uses of a woodchip pile

[teepeeat]

agree with Dean - you will strip the heat out quite quickly if heating a workshop or house. Would need to be done on an industrial scale to make it viable for a single house I would think.

On the other hand, it would do no harm if you put your chip pile over a buried pipe array for a geothermal heating system. It would surely improve the COP of the system and have the benefit of not having the pipes in the pile making it much easier to turn over periodically etc.

[Albedo]

Regarding the extraction of heat and continued supply of heat we have a chicken and egg situation.

 

It would help to understand exactly where the heat comes from as the bacteria don’t arrive after the heat… they produce it:

 

“The rise in temperature in a composting mass is caused by thermophilic bacteria as they break down (Nitrogenous) material for food and use the nutrients gained for reproduction they release energy as heat.”

 

“The bacteria, responsible for raising the temperature in the pile, feed on microorganisms found on high nitrogen organic materials so a C: N ratio of around 30:1 (high nitrogen) is recommended.”

 

(Source is some old notes of mine)

 

So if you maintain optimum conditions for the bacteria, the extraction of the heat they produce should not be a problem.

 

The bacteria feed on high Nitrogen material and woodchip is high Carbon so you can feed them by adding green matter or manure.

 

They need aeration (02) and moisture so turning the pile every couple of weeks will aerate it and cycle nutrients from the outside to the inside. You don’t want it too wet or you get anaerobic conditions, which is the end of your good bacteria.

 

The idea of pipes under the pile extracting the heat along with the above maintenance of the pile to keep the bacteria going should work in theory.

 

My guess is that it will slow down the composting as the bacteria will slow down a bit as a result of the heat extraction. This is fine as the goal is production of heat rather than production of compost.

[BTS]

we had a homeless man sleep in edge of pile when worked in london he said it was wonderful never got round to trying it myself yet

[Albedo]

we had a homeless man sleep in edge of pile when worked in london he said it was wonderful never got round to trying it myself yet

 

I believe homeless people are quite high in Nitrogen so adding them to the pile could work out well:001_smile:

 

Edit: a mate of mine used to sleep in the pile when between squats, can't remember the name of the firm now but in SW London...it'll come to me later.

Edited December 7, 2012 by Albedo

[face cord]

Read more: How to Compost Wood Chips for Heat in a Greenhouse | Garden Guides

 

How to Compost Wood Chips for Heat in a Greenhouse | Garden Guides

 

 

 

 

Interesting warning

 

Watch wood chip compost piles of any type carefully for excessive inner temperatures and spontaneous combustion. Grass clippings or poultry manure mixed with wood chips can provide the extra nitrogen wood needs for decomposition, but can also boost wood chip pile temperatures to the combustion point. Monitor CO2 and nitrogen levels in any greenhouse or hoophouse and ensure adequate ventilation for plant growth as well as human health.

[John Barleycorn]

I looked into this as well. You need at least a 3metre high pile of woodchip with pipes running through. In fact you need 2 heaps, because as the first starts to cool, you need the second to start heating up.

[face cord]

One someones made

 

Wood chip Compost Water Heater

[NoRush]

Face Cord that wont work very well as you need green matter to get things composting well. I my large pile you can tell when the chip was added because chip with no green matter dont rot to quick.

My idea of running a pipe in the pile would mean that the water would work like a central heating system once warm/hot it would continue to circulate around thus not extracting to much heat from the pile in one go. Anyway once composting is done no more heat is generated

[Albedo]

I looked into this as well. You need at least a 3metre high pile of woodchip with pipes running through. In fact you need 2 heaps, because as the first starts to cool, you need the second to start heating up.

 

An optimum height for a pile is around 2.5 to 3m. When it gets much bigger than 3m the process doesn't work so efficiently. So your 3m is an optimum height rather than a minimum.

[treedom]

Intersting stuff guys thanks for the info and links and thoughts.