Post in 'The Wood Shed' started by Bunsen, Nov 12, 2012.
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As requested, here are a couple of pics to show the general idea. I'm afraid they do not show the insides, as I didn't want to take the whole thing apart. I opened up the end a bit so you can see the wood clearly inside. It doesn't look it from the picture, but it is filled bottom to top and from side to side so that the air must travel through the wood stack, not around it.
Please excuse the leaves... =)
I built a makeshift kiln today. I put a $15 heater fan in the middle of some stacks along with my dehumidifier.
I then covered them with all my beat up tarps then wrapped it with an old roll of tyvek the covered it all with
$10 of black plastic sheeting. I ran it today and collected 1 and 1/3 gallons of water and the temp was 75f
3 hours after I shut off the heat, outside temp was 39f. I will run it the next few days while the temps are in
the 40's. I will rotate the rest of my wood next week. I'm buying a cheap dehumidifier off CL so my newish
dehumidifier doesn't get trashed. Before anyone asks there was no snow underneath.
when you're done, bring it down my way and I'll test it for you.
Looks similar to the makeshift one I made last summer except I just used a couple of 20" box fans. Can you put a Kill-A-Watt on the dehumidifier? I'd be interested to see how much electricity you use doing this. My fans used about 175 watts with both on high speed, which probably wasn't necessary. Also, can you tell what humidity the wood is being subjected to?
Even a slow setting on a box fan would seem excessive. Would clear the heat much too quickly. Doesn't much take air movement to clear humidity. in a small space. Look at Humidex's and how slow their fan speeds are for thousands of square feet.
I have municipal electricity which is cheap. My wood went in at 18-20% I will
Split and retest Thursday night. The $3 thermostat from Home Depot
has a a moisture gauge which read high normal when it went in and low
dry when I took it out. I have arranged the blowers to flow in a circle inside
the big black box. It looks like a hot tub with a crappy cover.
My 18-20% wood goes in my stove.
What gives? No green wood?
On the one I made, it was not intended to get hot inside, just to evenly move dry outside summer air through. Basically just a wind tunnel. It was large enough to justify two box fans for distribution, but yes, if the design allows nice even flow, then it doesn't take much flow rate to carry away the moisture from wood which dries really slowly.
An active dehumidifier like Schwaggly's design may prove to be more effective at drying than a solar heat approach which only lowers humidity indirectly by heating. The dehumidifier will have to be placed carefully to allow even distribution of the dry air through the whole wood stack. I like the idea of recirculating the air and letting the dehumidifier do it's thing.
The cost of running this may be worth it if you were really desperate for the first year's supply like I was, but 18 -20% seems really good already unless you are doing lumber or something.
Trying to dry wood for burning this way that is already 18-20% seems to me to be a waste of electricity.
Try some fresh cut wood & see how things work then. Checking moisture content periodically along with monitoring electricity consumption will give a more useful picture.
Hmm.. what interests me in this is how much water the dehumidifier is collecting. IF the system is reasonably well sealed then we may be able to assume the water is mostly from the wood and not air leakage. IF this is the case I expect one could monitor (indirectly) the rate of drying based on the water output.
I too would like to see the total electrical energy consumption for this as it may be interesting to see the cost vs buying kiln dried.
I can see the point of this beig a waste of electricity, but this is an experiment
therefore it's ok. I will be rotating in some green wood soon and have further
data. I shut everything down at 2:15 and it was 75f again at 6:15 I collected 80 oz
of water. It is 39f now.
I don't know if it really is/would be a waste as such - it is doing something useful after all. The question on my mind is roughly how expensive is it - I'd be interested in knowing how long you can take that green wood down to burnable. IF there were a reasonably convenient way for me to bring 3-4 cords of oak down in MC to good burnable state in less than a year I'm game - unless it brings the cost/cord up to the same or higher than kiln dried. Ok, there is a point below that where I may still find it too expensive, but you get the idea.
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