Drying Rates and Settings in a Dehumidifier Kiln

      How to understand your dehumidifier kiln's capacity and drying rate. December 6, 2012

Question
I am still new in drying lumber and I have a question about setting temperatures. I am drying 4/4 with mc of 25% +/- , and my settings are 125 and 104. The WB is staying at 106 with the compressor running nonstop, and it is losing 1.3% daily. If I raise the dry bulb, will it lose more mc? Or will it not make any difference once the compressor is running?

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
Basically, the DH unit will run and extract more moisture if it is a bit hotter, but I do not think it will change the drying rate that much if it is already running full time. When it begins to cycle, then go for it.



From the original questioner:
OK, so how can I change the drying rate to 1.6%?


From contributor J:
What brand of kiln do you have? I have a Nyle and I set temp at 100 degrees when mc over 25% but less than 35% - cubic air flow of 500--600 cfm. The compressor is set to 85% for white oak in this range of mc. Don't dry it too fast, it will get checks in it and cup.


From the original questioner:
Itís a Nyle, so is 1.3% daily is good enough?


From Gene Wengert, forum technical advisor:
With the compressor running all the time and your RH being still quite high, you are getting the maximum drying possible from your equipment. You need more HP to go faster.


From contributor W:
If the compressor timer is set at 85% then the compressor shuts off every hour for nine minutes. The water on the coil re-evaporates and when it starts again, it has to cool the coil down. All this reduces the effective drying capacity. Set it at 100% which is safe as long as you are sure everything in the kiln is below 20%. You didn't say how much lumber is in the kiln or how old the unit is, but if you check the manual, you can figure out if you are running right.



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


    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.



    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2019 - WOODWEB ® Inc.
    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.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB











  • WOODWEB - the leading resource for professional woodworkers


      Home » Knowledge Base » Knowledge Base Article