Pex use in baseboard heating

Al Corelli

I did one floor today and tomorrow I'm doing another floor.

I have had no problems. This ain't the first time I've done this.

jrc2905

Pex for baseboard heating.

Can I use pex pipe for connecting baseboard heating. It would make the install much easier that sweating fittings against the wall. If so can I run a return loop on top of the baseboard fins? I just went to a Pex class and this subject never came up

Rocky

Pex for baseboard.

yes you can use it to connect baseboard. just watch the temp rating of whichever tube you're using. Make sure your water temps won't exceed this rating. Pex tends to get all snakey and wants to come out of the baseboard enclosure when it gets hot. We use PEX_AL_PEX if we want to enclose the return in the baseboard cover, less expansion. But, we have used regular pex. just used nylon zip ties to strap it to the fin tube to keep it in place.
Regards,
Rocky

hr

A couple thoughts

pex along the top of the element like that would really expand when it goes from room temperature to 180°F or more!

I too would highly recommend PAP and I would not fasten it, or regular pex, tightly so it could arc up when it has to expand somewhere. If you watch copper fin baseboard when it first comes on it too will arc up if the ends cannot move. It's always wise to use expansion couplers on long runs, for this reason.

I prefer pex without the squeaky outer EVOH layer for more piece of mind. And outdoor reset controls will minimize the wide temperature swings the tube may see. Close to constant circ when adjusted properly!

Again PAP would solve all these issues, and they do have baseboard compression fittings available for ease of installation.

Run some calcs, often times 5/8" PAP is plenty. It is much easier than wrestling 3/4" PAP close to the floor like that.

hot rod

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jrc2905

PAP? This use of plastic piping is all new to me.

Rocky_2

PAP

PAP=Pex-al-Pex, meaning a layer of aluminum sandwiched between two layers of pex. Kind of like soft copper in the fact that if you bend it, it will stay, not spring back like regular pex. Has all the advantages of pex but low expansion coefficient so it will not "grow" when it gets hot and get all "snakey". Idea for stringing between boiler manifolds and baseboard.
Regards,
Rocky

jrc2905

Thanks for the information, after a particularly tough baseboard job; I have decided to use as much pex as possible from now on. I have never used it on a job before but the fact that my state, MA. , has just approved it for domestic water has me convinced. I have gone to a class on the use of pex but the information was limited and the counter people at the supply houses are not up on what is available for fittings.
Is there a web site that provides this information?

S Ebels

Ditto to what these guys said

We use PAP exclusively for baseboard, in fact, we use it for nearly everything that's not buried in cement. Much nicer to use and control due to bendability, noise issues and low expansion rate. I don't know if you're using any ProPress fittings but Viega just introduced a line of fittings that will press onto 3/4 copper and go directly to PAP or PEX. No soldering whatsoever. Check them out at their website. Awesome!