Whether to Run a Dehumidifier in a Solar Kiln

Solar kilns usually run too hot to be suitable for a dehumidification approach. Correct venting is the key. January 17, 2011

I just completed a solar kiln and I am running it now. Is it worth running a de-humidifier in the kiln as well?

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Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
Probably not...what species? What is the outside temperature?

From contributor T:
I agree. A solar kiln gets way too hot for a DH unless it's a commercial grade, and then why have a solar? The DH unit would not even come on in such high temps and if you wired around the thermal protection, it would fry it.

From contributor S:
If you have a lot of chilly, rainy days where the kiln isn't getting much solar gain and the drying is going slow, you could try it. I'd take the dehumidifier out of there if it gets really hot. Run the dehumidifier on a low setting early in the process. When in doubt, go slow. You can monitor how much water you are getting and change your settings accordingly.

Much depends on what species and if you have air dried first. Your cost of drying will be increased by the electricity usage but you'll get your lumber a little faster. If you are drying oak, a home D/H unit will be damaged.

From the original questioner:
Thanks for the advice. I am drying white oak right now. I think I have too large of a vent on the back side of my kiln. They are about 24" SQ. I am wondering if I am letting too much cooler air in there. I have 3 fans on a thermal switch set to come on at 80 degrees. Is that okay, or don't run the fans at all?

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From Professor Gene Wengert, forum technical advisor:
I think that the vent should be about 10% open at this time.