Kiln dried vs air dried

[rowan lee]

'Essentially kiln dried firewood is firewood that has been baked in an oven to speed up the drying of the wood. By drying the wood this way valuable energy is lost as volatile esters from the wood evaporate. Whereas if you burn air dried firewood that has been left outside to naturally dry by the sun and wind you will get more energy from the wood as these lost volatile esters are retained.'

 

I found this quote on a firewood website recently. Is this statement about lost energy in kiln dried timber true? Not really familiar with the science behind timber and 'volatile esters'

[ThrustSSC]

If there is any loss, it's minimal. And if the kiln drying is 'hard' enough, the loss is more than compensated for by the increase in efficiency of the burn.

 

Given most kiln drying is relatively low-temperature, I'd dismiss this one as being bunkum.

[openspaceman]

If there is any loss, it's minimal. And if the kiln drying is 'hard' enough, the loss is more than compensated for by the increase in efficiency of the burn.

 

Given most kiln drying is relatively low-temperature, I'd dismiss this one as being bunkum.

 

I'd agree, also I think he is confused about esters as I think you would be up into pyrolysis temperatures for organic compounds to crack this far, I thing he means Volatile Organic Compounds which are driven off before any pyrolysis starts, these can be a bit nasty but their calorific value is pretty insignificant and we didn't notice much even at 150C.