cornish wood burner

Lot of talk about the spores but don't forget the carbon monoxide. Oxidation increases with heat so your fermenting pine could be busy producing CO in the back of your van or chip store. I would expect the clouds of steam and spores seen rising from disturbed wood chip to also contain CO.

Two years on but I think this might be worth discussing. We store our biomass wood chip in a large open shed at anything from 20% to 35% MC. What we normally see is the chip heating up (even if it averages 20% to a degree )and the steam finding a way up through the chip. This causes damp patches on the surface so could be a likely growth area for mould. Not so much of a problem for us as we move it by telehandler but even then on occasions we have felt the need to wear a mask. However if your store in enclosed and you need to enter it to say clear a blockage you should be aware of a couple of dangers. 1 The mould spores could be highly concentrated in the enclosed silo area when disturbed. 2 Potentially worse would be the carbon monoxide from the decaying chip or pellets. To reduce the risks from either, ventilate well before entering a silo, wear a good mask and ideally have a safety line with a second person at the end of it.

Absolutely correct Bob except for the last bit. It has a very good scientific basis. Low fire box/ furnace temperature will give poor combustion. The large wood burners I run burn best/cleanest if they are run hard and I don't see any different principle for the smaller ones. I'm sure that is what Andrew (openspaceman) was endeavoring to find out but his query was not answered.

Sounds like it might even be something to do with wind or some other factor affecting the flue draw. Could this affect your secondary air input and cause your smoke. If your secondary air input is too low why not feed some in higher. Probably not difficult job and I expect it would improve your problem. Primary air under the fire , secondary over it

Bark is a couple of % down on energy and high in minerals so not top class fuel, according to Joseph Binder ( Binder Boilers ) who I met about 10 years ago. Looking back now he gave us some very good info, pity our installers didn't spend more time with him. Never knowingly burnt willow in the boilers but we have had ash melting at one stage in the early days when the Austrians changed the settings remotely. Looked bit like Portland cement and water with no sand. I sometimes burn willow in my Rayburn but funnily enough it doesn't seem to get quite that hot.

We notice the difference when burning slab wood compared to round wood. I'm farly sure that bark has a bit less energy as well

Could you be burning smaller diameter logs so more bark for the same volume of wood. More bark = more ash

I'm not familiar with the boiler you mentioned but I run a couple of larger chip boilers. Smoke is normally due to not enough secondary air in relation to the primary air. Incomplete combustion of the volatile gasses driven off, increase secondary or reduce primary whichever suits the output you require.

As a rough guide for you if you want to move 1 KW from a room at 30 deg C to another room at 10 deg C you will need to move almost 2.5 cubic Metres of air every minute. As Gillsgardening said you need a wood burner designed to do this. Feed your system hot air then the flow drops to a sensible rate.

That's all we fit now. When you have long tunnel (40 to 50 Metres )end vents don't do much unless its on a good slope. I have a couple of lads who have the hang of doing it. I believe they start at one end, one clipping on to the tube and the other keeping the poly straight and taut. Keeping every thing straight and square helps. I appreciate the expense thing but it would give you better temperature and humidity control as the seasons change. If you change your mind I will ask them for some hints. I presume you know about bracing the end hoops and not putting the polythene on upside down.

What vents have you planned Have you straight sides, if so there are some neat roll up systems

If you havn't already done it lay a water pipe to the centre of the tunnel so you can have a tap there.

Agreed. I've made up an extension lead with 2.5mm cable for my pressure washer which is 2.9 kw. Shorter the better though. Volt drop = more current= more heat= shorter life

It would take a lot of air flow to move much heat. Too breezy in your lounge then I would think. Back boiler in your existing fire heating your hot water and a rad ? Or go bigger but as you say more money.

So will the cable be 8 mm all the way? Remember the heavier the load the more sag you need otherwise the tension will be too high. If you are a featherweight then at least 3M of sag to keep within the SWL( assuming 8 mm cable. Do not tension then put a heavy weight on it. Other way around to give you a guide of the tension. Most IMPORTANT have someone looking on ready to scrape you off a tree or pick up the pieces if the tirfor or cable breaks.

Regarding the pressure it depends what you are splitting. Most of my wood has knots in so I find I often need 8 tonne. 300mm ash normally just needs 4 tonne. Sounds like you have decided vertical, I think both have advantages. I have a horizontal splitter, down side is a 2 ft ring is heavy to lift on, up side is you are loading, turning and taking off without bending. Still picking up from the ground unless its from the trailer. Not sure which is best but I am happy with mine.

Have either a two speed facility . I find that really usefull. It certainly speeds things up especially when you don't need full power or travelling up to the log. Look at the machine weights, that will give you an idea of the strength of the build. Spring return is good. Returns while you reach for the next log. Return stop to reduce stroke when not needed

I think I will need to get a piece of 441/444. Needs to be about 500mm x 400mm x 8 mm thick. The grate is sectioned into different areas ,and that supports a short section.Total furnace grate area is close to 1.4M x 1.8M. ( 4'8" x 6') Thanks anyway

Thanks but I suspect it might be a bit small. Our boiler is 1 MW. What size is your Charnwood

Hi Alec I did a spend a little time researching this afternoon and having two grades to look at really helped. Very relieved about the expansion on the ferritics and the cost can do no harm either. Absolutely top notch advice and information, thank you very much.

Not that it matters but I believe 50 M of 6 mm is only 7kg. Also only a proportion of that needs adding into our calculations. When we get to the heavier cable then obviously it will be more significant.

Agreed its 738 for 50 kg My mistake I never included wire weight. I presume 9kg is a proportion of the total cable weight. As you say bit much for 6mm.

Here's the start of an idea for you guys to think about. If you need the run your logs down hill it is going to take time to retrieve the pulley. So have two lines, then when a log is sent down line one it pulls the retrieval rope of line two pulley around a pulley to bring it to the top.

I make it 625 to lift 50kg. Remember the tension provides lift from both directions.

Thanks I will do a bit of searching. Problem is I don't know what the boiler manufacturer used originally. Would be good to upgrade slightly. Might bite the bullet and try a bit of 441 as Alec suggested