Author Topic: Gas vs wood fuel technical question  (Read 8824 times)

Re: Gas vs wood fuel technical question
« Reply #25 on: December 11, 2015, 09:07:20 pm »
My parents have given me some large rounds which are very, very hard to split.  It's more a case of knocking bits off the sides as they won't split through the middle.  The smaller they get, the less tough they are.   I think it's fairly old beech which has gone hard.
Never tell me the odds.

Re: Gas vs wood fuel technical question
« Reply #26 on: December 11, 2015, 11:31:59 pm »
It is far easier to split the wood when it is newly cut, before letting it dry.
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fuaran

  • rothair gasta
Re: Gas vs wood fuel technical question
« Reply #27 on: December 12, 2015, 01:14:36 am »
A hydraulic log splitter can make it a lot easier.

Mrs Pingu

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Re: Gas vs wood fuel technical question
« Reply #28 on: December 12, 2015, 11:06:36 am »
I'm still no closer to deciding what to do  :-\
Do not clench. It only makes it worse.

Re: Gas vs wood fuel technical question
« Reply #29 on: December 12, 2015, 12:12:19 pm »
It is far easier to split the wood when it is newly cut, before letting it dry.
I think that's why they gave them to me!
Never tell me the odds.

Re: Gas vs wood fuel technical question
« Reply #30 on: December 12, 2015, 12:34:29 pm »
We have had our wood burner for two years now and it is now the main source of heat in the flat. The central heating is set to 15c but rarely comes on. The flat actually feels dry and warm now, something we never felt with radiators alone.
Oh and stove top cooking is nice as well.

Wombat

  • Is it supposed to hurt this much?
Re: Gas vs wood fuel technical question
« Reply #31 on: December 12, 2015, 02:41:29 pm »
IF going down the open fire route should check flue lining. An unused sealed non ventilated flue will produce interstitial condensation.

CICO chimney linings retrofit new refractory lining via chimney breast.

http://www.chimney-problems.co.uk/

I am sure that there are other companies out there this is just one I know of.

Yup, CICO is the thing...  we had a wood burning (well, multi fuel, actually) stove fitted about 10 years or more ago, and didn't line the flue.  This was OK, but common sense said we lined it as it was a bit crappy, so we had ours done by CICO, and do not regret the £1800 spent for a moment.  Obviously the process introduces moisture in the lightweight insulating concrete used, but then the stove will gradually dry that out, and keep it dried out.  We own our house outright, and of course it adds to the value of the house, but you will need to consider if this is appropriate for your flat, which presumably is leasehold.

I'd be in favour of a woodburning stove, they really aren't much trouble.  Easy to light, yes, there's a bit of ash to remove, but generally no grief, and the hotter flue temperatures over a gas fires will help to keep the flue nice and dried out.  For solid fuel stoves of any sort, you need a better sort fo flue liner than you need for gas.  I think its either a double layer stainless steel one, or something like the CICO.  An additional plus point for us, for the CICO system, is that it structurally stabilised the chimney a bit.  This may or may not apply to chez Pingu.
Wombat

Mrs Pingu

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Re: Gas vs wood fuel technical question
« Reply #32 on: December 12, 2015, 03:01:33 pm »
Hmm, CICO stabilising the chimney might be a good idea as we do sometimes get bits of what I assume are the old lime parging https://www.spab.org.uk/advice/technical-qas/technical-qa-27-chimney-maintenance/ falling down the flue when it's windy and rainy. Having said that I'm just about to get the thing repointed to replace the cement pointing with breathable lime mortar at great expense so would putting an impermeable liner in be such a good thing? Also we're in Scotland so we own the flat, it's not leasehold.
Do not clench. It only makes it worse.

Mrs Pingu

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Re: Gas vs wood fuel technical question
« Reply #33 on: December 12, 2015, 03:11:15 pm »
Hmm, needs access point every 2 meters? Hahaha, that's not going to happen. We're talking granite here....
Do not clench. It only makes it worse.

Aunt Maud

  • Le Flâneur.
Re: Gas vs wood fuel technical question
« Reply #34 on: December 12, 2015, 04:55:59 pm »
My parents have given me some large rounds which are very, very hard to split.  It's more a case of knocking bits off the sides as they won't split through the middle.  The smaller they get, the less tough they are.   I think it's fairly old beech which has gone hard.

When you hit it with the splitting axe, strike it at the edge furthest away from you and not in the middle of the round. That way you can run the split from the edge into the centre of the round.

Re: Gas vs wood fuel technical question
« Reply #35 on: December 12, 2015, 04:58:39 pm »
And when it splits unexpectedly, your axe will go through, the handle will hit the log and either be damaged or the end will kick up into your face.

Strike the log side closest to you, not furthest away.
<i>Marmite slave</i>

Aunt Maud

  • Le Flâneur.
Re: Gas vs wood fuel technical question
« Reply #36 on: December 12, 2015, 05:00:35 pm »
And when it splits unexpectedly, your axe will go through, the handle will hit the log and either be damaged or the end will kick up into your face.

Strike the log side closest to you, not furthest away.

Strike the log closest to you and you're guaranteed to hit your shin with the axe and make a bloody mess, but if that's your thing, don't let anyone stop you.

Re: Gas vs wood fuel technical question
« Reply #37 on: December 12, 2015, 05:09:22 pm »
No - not unless you are doing many many things wrong.

I had to chop 1-2 barrowloads of wood from age 13 until 19, every day.
<i>Marmite slave</i>

Aunt Maud

  • Le Flâneur.
Re: Gas vs wood fuel technical question
« Reply #38 on: December 12, 2015, 05:30:12 pm »
And my chainsaw is bigger than your chainsaw.  ;)

Re: Gas vs wood fuel technical question
« Reply #39 on: December 12, 2015, 05:41:14 pm »
Typical.   A couple of cyclists bragging about their Choppers...   

Re: Gas vs wood fuel technical question
« Reply #40 on: December 12, 2015, 07:49:05 pm »
And my chainsaw is bigger than your chainsaw.  ;)
No, didn't use a chainsaw until I was 19. Firewood for heating and cooking for a household, all cut by hand.
 :P
<i>Marmite slave</i>

Re: Gas vs wood fuel technical question
« Reply #41 on: December 13, 2015, 08:04:33 am »
It's amazing what can be done with a couple of steel wedges and a 7lb sledge. ;)

PH
Bees do nothing invariably.

ElyDave

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Re: Gas vs wood fuel technical question
« Reply #42 on: December 13, 2015, 08:37:15 am »
We had a log-burner installed last year. Our external chimney stack had previously been taken down, back into the loft floor. They dropped a flexible steel liner tube down our old chimney and bridged the gap between loft floor and the roof tiles with stainless steel "double wall" tube.

We have a Burley wood stove which are claimed to be around 89% efficient when up to temperature.  Since their operating temperature is many hundreds of degrees I imagine the steel tube in the old chimney must be doing a good job of drying out any damp. 89% efficiency is up there with modern Gas boilers (though I expect there are all sorts of caveats if I expect to achieve that figure). They use secondary combustion to ignite unburnt gases.  The way logs burn in an efficient sealed stove is very different to how they burn in an open fire.

Burley call it "the fireball effect".  The logs aren't burning as you'd normally expect, they just get so hot that it "squeezes" the gas out of them and you see the gas burning.

I was so impressed I took a video of the effect... Fireball 2ndary combustion
The log just slowly turns to dust over a period of about an hour and kicks out 5kW (I have a very small stove which can turn out north-facing front room into a sauna if we leave the door closed).

You also have a 30Kg lump of iron acting as a radiator in the morning, many hours after the actual fire has gone out.

I clean the ash out my my log burner about once a month, because there isn't any ash left to speak of, possibly a few tablespoons of it. It burns logs to dust. They are very efficient.

Open fires are extremely inefficient unless you view them as an efficient way of getting rid of surplus wood rather than an effective way of heating a room.
Open fires are about 10% efficient and a really bad one, with a poorly matched chimney, can actually draw more heat out of the room than it puts back.

Cleaning a steel tube will also be less hassle than cleaning an old chimney I expect.

From a combustion point of view, you are always burning in the gas/vapor phase. Its a very complicated bit of thermodynamics/ chemistry where you are essentially taking the longer carbon chains and breaking them down into those that can burn hence you seeing that phenomenon of gas burning at the surface of the log

We used to have a similar cast iron fire and when I bought the house had some coal which left the obvious residue, we then found a source for some farmed beech which left almost no residue. It all depends on the mineral content in the wood as well.

The best fire I had by far was a gas fire that took the flue gases and put them through a catalytic converter which then threw it back out into the room. No heat wasted up the chimney, but of course that doesn't solve the current problem
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Gas vs wood fuel technical question
« Reply #43 on: December 13, 2015, 09:17:22 am »
There is a fundamental misunderstanding about how wood burners work.  Most people are familiar with gas central heating and radiators.  These don't radiate at all, in fact, but heat the air around and above them and cause convection around the room, so it feels warm because the air is warm.  Woodburners mainly radiate heat, although they do convect a little bit too.  Heat from the fire heats you quite directly and gives rise to that lovely deep warming feeling you get.  You can feel warm in a room with a wood burner going even though the air temperature can be quite low.  This is a good reason to get a wood burner on its own, but if you're not on the gas grid and/or have access to free wood they become a sensible option. 

They are not a sensible option if you live in an urban area and have to buy in wood and have access to mains gas.  Just use gas.

Fortunately the fad for wood burners seems to be passing as quickly as it came and there will be quite a few stoves sitting as ornaments in urban homes while the occupiers turn the central heating up a notch.  Wood prices can return to normal and we are seeing less townie wood scroungers in the woods this season.

Re: Gas vs wood fuel technical question
« Reply #44 on: December 13, 2015, 09:25:12 am »
I'm not sure what the situation is with gas fires, but a wood burner wouldn't usually have any requirement for a power supply, so can operate completely independently of whatever else might have occurred (power cut, central heating not working, excessively chilly, etc...). If your central heating runs on gas it also provides you with an opportunity to balance your heating costs a little between the two fuels depending on cost, or other factors. I currently pay about 6 to 6.5 p per kWh for reprocessed wood fuels (as pellets), you would probably pay a bit more for smaller quantities, and logs/briquettes may be a bit more too. I've no idea how the cost of gas would compare, although I wouldn't be surprised if it is cheaper. If you burn reprocessed wood you won't be a townie wood scrounger, and it is certainly a lot less hassle than real wood and probably not much more costly either if you don't have your own supply.

JennyB

  • Old enough to know better
Re: Gas vs wood fuel technical question
« Reply #45 on: December 13, 2015, 10:42:41 am »
Typical.   A couple of cyclists bragging about their Choppers...

Maybe they need one of these http://www.leveraxe.com/english/index.htm
Jennifer - walker of hills



Re: Gas vs wood fuel technical question
« Reply #46 on: December 13, 2015, 10:45:38 am »
I've seen that and read the reviews. Before I watched a vid of a review I'd formed the idea that it was the sinclair C5 of the axe world; the review confirmed this idea.

a standard splitting maul, an axe and a chopping block are all that is needed; well, that and the space to make a mess in.
<i>Marmite slave</i>

Wombat

  • Is it supposed to hurt this much?
Re: Gas vs wood fuel technical question
« Reply #47 on: December 13, 2015, 11:00:51 am »
Hmm, CICO stabilising the chimney might be a good idea as we do sometimes get bits of what I assume are the old lime parging https://www.spab.org.uk/advice/technical-qas/technical-qa-27-chimney-maintenance/ falling down the flue when it's windy and rainy. Having said that I'm just about to get the thing repointed to replace the cement pointing with breathable lime mortar at great expense so would putting an impermeable liner in be such a good thing? Also we're in Scotland so we own the flat, it's not leasehold.

Parging?  Luxury, when I was a nipper, we ....       no parging on ours!  Hence the desire to line it!

Ah, I wondered about the Scottish ownership situation, and owning a flat, just as I typed that bit.
Wombat

Wombat

  • Is it supposed to hurt this much?
Re: Gas vs wood fuel technical question
« Reply #48 on: December 13, 2015, 11:06:08 am »
Hmm, needs access point every 2 meters? Hahaha, that's not going to happen. We're talking granite here....

Eh?  Ours has a single access point outside, but that's as much for sweeping it the easy way as anything.  Best to get a CICO person in to look at it, if you are thinking that way.

Dunno about folk saying about the cost of wood.  Admittedly mine isn't the main source of heat, its additional, and backup, and for use on miserable damp days, but I've never paid for wood, it just sort of happens.  I know used pallets aren't the finest wood source, but when its free, and you work for an organisation that gets tons of paper delivered on nice clean non-returnable pallets, they'll do nicely, thank you.
Wombat

Mrs Pingu

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Re: Gas vs wood fuel technical question
« Reply #49 on: December 13, 2015, 11:26:35 am »
I read here https://www.google.co.uk/url?sa=t&source=web&rct=j&url=http://www.solidfuel.co.uk/pdfs/lining_old_chimneys.pdf&ved=0ahUKEwj_n8Df3NjJAhUJPhQKHXMQDhIQFgg-MAU&usg=AFQjCNH6oSFRsLMdLuYwBh7swyWDG2KDIw&sig2=ivpqMNdlXDOcl9bN-jpiZQ that they need to put something in the flue every 2 meters to make sure the rubber sausage that they pump the lining round is centered in the flue.
Do not clench. It only makes it worse.