I had a great idea for recovering all the btu's which normally just go down the drain. I did a little search on google, and found out that a company STOLE my idea--almost twenty years before I had it! Check it out:

http://oikos.com/gfx/index.html

Here's some similar ideas:

Bury supply pipes deep enough to have warmer water into house (save many kwh per year)

Wrap a “coil”, which can be square, actually, using oversize pipe to minimize friction loss, on top of septic tank, cover with rigid insulation, make sure that septic tank area has foolproof drainage to avoid cross contamination. Preheats water supply, saving big $$

Put manifold, pipes, in or under slab construction, and run cold water through it. Cools slab, warms irrigation water. Also, run main supply pipe through slab to preheat water to water heater, etc.

Run drain pipe from house alongside supply pipe (again, provide drainage protection to prevent cross contamination)

Run drainpipe alongside underground pipes of ground source heat pump.

These are very preliminary ideas; some of them will require some valving in oreder to utilize them only in the appropriate seasons..

Obviously, most of them are more practical for new construction.

Gotta go,

JOJ

-- Anonymous, August 07, 2001

Answers

"Put manifold, pipes, in or under slab construction, and run cold water through it. Cools slab, warms irrigation water. Also, run main supply pipe through slab to preheat water to water heater, etc."

Wouldn't that cooling of the slab cause condensation on the slab, making it very slippery? Not to mention dampening anything ON the slab? Would it work if you put vapor barrier, then insulation, then floor underlayment, then flooring (wood, vinyl, whatever)? Not trying to be an obstructionist -- I'm really interested in this.

-- Anonymous, August 07, 2001

Hi, Joy, like I was sayiing, this is a pretty rough sketch. Subject to local adjustmet. I've been hearing from a lot of folks about how hot and muggy it is where they live.

Here in SW Oregon, the air is DRY. In the summer. We get about thirty-six months worth of moisture in three or four months. Mid November to March, usually. Summers there isn't enough moisture to condense on a glass of iced tea, half the time. So condenstaion is not a problem.

What I had in mind for cooling the slab would work best for a slab with a non insulating floor covering, like tiles, for instance.

Since I didn't get the idea for this until right AFTER I poured the slab on my new place, and since my offer to plumb the floor for my son didn't work out (he wanted carpet on the floor, which would have insulated the floor too much to make it worth doing), I haven't any empirical data. I'd love to do this, if I ever do another house.

Thing is, it would depend a lot on your humidity level inside the house, plus the temperature of your well water. If you have air conditioning, for instance, a lot of the humidity is removed from the air.

Possibly, if you're really interested, measure your well water, after it's been running for a long time. Then take a piece of ceramic tile, or even a water glass or a mug. Put it in the refrigerator, full of water, and let it stay in there until the water reaches the temperature of your well water. Now, take it out of the fridge, and let it sit in the house for a while. If you get condenstation on the outside of the glass, you're right--you MIGHT get condensation. But this is a worst case analysis, since the well water will never get the slab down to its temperature.

Unfortunately, non of the ideas you suggested, if I'm understanding correctly, would alleviate the problem, if there is one. The whole idea is to have the cool floor available to cool the air in your house, and to cool your feet.

If condensation were to be a problem, it would be worse than just a slippery floor; it could cause mildew. Bad.

If you are REALLY interested, you could check the humidity level inside the house occassionally, using the "wet bulb/dry bulb" method, which is quite accurate, and look at a humidity/dew point chart. Of course, that would only tell you the data you need for the house you're already in, not the house you to build later.

Sorry I can't back up my suggestion with more data.

JOJ

-- Anonymous, August 07, 2001