solar kiln questions

[starmac]

We have long daylight hours in the summer, but the temps are not high. Probably average in the 60's with a few days hitting 80, how effective would a solar kiln be in those temps.
Would it make sense to use one to partially dry then swap to a powered kiln?

[DDW_OR]

for the month of December 2015 we got just over 19 inches of rain.
For November 2015 we got just about 2 inches of rain.
here is my plan.
level ground where stack is to be, about 2 feet bigger per side and each end.
lay runners side to side that will elevate the stack about 6 to 12 inches off ground.
12 inches gives most cats room to get the mice, mine need 18 inches, BIG cat.
stack lumber using 1x1 or 2x2 stickers to allow air flow around boards.
paint ends of lumber boards to seal end grain to reduce cracking.
cover to keep rain and snow off. stake cover to keep sides away from stack.
maybe 12 inches off ground to promote side ventilation
place a heavy weight on top of stack to reduce warping and cupping.
heavy weight could be anything from large logs to Rail Road track or iron beams.

[GeneWengert-WoodDoc]

Although you have many hours of sunlight, the direction of the sun in the early morning and then late afternoon is way north.  A solar kiln is made for southern exposures.  Having east, west and even north clear walls will increase the heat losses and the net effect is negative.  Bottom line is that a solar kiln will not work well above 50 to 55 degrees north latitude.

[starmac]

I figured someone would tell me that. lol
Maybe with big mirrors placed in the right locations. lol

[kantuckid]

FWIW, that guy was not just someone-he was THE someone for your answer.  :D

[starmac]

Yup, that is who I wanted to answer my question. I kinda figured it was the answer I'd get too, we have lots of sunlight, but it is not high in the sky, like down south.

[GeneWengert-WoodDoc]

You could have some polished reflectors to bring the sun around to the dryer.  You would need to keep them very clean and continually adjust the angles..By the time you spend the money and maintain them, a solar kiln will not be too profitable.  A DH kiln would be more profitable.

[starmac]

I know, was only joking about the mirrors. lol
The problem with kilns here is our great energy costs. My thought if it would work was air dry for a time, then partially in a solar kiln and finish off in a kiln, to help with costs.
I suspect that our energy costs, is why there are not many kilns, small or large around here, at least that I know of.
I don't know how cost effective a wood fired boiler would be for a kiln, but then would have to get out of the borough because of the legalities to even have one.

[kantuckid]

i went in a green house out on Sheep Mountain(I thinks that the name?) where I talked to the lodging owner about tomatoes she was growing in there. In SE AK I see no way to have a non DH kiln but up in N AK why not a solar if you can grow maters :D Maters in the fastest version are two months or up to 80 days. Also the airs dry there too-when not raining. I know Denali's nearly a desert at under 10" annually.
Now you have me wanting to go fishing in AK... :D

[pineywoods]

Starmac, a solar kiln in temperatures approaching freezing would be an interesting experiment. Why not build a small one, like 3X4 feet and play around with it. My recommendations would be
well insulated
reasonable airtight
double glazing
black sheet metal under the glazing
small cheap room dh unit inside
no vents
beg, borrow or steal a recording humidity/temp recorder, so you can see what's going on rather than guess.
I see 2 problems, humid air will condense all over everything and then freeze, de-humidifier flatly will do nothing when the air temp gets anywhere near freezing..
I suspect that your solar gain on sunny days wouldn't be a lot less than the cloudy overcast days here in the south.  I routinely see temp gains of 35-40 degrees over outside temps on those cloudy overcast days..Thats with single glazing, an enclosure that's nowhere near air tight and very poor insulation...

Who knows, you just might come up with the right combination that will work under arctic conditions, then you'd be sitting on a potential gold mine. :P

[starmac]

Piney. 2 things would (are) working against it.
First during the months that we have freezing temps, we have very few daylight hours.
During our warm months, we have long daylight hours, but the problem there is the sun does not get high in the sky, like it does down south.
Our sun for the most part hangs out like yours does the last 30 minutes of daylight, in other words, low on the horizon and blinding you through your windshield if you are driving towards it.

[Denny]

I figured someone would tell me that. lol
Maybe with big mirrors placed in the right locations. lol

Yup mirrors, thats how  my solar kiln is setup... here's a picture  ;)
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[GeneWengert-WoodDoc]

A greenhouse uses a lot of extra heat when the outside is cold to keep the temperatures at the desired level...solar alone will not help at night.  When drying lumber which requires lots of energy, compared to heating a greenhouse, you will need about three times more solar heat than a greenhouse needs.

You can air dry in the summer in AK, so a solar kiln will work, if the vents are large enough, as well as air drying when the wood is fairly wet.