Kiln dryed vs air dryed !!!

[Johny Walker]

what is the clorific differance between the 2, seen k/d adversised @ 15%/20% ?

 

are air dryed are under 20% ,

 

do k/d give of more heat or is it just a sales gimmick

 

 

cheers johnny

[tommer9]

Kilning should result in no more than 12% as far as i know, so that is nonsense.

[Johny Walker]

but do they give of more heat ??

[tommer9]

The dryer they are the less calorific value in them will be used to drive out moisture so will effectively give out more heat, yes. How noticeable the difference will be between logs at 20% and 25% M.C. is another matter.

[WFWales]

The calorific value depends on the moisture content of the wood - see the graph on this sheet - http://www.biomassenergycentre.org.uk/pls/portal/docs/PAGE/RESOURCES/REF_LIB_RES/PUBLICATIONS/FC-BEC-INFOSHEET09-LOGSFIREWOOD-2.PDF.

 

Nothing to do with the method of drying, although over cooked wood can lose some heat value if "over cooked". Generally soft woods have a slightly highr calorific value than hard wood.

 

Only burn dry wood!

[Peter]

Kilning should result in no more than 12% as far as i know, so that is nonsense.

 

Depends how long you leave it in for, and how good the kiln is. An old insulated truck body with a couple of fan heaters could be considered a kiln.......

[renewablejohn]

We can even achieve kiln dried results in a "Solar" kiln polytunnel with MC down as low as 12%. Totally pointless though if you deliver to a customer who leaves the logs out in the rain as the logs will act as blotting paper and soak up any available moisture. Even in a dry shed the moisture could reabsorb upto 20% MC.

[Alycidon]

We can even achieve kiln dried results in a "Solar" kiln polytunnel with MC down as low as 12%. Totally pointless though if you deliver to a customer who leaves the logs out in the rain as the logs will act as blotting paper and soak up any available moisture. Even in a dry shed the moisture could reabsorb upto 20% MC.

 

 

Last Sept my logs kept in a barn with 3 closed sides were soft 3% hard 9%. By December the hard had all gone and the remaining soft was 18% or so. Now we have had a long dry spell the remaining odds and ends were 5-7% when I checked a load out this week. This is only surface moisture though, a more accurate figure could be gained by splitting it and checking the newly exposed surfaces.

 

Sofwood at 25% will burn reasonably but Ash wont, it will burn yes but far from well.

 

A

 

A