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PEX-AL-PEX Recommendation

Parksman Member Posts: 2
edited October 2019 in Radiant Heating
I live in East Tennessee where radiant floor heat is not commonly used so expertise on the matter is difficult to find. I'm rebuilding a house destroyed by fire. The house is slab on grade with ICF walls(R-25) and high quality tilt and turn windows. The mechanical systems have been designed by an energy engineering firm so all the heat loss calcs have been professionally done and the systems designed by licensed engineers. The plumbers or mechanical systems companies in the area that claim to be knowledgeable and experienced in radiant floor systems are in-fact, not knowledgeable or experienced at all. With a professionally designed loop plan I will be installing the tubing and will be using PEX-AL-PEX. There seems to be several brands of the product and each distributor/manufacturer states their case for why their product is the best. I bought my wood stove from Acucraft in Bear Lake, MN and they have been 'over the top' helpful with their products so I'm hoping someone from a part of the country that uses radiant floor heating can direct me to a reputable source for the actual products I'll need for this part of the project.

I appreciate any input and/or recommendations.


  • Ironman
    Ironman Member Posts: 7,165
    Stay away from Chinese stuff.

    We use a lot Roth pex-al-pex. Good product, European made.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • GroundUp
    GroundUp Member Posts: 1,649
    Why on Earth would you want to use PAP in lieu of regular PEX or PERT in a radiant slab? Being a MN native, the only Acucraft I'm familiar with is in Big Lake (there is no such city as Bear Lake) and only sells fireplaces, not offering anything of the hydronic variety- how will you be heating the water for the radiant? Back to the tubing deal, it seems every MFG of PAP has ended up with a huge delamination suit of some sort or another and seeing as there are layers of dissimilar elements making up the tubing, it's not hard to fathom why. Exposed, Roth or FostaPex all day but I would absolutely not bury it in a new slab when regular PEX or PERT is available. Peace of mind goes a long way. With that said, I have Zurn PAP in the slab in my shop that's 9-10 years old now and one loop was found to have delaminated already at 3-4 years old but the other 6 are still performing well.

    6/7- would not recommend
  • Parksman
    Parksman Member Posts: 2
    I was going to use PAP because the only supply house in my area that I can find that even new what radiant floor heat was said that's the recommended material. Thankfully I located this website and some folks with expertise. As for the fireplace, my apologies to Acucraft which is in Big Lake, MN. I mis-stated the city name. But they are a great company to deal with. I have the 44" Hearthroom with the SS Water Jacket wrapped around the firebox. I will have a boiler for the backup water heating source. Does anyone recommend a source for PERT tubing? I'm certain I can't source it locally.

    Any other suggestions related to tubing? That's my primary concern at this point so I can get the slab poured and get the house in the dry before winter catches me.
  • psb75
    psb75 Member Posts: 730
    Uponor HePex is pex A. Get it on the internet at Supplyhouse.com.
  • Zman
    Zman Member Posts: 7,466
    Pex A by Uphoner or Rahau are the most common and time tested brands. No matter what type you pick, be sure it has an O2 barrier and is intended for heating.
    What brands are available locally?
    I am curious what type of design you have engineered. As much as I respect professional engineers and work with them on a regular basis, many of them just don't understand the nuances of radiant heating, especially the controls side. Do you care to post your design?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul Pollets
    Paul Pollets Member Posts: 3,639
    PAP is not the best choice for in-slab, PEX with an O2 barrier is. The better brands are Uponor, Viega, Roth or Mr. Pex. Most can be purchased online.
  • woobagooba
    woobagooba Member Posts: 177
    @Paul Pollets. What is your view of appropriate application of PAP? Thank
  • hot_rod
    hot_rod Member Posts: 19,844
    I would also recommend pex or PERT. Uponor, Rehau and Mr Pex seem to be the most flexible pex.

    PAP is nice for transfer plate installation, less movement. It does take care to install, kinks easily and needs a coupling to repair.

    Fittings may be more expensive for PAP.

    Are you pouring a new slab, or going over the old?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream