How to PEX radiant in shower walls

Bob Bona_4

should post this on a new thread Dana. I'll tell you right now that the circ is on the wrong side of the mixer, probaly causing your headaches..

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Jason Horner

How to PEX radiant in shower walls?

Looking for suggestions on how to heat the walls of a stall shower.

Walls will be stone faced - probably granite, laid on top of Durock cement board.

So far my thoughts have taken me to running Kitec in the walls with Ultra Fin (www.ultra-fin.com/c_prod1.htm) attached to the Kitec, and a foil/bubble radiant barrier behind.

Any other thoughts on how to do this effectively?

TIA

Mark Eatherton1

I've done it

using a router, routing grooves onto the studs, install the light aluminum Omega plates at a right angle to the studs, in the grooves, snap pex into the plates, cover with DUroc, noting elevation of tubes to avoid hitting during Durocking, and call it good.

No convective/radiant as in your method. All pure conductive radiant. Fill the stud space with unfaced fiberglass.

Siggy did it in his office this way, and he loves it too.

Quick response, virtually silent when done with ODR and TRV's.

I'll try and dig up the pictures.

Do the walls, ceiling and floor and turn it into a human hydronic microwave oven. It makes a GREAT steam room. Steams up RIGHT away.

HR's done this, I'm pretty sure.

ME

hr

A couple options

plates are great! A few ideas, make sure you insulate well behind them even if the batts touch the plates.

I've found running them up and down eliminates most of the nail puncture potential, and is quicker than notching studs. The wider spacing doesn't seem to matter. You could install 2X2 strips down the studs then the plates to tighten the oc spacing and eliminate the plate thickness on the stud, although the durorock doesn't seem to mind

These vertical install pics show RTI C fins with furring strips and the tube installed from the back side.

The horizontal install is the U fin from Radiant Engineering.

8 foot long ThermoFin U plates work about best, just the right length for shower walls. It easier to install the tube from the front, also. PAP is the easiest tube to install, and keep in place, also. That's my current and most sucessful method.

I've tried plain tube in the wall, forget it, waste of time. Use the plates for best results, you need the "connection" and more powerful conduction transfer

The copper in fin is a radiant wall project in my wifes office. I was able to work from behind the finished wall to retro fit this high output section.

hot rod

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Jason Horner

Thanks for the ideas guys.

Jason Horner

Forgot to ask....how do you zone this and what temperature do you run on the surface?

Do you put it on the same zone as the bathroom RFH?

TIA

kevin coppinger_4

my vote would be ...

Wirsbo Quick Trac...no grooving the studs just nail them up and install the tube...very fast response time..kpc

hr

To zone

yes, I put it on the same zone as the bathroom floor, BUT...I run a seperate loop to the wall so I can valve and balance it against the floor loop. On a couple jobs the shower walls were exterior walls. I found I had to balance more to the wall.


Another idea on a small bathroom loop, if the floor and walls needed under 300 feet of tube, would be to feed the supply to the wall first, then into the floor, especially if the shower walls are exterior walls, pretty hard to get them too warm.

Depending on the load of the room, generally 120F supply is plenty, with plates under the subfloor, backerboard, then tile.

You customers will love warm shower walls. One of my customers called when his circ pump went out and said his shower felt like a meat locker when the radiant quit! Amazing how cold a 72F tile wall feels after you get used to radiant walls!

The tekmar 500 series, also available as a Wirsbo item, dual sensing t-stats are excellent for bathroom controls, when you embed a floor, or wall, sensor. Very user friendly, percise control, tight differientals are possible, with that control.

Always, always, zone your master bathroom seperate. Run them off a buffer tank as they are generally a tiny load in the big scheme of your system. Even consider a seperate heat sourse if the boiler is disproportinatly large compared to the bath zone.

Actually electric radiant fits small bathroom applications very well. Rumors abound that some electric products are able to be retrofit below the subfloor. I'd stay under 300 square feet for electric, if you already have a boiler.

Some folks enjoy year 'round warm walls and floors. I do

hot rod

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Jason Horner

About exterior walls....have you ever done radiant walls for showers where the exterior wall was ICF concrete wall construction? In that case, are there much difference in how you balance the different shower walls themselves, ie. more tubing and plates in some walls than others?

Thanks a ton.

ps. sent you an e-mail - check your in-box.

hr

For ICF walls

you could screw the C fins directly to the block. Then strip between them with the CBS's. Or you could frame another wall and install on th studs, although that would burn some of your shower square footage.

I wouldn't groove into the foam. You would lose R value and you don't want to contact the concrete in the block, it would suck all the heat!

I used Green Block ICF's on my office wall. It has plenty of "ribs" to fasten to. I sided directly on the exterior with stainless screws, and sheetrocked to the inside. A great concept those ICF. Makes for a quiet and well insulated wall construction.

The Wirsbo Quick Trak system would work. I'm not a big fan of micro diameter tube Just a personal opinion. You can get 3/8" C fin from Radiant Engineering is you need. With 3/8" pex you could get a 4" on center bend. Doubt that you would need it. I find 12" works, even on exterior walls.

hot rod

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Steve Ebels

Shower walls

We've used Stadler Climate panel on a number of wall applications including showers and the results were great with each. The other trades like the fact that they can see the tube as they do their work. A shower with warm walls is the ultimate luxury bath accessory to me.

steve_26

climate panel

Stadler climate panel works great,
use them just about any place,did a sunroom with high temp.
shower walls and bench..Anyone ever do a counter top?

Hot Rod would you have a ph# for Radiant Eng. or adress.
steve

Mike T., Swampeast MO

501 E. Peach, Ste. "A"

Bozeman, MT 59715

(406) 587-6036

Bob Gagnon plumbing and heating

heated granite countertops

work great. bob

Bob Gagnon plumbing and heating

radiant walls

in an outside wall is there any chance of the pex freezing? it gets to -10 where i live, also can i run the shower plates on the same zone as a high temp. suspended tube system? thanks, bob

Dave H_2

Radiant-Trak Wall Pic

in the wall.

Just flip the Trak over, snap the pipe in.

Remember to insulate even if its an interior wall.

As Hot Rod said, same zone as the radiant floor, but a seperate loop to control the flow.

Dave H.

hr

Ideally

the pex is well insulated, behind it. Beef the wall up to a 2X6 to accomadate R-19 insulation, if possible.

Actually at that outdoor temperature most heating systems would be running non stop (design day)

I think you would want to mix the temperature from the suspended tube zone. Not much mass in a shower wall, probably easy to overheat and potentially crack some tiles. It may get to warm to touch at 140 supply!

Generally 90-110 is more than enough temperature for a transfer plate application directly behind the tile.

A simple 3 way mix valve would do the deed.

hot rod

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dana_2

radiant floor

just installed rad. floor in my home. doesn't seem to work right? one zone with three loops, 1(kitchen;330 feet),2(dining;280 feet), 3(bathroom,hallway;200 feet). kitch has linoleum, dining has hardwood, bath,hallway has tile and linoleum.. piping is as follows. taco 008 on the supply off the boiler, into the hot port of a sparco mixing valve, from there into a three port wirsbo supply header manifold; loops return to a wirsbo three port return header manifold,with balancing ports (already wide open), to a tee into the cold side of the mixing valve, then to the boiler return. the floor joists are 2x8 with 5 1/2 inch unfaced insulation in the bays.....the problem is not able to get 20 degree delta tee for return temp. on my supply/return temp gauges.. sparco valve is 80-180 temp range, reading 170 supply temp; getting 90-100 degree return temp!!!!! boiler temp at 190-200. there are no kinks or folds in the pex tubing. are the loop lengths to long ,then why not a 0012 for the head !!! any help would be greatly appreciated..i'm lost in my own design..thank you anybody!!!!!

Dave H_2

Circ placement

I agree with Bob, circ is in the wrong spot.

With Radiant, the circ ALWAYS goes after the mixing valve.

take a look at the attached pdf. The mixing valve here compared to the one you have used has a rotation difference, but the pump is still after the mix.

Dave H.

ScottMP

How about around a Tub

We did this install around a whirlpool tub.

Scott

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Kal Row

hot water source

if you happen to run your hot water tank at hi temp
with a thermostatic mixing valve,
then you can run a pipe from before the mixing valve to the
shower's radiant panels, then to it's own mixing valve
into the shower - this way it only runs with the shower,
and you dont need a pumps and control. i would run it through the towel bar first.

Earthfire

shower

What you have described is the perfect legioners disease generator. Lots of surface area for the bacteria to grow in ideal temp range and the perfect delivery system,with the shower head atomizing the water in an enclosed area for inhaling by the victim. Not a question of if but when will it strike. Ossamma bin Ladin couldn't have come up with a better delivery system.

Kal Row

shower

i was assuming at least 140+ degrees to the shower's mixing valve - otherwise the whole show will never work right, since, while radiant take low flows and temps, it take a lot of time, where as, here, we want to do it fast, so it needs higher temps - hence my opening statement "if you happen to run your hot water tank at hi temp ..."

i cant seem to find a real scientific cutoff temp point for legionnaires disease - there are way too many opinions, i you have a link with hard data I'd much obliged, i come form the air conditioning world, and over there it's a real problem with open systems, in a hot water supply which is basically pressurized to the point of discharge, the danger is overrated, IMHO

i work with one 6 story building with a DMHW return pump and the hot water heater set for 120 and in 14yrs there hasn't been a problem!

Cliff Brady

Seems like a germ factory and fruit rotter.

We keep fruit in bowls out on the formica counter and even having the dishwasher under them can hasten the spoilage. Anyone else think warm countertops are a bac idea?