Away from fossil fuels - House from 1999

...Many pipes also run under the screed in my case. If the pipes had also been added there, it would have caused complete chaos.

...because the cooperation between the screed company and the heating installer did not work well there, the screed along with the tiles cracked one after another in all rooms with loud banging noises....

All this together then persuaded me to stick with conventional radiators.

Since many people in our circle of relatives/friends also reported severe problems with their underfloor heating, we also decided against it. One person had to break up the entire screed twice.

For your problem of "too small" radiators, at least theoretically, the option of forced convection would still be possible to increase the heating performance at low flow temperatures. Especially with 3-layer flat convectors, the warm air throughput can be significantly increased without much reconstruction/effort by installing slowly rotating fans (12 cm) under the heating plates. However, you still have to set the heat pump’s flow temperature high, which unfortunately reduces the heating efficiency.

p.s.: and don’t forget to document this extensively with video ;-)

The underfloor heating is 25-26 (27…28) degrees, the radiator "runs" at 45-50 degrees, dust is stirred up there. The remaining reasons against underfloor heating are, sorry, just as much nonsense.

It was simply done that way back then, but if the solution today is to replace the radiators with 33ers, then that is an acceptable effort. Does anyone have any idea how to best find a really smart independent consultant in Berlin who will look at it with an open mind?

I was told that heat from below is not good for the body,

Do you still remember the probably very interesting explanation?

For your problem of "too small" radiators, at least theoretically, the option of forced convection would still be possible in order to increase the heating capacity at low supply temperatures. Especially with 3-layer flat convectors, the warm air throughput can be significantly increased without much reconstruction/effort by installing slowly rotating fans (12cm) under the heating plates. However, the supply temperature of the heat pump must still be set high, which unfortunately reduces the heating efficiency.

You are describing radiators that are exactly the same - only professionally made - specially for heat pumps, i.e. low supply temperatures, and can be purchased.

Otherwise : Don’t believe everything that a friend of an acquaintance’s sister once said or that isolated cases (cracked screed) can be generalized to most new buildings.

Does anyone have an idea how to best find a really clever independent consultant in Berlin who looks at the matter with an open mind?

For that you can take almost any experienced energy consultant or simply an engineering office that does calculations for you (e.g. Heckmann).

Do you still remember the probably very interesting explanation?

No. Back then, it mainly came from the only civil engineer in the family environment, who always had an opinion on everything, and for some reason came across so convincingly that people believed him and followed his advice. He was already old at the time and has been dead for a long time now.

Matthias