Geothermal heat pump single-family house 200m² underfloor heating kfw55 - setting/optimization

1. At least at Stiebel Eltron, this is not very precise / tends to be optimistic. I assume it is no different with others. 4. You ignore the installation distances. 2l/min sent through 10m length and 1l/min sent through 100m pipe. Where is more thermal energy transferred? (With corresponding Delta T)

That is why I wrote that the "guided" liters are comparable in both rooms. By that I meant that the pipe length is similar in both and the diameter is definitely identical everywhere.

here is the heating load calculation.
I have not received more documents, except that the calculation was done for each room (I have only attached the utility room and the bathroom) and that the hydraulic balancing was included for each floor.
The fact that the external company was not on site at all and therefore there are "errors in it" is quickly evident from the fact that the attic is no longer "cold" as originally planned and calculated here, but included in the thermal envelope and partially open (meaning the area is heated together with the top floor - it is a kind of platform/gallery/loft bed). The additional bathroom radiator does not exist either. We had requested this as an option and initially decided against it. The connection in the heating circuit distributor is present but empty. We can no longer get pipes over there through the door. So only an electric heater would be an option there.

You just have to decide whether you want to use the comfort of an ERR or not. Even when using the ERR, a hydraulic balancing must be done. I myself also use the ERR; you just have to make sure that the minimum flow is always guaranteed if you don’t have a buffer tank. If you use the ERR, you will also achieve higher temperature differences between individual rooms. What is your total heating load?

you just have to decide whether you want to use the comfort of an ERR or not.

What comfort?

Even when using the ERR, a hydraulic balancing must be done.

Because then you don’t need an ERR anymore.

If you use the ERR, you will also achieve higher temperature differences between individual rooms.

For that, you don’t need an ERR. Just a properly planned and adjusted heating system.

Exactly at your last point, it fails in 99% of the cases. A calculation with VA 5cm for the bathroom is theoretically nice but often not feasible in practice due to bending radii, etc. Furthermore, the heating installer very, very often installs an oversized heat pump. I am currently seeing this with my brother-in-law, with a (not yet built) 170sqm Kfw55 house and a heating load of about 5kW. The heating installer wants to sell him a Vitocal with a capacity range of 5-11.6kW and blatantly lies to him when explaining the arguments for it. The 11.6kW include the heating rod blablabla. That guarantees cycling issues!

So I continue experimenting on my own and it is also taking shape. The pump currently runs twice daily for about 3 hours each time + once for about 30 minutes for hot water. I have a comfortable temperature in the rooms. The COP this month is almost 4.9 – and that even though I am really straining the flow temperature due to the low cycling frequency. With this, I should already be approaching 4 with the "annual performance factor since May 21" and would currently expect to end up above 4.3 after a whole year. And that includes consumption for the distribution of the heating output via underfloor heating in the house. The only possibly estimated value is the specified amount of heat that I read from the heat pump. No one can tell me so far whether it is standardized or calibrated. I suspect it is calculated from the increased temperature and I would consider it a reliable calculated value.

Now to my question: What about passive cooling + distribution thereof in the house? Are there any guidelines whether this should be included in the annual performance factor? That increases the COP in winter but lowers it in summer. It is to be expected that the annual performance factor will decrease.

Sooner or later I will add more heating output in both bathrooms through additional wall/ceiling heating. I hope to be able to lower the flow temperature significantly then. In addition, I will soon go to 3-6 cycles / lower the hysteresis and also lower the flow temperature a bit. Let’s see what that brings.