Quick question - manufactured solid fuel vs anthracite

[Tim W]

Hi,

Just about to order some fuel for the stove and I'm confused...

The destructions mention only wood (stove tiny, not very practical) or MSF (manufactured solid fuels).

It's an Aga Little Wenlock Classic 4-ish kW jobbie.

However the Aga brochure for that stove lists recommended fuels as:

Ancit, Phurnacite, Coalite, Sunbright, Anthracite Large Nuts, Welsh Dry Steam Coal, Dry Seasoned Wood and a few other specific brands.

As I'm about to order a tonne, I don't want anything that's going to warp the stove from overheating or clag the flue.

There's a good deal on anthracite large nuts from a welsh company at little over 300/tonne so that would be my preferred choice.

I rang Aga to ask their tech dept and got some dippy woman who read the instructions which I've read already and said "no coal" because coal wasn't mentioned explicitly. She was unable to elaborate on which type of MSF was recommended and there are many, some are so cheap they much be manufactured out of part recycled material. Others are really expensive (getting on for

500/tonne).

So what do I believe - instructions (vague) or brochure? Is anthracite similar in burning properties to the random ovoid things?

Sorry - I don't have any experience of stoves - I was brought up with open fires that you could burn pretty much any old crap on.

Thanks in advance :)

[Mike Barnes]

Tim W :

We've got a Little Wenlock 2. We've burned - for about five years each - house coal, Coalite nuts, and anthracite. And lots of wood. No problems.

[Tim W]

Mike Barnes wibbled on Tuesday 01 December 2009 18:08

Brilliant - just the info I need :)

I have infinite wood from pallets here, so I'd better start breaking that up for kindling...

Having done some studying, a lot of the premium smokeless fuels seem to be made from anthracite dust anyway. On the other end of the scale are "eggs" made from "recycled materials". The latter look cheap and a bit suspicious.

On an aside, it is interesting that I can get a ton of coal from Blaenau to Sussex about 50 quid cheaper, including 57 quid delivery, than I can buy it from the coal merchant in the next town. Can't be arsed to negotiate so the welsh win :)

[geoff]

In message , Tim W writes

You want to speak to Gavin - he's the know-all there

[Tim W]

geoff wibbled on Tuesday 01 December 2009 22:12

Thanks Geoff - I'll ask for him if I ring them again.

[Tim W]

geoff wibbled on Tuesday 01 December 2009 22:12

Although I would have expected Aga to manage a bit better than dippy blond with a script for tech support... It was like talking to Virgin about broadband but with less random rebooting.

[The Natural Philosopher]

Antracite is almost pure carbion, welsh dry steam coal is a bit more bituminous.

Most of the manufactured pellets are just coal dust compacted.

Any will work, siome better than others.

Go for it. Not cheap, but good stuff.

Better and cleaner IME. less ash content.Those nuts seem to be largely powdwered rock..

[Tim W]

The Natural Philosopher wibbled on Tuesday 01 December 2009 22:29

That was my limited understanding about anthracite from its use in steam engines - low clinker production and low tar although I'm sure that's a very plebby way of describing it... Anyway, seemed to me to be a perfectly good option because of its use in steam boilers but I know I don;t know much about coal(!)

I was getting that impression looking at lots of random makes today. The only thing I can see going for manufactured fuel is regularity of lump size and density.

Jolly good :)

I don't mind trying a few as long as it doesn't become an expensive experiment!

You should see what the local lot want for it. 400/tonne... Comes of living darn sarf...

I'll go with the coal then. I can get the odd bag of random other stuff locally for comparison purposes...

This is going to constitute 50% of my heating this winter, hence the interest in saving a few quid.

Ta

Tim

[The Natural Philosopher]

Yes, the uptime on an aga is like a linux system. Generally as long as there is no definite hardware problem ;-)

[jim]

I looked into this Q when chez nous had solid fuel CH (Aga-made boiler IIRC, taken out in 1999).

Ancit, Phurnacite and Sunbrite are all manufactured from some form or other of powdered coal + a cement-like bonding agent). Anthracite is, of course, natural. Those were the 4 fuels we used. I did look into other options but sorry can't recall details)

I found out the thermal capacity of each fuel from the coal marchant. Alas I no longer have the exact data to hand, but in summary Sunbrite has the least thermal capacity; Phurnacite, Ancit and Anthracite are similar. Try asking your merchant Overall the cost of each fuel was much the same per heat unit. The difference comes in their burning characteristics and convenience.

IIRC Ancit came on the scene in the early 1990s when there were production problems at the Phurnacite plant. IIRC Ancit originates from Germany. Ancit burning characteristic is very similar to Phurnacite.

Sunbrite was best at the beginning and end of the season - it released less heat & there was less tendency for the boiler temp to run away. (overheated boiler =3D slag + over hot house + more fuel burnt than required + more attention required+++ etc etc).

In the depths of winter we turned over to Phurncite which burns at a higher temp and releases more heat.

In between we tended to mix Sunbrite & Phurnacite. In selecting which fuel, you tend to get a nose for the weather and house temp and, especially, how windy it is. Wind we found was the worst problem in keeping a steady boiler temp.

Burning Phurnacite in unsuitable weather meant boiler temperature control was more problematic - hence our preference for sunbrite in early & late season.

Our experience of Anthracite was that it burnt cooler than Phurncite

- more like Sunbrite but it released heat over a longer time span, so the boiler didn't need topping up so often.

Finally there are differences in the ash. Phurnacite and Ancit both produce much fine powdery ash which rarely slags. Sunbrite produces less ash but frequently slags - just a touch of over-temp can cause slag to form. BTW slag formation is something to avoid as much as poss as it intereferes with fuel combustion & thus the amount of heat you are getting.

Anthracite IIRC was easiest ash-wise, producing least of all and not inclined to slag.

HTH

[Tim Lamb]

In message , Tim W writes

During my research into log burners there seemed to be a potential issue with the composition of the metal used for the grate.

Solid fuel required something more expensive than for wood. Your burner is rated suitable for solid fuel so you should be fine.

I finally got round to moving the thermostat out to the hall and fitting an adaptable CH pump. The current problem is getting the main house down below 75 deg.F with all day firing on the log burner. Two big baskets of logs though!

regards

[Tim W]

jim wibbled on Wednesday 02 December 2009 10:32

Interesting. Maybe I've got lucky - my anthracite came in a bit cheaper than expected (delivery was actually 34 quid when I phoned the order in to DJ Davies Fuels) and *much* cheaper than anything else I can get my mitts on without another round of research and phone calls. Their MSF prices are comparable to the coal but I don't recognise the brands (Superbrite, Cosibrite and Blaze). Some suppliers are charging crazy money for Phurnacite et al, eg Ancit from coals2u.co.uk is 478/tonne (ow!).

That's very interesting.

That's very useful to be forewarned. The wind plays merry tunes on our chimneys and it's been strong of late, so I expect some fiddling to get used to this. Hopefully it will be a matter of playing with the air dampers on the stove to get the desired results.

That might be a good thing as there's furniture 4 foot from the stove, so whilst I'd like as much heat as possible, having a cooler burn is probably beneficial to avoid roasting everything.

Excellent. Stoves aren't cheap and flue liners cost as much again, so not buggering up either is a definate plus :)

I wonder how well anthracite slumbers?... I'll find out next week :)

One other thing - I don't have a proper bunker - so I'm stacking bags of it in an old pallet crate round by the shed. It's occurred to me that perhaps some of the MSFs might be quite water absorbant and thus a bugger to light if they get rained on. Coals better in that respect, should only get wet on the surface.

Thanks for the very informative response Jim - much appreciated!

Cheers

Tim

[Tim W]

Tim Lamb wibbled on Wednesday 02 December 2009 10:44

Yes. There are just so many MSFs around that I couldn't work out how different they all were. But I'm happy now.

Ideally I'd love to burn logs (lots of woodland round here so wood can get acquired for sensible money). Unfortunately the fireplace opening is only

20" wide so that limited the choice of stoves. Mine will burn wood, but you'd only get a 2-3 of 3" logs in at best. Pretty but not very practical.

[The Natural Philosopher]

Jim's data is pretty consistent with my ancient recollections of all this from childhood.

Anthracite banks down really well overnight. Its a very high density of carbon to almost anything else.

It will clinker up if run hot though.

But its the best, along with dry steam coal, there is. The use of cement to bind the manufactured nuts is probably why they have a high ash content.

[Andy Dingley]

Often used filter bed coke, crushed & eggified.

They presumably make them into eggs to try and explain the peculiar sulphorous smells generated when burning. You can also get a lot of clinker (i.e. a problem in a rotating grate) from the poorer grades of this stuff.

[Mike Barnes]

Tim W :

You said it was Little Wenlock IIRC. According to the instructions you can remove the bottom-grate, firebricks, and ash pan if you're only burning wood. That would improve the capacity a bit.

[Tim W]

Andy Dingley wibbled on Wednesday 02 December 2009 16:08

As in sewage farm filter beds? Ew...

I know what I put down the drains and I don;t want to see it on my fires ;->

I was right to be skeptical then - my tiny little rotating grate really won't like that.

When I did my 1/2 day steam train driving (birthday present) the bloke was bemoaning some of the coal they'd been getting - said at the end of the day that there could be a layer of effectively glass on the grate and if you didn't break it up whilst it was hot it was a bugger to get out later.

[Tim W]

Mike Barnes wibbled on Wednesday 02 December 2009 16:34

Interesting. Mine (which is a "Classic") comes with an extra plate that goes over the main grate for wood. Can't remove the grate as the refactory blocks it on it (AFAICT). I can remove the front guard metal though.

[Andy Dingley]

Oddly that was also my first experience of the joys of second-hand coke and its fireproof habits (albeit many years ago).

Welsh steam coal is finally back available, according to the last Old Glory

[jim]

yes - that slipped my mind. The Aga boiler we had was supposed to be filled every 8 hours which was impractical. But mostly we managed 2 x daily. Anthracite - when we had it in stock - was very useful in late autumn/early spring. A filling with sunbrite could easily be almost gone by the morning. Anthracite could burn all night & there would still be a useful amount left in the grate next morning.

Relighting the boiler in the morning was something I dreaded - in itself sometimes difficult in certain wind conditions & on top of that we would be rushing to get out to work. If it had to be left out all day, it was a cold house we'd be returning to. Something to avoid.

Also as another poster mentions, some of the manufactured fuels can produce a whiff of sulphur. That wasn't a perpetual problem, so it may have depended on the batch: sometimes I wondered if it was due to the fuel having got wet.

Quite good fun all in all. A solid fuel boiler is like having a pet in the house. You get to know its moods and when to feed it and it pays you back by keeping you superbly warm as you can't turn it off.

Enjoy.

HTH