Air-water heat pump current consumption and data

I think there is still room for optimization in your case, with a thermal balancing.

Ok thanks, your data suggests that maybe the construction moisture played a role in my case, or the monolithic solid construction has a few more weaknesses than calculated. Let's see how the second winter will be.

Thermal balancing has been done, of course it can still be improved. A performance factor of 4.2 would probably not really be possible with air-to-water heat pumps with ERRs and without the balancing.

Sorry, forgot to write... it is a KFW55 house. The electricity consumption is measured by a separate meter, the heat quantities come from the heating.

Ok thanks, your data suggests that maybe construction moisture still played a role for me, or the monolithic solid construction method has a few more weaknesses than calculated. Let's see how the second winter turns out.

Thermal balancing is done, of course it can still be improved. A performance factor of 4.2 would probably not really be possible with ERRs and without the balancing using an air-to-water heat pump.

So with a modulating one, this value of 4.2 is easily possible, unfortunately we have an on/off heat pump. And this one is also already a few years old.

I also think that construction moisture still plays a role for you, what settings do you have?

Hot water

Heating curve etc?

The winter was just cold and long...

So with a modulating one, this value of 4.2 is easily possible, unfortunately we have an on/off heat pump. And it’s already a few years old.

I also think that construction moisture still plays a role with you, what settings do you have?

Domestic hot water

Heating curve, etc.?

Well, the biggest efficiency killer for me is a poorly heat-conductive 3-layer parquet floor, because of which I probably have the heating curve set one degree higher than would otherwise be necessary. Currently, the heating curve in AIT notation is return flow controlled at 23.5/22.5/0, i.e. 22.5°C return flow at +20°C outside temperature, and about 26°C target return flow at -20°C outside temperature. Maybe in the deepest winter I still have to increase the target return flow to 26.5 or 27 degrees. The house is located in a small cold sink, meaning that early in the morning it is always 1-2° colder than a few hundred meters away – therefore the heating curve should not be too steep. Otherwise the heat pump would run at full power in the coldest time early in the morning. I’m still considering whether to do a slight daytime increase for the heating, but since I don’t have photovoltaics, I haven’t set that up yet.

Other settings for the modulating air-water heat pump from Alpha Innotec: heating hysteresis 1.0K, domestic hot water target 46°C, domestic hot water hysteresis 3.0K, domestic hot water enabled only from 12:30 to 23:00 (so that it does not produce hot water at the coldest time in the morning right after showering).

The screenshot shows the consumption values from the heat pump consumption database, values including domestic hot water. You can see that the standby consumption in the summer months somewhat lowers the annual performance factor.



What else besides better adjustment of the heating circuit flow rates by thermal balancing could still be optimized?

The heating is my model train substitute :)

Otherwise, the heat pump would always go full throttle there early in the morning at the coldest time.

Can you set an AT damping? I am currently trying a 24-hour average of the temperature for exactly that reason. In combination with slight daytime increase and a storage heater, it looks like I can quite well avoid heating at night. At least so far, at these temperatures.