Ideal Log Diameter??

[Witterings]

Is it me or do big logs burn slower and therefore more efficiently???

 

Mine are all cut to about the same length ... about 9/10" is ideal for our smallish stove ... but they vary quite a lot in how much they've been split / the diameter so I tend to use more of the smaller smaller diameter whilst heating up the stove which produces a more flame and embers as a bed then switch to larger diameter to keep it "ticking over".

 

Say for example you had a 10" diameter log and split it in half OR split it in quarters which would burn for longer the 2 larger pieces or the 4 smaller pieces??

 

Don't know if anyone has a definitive answer to this but be interested in hearing people's opinions.

[scbk]

34 minutes ago, Witterings said:

Is it me or do big logs burn slower and therefore more efficiently???

 

Say for example you had a 10" diameter log and split it in half OR split it in quarters which would burn for longer the 2 larger pieces or the 4 smaller pieces??

 

These are 2 different things

 

Having a knarly old lump of oak sat looking at you, smouldering away for hours isn't very efficient, it gives off more pollution, and doesn't give off much heat.

What is the main source of heating in the house?

 

For efficiency, I would think as a minimum, you want to be able to get atleast 3 logs on the fire at once, so it would depend on the size of the stove.

[Witterings]

12 minutes ago, scbk said:

These are 2 different things

 

Having a knarly old lump of oak sat looking at you, smouldering away for hours isn't very efficient, it gives off more pollution, and doesn't give off much heat.

What is the main source of heating in the house?

 

For efficiency, I would think as a minimum, you want to be able to get atleast 3 logs on the fire at once, so it would depend on the size of the stove.

 

It's gas central heating although we're a bungalow and whilst we haven't had any really cold weather since having it installed a few weeks ago, when we light the stove I switch the heating off and it provides enough heat throughout the property.

 

Can certainly get 3 logs in at a time if they're not all bigger ones.

[Rob_the_Sparky]

A lot of variables is what I find...(my stove also calls for 9" logs but my biggest logs are ~12")

 

As above to get a very longest burn then you have to stop the gases burning and that is inefficient and risks depositing tars etc in your flue.  Not a good idea.

 

Assuming you are not smouldering a log as above then I find it varies with wood type.  A single big hardwood log is often hard to get to burn well (stove has to be pretty hot when it is added).  A piece of lighter softwood in large chunks does work well, cut it small and it just burns very hot for a very short period of time, a bigger log gives a more sustained heat.  With dense woods I generally chop it smaller (exceptions when it is a git to split) and for lighter (less dense wood) I use bigger chunks.

 

To give you an idea I might split a 12" lighter wood into 4 pieces or 6 or even 8 pieces if it is a denser wood.  I don't think though there is a single right answer and I am certainly still experimenting and only have one stove to play with.

[sandspider]

I seem to remember seeing somewhere that 10cm diameter is the best size for optimum burning. Most of my logs are around this size (length varies), and it seems to work well in both my large and small stoves. Having said that, I will put a bigger one or two on sometimes to keep it going for a bit longer, as long as it's still flaming rather than smouldering.

[Woodworks]

Smaller the better for a clean burn I would have thought if you provide enough air.

 

From the Jotul website. I presume where it says 10cm in length it means width and got muddled in translation 

 

Wood sizes and surface area

The type of wood used is only part of the process of getting the right fire within your stove. The size of the wood logs is another factor to consider. The main reason that you always see wood being split is to take advantage of the surface area of the wood itself. Putting a full log into the fire will burn, but will not burn effectively. The outside structure of the log locks in the wood, making it difficult for the fire to penetrate the space. Splitting logs into fourths or eighths enables the surface area of the log to be maximized to the point where the log is large enough to burn for a long time but still allows the fire to penetrate properly. Any log over 10 cm in length needs to be split for proper circulation and efficiency. Most wood cutters know this and will maintain their wood stacks with this in mind, so it should be no trouble to purchase wood that is split properly.

[Steven P]

Whch would burn longer? (If it will continue to burn) the single larger log will take longer to burn, split it and it will burn quicker. I think it is all to do with the surface area of the log - the more surface area, the larger area for the fire (sort of - am sure there s a technical term for this).

 

Jotul website is probably correct, any log over 10cm in length should be split - not a translation error - 10cm long or more (so a 30cm long log should also be split...)

 

My preference is a smaller diameter log just to get the heat output, but also thinner logs dry quicker (I tend to split mine 4 ways regardless to maximise surface drying area)

 

 

[gdh]

Technically I would think smaller is better with the extreme being a woodchip boiler which is far more efficient than a log burner but in reality unless you can get a slow and consistent feed with no waste heat you'll probably use less wood overall (and effort) with bigger logs.

[Witterings]

Cheers for everyone's input ... seems like there's no definate answer so guess I'll probbly keep doing what I have which is putting on 2 smaller one's with one bigger .... the smaller produce more flame and possibly help the bigger burn as well and seems to be a happy medium.

[Silverhooker]

A good mix of both sizes and of hard and soft wood is the best for my stoves, larch mixed with sycamore and scot's pine mixed with beech is good. The golden rule is to only burn dry wood 'cos wet wood is worse than useless .