Air heat pump vs geothermal energy, new build 400m2

- even without it, it surprisingly takes very little time for warm water to come...

That I get to read that again Here so much is philosophized about saving potential through sophisticated settings on the weekend; but nobody talks about the fact that a circulation line (unnecessary, in my view) takes back a lot of that saving. Rhineland greetings

Circulation pipe

It’s not really needed in standard single-family houses, is it? I only know our house (without circulation), but I thought it was more common not to have circulation. Is it different?

Well, it always depends on the route - our parents' bathroom & the basement bathroom are quite directly connected - the kitchen and the children's bathroom are not. You notice it there again, but in my opinion, it doesn't bother me much.

Cost-wise, it was not worth mentioning, but afterwards, it’s all the more annoying to be upset about something missing. That's why I definitely wanted to have a circulation pump .

The pump hardly consumes any electricity, but the heat loss is noticeable - so I will also take another look at how to set it up optimally.

At least in my circle of acquaintances, I know almost exclusively houses with a circulation pump - my parents don't have it and you really wait a long time for warm water.

You don’t need it at all in standard single-family houses, do you?

Correct, because the pipe routes are consistently kept short.

I only know our house (without circulation), but I thought it was more common not to have circulation. Is that different?

The rumor still stubbornly persists these days that the water runs for "several" minutes before warm water comes out of the tap. This is similar to the assumption of many home builders that drywall has worse sound insulation than 11.5 cm interior walls made of a solid building material.

Rhenish regards

we have no circulation and it is limited.. so it is not ad hoc, but about ~ 7-10 seconds, I would say (denser tapping points earlier)

First of all, many thanks for the many responses and the discussion. (Unfortunately, I have not received any notification emails from the forum and did not expect so much feedback and only saw it now).

To answer a few questions:

- I have now received the heat load calculation, but I am a bit skeptical. It is a simplified calculation according to "DIN EN 12831 Beiblatt 2 2012-05," which results in 0.06 kW/sqm and 18.28 kW heating load (which, according to my probably too simply thought-out number juggling, should be a calculation for 18.28/0.06 = 304 sqm?). I currently cannot fully understand it but have to sit down and ask the energy consultant about it tomorrow, just a bit late now.

- Regarding the "sustainability question": Yes, it is a large house and planned for two families (so not "families" directly, as it is one family but currently two generations, with a third one coming). Even for that, it is still quite large, that's true. Nevertheless, that does not mean all other sustainability considerations are thrown overboard because of that.

- About the question with "drilling over 400 meters": I naturally meant the total length in meters - e.g., 5 drillings of 80 meters each are planned.

- I have now also learned in a conversation with the heating technology company why the cost difference between air heat pumps and geothermal energy is so high: It is because this really high number of drilling meters must be reached, as in Berlin the benchmark for extraction performance from the ground in the area where we are building is 35W/drilling meter. This is specified as a guideline by the state and must not be (significantly) exceeded. In Brandenburg, for example, this is not the case, and a higher extraction performance can be planned so that there only 3 drills would have to be done instead of 5, which would of course reduce costs.

- However, if the heating system is oversized, then perhaps in Berlin one drilling less could be sufficient, which should reduce the absolute price difference.

That's it for now. Thanks again for your responses!