dehumidifier for "green" wood

[skyline]

Stick it next to your stove with a big "Do not Burn" sign. You'll know it's dry when you can stick it in the convection oven over night and it doesn't lose any more weight. Once this is done you can monitor any split you originally weighed and calculate its moisture content by assuming the same starting moisture content.

Skyline, you can leave that split next to the stove until the cows come home. You won't be able to drive off the last bit of water without raising the temp of the wood up to 212º. Most you'll get it down to is about 6% MC, and that will take weeks. For analysis purposes, you need to be able to quickly get it down to 0% MC.


Although you really have no choice but to assume all splits have the same starting moisture content, nothing could be further from the truth. Even within an individual tree, green MC can vary considerably. Best thing would be to determine the starting MC of a large number of randomly selected pieces using the oven method, then averaging them all. My band saw would make quick work of acquiring these samples.


Oh, I do grams, even milligrams when needed. I scooped up an analytical balance and a triple-beam gram scale when the lab I was working in got lazy and went to all digital scales. The scale in the photo is just an old produce scale I use to measure ultralight canoes (check out the photo) while I'm building them. I'll definitely use metric weights/measures come data collection/analysis time. Then I'll have to convert everything to pounds so I can present the results in BTUs to the woodburning set, but I'll use a spread sheet to do that when the time comes.

It's bad enough you have the perfect firewood drying setup, but now you have to go tease me with my boat in your basement too! I'd rather do all the experiments so you use your bandsaw building my canoe %-P . Just how light is it?

Yeah I knew it wouldn't dry a split completely next to the stove until you get tired of waiting and start using the oven. I might skip the microwave and just put the wood in the oven when I want to add "wood seasoning" to my bread. While it would be nice to know the absolute dry weight right away, I can get away monitoring water loss for several weeks if not months before knowing the dry weight to calculate its moisture content correctly. I'm not really worried about the variability in my splits as long as I pick some representative of the pile or at least bracket it. I'm mostly interested in how the pile progresses in drying under different storage conditions. For that matter I could probably get away with just using published moisture contents for my species although I'm sure that varies a bunch.

While the overall trend is quick at first and then a gradual slow down in moisture loss, I'm thinking it is somewhat episodic under outdoor conditions. A couple of calm wet days and the splits might lose nothing or actually gain a bit, but some dry windy ones and they lose a bunch and perhaps every night in certain months they may lose very little. I'm hoping the right shed design will always keep them dry, allow good air flow and add some solar heat during the day and perhaps some convective airflow during the night as well. Reminds me of those boot dryers.

I'm just suspicious that wood in a common setup with tarp over the top with bare ground below, or even in a heap hausen isn't drying for much of the time it's stacked and that is why it takes so long. A few more guys out there with scales could shed some light on this. A cheap place to get them is here: http://www.oldwillknottscales.com/

Cheers to all and keep sharing your data.

 

[Battenkiller]

While the overall trend is quick at first and then a gradual slow down in moisture loss, I'm thinking it is somewhat episodic under outdoor conditions. A couple of calm wet days and the splits might lose nothing or actually gain a bit, but some dry windy ones and they lose a bunch and perhaps every night in certain months they may lose very little.

I'm just suspicious that wood in a common setup with tarp over the top with bare ground below, or even in a heap hausen isn't drying for much of the time it's stacked and that is why it takes so long.

Sky, I think your thinking here is spot on. There is precious little good drying time in an average day, and the number of good drying days is rather limited in a given season. No wonder folks doubt the results of experiments that run counter to their personal experience. If it took three years to get your oak ready to burn then, by golly, that's just how long it takes. Makes me wonder why so many folks readily embrace the current stove technology but don't trust that advances can also be made in fuel processing. We all accept the use of fractional distillation of petroleum instead of putting straight crude oil into our $30K automobiles. Why not allow for improvements in wood drying technology that would allow all to use a consistently high quality product in their $3000 high tech stoves.

It's bad enough you have the perfect firewood drying setup, but now you have to go tease me with my boat in your basement too! Just how light is it?

That canoe was a small 11' Adirondack pack canoe that weighed an even 20 pounds when completed. Here's a shot of my wife paddling my granddaughter around on an ADK pond. The baby, at 22 pounds, weighed more than the boat that carried them both.

And since this is a firewood thread, check out the wood on the deck of the canoe. It is from a burl-figured cherry crotch that came in my firewood delivery. Every year I accumulate a bunch of interesting wood that strikes me somehow. This year it was about a dozen splits of tightly-figured fiddleback hickory, which may end up as quarter-thwarts in my next few canoes.

 

[iceman]

Stick it next to your stove with a big "Do not Burn" sign. You'll know it's dry when you can stick it in the convection oven over night and it doesn't lose any more weight. Once this is done you can monitor any split you originally weighed and calculate its moisture content by assuming the same starting moisture content.

Skyline, you can leave that split next to the stove until the cows come home. You won't be able to drive off the last bit of water without raising the temp of the wood up to 212º. Most you'll get it down to is about 6% MC, and that will take weeks. For analysis purposes, you need to be able to quickly get it down to 0% MC.


Although you really have no choice but to assume all splits have the same starting moisture content, nothing could be further from the truth. Even within an individual tree, green MC can vary considerably. Best thing would be to determine the starting MC of a large number of randomly selected pieces using the oven method, then averaging them all. My band saw would make quick work of acquiring these samples.


Oh, I do grams, even milligrams when needed. I scooped up an analytical balance and a triple-beam gram scale when the lab I was working in got lazy and went to all digital scales. The scale in the photo is just an old produce scale I use to measure ultralight canoes (check out the photo) while I'm building them. I'll definitely use metric weights/measures come data collection/analysis time. Then I'll have to convert everything to pounds so I can present the results in BTUs to the woodburning set, but I'll use a spread sheet to do that when the time comes.

It's bad enough you have the perfect firewood drying setup, but now you have to go tease me with my boat in your basement too! I'd rather do all the experiments so you use your bandsaw building my canoe %-P . Just how light is it?

Yeah I knew it wouldn't dry a split completely next to the stove until you get tired of waiting and start using the oven. I might skip the microwave and just put the wood in the oven when I want to add "wood seasoning" to my bread. While it would be nice to know the absolute dry weight right away, I can get away monitoring water loss for several weeks if not months before knowing the dry weight to calculate its moisture content correctly. I'm not really worried about the variability in my splits as long as I pick some representative of the pile or at least bracket it. I'm mostly interested in how the pile progresses in drying under different storage conditions. For that matter I could probably get away with just using published moisture contents for my species although I'm sure that varies a bunch.

While the overall trend is quick at first and then a gradual slow down in moisture loss, I'm thinking it is somewhat episodic under outdoor conditions. A couple of calm wet days and the splits might lose nothing or actually gain a bit, but some dry windy ones and they lose a bunch and perhaps every night in certain months they may lose very little. I'm hoping the right shed design will always keep them dry, allow good air flow and add some solar heat during the day and perhaps some convective airflow during the night as well. Reminds me of those boot dryers.

I'm just suspicious that wood in a common setup with tarp over the top with bare ground below, or even in a heap hausen isn't drying for much of the time it's stacked and that is why it takes so long. A few more guys out there with scales could shed some light on this. A cheap place to get them is here: http://www.oldwillknottscales.com/

Cheers to all and keep sharing your data.

i may be off the deep end here, but wouldnt the best shed allow airflow from all sides, but instead of shingle roofing use the clear plastic ones? this would allow more sun on the wood? while maximizing airflow?

 

[ikessky]

Ikessky, I don't have a moisture meter either and figure from what I've read they have enough errors, that without more experience than I want to have with them I'll stick to the scale which I know is right. The trick is to take one (or more) representative split in length and weight, weigh it and then totally dry it completely. Stick it next to your stove with a big "Do not Burn" sign. You'll know it's dry when you can stick it in the convection oven over night and it doesn't lose any more weight. Once you get it to this point you'll know the moisture content that it started at and be able to monitor other pieces along the way. Weight of water lost/ Dry weight. (This is why the moisture content of some wood can be over 100%. Just assume that same starting moisture contents for your other splits that weigh differently at the start. This is different than what I figured in my moisture lost calcs as I used weight / original wet weight since I didn't yet know it's totally dry weight and was more interested in seeing just how much moister was lost by the fans.

As I said before, I find what you guys are doing interesting, but I'm not about to starting doing it myself. I've got time and space, so I'll let nature continue to do my drying for me. People have also been doing that for years!

 

[skyline]

Ikessky, I don't have a moisture meter either and figure from what I've read they have enough errors, that without more experience than I want to have with them I'll stick to the scale which I know is right. The trick is to take one (or more) representative split in length and weight, weigh it and then totally dry it completely. Stick it next to your stove with a big "Do not Burn" sign. You'll know it's dry when you can stick it in the convection oven over night and it doesn't lose any more weight. Once you get it to this point you'll know the moisture content that it started at and be able to monitor other pieces along the way. Weight of water lost/ Dry weight. (This is why the moisture content of some wood can be over 100%. Just assume that same starting moisture contents for your other splits that weigh differently at the start. This is different than what I figured in my moisture lost calcs as I used weight / original wet weight since I didn't yet know it's totally dry weight and was more interested in seeing just how much moister was lost by the fans.

As I said before, I find what you guys are doing interesting, but I'm not about to starting doing it myself. I've got time and space, so I'll let nature continue to do my drying for me. People have also been doing that for years!

ikessky No Problem on that, every experiment needs a control ;-) And as I said before, hats off to you guys who are 3 years ahead on their wood supply. Out of curiosity, do you ever put plastic down as a vapor barrier beneath your stacks. My experience points to this improving drying especially the bottom layers, as long as it doesn't become a low point that collects water. I believe black plastic lowers the RH significantly during wetter periods and raises the temperature around the pile on sunny still days as well, but I don't see it many pictures of stacks on here.

i may be off the deep end here, but wouldnt the best shed allow airflow from all sides, but instead of shingle roofing use the clear plastic ones? this would allow more sun on the wood? while maximizing airflow?

+1 on that Iceman, I definitely am planning on using the clear glazing material for my shed. I'm surprised I don't see it in more of the sheds pictured on this forum The better stuff tends to be pricey and you generally need an extra layer of purlins running across your rafters to support it which may be more than most want to do.

I am a firm believer in maximizing air flow but I'm think on days like this morning which we have a lot of, where visibility is 100', temp. is within 2 °F of dew point (we're in the fog or a cloud, hard to tell which) an open sided shed wouldn't be better than one closed up. If it was closed up and maybe 5-10 degrees warmer than outside, that would drop the RH quite a bit. Proper placement of venting and slight air circulation might significantly increase the total # of drying hours. And I think that is really the key, increasing the "actual" number of hours the wood is drying and not just sitting at or very close to equilibrium.

Kilns show and others posted here suggest a few hundred hours are all that are needed to dry wood with extra energy added. Divide that over 3 months and the extra energy is around background levels. Ultimately this should be easy to figure out with a computer hooked to a scale monitoring the weight of a split 24/7. Along with temp. RH and wind and one should get good idea of what is changing moisture loss the most under different conditions and how much of the "seasoning" period is really effective or not. If Battenkiller weren't so busy building my canoe he would get right on that ;-P Also, as he pointed out, I'm sure I have lost BTU's from decay over drying for longer periods.

For now, I'll plan on open sided shed, clear glazing on the roof, plastic vapor barrier on the bottom and some additional solar assistance (fan, heat or both). To repeat Ikessky I think, it's not "new technology", the same principals nature has been drying wood for years with, but whether we chose to harness them and improve on it is what I'm after.

 

[ikessky]

I haven't put any plastic down, but I think this year I'm going to make some spacers out of rebar to lift the wood off the ground an inch or so.

 

[skyline]

I haven't put any plastic down, but I think this year I'm going to make some spacers out of rebar to lift the wood off the ground an inch or so.

Now don't go modifying our "slow" control It will be harder for us to show any improvement over traditional methods. If you can increase the height a few more inches closer to 6 you may remove most of the ground effect in lower temps and higher RH. This is just my feeling no hard proof, although sometimes I see a "dew" line about this high in the grass. I think that along with the plastic will make a difference . I figure every morning I have dew on the grass I've have had hours my wood wasn't drying.

 

[ikessky]

The area is on top of a hill too. Once I take down a couple more trees, the piles will get wind no matter what direction it is blowing. If I could blacktop the area, that would make it even more ideal! ;-)

 

[LLigetfa]

I see a "dew" line about this high ...

Ja, one might be surprised just how high (thick) the layer of dew can be. I would use something much taller than the thickness of rebar to elevate the stacks. I often put down a bottom course of junk Poplar rounds and stack the good stuff on top of it. Sometimes I build a base out of Poplar poles as well.

 

[ikessky]

I never said the rebar was going to be laid on the ground. ;-) If time permits, I'm going to weld up some "racks" that hold the stacks about 4"-6" off the ground. Being on the top of a hill though, the ground never stays very wet, so I'm not overly concerned if I get this done or not.

 

[skyline]

The area is on top of a hill too. Once I take down a couple more trees, the piles will get wind no matter what direction it is blowing. If I could blacktop the area, that would make it even more ideal! ;-)

Ikessky, sounds like a great setup, pretty soon your wood will be dry in a few weeks too ;-)

I actually used my asphalt last summer and weighed a few pieces and was shocked by the pounds of water lost in a couple of days. It was before I started recording all this. They were big splits but it has got me thinking ever since. Perhaps more realistic for me, I want to try black metal roofing that doubles as a vapor barrier under my pile and heat radiator. If I extend it out from under the pile a few feet to the south it should add a few degrees. Maybe put the part our front under a glass frame and the heat should transfer to the cooler metal under the pile nicely. I think aluminum would be best, just need to find some large scraps for free. It would probably work best under no wind conditions which covers the time the wind isn't drying your pile out. I would think this would sure help out the heap hausen stacks as well. Anyone want to try?

 

[robsam]

How Can I Dehumidify my Basement ?My basement is full of humidity and I have fear that me or my family member's health can be affected because of it. Someone has suggested me to buy a Basement Dehumidifier from getting rid of this humidity . Anyone can suggest me a good one ?Any other ways by which I can get my basement dry quickly ? Please Suggest .

 

[EL DRIFTO]

it's really humid here during the summer, so once a year, just before i fire up the central AC for the first time, i run the AC system continuously for 24 hours, with the forced air side & cold air return wide open, in the basement alone.

it's all sealed concrete, but it still gets muggy to the point of mildew, but after my 80,000 btu dehumidifier, it's dry. :zip:

i haven't taken any actual RH measurements...

i have some vents open in the "unfinished" basement which keeps it nice & dry, like the rest of the house, once i annually dehumidify.

i also duct my electric clothes dryer inside during the winter, it may be saturating the basement before i route it back outside every year...

 

[Battenkiller]

How Can I Dehumidify my Basement ?My basement is full of humidity and I have fear that me or my family member's health can be affected because of it. Someone has suggested me to buy a Basement Dehumidifier from getting rid of this humidity . Anyone can suggest me a good one ?Any other ways by which I can get my basement dry quickly ? Please Suggest .

Number one rule is don't try to "air out" the basement in the summer by opening the doors. The cooler air inside the basement can't hold as much moisture and it condenses on the cool surfaces, making mold and mildew a big problem. Keep the basement doors closed in the summer.

Yes, without a doubt the dehumidifiers you linked to will do the job perfectly. You may not even need one that big. My dehumidifier is only rated at 55 pints/day and it does the job perfectly for me. Takes about a week to get all the moisture out of the cement and the floor joists and sub-flooring overhead, but then it is relatively easy to maintain as long as you empty the bucket every day (or rig a drain hose to the outside). Mine runs full-time on high.

Best thing about the bigger units is that they are probably more efficient and will produce less heat for a given volume of water removed. These things create a lot of heat, and they use plenty of electricity. My July electric bill is higher than my January one, mostly because of the dehumidifier running 24/7. The bigger units won't ice up on you as much, either.

 

[iceman]

How Can I Dehumidify my Basement ?My basement is full of humidity and I have fear that me or my family member's health can be affected because of it. Someone has suggested me to buy a Basement Dehumidifier from getting rid of this humidity . Anyone can suggest me a good one ?Any other ways by which I can get my basement dry quickly ? Please Suggest .

Number one rule is don't try to "air out" the basement in the summer by opening the doors. The cooler air inside the basement can't hold as much moisture and it condenses on the cool surfaces, making mold and mildew a big problem. Keep the basement doors closed in the summer.

Yes, without a doubt the dehumidifiers you linked to will do the job perfectly. You may not even need one that big. My dehumidifier is only rated at 55 pints/day and it does the job perfectly for me. Takes about a week to get all the moisture out of the cement and the floor joists and sub-flooring overhead, but then it is relatively easy to maintain as long as you empty the bucket every day (or rig a drain hose to the outside). Mine runs full-time on high.

Best thing about the bigger units is that they are probably more efficient and will produce less heat for a given volume of water removed. These things create a lot of heat, and they use plenty of electricity. My July electric bill is higher than my January one, mostly because of the dehumidifier running 24/7. The bigger units won't ice up on you as much, either.

but holy toledo batman! those things are expensive!... i will stick with my little one for $100 wow! those are expensive

 

[Battenkiller]

Yeah, they're out of consideration for me as well. They really can crank moisture out of the air compared to the W-Mart variety like I have. I saw that they rate them very honestly, basically how much water are they removing at 60% RH. The cheap portable ones appear to be rated for use at 100% RH, which explains why I could never get mine to do anything beyond 45% RH. It ain't too hard to remove water from saturated air. It becomes more difficult the lower the RH gets.

 

[geoxman]

I used a Lowes unit that I drilled a hole in the collection cup. I then installed a uniseal and ran some 3/4 inch pvc from the cup to the drain. I never have to empty it and it works just fine

 

[iceman]

Yeah, they're out of consideration for me as well. They really can crank moisture out of the air compared to the W-Mart variety like I have. I saw that they rate them very honestly, basically how much water are they removing at 60% RH. The cheap portable ones appear to be rated for use at 100% RH, which explains why I could never get mine to do anything beyond 45% RH. It ain't too hard to remove water from saturated air. It becomes more difficult the lower the RH gets.

i measure mine with one of the wether station thingys.. in the summer though i also run a fan in the room, so between the 2 i stay in the high 20s-30s.. if i turn them off i can get to 50 in a couple of days.... so our walmart dehumidifiers do work.... also if it gets to fifty i run the ac for for about an hour which helps bring it down

 

[KevinM]

The area is on top of a hill too. Once I take down a couple more trees, the piles will get wind no matter what direction it is blowing. If I could blacktop the area, that would make it even more ideal! ;-)

Ikessky, sounds like a great setup, pretty soon your wood will be dry in a few weeks too ;-)

I actually used my asphalt last summer and weighed a few pieces and was shocked by the pounds of water lost in a couple of days. It was before I started recording all this. They were big splits but it has got me thinking ever since.

My favourite place to stack wood is on the asphalt driveway on the south side of our house. Between the asphalt and the bricks it can be rather warm there after sunset. Why the previous owner had an air conditioner installed there is beyond me.

Anecdotaly wood stacked on the east side of the house up on the deck doesn't do well compared to on a pallet on the grass.

Kevin.

 

[MyFyrByrd]

As I continue to read posts on this site , I think about the Mythbusters and how they would never have a problem coming up with new ideas to test for their episodes.

 

[BillLion]

I was wondering if a humidifier would "finish" nearly seasoned wood, Google it and found this dead thread!

I wonder 3&1/2 years late if anyone here has an opinions/experience re: this...

 

[Jags]

It is pretty well accepted that wind is the biggest influence followed by heat/sun. The ambient humidity level obviously plays a part too, but I think you would be better off with an extra couple of weeks in the dry fall air than you would be stacking in a basement and running a de-humi. Although I would expect the bugs to love a new environment.

 

[roddy]

I was wondering if a humidifier would "finish" nearly seasoned wood, Google it and found this dead thread!

I wonder 3&1/2 years late if anyone here has an opinions/experience re: this...

three and a half years later my opinions have not changed,,,,i will post some findings with my off beat drying methods in a while...by the way...still love this forum read here everyday,just don't post much
rod

 

[isipwater]

As you know, I use the heat from my stove to drive down the RH in my basement, but if you really want to use valuable electricity to do the job:


http://owic.oregonstate.edu/pubs/dhkilns.pdf

I am new to wood burning. How do you do this and what is RH?

 

[Jags]

I am new to wood burning. How do you do this and what is RH?

RH = Relative Humidity.