Best pipe for in floor radiant (joist bay install with Ultrafins and cold expansion fittings)?

watercourse

What are your top picks for in floor radiant, with pipe going in between joist bays, and using Ultrafins to spread the love?

Looking for pipe that is...

• quiet
  
• flexible
  
• good with cold expansion fittings
  
• durable
  

Looking forward to your recommendations, thanks!

GGross

There is no such thing as quiet pipe, it's all about how it is installed and operated! That being said Uponor is the clear winner for cold expansion connections

Ironman

What type of boiler are you using? A mod/con or a cast iron atmospheric?

Running the high SWT needed for Ultra Fin (180*) will cause pex to greatly expand and act like spaghetti. You’ll need a lot supports and allowance for that.

Pex-Al-Pex has minimal expansion and is a much better choice for a high temp application.

If you have a mod/con boiler, then I’d use heat transfer plates instead of Ultra Fin where you could run a much lower SWT and have a more efficient system.

hot_rod

First what are the heat loads of the rooms? UF can work at much lower temperatures then 140, if the load is reasonable.

Any of the A type pex will work, properly installed. Rehau, Mr Pex, Uponor.

PERT seems to be another flexible tube option, I've never run it myself.

PAP is not a very friendly DIY tube for joist bay work.

watercourse

Thanks for all your answers here. After much shopping around I'm going to try Vipert, PE-RT that is compatible with cold expansion.