question about building a firewood kiln out of a container

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fireemt799

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I am building a firewood kiln out of a 20 foot land sea container. I am using an air stove to heat the kiln and pump the heat in thermostat controlled. I have the design of the chamber as far as the tin can studs, insulation and metal sheeting down how i want it. My question for anyone who has experience building or operating their own firewood kiln is placement of fans and vents? specifically what size fans and motors did you use? how many? what did you use for venting moisture out? I am using it to dry pinyon juniper and pinyon pine. I am in the very long process of getting a much larger yard and putting in a manufactured kiln. That is a couple of months out still and I need to get this kiln up to meet demand in the mean time. I plan to have the kiln built and producing in 2 weeks. I know 20' isnt very big for a firewood kiln but is all the available space i have available at this time. Any help and suggestions will be greatly appreciated.
 
I don't have exact answers to your questions, but will be watching this thread also. I'm in the beginning stages of planning to build a solar kiln with wood frame and heavy (12 mil) UV resistant greenhouse plastic as the roof and walls.

From my internet research, there's plenty of very detailed and in-depth resources out there on solar kiln design/function for drying lumber, but hardly anything concrete or conclusive for drying firewood. Don't know if it's because they're less popular or because there isn't as much to it as far as design?

As I see it, drying firewood can be accomplished with sun and/or airflow. With a kiln design, I think the most basic function of it should be that the enclosure is building heat enough to "sweat" the splits. How you get rid of the moisture that accumulates is up to you and your particular design. Land sea container (shipping container?) will need some modification to let that moisture out and fans and vents are probably the best way...no idea on the size need to properly dry the wood. You could maybe borrow some figures from a lumber solar kiln design to get a starting point here? What do you mean by air stove?

Where are you getting a manufactured kiln from in the future and how much do you plan to charge for your firewood? Kind of a different ballgame out your way than here on the easy coast. Softwood vs mostly hardwood and super-arid conditions vs relatively humid. You should be able to kiln dry juniper and pine in no time (less than a month?) if you figure out an efficient kiln design for the container.

My kiln plan is a bit simpler and off grid. I plan to set some wood posts in the ground and build a wood frame big enough to stack 4-6 cords inside with at least 3-4" airspace in between each stack. ^ shaped roof and sides/walls covered with heavy duty greenhouse plastic. Couple of hinged doors for relatively easy access to wood for stacking/loading out. I plan to leave a gap (not sure how much) between the bottom of walls and the ground for air to enter kiln and another gap between top of walls and roof overhang for air to circulate out. Clear plastic roof and walls should provide lots of heat inside kiln to sweat the wood. Condensation will hopefully accumulate on walls and less so on inside of roof and just drip down the plastic on to the ground.

We'll see....
Best of luck with your project and I hope some other more experienced folks chime in!
 
Air stove is the brand name of the forced air boiler I am using. As insulated as my kiln will be along with the stove I should run around 200 degrees. All the research and tests that have been done so far show at that temp I can dry a load in 2 days. Pinyon pine and pinyon juniper are both classified as hard woods producing 26 to 27 million BTUs per cord. So reaching the high temp won't be a problem. I will be buying a mini quick from kiln direct. I will sell most of my wood as bundles after this winter. The best information I have found has been on forest products laboratory. The biggest difference between drying firewood and lumber is getting the moisture out as quickly as possible for firewood. Drying lumber you take the moisture out slowly at lower temps over a longer period to prevent warping and cracking. Do you plan on selling your wood or is it for personal use? If selling look into the regulations in your area about eab and other pests. The main reasons for using a kiln to dry firewood is the quick turn over of wood versus waiting for it to season and to meet USDA heat certification for pest controlled areas.
 
Wow! 2 days!?! That's super fast...Got any photos of what you're working on to share?

Shows what I know about pinyon pine and juniper ;)

Haven't checked in regulations about selling kiln-dried wood; need to get on that and see if there's any red tape with advertising as kiln-dried around here. Quick turnover for seasoning time is my main motivator for building kiln, as I have limited space to let wood sit stacked up for a year to season.
 
I think the reason you don't see more of these is that the vapor produced by the wood is rather acidic, and it will rust your conex box.

I looked into using one too, only for lumber production.
 
They aren't fun to cut holes into.... I had to have one cut apart to get it out of a backyard. The old scrap guys oxy torch struggled.

Send pics, I'd love to see it.
 
No pics yet still trying to figure out the fans to order everything. I will have the entire chamber sheathed and sealed with either galvanized steel or stainless steel so rust won't be a problem. I think the plasma torch will cut it good have to find out though.

Sent from my XT907 using Tapatalk
 
I am building a firewood kiln out of a 20 foot land sea container. I am using an air stove to heat the kiln and pump the heat in thermostat controlled. I have the design of the chamber as far as the tin can studs, insulation and metal sheeting down how i want it. My question for anyone who has experience building or operating their own firewood kiln is placement of fans and vents? specifically what size fans and motors did you use? how many? what did you use for venting moisture out? I am using it to dry pinyon juniper and pinyon pine. I am in the very long process of getting a much larger yard and putting in a manufactured kiln. That is a couple of months out still and I need to get this kiln up to meet demand in the mean time. I plan to have the kiln built and producing in 2 weeks. I know 20' isnt very big for a firewood kiln but is all the available space i have available at this time. Any help and suggestions will be greatly appreciated.
 
OK, for you, quoting a national kiln suppliers words to me;


The simplest and least costly way for any one that wants to
do this is to simply install a hot air furnace and be done with it.


WHAT you need to do is simply install a forced draft duct system in
the ceiling with a cold air return duct to the furnace

Lumber Kilns have moisture vents along the roof line of the kiln.

The only more efficient way is to use steam heat with venting.

The issue is handling the firewood
.
I have talked quite a bit about this on the forum.
 
As I see it, drying firewood can be accomplished with sun and/or airflow. With a kiln design, I think the most basic function of it should be that the enclosure is building heat enough to "sweat" the splits.

Depends on what your market is -- if you're kiln drying wood to serve a quarantined market, then there are going to be specific regulations as to how hot for how long the kiln must get to kill the bugs. NY specifies the reaching a core temperature of 160º for 75 minutes.

I suspect the solar kilns can't develop the combination of heat x time you need to qualify as sterilizing the wood...you might get the air to 160º, but could you hold it long enough to heat up the middle of the middlemost log in the kiln to 160º before the sun goes down?
 
I do not know how to make a link for these things.

I would just look up my posts. I have a small brood herd of posts about kiln drying firewood
 
I have a customer in northern VT who has 3 firewood kilns, 2 running off our new wood chip boiler and one that is cordwood, hot air and auto feed( load the track about every 8 hours) The hot air unit certainly dries the firewood faster than the chip boiler but he says it is a pain in the but to load, we are working on a hot air wood chip unit for this exact application, any input we can get for the design stages would be greatly appreciated, do you think there would be a market for it, what do you think , greenhouses.
 
I have a customer in northern VT who has 3 firewood kilns, 2 running off our new wood chip boiler and one that is cordwood, hot air and auto feed( load the track about every 8 hours) The hot air unit certainly dries the firewood faster than the chip boiler but he says it is a pain in the but to load, we are working on a hot air wood chip unit for this exact application, any input we can get for the design stages would be greatly appreciated, do you think there would be a market for it, what do you think , greenhouses.

That was a winning combo I thought of before, a wood kiln that dumped the extra moist exhaust directly into a greenhouse. I'd want one for here, but no way could I buy a commercial unit, have to make it with scrounged materials.
 
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