Which Pex Al Pex Make ?

[Barnboy]

 

I've found a route to get a feed and return into my barn conversion for an ASHP and have been advised to use Pex Al Pex for the bending memory of it, but I'm after some recommendations for which makes to look for, I'm not finding too many with Google searches and the local merchants over here only have PEXb-AL-PERT.

I'm also thinking of using 16mm Pex-Al-Pex for my ufh as I'm sure I read somewhere in a thread that @Nickfromwales recommended this over Pex-Al-Pert.

[JohnMo]

I used a mix of copper and Hep2O from ASHP to house. Much easier to get hold of.

 

Pert-al-pert for UFH is way easier to get where you need it.

[Barnboy]

6 hours ago, JohnMo said:

I used a mix of copper and Hep2O from ASHP to house. Much easier to get hold of

I've got to come up through an adjacent shed and then through my posi joists, so I'm thinking Pex-al-pex to be able to form the bends and save any reductions in bore that fittings would cause, I'd also like to run it in from a coil not to have any joints in the ceiling.

[Nick Laslett]

Here is the thread where @Nickfromwales states his preference. 
 

 

[Barnboy]

Thanks @Nick Laslett that was where I saw Nicks comment, I'm trying to find a recommendation for a make or supplier.

[JohnMo]

1 hour ago, Barnboy said:

trying to find a recommendation for a make or supplier.

 

To make things easier, what size are looking for? Assume not 16mm for ASHP connection.

[Barnboy]

3 minutes ago, JohnMo said:

 

To things easier, what size are looking for? Assume not 16mm for ASHP connection.

I was looking at a 32mm with a wall thickness of around 3mm so that I end up with a bore as close to the internal of a 28mm copper pipe as possible. 

[Nickfromwales]

For the 16mm stuff, contact Paul and the team @underfloorheating trade direct. That's who I've used for ages, great service and stuff is always delivered as / when promised.

01925 571999

 

No clue where to get the bigger stuff, but you could ask Paul maybe? 

[garrymartin]

I keep reading different opinions on this one and I'm struggling to find a definitive answer (is there one?), specifically relating to in-slab UFH where I'm likely to do the pipe installation myself.

 

@Nickfromwales UFH Direct only seem to sell PERT pipes but you mentioned you prefer PEX?

 

@Nick Laslett has previously mentioned that Wundatrade recommend their Pert-Al-Pert for over floor systems,and their PexB-Al-HDPE for screed. But when researching this topic, he found very little to confirm a specific pipe for going into a concrete insulated slab foundation.

 

@PeterW has previously mentioned that "PERT and PEX are broadly the same thing - a polyethylene pipe, the difference being PERT has a modified binder to deal with continuous high temperature (ie 55°C plus) which isn’t needed in most UFH installations. The AL layer is key to oxygen diffusion but has nothing to do with the flexibility or tightness of bends etc."

 

@JohnMo noted that "Pert-al-Pert pipe is nice to use as it has no memory unlike PEX" but @Nickfromwales seemed to prefer PEX because it *did* have memory.

 

Is there a simple table or decision flow that would see me getting to an answer based on some parameters like pipe spacing and whether it's tied to a grid or stapled to insulation etc? Bit confused right now...

[Nickfromwales]

1 hour ago, garrymartin said:

@Nickfromwales UFH Direct only seem to sell PERT pipes but you mentioned you prefer PEX?

Pert (alu) for me, and just looked at the last invoice from UFHTD Ltd and that's what's on there. Not sure where I've mentioned PEX, but I have used both over the years. FYI, Pert Alu on every job nowadays. Just bombproof stuff tbf.

 

Ah, yes. That was an old thread from 'back in the day' (2017) referenced earlier in the thread.

 

Pert-Al has a memory, a-la "lay flat" etc.

[garrymartin]

@Nickfromwales I'd settled on PE-RT / AL / PE-RT in my notes but this thread had me questioning myself again! Thanks for the clarification.