Replace oil heating in a 60s house?

Try it out in winter to see how low the flow temperature can go. Turn the radiators fully on. You should aim for around 40 degrees. At 50+ it already becomes very expensive and inefficient.

So: Up to 55° flow temperature, the use of modern heat pumps is NOT a cost trap. The heat pump only loses 13% efficiency compared to 35° flow temperature (study from last year).

And if that has already been done:

Fassade gedämmt und verklinkert, 2-fach verglaste Fenster ... , Keller wurde irwann noch trockengelegt und isoliert, usw

At most, the top floor ceiling or the roof is still missing. Then simply install a suitable heat pump and that's it.
If you want, you can still replace the radiators, then you can get down another 6-8 degrees.

So: Up to 55° flow temperature, the use of modern heat pumps is NOT a cost trap. The heat pump only loses 13% efficiency compared to 35° flow temperature (study from last year).

Well, I rather have such data sheets in mind. That is a bit more than 13%, even at rather mild temperatures. The whole combined with high heat demand...

Try in winter how low the flow temperature can go. Turn the radiators fully on. You should aim for around 40 degrees. At 50+ it already becomes very expensive and inefficient.

So with "fever temperature" you definitely cannot heat a 60s house (without insulation measures) via radiators.

So: Up to 55° flow temperature, the use of modern heat pumps is NOT a cost trap. The heat pump only loses 13% efficiency compared to 35° flow temperature (study from last year).

As far as theory or in the lab. COP instead of 5 still just above 4? :rolleyes: 50 degrees would be like producing hot water all year round. The annual performance factor would probably hover around 3. (I already see that with our VWS (brine), albeit from 2009, that anything above 45 degrees significantly reduces efficiency.) It would be nice if it were different, but I don’t believe in quantum leaps in heat pump technology. Brine heat pumps would then be virtually completely unnecessary.

You have to find the study from ifeu yourself - unfortunately, I am not allowed to provide a link. (And I have to correct myself, it was 14% more electricity between 35 and 55°)

And don’t get me (or the study) wrong: I am not advising anyone to go to 55°. But with that knowledge in mind, you don’t worry so much if you happen to need 45° flow temperature. And with 45°, you can already heat a lot of houses! And if nothing has been done to the house for 30 years, it shouldn’t be blamed on the heat pump now. Renovations are due anyway.