Wood Drying Topics > Moisture Variability

Deciding when to use equalization

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TILLAMOOK:
Deciding when to use equalization.  If your standard deviation is high (above a 4) can equalization be a viable and economically valuable tool specifically with Hemlock or other white fir?

ingo wallocha:
Hello Eric,

If your standard deviation is 4% an above equalization or reconditioning would most probably be a good idea. What species do you dry and what would you have available for reconditioning? High pressure hot water or low pressure steam? Or just cold water sprays?

What is your incoming standard deviation? I mean you can sort of reverse engineer that problem by introducing very uniform initial moisture contents in the kiln but that would require some kind of sorting. 

I need some more information to make a final judgement and give you some suggestions.

Looking forward to your reply!

Regards,
Ingo

HencoV:
If your standard deviation is that high, I would first try to eliminate all factors that could cause variability. "Reverse engineering" as Ingo puts is a good start. I suspect a lot of people will be shocked to see actual wet variation!
Always start with the basics: dimensions, air flow, heat distribution. A simple thing like one vent opening slightly more or less than the next vent on the same kiln can do funny things to air flow, energy transfer and final moisture content. Even many steps with big jumps can result in greater MC% variability.

If the basics are right and your schedule is optimal...equalizing and conditioning should (almost) not be necessary.

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