Micro-Scale De-Humidifier Wood Drying

How to cobble together a miniature dehumidifier wood-drying kiln. September 17, 2008

Question
I saw a small amount of lumber with my Husqvarna 386XP and a chainsaw mill. I have a lot of nice walnut, oak and birdseye maple. I want a way to dry it besides traditional air-drying. Is there a way to get it down to 5-8 MC without buying a kiln or taking it to a dryer? I only saw on weekends and usually have about 10 boards 4/4 5foot long and 10 inches wide. I have a woodburning stove with a blower, what if I stacked and stickered them in front of it?

Forum Responses
(WOODnetWORK Forum)
From contributor D:
Try laying a piece of thick plastic film out on the floor twice as long and three times as wide as the stack of lumber is long and tall respectively. Sticker lumber in the usual manner and then wrap it up with a residential dehumidifier. Run the dehumidifier full blast draining to the hose. I have dried 4/4 crotch and root this way with great success. 2-4 weeks for material previously air dried a few months per inch. You can go too fast if not air dried for a few months first causing checks and radial honeycombing.



From the original questioner:
Thanks so much, I love the idea. I will give it a shot. The residential dehumidifier I already have should work great.


From Gene Wengert, forum technical advisor:
If you use this DH idea, which releases the refrigeration gasses into the atmosphere every few years, you need to also consider the fire hazard. Make sure you locate the kiln away from your home or shop. Home DH units have a habit of having a motor burn out and then smoke, etc. Of course, if you locate the unit outside, then the plastic walls will not work well except when the outside temperature is over 70 F; much cooler and the unit will freeze up and over heat.

In a regular small kiln, we will control the temperature and the RH to achieve the desired quality. You may have some quality losses without such control. Also, never mix MCs in the kiln. That is, do not add lumber sawn this weekend to a load that has already started to dry.




From contributor W:
I air dry in my shed, then put small quantities that I want to get dryer in my house stickered behind the couch for a month or so to let that last bit of water dry to the in-use level. Check the moisture with a moisture meter.