You can choose according to your own requirements:
Under normal circumstances, s5 series is basically enough, and s4 pipe wall can be thicker, of course, the price is higher.
If the budget is enough, you can choose a higher specification of oxygen-resistant floor heating pipe.
Of course, there must be a good construction team, standardized technology and construction process, and good other materials such as benzene board, reflective film, etc. ). There are also good water separators and wall-hung boilers, hehe.
I hope it helps you ~