Night-time Reconditioning in Solar Kiln Operation
The nightly humidity increase in a solar kiln is not harmful to the drying lumber, but helps to relieve stress. December 31, 2013
According to all I've read about the VT designed solar kiln, when it cools down at night and the RH rises, it effectively conditions the lumber and relieves stress introduced during the day.
I read recently from a supposedly knowledgeable source (formerly with the Forest Products Lab) that the RH humidity increase at night was not only an unintended consequence of the design, but was in fact detrimental to the lumber, since re-wetting the boards would lead to surface checks and worse.
My response was that "re-wetting" was not the correct terminology for the absorption of water vapor, but I'd like some additional information on the subject. Dr. Wengert, if you read this, please respond with clarification on the nighttime conditioning issue with a solar kiln. Does it degrade the lumber or not?
From Professor Gene Wengert, forum technical advisor:
The high RH is indeed a good thing. The info from the other source is incorrect regarding rewetting and damage in a solar kiln. The slow increase is safe.
Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?
Have you reviewed the related Knowledge Base areas below?
KnowledgeBase: Knowledge Base
KnowledgeBase: Primary Processing
KnowledgeBase: Primary Processing: Kiln Operation
All rights reserved. No part of this publication may be reproduced in
any manner without permission of the Editor.
Review WOODWEB's Copyright Policy.
The editors, writers, and staff at WOODWEB try to promote safe practices.
What is safe for one woodworker under certain conditions may not be safe
for others in different circumstances. Readers should undertake the use
of materials and methods discussed at WOODWEB after considerate evaluation,
and at their own risk.
335 Bedell Road
Montrose, PA 18801
Copyright © 1996-2017 - WOODWEB ® Inc.