Lincolnshire farmer and engineer Tom Lamb has set himself the challenge of building a low-cost heating system powered by farmyard manure.

To do so, he’s exploiting the exothermic properties of decomposing muck and straw – a free resource on his 200ha beef and arable farm.

This process is in a similar vein to Victorian gardeners who managed to grow tropical plants in British greenhouses 150 years ago.

See also: Managing welding fumes on farms – all you need to know

Rather than spend big, he’s limited his proof-of-concept budget to £200, a chunk of which he spent on the series of water-filled steel pipes welded to the floor of his 12t Marston trailer.

These are routed down through the deck near the tailgate, where they are fitted with quick-release couplings.

© Tom Lamb

Once the trailer has been positioned near to the workshop radiator, the pipes are joined and the 12V pump fired into action to push the water through the system.

Heating up

With the hardware in place, Tom has turned his attention to the art of extracting as much heat from the muck as possible.

His heap, typically made up of soiled cattle bedding, tends to range in temperature from 50-70C.

However, it can be supercharged, both by mixing and aerating the material and through adding other ingredients.

© Tom Lamb

“My hunch is that heat output peaks at around 50-70% decomposition. To get the temperature higher, I’m going to experiment with compost, grass clippings, horse muck and wood shavings,” says Tom.

“They should give it a serious boost; I’ve mixed wet grass clippings with cattle muck before and it self-combusted when it reached 150-200C, so I know the potential is there.”

So far, the warmest he’s got the water in his heating system is 50C. You can follow Tom’s efforts on his YouTube channel.