Can anyone suggest a simple solar kiln design. A search of this forum and the web turned up a bunch but how do I know what works well or not. My method of air drying in a shed has worked well for building my cabin but Sarah has decided that she wants a red oak living room floor so I guess a kiln is the only way to get wood ready in a timely way. I only need enough wood to cover 300 sqft so I won't need a huge kiln.
Thanks for your input.
BTW, we dried red oak that had been under water for a long time by sticker it up in our loft and it was very dry after 7 months. I used it to make cabinets and it came out great.
Quinton
A proven design is right here.
http://www.woodscience.vt.edu/about/extension/vtsolar_kiln/
I built my kiln in 1994 from Dr Gene Wengert's plans and it was in operation until last year when I moved to beautiful Nob Hill Arkansas. I could dry two to four loads in a year down to 8% MC...less if I left the load in longer. It gets hot enough...180 degrees...to kill bugs and set pitch. I assisted with building four similar kilns over the years...some worked well while a couple had problems.
You can change the size, alter fans, improve doors, and make a different solar collector. You CANNOT skimp on insulation, caulking, or double glazing for the roof...or your kiln may have a problem.
(https://forestryforum.com/gallery/albums/userpics/10125/P6120001.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/P6120003.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/P6210001.JPG)
(https://forestryforum.com/gallery/albums/userpics/10125/P9060001.JPG)
I take it the tilt is for better solar collection?
you angle the roof at your latitude + 10 degrees. then you point the kiln due south if in the northern hemisphere and north if in the southern hemisphere.
Qweaver, you can't go wrong with the VT solar kiln plan as mentioned by Larry. There are many variations on the plan available at various college extension websites. The VT 2000 bd ft plan is on the VT site, but I think if you email Brian Bond, he has a smaller plan as well. I believe the kiln that Larry is showing is based on an early version of the VT kiln. The current plans utilize large doors on the back and do away with the lift up top.
Here's a link to a pdf set of plans from U of Wisconsin for a 750 bd ft kiln.
http://forest.wisc.edu/extension/Publications/98.pdf
Gene Wengert helped develop this style of solar kiln while at VT. He has since moved to UofW and the kiln plans have followed him there.
Last spring I took the solar kiln class at VT and I'm in the process of building my kiln. Hopefully, when I'm all done, I'll put all my construction pictures on a website for the world to see.
Dan, I'm aware of the roof pitch and direction requirements, I just never read or saw anything about canting the whole kiln at a compound angle. I'm assuming it is to better track the sun through the day.
compound angles? you lost me....
Ground slope!
Ground slope was my next guess.
Dan, If you look at the posts under the shed they are uneven in length. Maybe it's just me or simply camera angle, but it looks like the kiln is canted to one corner, thus setting the roof at a compound angle.
Down here, the sun travels nearly overhead. The Latitude is 10°. If I add 10° more, is that 70° or 110° ???
Will the collector be nearly flat facing the sky ???
If you add 10 more that wood be 20*, or nearly flat.
Well guys...I thought I built it plumb, level, and square ???...but Kathy tells me quite frequently that I'm a bubble off. :D ;D :D
Maybe you need to do an alignment on your camera. :)
Could be the operator needs an alignment. :D :D
We'd like to start building a kiln tomorrow based roughly on the solar kilns suggested in the posts above.
While I'd like to be able to fully dry my lumber my main reason for making the kiln is for setting the pitch and killing any vermin that may be a problem...and I need to do this setting and killing as soon as possible so that I can use the wood as interior paneling.
My main question is, can I add a dehumidifier and heater to the solar kiln design to get the temps up to the killing/setting treshold as quickly as practical? And considering the cool spring temps here in WV, how long will it take? We won't be getting a lot of help from the sun on a regular basis. What temp to I need to reach to do the setting and killing?
I've decided to make it 5' wide x 14' long.
I really appreciate any info that will help me avoid "re-inventing the wheel" ;D
Quinton
Do a search on Piney woods solar kiln. Think he has actually improved the design. The layer of sheet metal under the glazing eliminates the need for the black paint and the layer of plywood over the lumber, plus he says it is hotter, course he's in Louisiana. And the dehumidifier sounds like a good idea for woods that you can't hurt by drying too fast. Probably wouldn't want to do it to red oak. Where I live there's a lot less humidity than where he is, so maybe want to wait a little on the DH. Jim
The cool thing (no pun) about the VT kiln plan is it's almost "idiot proof." The engineering of the collector size will limit the drying rate and make it almost foolproof. It's designed to dry red oak, which is rated as one of the hardest lumber's to get good results from.
I was up there last week at the VT drying seminar, and they had just loaded the kiln with red oak right off the mill. Keep the vents closed, and let her dry.
I'm loading mine with cypress this week, (6/4) which is one of the more forgiving woods and dries quickly. Good luck and keep us posted.
By the way, don't even consider the hinged front plan. The latest plan utilizes large doors on the rear and facilitates loading with a tractor or bobcat if you have access to one.
Reviving an old thread here...
Based on the pics and info in this thread I'm thinking of building a VT style solar kiln. My main question for those who have built one, or one similar, is if it's possible to build without using plywood?
Almost seems criminal to buy any kind of wood products when you own a sawmill. My thought was to use board and batten siding (pine or poplar) and caulk the little gaps between the boards at the edges. Probably would use 6" wide 4/4 oak for the floor, relying on the plastic vapor barrier to keep it sealed. Thoughts?
You can use lumber if it is sealed well, but it is so much easier when building to use plywood. CD-X is OK which is not too expensive. Use two layers of thinner material for the floor perhaps. The vapor barrier is on the inside. You need a layer of wood on both sides of the wall.
The best angle is an angle equal to the latitude so that the sun is perpendicular to the collector on March 21 and September 21. To get better fall and spring performance, raise the roof angle (more vertical) by 10 degrees. But, this will drop summertime performance. The difference is small, however, so use the latitude most of the time.
Thanks for the info. I'll probably build it using the angles and dimensions in the plans, I'm just 30min south of Blacksburg, so the latitude in the design should be right for my location.
Not a scrap of plywood in mine. Every piece came off my woodmizer.. Works good.
Quote from: pineywoods on January 07, 2015, 11:09:36 AM
Not a scrap of plywood in mine. Every piece came off my woodmizer.. Works good.
Do you have a thread on building it? What method did you use for the walls and interior (Lap siding, board and batten, ship lap, tongue and grove, etc?) Floor? Thanks
Here's my "tried and true" solar kiln, and it looks like it's been in a war zone. It's dried a lot of lumber, many, many thousands of Bdft, and has taken some pretty good baseball sized hailstones going through both layers of plastic, survived a nearby tornado, and had half the plastic panels ripped off during big storm a few months ago. It's been patched, melted (thats what happens when power goes out and the fans stop turning) and faded but it still cranks out the lumber. I use an 8 gallon per day low temp dehumidifier to keep it working on cloudy, winter days, and it's my go to kiln for drying high dollar quarter sawn white oak. You can see some boards just visible in the picture.
I used sawmill oak on the outside and for all framing members, and pressure treated plywood on the inside,
YH
(https://forestryforum.com/gallery/albums/userpics/21488/solar_kiln.png)
Is that a Southern hemisphere special? (upside down)
Quote from: Verticaltrx on January 09, 2015, 04:05:15 PM
Quote from: pineywoods on January 07, 2015, 11:09:36 AM
Not a scrap of plywood in mine. Every piece came off my woodmizer.. Works good.
Do you have a thread on building it? What method did you use for the walls and interior (Lap siding, board and batten, ship lap, tongue and grove, etc?) Floor? Thanks
Here's the link to Planman's thread on the Pineywood's Wood Dryin Chicken Coop.....aka Solar Kiln. Gonna fashion one of these myself really soon!!
https://forestryforum.com/board/index.php/topic,50281.0.html
Quote from: Ianab on January 10, 2015, 02:54:36 AM
Is that a Southern hemisphere special? (upside down)
The wind from my computer must have rolled it over, :D I fixed it this morning...the lumber even stayed stacked :D
YH
So here's a question for the more experienced and technical minded..... @Planman built a great functional Pineywoods Kiln, but made it 18ft long to dry 2 stacks side by side. Is it possible, instead, to make the shed something like 12' x 10' and put two stacks in front and back? Or is the air circulation inhibited by the depth? I guess, too, the roof would be tall and long, increasing that cost.....At that point, maybe it's better to build two smaller kilns on skids......
You can certainly put 2 stacks back to back but if they are not in perfect alignment, the air will not get to the back stack. To eliminate the problem, you will need to leave more space between the stacks so the air can find its way through the 2nd stack.
Glenn
Planman's 18 ft length will indeed allow loading two stacks of 8 ft lumber, but that wasn't the main reason for the 18 ft length. Drying 16 ft lumber is why.
The original is 13 ft, but we discovered that there's not much demand for 12 ft boards. Placing 2 stacks side by side effectively is an 8 ft wide stack, which is too much for decent airflow, and even drying. Stack width in these kiilns is pretty much determined by the length of the forks on whatever loader is used to load stickered stacks of boards. Not much point in making the enclosure much wider even if cost was not a factor. Building 2 kilns and staggering the loads might be a good idea.