storage tank itself, 30l per kW. That would be 300l for you and not 800. And make sure it is not supposed to serve as a heating buffer as well.

Overall, starting from a single-family house with normal consumption, 5000€ would be too expensive for me. But that may be within the range of regional fluctuations – where are you building?

Storage is necessary for the fresh water station, can be done. However, storage should not be used as a buffer for the heating circuit.

Groundwater: the pump for the groundwater may consume a lot of electricity and reduce the otherwise probably good efficiency (if everything runs well). This can be avoided with the siphon principle.

The heat pump is certainly oversized. Is it at least modulating? Is the groundwater suitable?

The usual notes:
- no buffer storage
- plan surface heating for low (<=30°) flow temperature, check everything yourself
- individual room control must be deactivated at the latest upon moving in

I have already been in contact with the responsible water management office and a permit is not a problem, you would have to drill about 12 meters deep. I just wonder if it will be economical with the pump?

The heating engineer is working on the heating load calculation, I haven’t received it yet. The building is not KFW standard, it will be a solid brick house with 36.5 insulated MZ-70 bricks.

What do you mean by the € 5000,- or how do you come to this amount?

We are building in Bavaria, Landkreis Landsberg