Comments on solar kiln design

[holliwr]

Hello all:

I'm thinking of building a solar kiln "around" my existing stack of cherry, beech, and persimon (sp?).  Based on many designs I have studied, here's what I'm planning to do.....

Simply build a 2x4 stud wall around the stack (it's on my porch by-the-way covered but with a Southern and a Western exposure).  Anyway, build 2x4 stud walls around the stack, then cover them with 6 mil poly.  The back wall will be 8" higher than the front (exposed) wall and will have 2 small openings cut as hot air outlets.  A small fan will run 24 hrs a day just to circulate air.  The top will be another stud wall covered with poly and just sit on top.  I'll add 3 industrail hinges to the front so I can prop up the rear of the top if it gets too hot inside.

Well, pretty simple, but I would like to entertain suggestions from anyone who has built or studied solar kiln designs.  Note that this design is only good for 2 or 3 chatges probably and will need to be rebuilt if the idea works well and i decided to make it permanent.

Thanks for any suggestins or comments.

Richard Hollingsworth

[DanG]

Hi Richard, and welcome to THE forum.

Now, I'm probably the biggest fan that Simple ever had, but you might be getting a bit carried away.  What you're proposing will probably get your boards drier than they are right now, but I doubt if you'll reach your target EMC doing it that way.

First, I think you need 2 chambers, one for the lumber stack, and one for the collector. You also need 2 fan systems, one to circulate the air over the lumber, and one to exhaust the moist air from the lumber chamber, bringing in the hot, dry air from the collector. I agree with using the cheap poly during the experimental stage. It's easier and cheaper to make changes. You can go to more expensive stuff when you have it perfected. You shouldn't need 2x4 construction. 1x2 firring strips should hold it up fine, with a little "engineering."  Celotex insulating board might be a good choice for the lumber chamber. Build that around your stack, then construct a little greenhouse over it with the plastic. Put in a couple of oscillating fans for circulation, and a small exhaust fan from the lumber box to the outside. Locate an intake vent for the collector at the other end, and a vent between the 2 chambers to transfer hot air, and you got a el-cheapo solar kiln. If it gets too hot, turn up the volume on the exhaust fan.

Now, on this other matter!  You're in SE Alabama, and I'm in NW Florida, so we can't be all that far apart. Where is you?

[holliwr]

Dan:
Thanks for the advise.  In all my research, I never noticed the inner chanber you speak of.  Glad you told me about that.  I'll do some more looking before starting construction and see if i can see a pic or something.  

I live in Hartselle, Al.  Not that far north of you.  In this area I have access to Amash mills in Tenn. where I can get ash, oak, cherry, maple, beech, poplar, pine, persimon, red cedar, black walnut, and birch.  All I have to do is dry it, perferably in less than a year.

Thanks again for the info.

Richard