Compost Heat

[badlander]

Hi guys
I was talking to a patient in my office last week and he mentioned a friend of his who heated and got his hot water from a rather large compost pile. The gentleman I am describing lives completely off the grid.

The pile is about 10x20 feet I don't know how high. He has lots of pex tubing at the bottom which he taps off for hot water and radiant heat. His water comes back into his house at about 110F.

We have a part time home which my wife has described as not acceptable for insurance companies.
Anyone have any experience with this type of heat/hotwater?

My wife is the primary person on this site. I am her spouse.

Our Missouri house is primarily wood heated but we don't live here full time because of our practice.

If anyone needs more specific info please contact me off list.

[SolarGary]

Hi,
I've been gathering info on this kind of large compost pile heating -- I've put it all here:
http://www.builditsolar.com/Projects...tm#CompostHeat
There is some good material there from Jean Pain and others who have done work on this concept.

The more I look at the idea, the more I think it might be practical. Sounds like its working well for your friend.
Roughly where are you -- just wondering how cold your winters are?
Any idea how long he gets heat from a single pile?
Or, what kind of material he uses to make the pile?

If you friend is willing to provide some description and pictures, I'd really like to add them to the collection -- you can send me a PM or get me at
gary AT BuildItSolar DOT com

Gary

[highlands]

I can believe it and have though of doing the same to warm water for our livestock. We have compost piles here on our farm that are about 140 cubic-yards. They are hot all winter. The tricky part is not destroying the piping that one recaptures the heat with. I have wondered about putting the PEX inside concrete for the walls and floor. Then there is the problem of what if an area, a bin, is left empty and freezes.

Cheers

-Walter
Sugar Mountain Farm
in the mountains of Vermont
http://SugarMtnFarm.com/butchershop

[AngieM2]

badlander - forerunner is in MO has a large compost pile like that, and heats his house with the compost.... he has posts about it Survival forum...

Compost as a Matter of Survival

That is a link to the first of four information threads he's started...

Angie

[FarmersDaughter]

Originally Posted by AngieM2

badlander - forerunner is in MO has a large compost pile like that, and heats his house with the compost.... he has posts about it Survival forum...

Compost as a Matter of Survival

That is a link to the first of four information threads he's started...

Angie

I believe Forerunner lives in Illinois. It might not matter much to the discussion, except that he lives farther north than the most northern part of MO, so it shows that the compost pile can assist with heating even in a colder climate than MO.

(Correction: I was wrong...he lives in Illinois, but at roughly the same latitude as Northern MO.)

[Micheal]

I can see where it's a good idea and people have even got it to work.
BUT personally I just can't imagine gathering or having available that much compostable material.........

[Forerunner]

Sawmills have sawdust.
Sale barns and horse farms have manure.
Straw is cheap in bulk.
Some farmers offer dirt cheap round bales of corn stalk stubble.
Most municipalities at least have a spot where they allow residents to dump grass clippings, leaves, wood chips, stump grindings, etc.

If you live in the arctic or a desert, there may be a shortage of material.


My latest discovery in the top of one of my largest piles is an extremely large and healthy swiss chard plant. Around the gardens we have a lot of black mustard (brassica nigra), and it's already got it's outer leaves frost burnt.
Black mustard is often green and lush to as low as twenty degrees.
But that swiss chard is green and lush as though it was June.
I'm thinking that a light duty, portable frame with double plastic shell greenhouse assembly right on top of that compost pile might be the ticket for cheap and easy produce through the winter.
A south facing slope could even be fashioned to more effectively capture the sun's rays and protect the area a bit more from north winds.

As for building a concrete structure with tubing to capture the compost heat....good idea. If the facility sits empty and there is danger of a freeze, simply blow the system out with compressed air until you are ready to accumulate more compost materials.

[fishhead]

We dug into a relatives sawdust pile at least 20 years after he quit sawing and it was too hot for our hands and we had to quit. It was so old it had aspen trees growing on top.

Really old piles stop heating but I bet they could be restarted by adding some nitrogen.

[Chixarecute]

Cryofreeze is a good solution to put in pex instead of water. I believe Dh mixed it 50:50 with distilled water, and the temperature protections is still way below zero.

[Trisha in WA]

Originally Posted by Micheal

I can see where it's a good idea and people have even got it to work.
BUT personally I just can't imagine gathering or having available that much compostable material.........

You sure do if you live on a farm.

[rambler]

Originally Posted by Micheal

I can see where it's a good idea and people have even got it to work.
BUT personally I just can't imagine gathering or having available that much compostable material.........

The trouble is the EPA types are getting pretty tough on piling up manure & letting it decompose. Going to be issues _there_ in many states.

--->Paul

[Forerunner]

I can't wait 'til bureaucracy grinds this once productive and innovative nation to it's long intended screaming halt.

Only then will some people develop a back bone.

[Paul Wheaton]

I took some video of something like that just a month or two ago - gotta put it up on the mighty youtube.

There was a LOT of discussion on this earlier .... digging ... here it is: jean pain method

[howie]

Forerunner, Don was talking about doing just that with the boxed in frames on a southern facing slope and one of your piles. I like the idea.

As for running water lines underneath the piles, great idea, and I'm thinking I've got some neighbors who would flip!

I can remember digging in sawdust piles when I was a kid, and this stuff was fairly fresh. Didn't have to dig very deep at all before it got HOT!.

[Micheal]

Sorry for the "mis-interpretation" to my post. I was sorta talking about the average person, not large scale farmers, saw mills, etc.....
Although in some of my readings states like NH, VT, and even NY among others, are footing part if not most of the bill for large farms (and other select industries) to use their waste and convert it into methane. Then use that not only as a fuel source but also for electrical and heat generation.
Which to me sounds like a more useful use of a "large" quanity of compostable material.
But hey that's just my opinion.......

[fishhead]

I think an average person could gather enough sawdust to heat their house if they live in an area with sawmills. They don't give off much smell so that shouldn't be a problem.

I doubt you could do it in a subdivision but most rural areas should allow it. You may have to visually screen it with bushes or something.

Last night a friend and I were talking. He said an old sawdust pile in his town still catches fire and that pile is probably 40 years old. He's not that far from retiring so a sawdust pile "furnace" would be a nice way to heat his house without having to cut firewood every year or to pay the gas company over and over.

I wonder if wood chips from the tree removal companies would heat up? That might be a free source of delivered chips in some areas. They should last a long time too.

[Forerunner]

Indeed methane can be drawn off most of what would go into the compost pile... but there is a method to it that serves all purposes.

A methane digester is nothing more than an artificial stomach.
Fill it with the right blend of materials and the right amount of water and it will produce gas, anaerobically, until the material is spent for that purpose.
There being no nitrogen in the methane analysis, that nutrient is largely unaffected in the digesting process. The carbon is lightly affected, as methane does contain one carbon atom per molecule, but it is the moisture content that "suffers" the most, via hydrogen loss.
Methane content is CH4.

After the anaerobic microbes have had their say and productivity of methane falls below practicality, draw off the slurry in exchange for new material.
Use the spent slurry as your nitrogen source and mix 1 part slurry to three parts carbon mass, i.e. sawdust, straw, etc. and you'll get close to the same duration and intensity of heat that you would have from the fresh ingredients and a product as rich or richer than would have been produced
by simple composting.

It would be a fascinating study to see the flow charts, say five years into the project, in a complete agriculture/recycling venture where everything was utilized in a methane/compost process for energy production and the "by- products" used for fertilizer.
After that we'd take a mid-sized municipality and convert all the waste therefrom into methane to generate electricity and compost to feed the community gardens.

Hmmmmmm............

{cross post edit}

Wood chips do heat, especially if ground with the green leaves intact.
Wood chips make a longer duration heat as they break down slower.
Just mix half and half with your favorite stall cleanings to get the nitrogen up for quicker decomposition.

[Marcia in MT]

Mother Earth News ran an article about this a long time ago. If I recall correctly, the pile was made of nothing more than wood chips. Black plastic tubing was run throughout the pile, and then the pile was watered.

It still sounds like a neat idea.

[bruceki]

I get loads of chips from local tree service companies; usually 30-50 yards a week, and the piles are very hot. I spread them out 2-3' deep in pads and my pigs bed down on it. If they're cold, they burrow into it. Incidentally, while they're doing this they're also stirring it and fertilizing it. Works well for everyone.

Bruce / ebeyfarm.blogspot.com

[Ken Scharabok]

I'm wondering if you couldn't make a bin out of 4' x 4' pallets held upright by 4" posts. two rows. One inner and one outer. Put insulation (e.g., straw bales or composting material) between the rows. Then run your piping within the pallets in the inner row. In that manner you could remove the pile with a front end loader if it needed to be replaced without damaging the piping.