3/8" "omega" heat transfer plates, who's got them?

bmwpowere36m3

I'm hoping to install a sleeper system in my bathroom. The plan is to use Roth AluPex 3/8" (used to plumb the panel radiators). I've debated on actually using the heat transfer plates vs. just dropping the PEX into grooves in the floor and covering with thinset > hardiboard > thinset > tile.

My concern is that the rest of the system (panel radiators) will require a higher supply temp (closer to 140-150*). I know I can put in mixing valves, etc... but at this point I've only done calculations (heat loss, panel sizing, boiler, etc...). I know it sounds counter-intuitive, but I don't want to make it so the supply temps just for the floor are too low.

If I install the 3/8" PEX 6" oc (no plates), will I having issues with striping? Or should I just go ahead and install the plates? Roth only sells 1 omega plate for 3/8" to 5/8" tubing. Spoke with a tech and his comment is that you have to "bend" the plate to accomidate those various sizes. I was hoping to find an omega plate that the 3/8" tubing would "snap" into.

Bathroom:

• ~140 sq ft, with 88 sq ft of actual floor space to put down radiant
  
• Heatloss is 3100 BTU/hr
  
• Offset some of that with a towel warmer.
  

bmwpowere36m3

Looking at Uponor design manual... for example:

Joist heating, 8" oc, 20 BTU/h/sq.ft. and floor R value 0.5

No plates 150* supply
Plates 105* supply

Really?

Rich_49

Are your baths zoned separately ? What is your location also ?

SWEI

http://radiantengineering.com/productsthermofin/

bmwpowere36m3

Rich said:

Are your baths zoned separately ? What is your location also ?

Only 1 bathroom at the moment and the one in question.

Right now nothing is "zoned" per se… I have Loch Knight Mod Con, P/S, single manifold, circ (alpha pump) and thermostatic operators for the panel rads. Planned on constant circ.

My though process was… hook everything up to one manifold, close the supply to the radiant floor in bath and see what the supply temps are when they stabilize. Then slowly open up that zone as see what happens (i.e., will floors get too hot, maybe add zone actuator and in-floor slab sensor/thermostat).

Likely I'll have to mix in the future when I redo an addition with radiant in the slab (but that might be a few years away).

Connecticut

Install so far, sad but that's all I've done… I didn't get the panel rads till about a month ago. http://forum.heatinghelp.com/discussion/153460/lochinvar-whn055-direct-vs-p-s-piping

bmwpowere36m3

SWEI said:

http://radiantengineering.com/productsthermofin/

Yup, called them…. extruded plates ~$190 for 20 4' lengths shipped. I think they're a little overkill for a over-the-subfloor install. But what do I know

I found a guy on eBay that has some 3/8" omega plates coming (globaltradeco)… Maybe their "cheap", but I think they'll be good-enough.

Rich_49

You could easily just make the baths their own zones and be done with it .

bmwpowere36m3

Interesting @Rich

Maybe I'm confused, but how are they getting multiple SWTs on the same, common, manifold. Or are they just supplying the highest temp required (150*) to all zones?

I get the multiple thermostats + "zone" actuators…

I could pipe in another "zone" into the "secondary loop" of the boiler piping, but then I'd need a circulator just to run the bathroom floor.

Rich_49

Just the highest temps . When zoned separately the surface temp reaches the temp it needs to more rapidly , T Stat satisfies , flow stops , done .