Since I often read here that compost piles reach a tempature of 160 degrees, would it be practical to use this heat for heating domestic hotwater? Does the pile stay hot long enought to consider this? Would this be enough heat to run a sterling engine?

-- mitch hearn (moopups@citlink.net), December 15, 2001

Answers

Response to Compost pile waterheater

Mitch,

I am experimenting with the concept with one of my worm bin compost units as a means of better bin climate control and my results there have been that the water I am circulating through the plastic piping in the bedding works well to equalize the coils and bedding at about 75 degrees between turnings. I would think if you used bacterial decomposition only, it should make a nice heat radiator. Try making a small functional model to evaluate your theory. BTW I am also considering using anearobic compost cannisters with water locks to relieve pressure as heat elements in my worm bins this winter.

-- Jay Blair in N. AL (jayblair678@yahoo.com), December 15, 2001.

Response to Compost pile waterheater

I read somewhere that someone, someplace is useing composting pig manure to heat water with. Pig sh*t heats up hot and fast,, but since a "normal" compst pile doesnt maintain a steady temp,,youe hot water would be unrelaible, unless you could rig up a constant turner and add fresh nitrogen when needed

-- stan (sopal@net-port.com), December 15, 2001.

Response to Compost pile waterheater

In the late 1970s, either Countryside or Mother Earth (both?) had a series of articles about compost-pile water preheaters. Anyone got an index from those days?

-- Cash (Cash@andcarry.com), December 17, 2001.

Response to Compost pile waterheater

Won't running cool water through pipes cool and hence slow down the action of the composting process?

-- john hill (john@cnd.co.nz), December 17, 2001.

Mitch: I hope you will forgive me because one of your pet peeves is people who don't answer the question that is asked:)

But I wanted to put in my two cents worth for folks who may not be as familiar with the benefits of hot compost as you are:

The Pennsylvania Dutch had these barns that were built into the side of a hill. The cows entered from the upper level into the barn and there were grates which allowed the manure and stray, etc. to fall below. I have heard that this was an efficient way to heat the barn in the winter plus in the spring produced composted fertilizer for the garden.

Back to the main question: I would think it extremely hard to maintain the high amount of heat (e.g. knowing when to add nutrients or turn).

Good Question though. Gets the old brain muscle going....

-- Ann Markson (tngreenacres@hotmail.com), December 17, 2001.

I am trying to use this principle to try to keep a water hose from freezing in central Illinois.I have pilled a lot of leaves onit and hope there will be some heat from decomposition as well insulation. Keith

-- Keith Etheridge (grandpa@chipsnet.com), December 17, 2001.

some people around here,, use hay/straw bales,,till we get enough snow to insulate it. The insulation should be enough without the heat. ANd leaves alone shouldnt make that much heat to matter,, manure and leave,, thats another story

-- stan (sopal@net-port.com), December 17, 2001.

And the winner is CASH.

Mother Earth News #62 March/April 1980 Cover Feature, story on page 92.

Back when MEN had lots of stories and was printed on rough paper like newsprint. Anyone remember when a 3# coffee can had 3# of coffee in it?

The article tells of a man in France who heated his water and his house with a large compost setup. He also captured methane gas in inner tubes to operate his car.

His name is Jean Pain, and his compost pile was some 14 feet tall. He had a chipper and chipped and composted brush from his farm in France. According to the article he was able to get 140 degrees (f) from his pile. Not too shabby if you ask me.

-- Ed Copp (OH) (edcopp@yahoo.com), December 17, 2001.

How about a composter that is set in the ground- some sort of bin- with a plexiglass lid. You could pipe your water around the bin- on the outside- and it would surely get hot. It would use solar and compost power. This one has really got me thinking. And dang it, for all the things Ive thought of around here, why didnt I come up with this one!? One side note. Cities/ counties that do the fall leaf clean up give away free leaves for composting AND composted leaves they "made", and even offer FREE delivery of leaves. Well, at least here thay offer this, not sure on else where, but its worth inquiring.

-- Kevin in NC (Vantravlrs@aol.com), December 17, 2001.

Good Question Mitch. a year ago while having a serious winter plumbing headache, I had a conversation with the backhoe operator who had seen the hot water radiators in my house. He told me of a friend of his in West Central Manitoba who used radiators to heat his house. The water was heated in a large pit filled with silage (a fermeted hay substance used to give cows 'live' food with B-vitamines in the winter) In the pit was a lot of coiled copper pipe. The size of the pit, whether it was covered , how much copper, how much fermented hay... this I don't know. What I was told was that this silage pit was his sole source of heat for a large house, and in that northern prairy location, that's a substantial achievement. I think your idea is very possible. It is the scale of your endeavor that must be put into question. I think that a machine was involved, but I'm not sure. I know that excrement pits might put you in a higher heat yeild per volume. I think it's a nitrogen trip, but I could be wrong. High carbon loads such as sawdust, and wood chips get really hot, especially in a sunny place after some rain, but I think this is a chemical rather than biological reaction. Best of luck. Please post your results.

-- Roberto Pokachinni (pokachinni@yahoo.com), December 18, 2001.