Greenhouse or Polytunnel heat

Have you ever heard of this type of heat not elec in your greenhouse.

Woood chips.

Manure both off these seemingly give off a type of heat for a greenhouse or polytunnel.

Be intereseted to hear your views or if anyone has heard of this method.

 

Works in theory, but I suspect not in practice. It would have to be a very large pile of woodchips. I have collected woodchips from a sawmill yard. The pile was 15 foot high and when you put your hand inside it was really hot.

Anything that composts gives off heat. Its the same principle that made haystacks burst into flames, if the hay was a bit wet. I remember as a boy going round with a farmer and a haystack thermomiter on the end of a long pole, measuring the temperatures. But I suspect that the pile needs to be pretty big.

At the Lost Gardens of Heligan, they have a greenhouse that used to be heated by rotting manure. It needed a lot, and I think that they had to renew it about three times over the winter. This was the original and only way of heating greenhouses in the distant past. Similarly they would grow winter produce that was simply planted on top of a manure heap.

 

I heard that too about the Lost gardens of Heligan. There was something about it in 'Grow your Own' magazine.

So yes it is possible to heat your greenhouse this way, but not the cleanest way, but possibly the smelliest.

:D :D :D

 

As this is also going to be an educational and opedn to the public nature reserve.
Think they may want to use cheapast aspect or even show different methods.

Its certainly going to be an interesting and on going project for some time in our area as there will be ever growing changes.

 

Hi Scotkat,

If it were a polytunnel.. the very first thing i would do before considering any type of heating would be to put a double skin on it and inflate it! (1/4" - 1/2" wg.h20)

This alone could cut your heating requirement by 30-50% so a few lorryloads less manure to find

Stateside and elsewhere in the world have been using this technique for decades (well over 40years!) while amazingly we continue to waste winter energy in inefficient greenhouses.

If you ask your local greenhouse supplier.. chances are they won`t have heard of them, much less be able to sell you one.

With energy prices continuing to skyrocket, the proverbial penny will eventually drop.

As always, just imho

 

Hex this nature reserve is a big concern and I think they have put alot of thought it to this.

A polytunnel is getting donated to them.

Thankyou for you reply very interesting.

 

Here`s some interesting info on compost heated greenhouses,

The composting component needs to be sized on the basis of its carbon dioxide production.
If the composting component is sized to heat the greenhouseââ?¬â?in a mild climate, half a cubic yard of compost per square foot of greenhouse(!)
ââ?¬â?the amount of carbon dioxide generated will be six times that needed for optimal CO2-enriched atmospheres, and the amount of nitrogen (ammonia) released will be fifty times that needed for optimal plant growth.
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By that token, a 20` x 30` polytunnel (600sq.ft) will need a compost heap 26` x 26` x 12` high (300 cu.yds)

..that`s an awful lot of manure