Solar Kiln Too!

[JackLeg]

Well, since I think I have the pic posting figured out, here's a couple more shots of the front and roof.



This is the "south" wall and also the roof. This is where the polycarbonate clear panes will be placed.



And this is the back or "north" wall. This is where the 6 X 6 doors will be hung. This is the side from which we'll load the kiln.

The capacity is approximately 800-1000 bf of green lumber. Plans by Virginia Tech School of Forestry.

Thanks for looking.

:notworthy:

 

[JimmyC]

Reggie,

The kiln is starting to look great ! I see that you suscribe to Sawdusters policy on rehab !:lol: It's good to see you back out and around.

Jimmy

 

[JackLeg]

Yep, ol' Sawduster and me commiserate on lots of things, including rehab strategies! I'm a blessed individual.

Thanks for commenting, Jimmy.

:notworthy:

 

[jeff...]

Reggie hard to tell from the pics, I tried to count the full plywood sheets on the floor, what is the inside dimensions?

Thanks

 

[JackLeg]

She's 160" long by 76" wide. Small stacks only.

 

[jeff...]

She's 160" long by 76" wide. Small stacks only.

So your looking at drying 12 ~ 13' long boards then?

 

[JackLeg]

Yep. Actually, most of what we use is 8 & 10' stuff. This thing will be primarily for our use. I know there's a big learning curve ahead, so I'll learn on our stuff where I can "eat" my mistakes.

Going to the 2 day seminar in April at VT. Should help. Looks good online.

 

[jeff...]

Yep. Actually, most of what we use is 8 & 10' stuff. This thing will be primarily for our use. I know there's a big learning curve ahead, so I'll learn on our stuff where I can "eat" my mistakes.

Going to the 2 day seminar in April at VT. Should help. Looks good online.

Yeah 8' and 10's are good lengths, not so long you have to man handle the boards. When I was doing lumber runs, I would cut my grade logs in half into two 8'ers. 8 foot seemed to make it easier on everyone. As far as a learning curve, that's no biggie... everything new requires learning, learning from my mistakes is my best teacher. A few years ago I was going to take the same class a VT - I'm glad your going, it seemed to be very good when I last looked into it.

I'm still baffled how a solar kiln works - I know if I leave green lumber out in the sun for any length of time it dries out to fast and face checks. I have to cut thin sheets of cull to cover the lumber so the sun doesn't cook it. Maybe it's something as simple as throwing a few sheets of plywood over the stack to keep the sun from beating down on it? whatever it is, I'm sure you'll learn the right techniques in the VT class.

Please keep posting on your progress, this is a very interesting topic and looking forward to learning a lot from you.

Thanks

 

[Ivey]

:notworthy:Lookin good Reggie, Get that thing closed in so we can filler up:eusa_danc

 

[scsmith42]

Looking good Reggie!

Jeff, a solar kiln works by trapping the moisture released by the sun heating the chamber, and maintaining a high RH inside the chamber. It's not the sun that causes degrade to the boards, it's the rapid loss of moisture. You can controll this through a combination of RH and temp.

Solar kilns cool down at night, which helps to even out the drying cycle; otherwise the wood would suffer from too much temperature while it had a high MC%.

 

[JackLeg]

Just in case this "hot box" doesn't work out, I've been thinking of other uses for it.


Sauna, chicken coop, greenhouse, torture chamber, dynamite storage, rental appartment are a few that come to mind.

Whadda you think??

:rotflm::rotflm:

 

[JimmyC]

It'll work Reg, it may just need a little tweaking:icon_thum before it's done.

Jimmy

 

[cpowell]

Just in case this "hot box" doesn't work out, I've been thinking of other uses for it.


Sauna, chicken coop, greenhouse, torture chamber, dynamite storage, rental appartment are a few that come to mind.

Whadda you think??

:rotflm::rotflm:

I think readings posts from Jeff and Bas are rubbing off on you. :lol::lol:

Seriously, the solar kiln is a pretty neat idea. Keep us posted.


Chuck

 

[jeff...]

Just in case this "hot box" doesn't work out, I've been thinking of other uses for it.


Sauna, chicken coop, greenhouse, torture chamber, dynamite storage, rental appartment are a few that come to mind.

Whadda you think??

:rotflm::rotflm:

I really like the dynamite storage idea

 

[jeff...]

Looking good Reggie!

Jeff, a solar kiln works by trapping the moisture released by the sun heating the chamber, and maintaining a high RH inside the chamber. It's not the sun that causes degrade to the boards, it's the rapid loss of moisture. You can controll this through a combination of RH and temp.

Solar kilns cool down at night, which helps to even out the drying cycle; otherwise the wood would suffer from too much temperature while it had a high MC%.

I thought the idea was to slowly decrease the RH while at the same time increase the temp. Although I understand RH has a lot to do with temp and moisture in the lumber. In the beginning of the kiln cycle it might take some amount of time to be able to control the RH. So in a DH kiln water collects on the coils of the DH unit is chilled and drips into a pan which is piped to the outside. Same basic principle as a dehumidifier, only on a larger scale.

With a solar kiln you'll have variations of the amount of sun, temp and outdoor humidity and at night 100% humidity inside the chamber. How does wood consistently dry under such conditions? how do you control the RH and get rid of the right amount of excess water to maintain proper RH when you have inconsistent temps and RH in the kiln chamber because solar radiation is your primary heat source?

Perfect example is the last few days:
* Friday it was sunny and 80 degrees with low humidity
* Yesterday it was partly sunny and 50 degrees with low humidity
* Today it's overcast raining 40 degrees 87% humidity

Does the wood just not dry any or very little during these conditions? Seems like if it doesn't then it would be an opportune time for the wood to develop internal stress but obviously will increase the length of time to dry the load.

I'm sure Reggie will get the answer when he attends class, I hope he shares it with the rest of us.

These questions, 2 bad experiences with solar kilns and log yard owner saying no - stopped me from building a 4K ~ 5K BF solar kiln.

Thanks

 

[JackLeg]

I promise that whatever "learning" I get at the seminar I will share with anyone who's interested. But not to the point of boring anyone.

I'm just working on the "first step" at present, which is getting the kiln built and ready. I'm fascinated somewhat by the entire process, especially since it's "green" technology that uses only a bit of electrical energy. The air circulation is provided by 3 standard box fans and outside air is controlled by sliding vents that can be opened or closed as needed.

I am planning to ask about putting the kiln on a timer to turn the fans off at night, since I understand that helps to acclimate the lumber and prevent reducing the moisture too quickly.

MUCH TO LEARN! :eusa_thin:eusa_thin

 

[Bas]

Scott got me interested in a solar kiln as well. Not so much that I've started to clear out the trees on my property and pour a concrete pad, but enough to keep me out of the shop reading some very dry (no pun intended) material

From my extremely limited understanding, the kiln is nothing but a buffer. As the sun shines on the boards, they heat up and release moisture. But, that causes the humidity in the kiln to rise, slowing down the evaporation. We all know it's hard to sweat when the air is damp. On a cooler/ overcast day, moisture is released more slowly but steadily, since the humidity in the kiln doesn't rise as fast.

But that brings up an interesting point. If you build a massive kiln and only put two boards in there, the wood is likely to dry too quickly if its very sunny/ warm. I wonder if under such conditions you may even want to put a pan of water in the kiln to slow down the drying.

 

[Bas]

Just in case this "hot box" doesn't work out, I've been thinking of other uses for it.


Sauna, chicken coop, greenhouse, torture chamber, dynamite storage, rental appartment are a few that come to mind.

Whadda you think??

Build a second one, and sell it as a double wide.

 

[JackLeg]

Good point, Bas! I was wondering if I could sell this one to some of my "slanted" friends!

 

[toolman]

I promise that whatever "learning" I get at the seminar I will share with anyone who's interested. But not to the point of boring anyone.

I'm just working on the "first step" at present, which is getting the kiln built and ready. I'm fascinated somewhat by the entire process, especially since it's "green" technology that uses only a bit of electrical energy. The air circulation is provided by 3 standard box fans and outside air is controlled by sliding vents that can be opened or closed as needed.

I am planning to ask about putting the kiln on a timer to turn the fans off at night, since I understand that helps to acclimate the lumber and prevent reducing the moisture too quickly.

MUCH TO LEARN! :eusa_thin:eusa_thin

Any info you can share would be helpful! I have been thanking of putting up a Kiln. But it is about one to two years off. :rolf: