Which to build? Solar or DH Kiln

[GeneWengert-WoodDoc]

Let's say your wooded location gives you 2/3 of the open location.  So, instead of 45 days to dry green oak, it will take you 67...that is, 50% longer.

[Glenn1]

Here is a hypothetical sizing question.  If I build a kiln that is 8 feet high in the back by 8 feet deep and 12 feet in length, I come up with approximately 132 sq feet for the collector.  Based on the 10 bf of wood to 1 sq ft of collector, I should be able to dry upwards to 1300 bf at a time.(I think)   Now what would happen to the wood if I only put 300 bf into the kiln either as green wood or air dried wood?  Would the heat from the kiln  overpower the 300bf of wood and cause all kinds of problems or would it work fine for any amount smaller than the maximum?

[WDH]

For many species drying from green, the answer is Yes.

With very fast drying species like most softwoods and some soft hardwoods, you might get away with it.  With green oak or other slower drying species, that would wreck it. 

Air dried wood would tolerate it better. 

[GeneWengert-WoodDoc]

With thicker wood, slower drying is required.

[Ianab]

You can always rig up a removable cover for part of the collector. Couple of sheets of tin and some studs and wing nuts to hold it in place. Cover 2/3 of the collector area and your ratio is sensible again. Of course if you are drying softwoods, then just let it cook.

Ian

[Glenn1]

You can always rig up a removable cover for part of the collector. Couple of sheets of tin and some studs and wing nuts to hold it in place. Cover 2/3 of the collector area and your ratio is sensible again. Of course if you are drying softwoods, then just let it cook.

Ian


Hello Ian,
So you are saying  to put the tin cover on the outside of the clear collection plate to block the sun? Possibly, I can find the same corrugated sizing so the tin cover fits right on top of the clear top.  Since the cubic footage of the larger kiln will be considerably larger than the stack of lumber, I am guessing that it will be a trial and error scenario adding coverage until I get the correct temperature.    Would that be a correct assessment?

[Ianab]

Yeah, it's not an exact thing. But the collector sizing doesn't need to be exact, you have quite a margin between too fast and too slow. Covering part of the collector is just a way of "throttling" the solar power.

Ian