Wood Chip heating (not pellets)

[josa]

Hi - does anyone have experience of domestic heating by burning wood chips? (not wood pellets as they seem to need some more specialist equipment to produce for fuel than my fairly sturdy wood chipper) -  I have a couple of acres of woods and coppice that could produce a lot of wood chip material and I was wondering how it could be used for heating. I currently have a Rayburn which burns coke in the winter running two gravity fed radiators, and gives hot water (supplemented by cheap rate electric). I also have a log fire for the main living area, again supplemented by cheap rate night storage heating. My energy costs are quite low, but I have the opprotunity to look at the system as I could change during renovations  -  and I would welcome any views.

Thanks - JD

[Poolguy]

By a long shot the best heating solution for those equipt to do it.

Least maintenance, most energy, least cost, DIY if you want it.

The secret is to build you own chip dryer, as you point out any chipper large or small will produce the material to burn but you need to dry it and store it for when you want it, otherwise you risk spontaneous combustion. That stage is not so simple but, I designed a solar powered dryer (thermal not electric) for use in africa (low tech) and a feeder, not rocket science.

The burner is specific as well and you need to get the dimensions of the chips right otherwise you get endless blockages, but its simple enough stuff. If you looking at burners get one with forced air or even better pressurised oxygen to the combustion chamber. That way you get a complete burn and little or no ash to shift every so often. THe ones I am looking for will produce an ash pellet the size of a hockey puck every 3 weeks. Keen stuff.

There are also many other things that you can burn, quit surprising too, dried corn for instance, rubber chips, .....the list goes on.

Free energy, .... not quite,  but going in the right direction. Connect it up to an accumulator and its cosy time for the duration, solar for a boost through the warmer months.

Andrew

[josa]

Thanks - I am really attracted by - as you describe - almost free energy - do you have any recommendation for suppliers or even plans for a dryer etc - DIY is also attractive for me - I have looked on the www but they all seem to be for pellets, not chips.

Best wishes for Christmas to you all - JD

[Vanman]

We are having a Hargassner chipped wood burner installed to heat our barn conversion. I expect it will be great, but:

• It is expensive initially: these boilers cost more than most other types

• You need a large silo to store the dried wood-chips in (they are light and bulky - we are using an old external rainwater cistern)

• The feed from the silo to the burner is via an archimedes screw, which can be noisy (metal on metal, and no lubrication - squeaks and screeches)

• These boilers require 3-phase electricity - there are no single-phase ones available

If you can live with all that, it's certainly the way to go: renewable energy, complete with a 50% tax credit if you are a French taxpayer.

Even if you don't go the whole hog to chip and dry your own fuel (the chipper needs to attach to quite a large tractor, I believe), there is the advantage that chipped wood can be dried to the correct moisture content much more quickly than logs do.