Convection venting solar kiln

[59Billy]

Here's an idea I've been kicking around:

Build a small kiln, 100 bf or less, with an external solar collector. Feed the air from the collector into the bottom of the kiln, with vents at the top of the kiln.

Would convection supply enough air flow, or would Ijust be building a mold farm?

[Radar67]

Try a search (at the top of the page) for solar kilns. You will find a lot of useful information and plans there. Air drying in our neck of the woods is too fast for some wood. I would air dry it first, then put it in a solar kiln to finish it off. Also, you need to use something like anchor seal to slow the drying down. It helps prevent the checks and cracks that come from drying too fast.

Stew

[59Billy]

Try a search (at the top of the page) for solar kilns. You will find a lot of useful information and plans there. Air drying in our neck of the woods is too fast for some wood. I would air dry it first, then put it in a solar kiln to finish it off. Also, you need to use something like anchor seal to slow the drying down. It helps prevent the checks and cracks that come from drying too fast.

Stew

I did the search (both here and "over there"), but it seems like all the plans involve fans. That makes me suspect that the convection idea isn't feasible, because it's a pretty obvious idea ID IT WORKS.  I do plan on the air-dry-first route. I'm mostly just curious about the convection thing.

[Radar67]

I read an article a few weeks ago about solar collectors for heat. The individual used them to heat his shop, he also used convection to circulate the heat from the collector to the shop, using an adjustable vent to regulate the amount of heat. I think it would work for a solar kiln as long as the wood had a chance to air dry first. Mold needs moisture and a food source to grow, if you get the moisture content down to say 20% air drying, then make sure the convection allows good circulation through your kiln, there should not be enough moisture available for the mold to grow. Also remember to allow enough spacing in your stacks to promote good circulation through them (it is easy to reduce the amount of spacing to get more wood on the stack...and that is a bad thing ) Direction the flow of air in the kiln would be the biggest concern IMO. Your baffels would have to be just right to make sure everything flowed properly and got even coverage of the wood.

Stew

[59Billy]

That's a good point about airdrying first --- pretty much safeguards the wood.