PEX on slab... need some way to replace carpet...

[Minimac]

The easiest way to do this, at least that I can think of , would be to cover the existing concrete with some 1/4" luan. it won't be as good as foam for insulating, but should stop the majority of downward heat migration. Lay out your tubing and the either cover it with fiber cement(doesn't crack)or furring strips on either side of the PEX and cover with 1/2" or 3/4" plywood. The furring strips should be close enough to each other to prevent flexing of the covering plywood, similar to what Doax pictured above. The additional height(thickness) would be kept to a minimum. Possibly consider 3/8" soft copper tubing instead of PEX for maximum heat transfer. It shouldn't cost any more when the cost aluminum transfer plates are factored in.

[AC_Hacker]

Originally Posted by Daox

...but it would be SO much faster and easier than DIY... I'd at least like to get a cost. What was the estimate for your 12x12 room? Thats not too far off from what my room size is.

Well, if you go to THIS PLACE, they sell Roth Panel for $828.00 per box (96 square feet).

From the research I have done, Roth Panel is always among the top of the list when high-efficiency radiant floor geeks list their favorite systems.

Covering RP with some kind of floating floor system (like bamboo, etc) seems to be mentioned favorable most often. But covering with 1/4" Hardibacker and then linoleum would be even more efficient... if you can go with the look.

* * *

Originally Posted by Minimac

The easiest way to do this, at least that I can think of , would be to cover the existing concrete with some 1/4" luan.

Wood is R-1 per inch, so 1/4" luan would give you R-0.25... not so good, especially when the system is in direct contact with a cold, massive concrete slab which is in contact with cold, massive earth (the mother of all heat sinks).

Originally Posted by Minimac

Possibly consider 3/8" soft copper tubing instead of PEX for maximum heat transfer. It shouldn't cost any more when the cost aluminum transfer plates are factored in.

Metal pipe (both iron & copper) in hydronics got a bad name because of the long term corrosive effect of concrete. But in this application, at least the copper wouldn't be so likely to corrode.

But aluminum heat plates are used because aluminum is a good thermal conductor, and the area of the aluminum plates is very large. 3/8" copper tubing is a great conductor, but it wouldn't have a very large area... so not so good.

-AC

[Daox]

Sorry to get us off track. Did we answer your question RobbMeeX?