Radiant in Walls

The Wire Nut

heat loss calculations the same for doing radiant in a wall as it would be for doing it under the floor?

I ran the Slant/Fin HE2 to calculate the loss for my bathroom remuddle (previous post of a few days back), and in thinking about tearing up the floor to put tubing I began to think of some alternatives. Since I am tearing up the walls and installing some new partitions, it would seem to make more sense to do it that way.

The HE2 calcs came out to be about 2000 BTU heatloss on 54 sq feet of bathroom with about 90' of 3/8 PeX. Can I just transpose that from the floor to the walls?

Thanks again,

<A>

Constantin

Yes there is heat loss...

... but the heat loss from a conditioned space to a semi-conditioned space (i.e. your basement) is usually lower than the losses to the exterior.

I like your project and I would examine what you can do with wall-based radiant as well as the floor based stuff. My personal preference leans towards radiant in the floor, but that's because I have sensitive toesis. The towel warmer can then supplement as a 2nd-stage heat source, if necessary.

It's hard to beat the efficiency with which tube set in concrete and tile or stone above can radiate. In the Maine house I described earlier, you can always feel the difference between the slate and the wooden floors, even though the underlying water temperature is the same. I would examine whether or not you can't set a thin layer of concrete with stone above.

For what it's worth, the concrete in our home for the bathroom systems is < 2" thick.

zeke

Floor is the best. You not only get convective heat transfer but a radiative component that, if you are standing in the center of the heat panel, it acts as if the whole floor is radiating.

rb_6

Here a pic of my radiant wall

I did an article for HPAC Mag last year c/w calcs...here's the link:

http://www.healthyheating.com/blog/index.php?cat=3

You'll have to scroll down to find the title:

"Lean On Me"

Check out Hot Rods post on radiant walls - cool (hot) stuff!

The Wire Nut

The problem is

that I am not going to have the time or expertise to do a concrete job... The current floor is 1" thick old wood mounted on 3" * 10" joists. The space below is the other bathroom (yet to be renovated). I intend to have the space filled with Icynene.

We were going to do a tile floor, but don't have the time or money (we have a little wethead due 3/27). If we do radiant floor we could put down Warmboard as sub-floor and have the current 1" floor sawn and planed to about 3/8th. Since we have to refinish it anyway and replace some damaged pieces, it might work out...

But since I am putting up new walls anyway, it might just be simpler to warm them...and the tub... cold tootsies and all...

What do you think?

BTW, here are 2 shots of the walls that are coming down. Although I don't like destroying the old, the removal of the se walls has given me additional respect for the deadmen who built them. The house was built in 1841.

The weight of the plaster from each stud bay has to be over 50 lbs (my poor back). The 2 * 4s are hand cut and a full 2" * 4". They rotated them to make the walls thinner as they only delinated closets. The lath is at least 1/4 thick and straight as an arrow. All the nails appear to be hand cut.

jerry scharf_2

what's on the other side of the walls

Doing radiant is mosty about getting the heat to go the direction you want in sufficient quantitiy to keep up with the heat loss.

I would not recommend radiant on exterior walls without a full thermal break. You need to see how much interior wall space you have after the cabinets and tubs are in, then look at whether you can get enough heat out of them.

There are some nice ways to do radiant in the ceiling, but again you need to make sure it's interior or there is a thermal break.

I've torn down some walls that looked like that except for the turned studs. I was much younger and my back in better shape then. Now my back hurts looking at that. I don't even let it think about the big boilers...

jerry

Weezbo

some days Jerry, God was the only one helping me drag

the six section down the straight flight of stairs on my back......across the landing ,down the steps, across the floor and up onto the blocks *~/:) lets hear it for the man upstairs...