Basic info radiator replacement old building

It is hard to bypass physics.

Exactly. So please spare us your nonsense that has nothing to do with physics. Type 33 radiators are sensible and future-proof.

Is it possible to read somewhere which type the existing radiators are? We want to switch to a heat pump in the next few years, and some of the radiators in the house are significantly newer than others, but no idea if they are already suitable for a heat pump.

Such a picture is simple, like when I write a long text ;-)

Such a picture is simply like when I write a long text ;-)

Thanks! Accordingly, ours are probably Type 22, too bad

Type 33 radiators, i.e., the thickest on the market, have always existed and have nothing to do with heat pumps. They were already installed 40 years ago.

You can also install 2 x 22s instead of one 33 if you have space.

It will not get warm. I wonder why all these years the owners of gas or oil heating systems have not lowered their flow temperature to 30 degrees and thus greatly reduced their consumption. If that would work.

If I have a 22 radiator with 2 heating surfaces of, for example, 1.40 x 0.60 m in the room today and 60-degree flow temperature, it is useless to install a 33 and lower the flow to 35 degrees. The place will stay cold. It’s that simple. I don’t need to calculate heating load or anything else. My common sense is completely sufficient.

Type 33 radiators. So the thickest on the market have been around forever and have nothing to do with heat pumps. They were already installed 40 years ago.

You can also install 2 x 22 radiators instead of one 33, as long as you have the space.

It will not get warm. I wonder why all these years the owners of gas or oil heating systems haven’t lowered their flow temperature to 30 degrees and thus greatly reduced their consumption. If that would work.

If today I have a 22 radiator with 2 heating surfaces of e.g. 1.40 x 0.60 m in the room and 60 degrees flow temperature, it is useless to install a 33 and reduce the flow to 35 degrees. The place will stay cold. It’s that simple. I don’t need to calculate a heat load or anything else. My common sense is completely enough.

I am seriously sorry for your common sense if you dismiss factual calculations as "my common sense knows better." Sorry.
Then my tenant also doesn’t have 23 degrees at all, but she only imagines the temperature really. And the electricity bill is just an illusion as well.
Do you also still believe that people cannot survive at speeds over 30 km/h on trains and that the Earth is flat? Because your "common sense" says so? Or do you believe in facts? No wonder Germany is going downhill if we have residents like that...

Oh yes, the conversion from 2 x 140 x 60 22 radiators with 60-degree flow to 2 x 140 x 60 33 radiators leads to a reduction of the flow temperature by about 15 degrees at the same heating output of the radiator. THAT is science and not a gut feeling. And if I can use 160 x 60, I reduce the flow by 20 degrees (with a difference of 5 degrees each between flow and return). That makes the place equally warm. Two small pieces of wood give off the same heat as one big piece. Maybe you just need understandable comparisons so that you get it ;-)