oxy barrier pex in staple-up

Unknown

for years our pex supplier has been telling us not to use oxy barrier pex in staple up (plated) underfloor systems, the reason being is because it squeeks when the tubing expands and contracts in the plates/clips etc. which apparently is the greater of 2 evils when compared to oxygen infiltration.

i can see this being the case with a typical n. american thermostatically controlled on/off system, but with a correctly set-up ODR control with constant circulation would this be an issue?

on a side note: short of asking them, why would a local municipality require us to use oxy-barrier pipe in poured concrete infloor systems where the embedded pipe would be exposed to minimal amounts of oxygen, but the manifold mains that pass through joist spaces and are completely surrounded by oxygen are not required to be oxy-barrier?

Unknown

Use heavy extruded plates. To the best of my knowledge, no major pipe brand on the market still has any noise issues with them.

However, *some* tubing brands make more noise in contact with wood than others. If it really worries you, use PEX-AL-PEX. I know Uponor and Mr. Pex have done good things to prevent squeaks with their pipe, and I'm sure others on here can pipe up for other brands.

Proper control goes a long way to preventing noise.. as close to constant on as possible.. if it's constant on, you'd have a hard making it make noise. Proper downward insulation helps as well, for any off-cycles, slowing down the cool-down rate to reduce the on-off temperature differential. But again, with heavy plates all this may not be necessary from a noise standpoint.. but very nice for comfort and efficiency for sure.

Your municipality has no idea what they are doing, it sounds like, to answer your side note