90 degree PEX bend through subfloor?
Planning for 1/2″ PEX tubing in a DIY sleeper/AL plate/ with a variety of finish floor RFH sandwich.
But just for brain food while the sheet rock goes up, plumbing gets roughed in etc…What configuration of fittings (or NO fittings?) is typically used where the PEX tube penetrates the sub-floor from below?
In my case, the subfloor is 3/4″ Advantech, and the mechanical room is below, in the basement. So after the tube leaves the supply manifold, and again when the loop comes back to the return manifold, the tube has to go from horizontal to vertical in only 3/4″. Too tight for a bend in the tube. So is there a fitting designed for this transition, or do you actually drill an oversized hole through the subfloor at really shallow angle such that the tube is able to transition down within its bending limits, and then takes a more gradual bend to vertical for the manifold connection?
I realize this is not a problem with thin slab or staple up systems, but for a variety of reasons, I am locked-in to a sandwich method, and have not yet seen this sharp transition issue addressed.
Is this question clear? If not, I will be happy to correspond with more information, and thanks in advance!
And, BTW, with 3/4″ OSB @ >$20 and 3/4″ Particle Board more like $10…why not use the particle board for sleepers? More formeldehyde?
Replies
Wirsbo makes a tubing support that will let you do a 90-the radius is about the size of a maxwell house coffee can..
From what I understand, I'm an electrician so what little I know has been picked up by osmosis, every fitting, particularly those hidden by finish surfaces or inaccessible, are an 'invitation to the blues'. The fewer fitting the system has the more reliable it is likely to be.
How about a copper 90 degree fitting and some threaded adapters? Run copper from the manifold and 90 in the floor and transition to PEX. I'm new to the radiant thing, but the reasearch I've done says most companies have adapters for PEX tubing repairs, etc. You know, brass compression type and others. Just a thought. Mike
Can you drop your manafolds down alittle so that you can make the bend ? I plan to do that with my floors. I have gotten Kytec to bend a five inch dia.
If I understand correctly, you're running PEX on top of the subfloor with sleepers and AL plates, and are trying to figure out how to get the tubing from on top of the subfloor to under the subfloor, to the manifold?
Don't use another fitting, just make an elongated hole or slot in the subfloor to transition the tubing from above to below.
If the manifold located close to where the tubing goes under, don't make a direct connection...add an "idiot loop."
See the very specifically drawn graphic attahced to this post. I spent hours on it, so I hope you appreciate the effort...
Gottcha...thanks for this tip and your other contributions to the various radiant heating discussions. You've obviously been there and done that, judging from the tone and helpful nature of your advice.
Mongo,
How did you achieve the free hand look with CAD?
Jon Blakemore
Mongo -
Do you make that print available matted and in a variety of sizes ready for framing?
If it was a true working copy, I'd definitely charge cash for it.
Since this one is pure art, it's be a shame to keep all from enjoying it by charging a fee...so feel free to print it out at your leisure.
PS: If you print it in black & white there's less distraction to the eye. That will allow the viewer to better appreciate the fusion of the line to the paper, and to appreciate the deft touch used to create such a masterpiece.
Naw... I'll bet that's a cut and pastie job from Precision Plumbing magazine.
SamT
<g>
Is there a concrete need for the loop ? I hooked mine straight on to the manifold.
I think that you ought to do that drawing on canvas and have an exhibit at your local art show. LOOK ..IT'S a MONGO! Kind of has a ring to it like van-go or whatever his name is . And much better than that Picasso guy.
Don,
No, no need for the loop. Sometimes it just makes it easier to 1) run the tubing, and 2) maintain it should the need arise in the future. But no, no definite requirement.
If you want, send me a SASE and I'll send you an autographed copy of my previously posted pic, which, thanks to encouragement from you and others, I'm now marketing as a piece of art. It's now titled "PEX Through the Floor".
Hey, if the NY Metropolitan Museum can call "Blue" art, and pay a few hundred thou for it...I can justify asking you to send me a SASE for you to get your own copy of "PEX...".
I suppose that now that I'm a true artist (I prefer it pronounced "are-teest" thank you very much), everytime I roll paint on a wall...
<cha ching!>
SASE , it's in the mail .
Uh buy the way whats your address?
Jeff Buck swapped me the CAD program in exchange for me sending him some good Belgian Beer. I was all excited until I loaded it on the computer, only to discover that in this case "CAD" stood for "Can't Accurately Draw."
(Used MSPaint)
I also had to sandwich my pex pipe between the subfloor and the t& g pine flooring I used a aluminum foil with 3/4 " strapping and ran the pex pipe between the starpping. I then covered the strapping and pex pipe with the flooring, I cut a larger hole through the subfloor to allow a gentler bend with a loop prior to the manifold.
Did you really use aluminum foil or beefier plates. Some folks I know have fabricated thier own plates out of AL coil flashing. You can buy softer, extruded plates for between .80 and .90...adds alot of $ to the job, but is supposed to pay off in reactive time and lower water temps.
I used that foil that is used as a vapour barrier for sauna walls it is a reflective material looks and feels alot like thin tin foil, I am still having problems with my heating system I cannot seem to get my main floor up to temp it seems to be stuck around 55 degrees, I think I have to much space with the vaulted ceilings and loft to heat with one floor of radient and the floor covered with t&g pine, I did sandwich the pex tubing between the subfloor and the pine and underneath i have insulated but I think i have to much room volume along with heat loss through the logs and windows I have been going through about a 200 gallon tank of oil every twenty days and this is suppose to be efficient, I think my next move is to add some rads and try to achieve room temp which might then bring the room up to thermostst temp and shut off my boiler for more then ten minutes, I hope you have better luck then me.
What kind of exterior temperatures are you dealing with? There's a pretty easy way to roughly calculate what your BTU requirements are...this takes into account the R-value of your enclosure, windows, doors, etc, and then you compare what your requirements are with the potential output of your system.
In-floor radiant heat is nice, but you still have to do the math to get sucess.
I think this is a free download:
http://www.wetheat.org/hydronic/hea/
It is fairly common to use pvc electrical conduit fittings to guide a gentle 90 bend, and protect the pex from any sharp edges. Sure you can use a fitting, but better to avoid it. Plus, a sharp 90 fitting reduces flow.
Good idea, and the pvc conduit comes already with a nice gradual bend....think that's what I'll do.
How about bending your tubing up instead of down and having the manifold above the floor with an air vent on the manifold. See attached pic