Greenhouse/kiln

[kenfrommaine]

Would a regular greenhouse maybe with some shade cloth over the lumber and some large fans work on drying lumber? I am thinking of putting up a god sized greenhoiuse for gardening and was thinking of making it longer and using one end for drying lumber, what would be the down side of doing this? I have plenty of room, and was wondering if this would work. thanks for the feed back.

[kenfrommaine]

I realize I wont be able to dry it down to 6 -8% but hoping it will speed up the process and get the lumber stabilized a lot faster 10 -12% then just stickering and covering it out side.  Any problems seen with my thought process on this?

[Southside]

I am interested to hear what other say.  I would also like to know just how big a "god sized" greenhouse is.   Gonna grow apples in there?  

[GeneWengert-WoodDoc]

A greenhouse has a few heat losses through the roof and walls, but does not have enough energy to evaporate all the water from wood...for example, green oak has around 4000 pounds of water per 1000 BF...that is about 500 gallons.  A green with drying lumber will heat to 30 F above outdoors.

[69bronco]

I think a lot would depend on what type of greenhouse you have. Mine is single layer greenhouse film and there is a lot of condensation. I have the bottom 32" solid and insulated. I can easily hit +100 during the day, night time temps are the same as outdoors by midnight or so. Hope this helps.

[kenfrommaine]

I am interested to hear what other say.  I would also like to know just how big a "god sized" greenhouse is.   Gonna grow apples in there?

:D not apple trees, figuring it will be 14' tall +- and 20'to 24' wide thinking 50' to 60' long. Just thinking of maybe speeding up the drying process of fresh cut pine and hemlock. I have the space and time. The area in it I use for gardening is just a bonus really I already have plenty of garden space and figure this might gain me a few weeks advantage on both ends of the growing season. I guess I shouild have worded the heading different, not really kiln drying but trying to accelerate the "air drying" part. 

[LeeB]

I would suspect that humidity in the greenhouse could cause issues with trying to use it to dry also.

[GeneWengert-WoodDoc]

The amount of moisture released from pine will quickly saturate the air.  This means mold.  If you vent, you will lose any solar heat.  You will find better drying- quicker drying and less expense - if you build an open shed without walls.  You can add fans to help the drying.

In Maine, the low sun angles and short daylight hours mean little solar input, October through March.  A fan shed will work well whenever you are above 50F.

A solar kiln would have four insulated walls and floor.  Only the south facing roof, at about 45 degrees is open to solar input.  Even then it will not work well October - March at your latitude.