Operating costs of air-to-water heat pump, consumption and defrosting

As long as you haven't moved in yet, you shouldn't scare horses here. As long as craftsmen are coming and going, leaving doors and windows open, you can't rely on the consumption values.

I can absolutely confirm that. The tilers practically leave the construction door open all day. Since they constantly have to go out to grind. That's why we only set the flow temperature to 19 degrees to avoid cooling the house down too much. The temperature sensors in the house report between 12 and 14 degrees. That's okay since the craftsmen are constantly moving ;-P I would simply wait until the technology is completely finished and the craftsmen have left, and then measure again. If necessary, completely shut off the upper floor at the heating circuit distributor, that should save quite a few kW as well. In our case, only the underfloor heating in the basement is running. There it's 14 degrees, and in the upper floor still 12 degrees. *Edit: Of course that only works because everything has long been dry here and the humidity is constantly at 40%.

Well, whether the room thermostats are installed or not doesn't matter. Keyword "hydraulic balancing," there are no room thermostats anymore anyway. The problem is, at 26 degrees flow temperature, the pump will only stop when the return temperature reaches 2x degrees. Simply put, then you also have 26 ° in the house. This means it basically runs continuously. That's why it would be important to know how the heating curve is set. 26 ° is not an unusual value for a reasonable 55 model at the outside temperatures. You could now try to limit the flow by reducing everything to half, but it's always tricky in the "shell construction" phase.

I also hope that it will somehow even out once everything is fully installed. However, I am still shocked that the consumption of the pump is significantly higher than the electric fan heaters from the previous weeks – especially since comparatively low operating costs are promised everywhere with a heat pump, but here it is precisely the opposite. Ultimately, this is an ongoing cost factor that I naturally want to get rid of as soon as possible.

I also looked at the display again today. The defrost cycles have decreased (2.5h between defrosts), the power consumption is slightly lower at just under 40kW. However, I still find that quite high, especially since according to the display no additional heaters were active over an extended period (same operating hours as yesterday) and I had lowered the room temperature on the unit from 19 to 17 degrees. Otherwise, I was able to read the following operating data and times (since last Tuesday):

[*
Operating times
[LIST]
[*]Outdoor unit 111h
[*]Heating 97h
[*]Hot water 13h
[*]Auxiliary 1 23h
[*]Auxiliary 2 12h


[*]Operating data


[*]Heat demand 0
[*]outside 0°C
[*]Hot water 47°C
[*]Flow temperature 25(25)°C
[*]Condenser OFF 25.0°C
[*]Condenser ON 22.6°C
[*]Cooler 1 21.5°C
[*]Cooler 2 -6.3°C
[*]Pressure line 63.7°C
[*]Compressor temp. 52.0°C
[*]Ambient temperature outdoor unit -0.5°C

Settings of the and heating curve here:

"Zusatz 1" and "Zusatz 2" are auxiliary heaters?

When the temperature dropped below -10 degrees here a few days ago, they also turned on for a few hours in my system. Then easily 6-9 kW per hour pass through.

Until moving in, I would definitely save hot water. Especially set quite high, the heating element might turn on, depending on the settings. It can really make a difference.