[Strawbale] re. Re: PEX, Concrete Slab, Fear of Death (by contractor)(Speireag Alden) (Speireag Alden)(Speireag Alden)(Speireag Alden)

[Speireag Alden]

On 2008, Jan 07, at 13:39, MKL wrote:

> Just a guess the order of strata would be planet,
> sealed vapour barrier (6-10 mil Poly or similar),  2"
> -3" XPS foam board, 3/4" washed gravel 2 inches thick,
> 10 inches of top soil mixed with Type S lime in ratio
> of 5 parts soil to one part lime, top finished and
> sealed with non VOC expiring oils? The pex tubing
> being at 5" up or down from top of earthen mass? (in
> the middle?)

     Planet, 6-mil poly (not well-sealed, because I didn't understand  
the importance at the time), 4 inches of XPS, 3/4 gravel about 6  
inches thick, a layer of 8-inch block (Kachadorian-type floor, later  
sealed up; bad decision), four inches of local clay mixed 50% with  
local sand, topped with three coats of citrus-solvent, heavy-metal- 
free linseed oil.

     The PEX is two to four inches down in the earthen layer, laid on  
top of the blocks.

> Heres a question then…    Lets say you are 20 years
> old know all you do at this point and plan to live in
> the house all your life would you still install R-20 ?

     Probably.  But remember that I'm experimenting in this phase  
with an earth-coupled house, so I expect to be using solar heat to  
warm the earth under that R-20.  So if things work, the temperature  
differential across that R-20 will be less than it is in most  
situations.

     If I weren't going to do this earth-coupling experiment, I think  
I'd go to R-30 as a minimum.  After all, I've probably got about R-35  
in the walls, and I've got R-56 to R-60 in the roof.

> which evac tube collector did you choose and why ?

     Apricus tubes.  I got a good deal on them, so that they were  
price-competitive with a flat-plate collector of roughly equivalent  
output.

     We'll see if I was right.  Locally, two experienced builders  
have had a lot of trouble with Thermomax tubes, so I avoided those.   
The local solar installer likes Sunda tubes, and it did seem to me  
that the design of their seal was mechanically better, better able to  
accommodate differential expansion of different materials.

> Got it, and the hot tap water once used could return
> still hot through the storage tank before going off to
> a septic system or similar or even to a "cooling off"
> holding tank buried below a greenhouse (before it
> flows out to a sump in the garden below the frost
> line). Or to a metal tank in the space as a sort of
> radiator.

     It will flow out a long drain pipe which runs through the  
greenhouse.  I'm not planning on installing a GFX.

> I'd like to ask you which storage tank you chose or
> had made but think Ive reached my inquisition limit
> for the day…

     I haven't chosen it yet.  I may build a plywood enclosure and  
line it with EPDM.  However, if I'm going to rely on thermosiphon at  
all, then I may need a tank with pipe plumbed into the sides or  
bottom, rather than pipe running into the top of an unsealed tank.

-Speireag.