Today's
Sponsors:


Finish Systems

Firth Maple Products

FORDAQ

FormWood Industries

Freeborn Tool Company

Fuhr International

Fuji Spray

Gabbiani Machine

Gary M. Katz

Global Hardwood Flooring

Glue Machinery Corporation

Goby Walnut Products

Graco, Inc.

Granite Road

Grayson Ferguson Woodworking Inc.

Great Lakes Kiln Drying Association

GreCon

GUHDO

Hanson and Leja Lumber Company

Hardwood Council

Hardwood Store of N.C. Inc.

Heartwoods, LLC

Her-Saf

Hermance Machine Company

High Point Grinding - Total Saw Solutions

Historical Plus Wood

CNCROUTERSTORE.com

CNT Motion Systems

Colonial Saw

Construction Programs and Results

Cook's Saw Mfg.

COOLwoodworkingstuff.com

Country Saw & Knife, Inc.

Courmatt International Inc.

CP Adhesives

CSH Custom Service Hardware Inc.

CTS Manufacturing Inc.

CustomMade.com

Cutlist Plus

D.S. Brown Machinery

Dancer Lumber

Delle Vedove USA, Inc.

Delmac Machinery Group

Delta

Denray Machine

DeVilbiss

Dispoz-A-Blade

Diversi-Tech

DMC

DODDS

Don Hall & Associates

Donald Dean and Sons

Durable Wood Products

E.W. Tooling Inc.

Eagle Machinery and Repair Co.

ECabinet Systems

Edge-It Edgebanding

Edwards Wood Products

Electrophysics

Elias Woodwork & Manufacturing

Elkom North America

Emerald Hardwood Floors

Endeavor Hardwoods

EnRoute WOOD

ETemplate Digital Measuring

ETK International

EX-FACTORY

Excel Dowel and Wood Products Inc.

Extrema Machinery

ez-Router

FastCap




Temperature maximums for dehumidification units       and that's plenty. 1998.

by Professor Gene Wengert

Q.
Who might I contact to get advice on the construction of a dehumidification unit capable of processing 5-20k bf? I am not clear on the differences between a conventional dehumidification unit and one that is operated in an up to 180F environment.

A.
Because of the gases used in the original DH units (freon 20), the units were restricted to 115 F maximum, which meant that they could not sterilize the lumber and could not set the pitch. Plus drying was perhaps 3x longer than conventional.

When freon 12 was introduced to this industry, then the peak temperatures were about 150 F, which provided for sterilization and some degree of setting the pitch, but not total setting. Drying times were very close to steam kilns. I do not know of any that can go to 180 F and stay on DH operation.

Naturally, you can remove the DH unit and use steam to get from 150 to 180. But why? Nothing wrong with 160 F; in fact the wood is often better--it machines and glues better--if the maximum is 160 F.

I have seen plans and advice that NYLE Corp provides--they are in Bangor, ME.

Keep in mind that the difference between DH and steam is merely the energy source; the wood doesn't know how the heat got to 140 or 150 F or how the RH got to 45%. Therefore, either kiln, if properly operated, will produce the highest quality. (Don't fall into the trap of blaming GM for getting speeding tickets in your new Corvette--the operator determines the quality if you have a good system.)

Have you read "Opportunities for DH Drying" from the Virginia Forest Products Assn (804)737-5625?

Professor Gene Wengert is Extension Specialist in Wood Processing at the Department of Forestry, University of Wisconsin-Madison.

Click on Wood Doctor Archives to peruse past answers.

If you would like to obtain a copy of "The Wood Doctor's Rx", visit the Wood Education and Resource Center Web site for more information.



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: Primary Processing: Kiln Construction

  • KnowledgeBase: Primary Processing: Kiln Operation

  • KnowledgeBase: Wood Engineering: Wood Properties

  • KnowledgeBase: Knowledge Base




    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 © 1996-2009 - 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.
    RR4 Box 265A
    Montrose, PA 18801

    Contact WOODWEB













  •   Home » Knowledge Base » Knowledge Base Article