Last spring I posted about our compost water heater and how pleased with myself I was at the time. The system was a bit improvised though, it worked quite well as far as the water temperature went, but there were a few of problems.
We used a common plastic hose which was not really fit for purpose. Often the water had a slight smell after passing through the hose, this is I think was a combination of the material deteriorating due to the heat and the fact that, because at the time we were not living here full time, sometimes the water was sitting inside the hose for two or three days as it was not being used.
The other problem was that the point at which the plastic hose joined the blue PVC pipe was a weak spot. The hose split a couple of times near the joint, and as a result water was leaking into the compost pile and making it too wet.
The new system has addressed these problems and it seems to be working well so far, the water gets heated, the smell has gone and there are no problems at the joint. This time we have used thick 1″ irrigation type PE pipe and the connector is designed to fit the PVC pipe.
Other improvements are that the water pipe is on blocks, raised from the ground and also that we have kept it in its original coiled form, which should make it much easier to move when it’s time to change the compost pile.
It is possible that there is an ideal ratio between the amount of water being heated and the size of the compost pile, and that we have not found it yet, or that different ingredients in the compost pile produce heat at different rates, this time we used a lot of corn stalks through the wood chipper, at the beginning the water was too hot to use and had to be mixed, now it has cooled down a bit, we have had about six weeks of hot water so far, we just need to keep the pile wet to keep the heat going.