Experiences with brine heat pump

42,000 kWh of generated heat and only 6,600 kWh of electricity consumption for it can hardly be true.
That would be an average annual performance factor of 6.6.
Common for ground source heat pumps is 4 to 5.5.
The heat demand in typical modern houses is between 6,000-12,000 kWh.
That means your specified generated heat can quite well be correct.
But the required electricity consumption has some kind of error or is there a photovoltaic system on the roof that reduces the electricity consumption especially in summer and on sunny winter days?

:
I just looked up comparison values:
For a bit under 4 years: 6600 kWh electricity consumption for:
According to heat pump 42 MWh energy (16.2 WW+25.8 heating)
With runtime 4545 hours and under 6000 compressor starts.

42,000 kWh of generated heat and only 6,600 kWh of electricity consumption can hardly be true. That would be an average seasonal performance factor of 6.6. Usual for brine heat pumps is 4 to 5.5. The heat demand in typical current houses is between 6,000-12,000 kWh. That means your stated generated heat could quite well fit. But the electricity consumption required for it must have some error or is there a photovoltaic system on the roof that reduces the electricity demand especially in summer and on sunny winter days?

No, I have such a good seasonal performance factor. This is because everything is well coordinated and my source even provides me a brine inlet of over +5°C after long cold periods, otherwise rather towards 8-9°C, but on the other hand I can work with low flow temperatures (without ERR, with hydraulic balancing), at 0° outside I am still well below 30°C -> the temperature lift the heat pump has to manage is very low and therefore the compressor operates on the right side of the performance factor diagram. The measurement (e.g., electricity) is done by a calibrated meter (by the way, the cost savings of the heat pump electricity are just barely balancing out for me).

Thank you all for the feedback - Sarrus, your values are very insightful - my primary goal will be to minimize compressor starts and run the heating cartridge less - hot water was set to 52 degrees... here 48 is certainly better.

Regarding adjusting the heating curve, I will gladly continue to read and inform myself here in the house construction forum.

My plumbing company had deeper holes drilled during the construction phase and chose a larger heat pump with safety reserves. Apparently, they were not really proficient in the subject. My heating curve was set to a max of 28 degrees... hence certainly the many starts.

Can someone give me an explanation regarding the point from Mastermind1 about individual room temperature controllers? Why is it counterproductive to set these to zero in individual rooms? Or did I misunderstand something here?

Thanks to you all for the feedback - Sarrus, your values are very insightful - my primary goal will be to minimize compressor starts and to run the heating cartridge less - hot water was set to 52 degrees... here 48 is certainly better.

Regarding the adjustment of the heating curve, I will gladly continue to read and inform myself here in the house construction forum.

My plumbing company had drilled deeper holes during the construction phase and chosen a larger heat pump with safety reserves. Apparently, they were not really knowledgeable in the matter. My heating curve was set to max. 28 degrees... hence certainly the many starts.

Can someone explain the point from Mastermind1 regarding individual room temperature controllers? Why is it counterproductive to set these to zero in individual rooms? Or have I misunderstood something?

A heat pump requires a minimum flow rate. Have a look at the datasheet of your heat pump. And if the heat pump was chosen too large, then even more so. Usually, it states a minimum flow rate of x liters per hour somewhere. On the underfloor heating manifolds, you can read during operation how many liters per heating circuit is set. Usually, it is given in liters per minute. Convert that to hours, and you will see that it is already tight to reach the minimum flow rate.

If your individual room controllers close too early (because one is economical with room temperatures), then one heating circuit after another closes, and the heat pump either switches off because the flow or return temperature for the remaining heating circuits is reached, or it switches off for safety reasons to avoid a high-pressure fault.

That means your throttled individual room controllers act as a bottleneck.

Individual room controllers only really make sense for rarely used rooms....

And even nowadays hardly at all, as long as rooms are all within the insulated envelope, you heat through the neighboring rooms as well. Even if you completely turn off a room, the temperature in newer houses (not exactly 40 years old) only drops by 2-3 degrees. Even if you do not fall below the minimum volume flow, the return temperature rises faster if some ERRs are turned off, and the heat pump also stops working. In all cases, definitely a higher cycling frequency. In a properly insulated house, you should easily be able to set all ERRs to 30 degrees and turn down the heating curve until you have a comfortable temperature (the only possible problem might be bathrooms that have too few heating coils).

Thank you Mastenmind1 for the explanation - principle understood .... basically we have a fixed setting for the controls in the house and never touch them. The bedrooms are set to zero, as is the guest room, which is the only one modified depending on the situation. The rest is constant.

I have one more question if the lady of the house wants a cozy warm bathroom floor. Lower the base temperature and turn the room thermostat up all the way or increase the base temperature and lower all the other controls in the house?