ᐅ Is a brine-to-water heat pump still worthwhile for a KfW 40+ energy standard building?

hampshire schrieb:

In the long run, energy will become cheaper again. The transition period right now is simply expensive.
(Please don’t generalize from energy to other resources – some things will just remain scarce and costly...)

Fun fact: the total global energy demand across all sectors — basically everything — equals the solar energy hitting the Earth in 90 minutes. If we add the current agricultural land used for "energy crops" (biodiesel rapeseed, biogas maize, etc.) and put some wind turbines on it, an hour might be enough.

hampshire schrieb:

That calls for a smiling face. Ignoring economic viability is a daily human habit.
...
Enjoy the lack of an outdoor unit – I find decisions like that practical in real life, at least in private homes.

I’m personally happy about it too! I don’t know if @009_frank finds the missing economic viability just as pleasing. If yes: go for it – there’s nothing better than a 140m (460 ft) deep hole in front of the house.

Benutzer200 schrieb:

But in a standard house, with a price increase of €5,000, you are already far from an economically sensible decision.

- If the brine-to-water heat pump lasts longer due to fewer moving parts exposed to weather and requires less maintenance, this should also be taken into account.
- You are only considering the initial investment. Every system will eventually need to be replaced. Some can continue to use the heat source, while others will have to invest in a new one.
- Appearance and noise level also have value.
- Possible subsidies or grants may apply.

It strongly depends on the location and whether you receive reasonable offers.

Hangman schrieb:

Fun fact: the total global energy demand of all sectors, basically everything

The phrase "of one year" is missing here. 😉

For surface collectors, keep in mind that vegetation can cause problems and, in any case, no sealing or covering of the ground is allowed.

In your case, I would recommend going for an air-to-water heat pump and investing in photovoltaic panels instead. For systems over 40 kW, there is usually a storage unit included as well. Compare offers to ensure the storage system is cost-effective.

Photovoltaic systems pay off quickly on their own, storage is affordable with subsidies, and your air-to-water heat pump can easily handle the heating load.

guckuck2 schrieb:

- If the ground-source heat pump lasts longer due to fewer moving parts exposed to weather and requires less maintenance, that should also be taken into account.

Which moving parts and less maintenance? The basic principle of both heat pumps is identical, and the maintenance effort is the same.

guckuck2 schrieb:

- You are also only thinking about the initial investment. Every system will need to be replaced at some point. Some can continue to use the heat source, while others have to reinvest in one.

It’s about time a gas supporter comes along and says, ALL heat pumps don’t last long anyway 😉. By the way, if the borehole as a heat source is depleted, the ground-source heat pump is actually at a disadvantage... Good that you mentioned that. It’s definitely something to keep in mind.
And no, I do consider when the investment pays off. And in case of doubt, I just install a new air-to-water heat pump if the old one fails. Then I spend another several thousand euros and still come out cheaper over time (and with a brand new unit).

guckuck2 schrieb:

- Appearance and noise level are also valuable factors.

Undisputed.

guckuck2 schrieb:

- Subsidies might also be applicable.

Is the ground-source heat pump really supported significantly better than the air-to-water heat pump?

Wassermann schrieb:

When considering ground collectors, keep in mind that plants can cause problems and, in any case, nothing should be sealed over.

In your case, I would recommend going for an air-to-water heat pump and investing in photovoltaic panels instead. For systems over 40°C (104°F), a storage tank is usually included. Compare offers to make sure the storage system is cost-effective.

Photovoltaic systems generally pay off quickly, storage tanks are affordable with available subsidies, and your air-to-water heat pump will easily handle the heating demand.

That's true, I hadn’t thought about that. We will actually have photovoltaic panels on the roof plus a ventilation system with heat recovery. And this is for a household of two people. I can definitely imagine that a ground-source heat pump might no longer be worth it in our case.