Compost heat pump?

[richbee]

Has anyone ever used the heat from a compost heap to heat water?
https://en.wikipedia.org/wiki/Compost_heater
I started thinking about it as I bought a compost thermometer, mainly our of interest to see if my pallet compost bins would get hot enough to kill weed seeds.
Yesterday it was at 64°C!!!
I realise it would not be so hot in the winter, but makes me think there should be a way to use some of that heat

[Marcus]

I know of someone who managed to use a compost heap to warm his greenhouse a little, but it required regular turning of the compost to sustain heat generation, and of course continuing new 'fuel' supply

[Stinsy]

I used to know a guy who kept horses. He had a setup whereby the “solar” loop at the bottom of his tank circulated through the manure pile.

It wasn’t possible to measure how much heat was scavenged but it must’ve been significant and worthwhile running the circulation pump and paying for the pipe/pump/antifreeze. Having the manure pile right next to his house had downsides and digging the rotted manure out around the plastic pipe was a pita, though.

How many watts of heat do you think a typical compost heap gives off? Should you maybe insulate the heap?

[Bugtownboy]

If you ever get to Madrid, visit the Botanical Gardens. There is a tropical/palm house that has a central trough with cast iron grating.

This was used to heat the place over winter after it was filled with manure/compost in the autumn.

I think there’s also a thread either on here (or the other place) of using very large compost heaps to provide heating to dwellings.

I suppose it’s feasible, just depends how practical.

[Joeboy]

There was a fella that did this in forests. Made monster compost piles and heated everything he needed.

Worth a read.
https://www.permaculturenews.org/2011/1 ... -pain-way/

It would be easy enough to run a gravity fed system ending in a tap for outdoor hand-wash testing. If it works upgrade to a 2nd hand mixer tap and run the cold water feed from the top tank.

[AE-NMidlands]

If you ever get to Madrid, visit the Botanical Gardens. There is a tropical/palm house that has a central trough with cast iron grating.
This was used to heat the place over winter after it was filled with manure/compost in the autumn.
I think there’s also a thread either on here (or the other place) of using very large compost heaps to provide heating to dwellings.

I suppose it’s feasible, just depends how practical.

I'm sure the Victorians had "Melon beds" which were big cold frames installed on a manure pile - or one with deep foundations filled with the stuff - for the heat.
I was surprised that there wasn't a problem from either ammonia given off or excess humidity.
A

[Moxi]

Didnt someone from St Elsewhere used to do this I recall their avatar had a straw pile with perspex or something over the top and black hose in-between, I want to say they were based in Ireland but that could be compete hogwash and I could be mixing up several threads.

Moxi

[richbee]

I used to know a guy who kept horses. He had a setup whereby the “solar” loop at the bottom of his tank circulated through the manure pile.

It wasn’t possible to measure how much heat was scavenged but it must’ve been significant and worthwhile running the circulation pump and paying for the pipe/pump/antifreeze. Having the manure pile right next to his house had downsides and digging the rotted manure out around the plastic pipe was a pita, though.

How many watts of heat do you think a typical compost heap gives off? Should you maybe insulate the heap?

With a very rough calculation - If the compost heap is approx 1 cubic metre, and the temperature is roughly 50 degrees above ambient, and the compost is largely water, or at least has the same specific heat capacity as water (4200j/kg/°C) - and assuming the whole heap is the same temeprature - which it won't be:
1000 x 50 x 4200 = 210MJ of energy - that sounds like a huge amount - but equivalent to 58kWh if my calculations are correct!

[richbee]

There was a fella that did this in forests. Made monster compost piles and heated everything he needed.

Worth a read.
https://www.permaculturenews.org/2011/1 ... -pain-way/

It would be easy enough to run a gravity fed system ending in a tap for outdoor hand-wash testing. If it works upgrade to a 2nd hand mixer tap and run the cold water feed from the top tank.

Or an outside hot tub or paddling pool, take advantage of the spring / summer high temperatures.....
https://www.cotswoldkoi.co.uk/product/s ... mkQAvD_BwE

[Mr Gus]

Didnt someone from St Elsewhere used to do this I recall their avatar had a straw pile with perspex or something over the top and black hose in-between, I want to say they were based in Ireland but that could be compete hogwash and I could be mixing up several threads.

Moxi

Yes, wasn't that DH? I get confused, so many folk in the migration changed monikers or got lost.