Why do some woods produce more ash than others?

[Flyguy]

Ash (as opposed to unburnt chars) is the mineral content that doesn't burn. Think calcium carbonate, potash (i.e. poassium salts) and various phosphates in diminishing order. As the chemical composition of wood varies from species to species, so does the relative content of these compounds.

 

And then you get impurities that don't actually form part of the chemical structure of the wood as well, sometimes known as adjuncts.

 

 

Good post !

 

Not only will the amount of such unburnable mineral content vary from species to species but also from tree to tree depending on the soil conditions they grew in.

 

Just one of those things I'm afraid....

[Woodworks]

Ash (as opposed to unburnt chars) is the mineral content that doesn't burn. Think calcium carbonate, potash (i.e. poassium salts) and various phosphates in diminishing order. As the chemical composition of wood varies from species to species, so does the relative content of these compounds.

 

And then you get impurities that don't actually form part of the chemical structure of the wood as well, sometimes known as adjuncts.

 

Thanks for this, it makes sense.

 

Our firewood customers have mentioned that they get more ash from our wood than other suppliers but find ours the driest. Could the mineral content be effected by how fast a tree grows? as all our wood is coming off hedges from land around the moors so slow growing due to height and wind.

[tree monkey]

the hardwoods are slower growing so the annual rings are smaller so the capilleries are smaller resulting in smaller volume of air in the timber unlike fast grown softwoods and willow etc so maybe theres more ash due to the density of the wood.

Maybe just a thought

[HCR]

Apart from moisture content, does it also not depend a bit on the particular stove setup with regard to efficiency, fire box temperature (in relation to wood type)etc?? These factors seem to be focused on by manufacturers when it comes to emissions and also effect what is deposited in the flue.

 

It can do, but not hugely.

 

If it gets hot enough, some compounds/elements will vaporise and go up the chimney. Some small particles will go up on the draught as well.

 

Stove factors aside, the composition of wood from a particular species will produce a fairly constant level of ash.

Edited November 23, 2012 by HCR

[teepeeat]

It can do, but not hugely.

 

If it gets hot enough, some compounds/elements will vaporise and go up the chimney. Some small particles will go up on the draught as well.

 

Stove factors aside, the composition of wood from a particular species will produce a fairly constant level of ash.

 

Ta HCR

[gensetsteve]

It can do, but not hugely.

 

If it gets hot enough, some compounds/elements will vaporise and go up the chimney. Some small particles will go up on the draught as well.

 

Stove factors aside, the composition of wood from a particular species will produce a fairly constant level of ash.

 

This also makes sense as softwood often leaves a very light fluffy ash which could easily be drawn up the chimney. self cleaning ash pan with softwood then