Which heating pipes are used nowadays?

Hello everyone,

I have a question. I am currently renovating 2 rooms, where there are 2 old cast iron radiators in window niches. I want to close the niches and install new radiators.

There are still steel pipes installed and I would like to partially renew them. The good thing is that all the pipes run along the ceiling in the basement and then go through the ceiling into the niches.
So I can lay new pipes along the ceiling. However, these would need to be connected to the steel pipes until I renovate the other rooms.

Now, which are nowadays the best pipes to install?
The flow temperature is 80°C.

Copper
Aluminum composite
Plastic pipes

And what is the best way to connect the pipe to the steel pipe? Cut a thread and screw on a threaded/press fitting?

Thank you very much in advance.

Olli

Like 80 degrees ops:

Sorry my mistake. My 70/50.

Ah ok, I understand the picture. But copper is still the current standard, right?

Can you by any chance recommend an affordable thread cutter for steel?

Copper is still good. MSVR is also common. No, unfortunately I can't. I didn't do it myself.

Your plan sounds strange.

I did something similar myself. Removed old cast iron radiators. Bricked up the niche and placed new radiators in front of it.
I dismantled the old radiators. And on the pipes that came from below and were exposed, there were already threads. I simply connected a copper pipe to those, drove it inside the radiator niche to the appropriate spot, and then forward. I then bricked up and plastered the radiator niche and had the new pipes coming out of the wall exactly in the right place.

So no thread cutter was necessary, no breakthrough through the floor. Everything went pretty quickly with two people. We did it that way for 14 radiators.

So you left the old steel pipes in the wall? That's exactly what I don't want. I want to completely remove the old pipes. For that, I also need to drill 2 holes for the supply and drain. Unless I can get the old steel pipe out, then I could use these holes. Did you then press the pipes? That the pipes already have a thread from below, to be honest, I haven't even checked yet. I'll do that later.