Moisture content

[Heatmiser5]

I just got the moisture meter at lowes. What % are we looking
For before burning? Are different types of wood desired at
Different %'s or are the pretty much the same?

 

[steeltowninwv]

No expert..but 20% or lower is ideal

 

[BlankBlankBlank]

I second the <20% moisture content. Just remember that different woods have different rates of drying. So oak takes 2-3 years, while ash or silver maple take 1 year.

 

[Monkey Wrench]

No expert..but 20% or lower is ideal

Don't check old splits, you need to re-split a couple of splits to get an correct reading.

 

[BlankBlankBlank]

No expert..but 20% or lower is ideal

Don't check old splits, you need to re-split a couple of splits to get an correct reading.

Monkey Wrench has it right. For test purposes, I checked a pine split the other day. The exterior of the pine log was at something like 12%, but after splitting and checking, the inside was at 18%. There is a big difference. But still burnable in this case.

 

[soupy1957]

ditto all the above........I personally look for below 25% moisture content, but also ..........remember that it is valid and useful to add a piece of wood every now and then that HAS "some" moisture in it, to the fire. When wood is TOO dry, it's burning up way too fast and not giving you the full benefit of the heat it could have produced with a slower burn.

-Soupy1957

 

[CTYank]

ditto all the above........I personally look for below 25% moisture content, but also ..........remember that it is valid and useful to add a piece of wood every now and then that HAS "some" moisture in it, to the fire. When wood is TOO dry, it's burning up way too fast and not giving you the full benefit of the heat it could have produced with a slower burn.

-Soupy1957

Dunno what sort of stove you find that to be true for, but the behavior of my little Morso is nothing like that.
The primary draft setting controls the burn rate, and the optimum MC is 0%.
How you place the pieces in the stove has large effect on the burn rate, with tighter packing burning slower.
I work for my wood and don't want to burn any just to dehydrate splits up the flue, if it can be helped.

 

[Battenkiller]

The primary draft setting controls the burn rate, and the optimum MC is 0%.

Even if that was true (which it most definitely is not), just how do you propose getting the wood down to 0% MC? Then how do you keep it there once you do?

A certain amount of water is necessary for a well-regulated and efficient burn. You can believe anything you want to, but when you plug one of these puppies into an EPA test flue, the numbers tell a different story. These EPA stoves are designed to be most efficient at the MC used to test them. That is, 16-20% MCWB, or 19-25% MCDB. Your meter reads MCDB, so the best range is 19-25% on the meter. Above and below that, overall heating efficiency decreases (more so on the "too wet" end of the spectrum than on the "too dry" end).

Of course, this is a broad generalization. Stoves, flues, wood type, operator effect, etc. are all contributing factors that could create differences in the findings, but the general trend for all wood burning appliances is to have an optimum MC that is well above 0%.

 

[snowleopard]

It's 9:45 on Saturday morning, I have all my wood hauled inside for the week (2 sled loads of birch, three of spruce) and the various kindling boxes full. Tried my first top-down fire (meh), and figure it's time to take a break and see what's happening on h.c. Read Soupy's post, and decided it's time to break out the popcorn and enjoy the show from a safe perch. Let the games begin!

Actually, I'm interested in this question myself. I bought a couple of cords of spruce that I was told would be great stuff, and threw some in the stove and got a bit of sizzle. Decided it was finally time to get a MM, and learned that the wood was 20%, and the bark had the MM red-lined--makes sense because they had a few breakdowns and the wood sat in the truck for three days in inclement weather. Wood may not be a sponge, but the bark is pretty close to it.

Checked the rest of my wood, and was surprised to see that the cord-and-a-half of birch I planned to use this winter (cut in March before the sap started running, and split in May) was running around 16%, and my cord+ of fire-killed spruce is about 10%. This means that I'm pretty well set for the burning season, which feels wonderful.

 

[cptoneleg]

ditto all the above........I personally look for below 25% moisture content, but also ..........remember that it is valid and useful to add a piece of wood every now and then that HAS "some" moisture in it, to the fire. When wood is TOO dry, it's burning up way too fast and not giving you the full benefit of the heat it could have produced with a slower burn.

-Soupy1957

Dunno what sort of stove you find that to be true for, but the behavior of my little Morso is nothing like that.
The primary draft setting controls the burn rate, and the optimum MC is 0%.
How you place the pieces in the stove has large effect on the burn rate, with tighter packing burning slower.
I work for my wood and don't want to burn any just to dehydrate splits up the flue, if it can be helped.

My Great Great Granmothers rocking chair sitting by the fire for 200 yrs is not down to 0% yet.

 

[pdxdave]

The primary draft setting controls the burn rate, and the optimum MC is 0%.

Even if that was true (which it most definitely is not), just how do you propose getting the wood down to 0% MC? Then how do you keep it there once you do?

A certain amount of water is necessary for a well-regulated and efficient burn. You can believe anything you want to, but when you plug one of these puppies into an EPA test flue, the numbers tell a different story. These EPA stoves are designed to be most efficient at the MC used to test them. That is, 16-20% MCWB, or 19-25% MCDB. Your meter reads MCDB, so the best range is 19-25% on the meter. Above and below that, overall heating efficiency decreases (more so on the "too wet" end of the spectrum than on the "too dry" end).

Of course, this is a broad generalization. Stoves, flues, wood type, operator effect, etc. are all contributing factors that could create differences in the findings, but the general trend for all wood burning appliances is to have an optimum MC that is well above 0%.

What evidence do you have that points to less than 16% MC being less efficient ? That simply doesnt make any sense. Just because they tested wood at 16% doesnt mean this is most optimal. I would venture to guess that they wanted to make a realistic test based on a reasonably achievable MC with backyard drying.

 

[Battenkiller]

What evidence do you have that points to less than 16% MC being less efficient ? That simply doesnt make any sense. Just because they tested wood at 16% doesnt mean this is most optimal. I would venture to guess that they wanted to make a realistic test based on a reasonably achievable MC with backyard drying.

As I said, this is a broad generalization. There is no such animal as an "EPA stove", just stoves that passed the EPA test. There are many ways that this is achieved, some better than others, and some will get peak efficiency at higher or lower moisture contents than others. All I really mean is that you can't go wrong by sticking to the EPA test load standard. Your stove got stellar results using that test, what evidence do you have that it would be better at a lower MC? However, there has been a massive amount of research that shows that increased moisture content actually improves combustion efficiency up to a point. That's all the evidence I can provide, that and the theories behind the observations.

I talked to the folks at Woodstock Soapstone and they told me that wood seasoned beyond three years old was "too dry" for the best efficiency. I don't think they meant three years in the Mohave Desert, so that indicates to me that Woodstock feels that wood seasoned to the EMC in most areas is not as efficient as moister wood. EMC in most areas of the U.S. is down around 14-16% MC. That leads me to believe that they think that their stoves work best at a MC no lower than 16%. That's just Woodstock, but they're careful folks and they don't just make idle claims. I'm sure that their results are based on actual flue gas measurements and not just conjecture.

Wood combustion inside a stove is an extremely complicated and chaotic chemical reaction with numerous variables that can give dramatically different results. It doesn't have to make sense, it just does what it does. I have yet to see even a slim bit of evidence that anyone has pointed to that proves wood burns better the drier it gets. Saying it's so just because it makes sense to you doesn't prove anything.

 

[Battenkiller]

Read Soupy's post, and decided it's time to break out the popcorn and enjoy the show from a safe perch. Let the games begin!

Uh.... could you pass the popcorn, please? ;-P

 

[onetracker]

ditto all the above........I personally look for below 25% moisture content, but also ..........remember that it is valid and useful to add a piece of wood every now and then that HAS "some" moisture in it, to the fire. When wood is TOO dry, it's burning up way too fast and not giving you the full benefit of the heat it could have produced with a slower burn.

-Soupy1957

Dunno what sort of stove you find that to be true for, but the behavior of my little Morso is nothing like that.
The primary draft setting controls the burn rate, and the optimum MC is 0%.
How you place the pieces in the stove has large effect on the burn rate, with tighter packing burning slower.
I work for my wood and don't want to burn any just to dehydrate splits up the flue, if it can be helped.

My Great Great Granmothers rocking chair sitting by the fire for 200 yrs is not down to 0% yet.

'course not...its probably oak

 

[fossil]

...Saying it's so just because it makes sense to you doesn't prove anything.

I believe this is so. It makes sense to me.

 

[Battenkiller]

...Saying it's so just because it makes sense to you doesn't prove anything.

I believe this is so. It makes sense to me.

:lol:

 

[Danno77]

These endless threads about moisture are getting old. If I thought I was learning something in each new thread, then I'd be cool with it, but it seems to just be the same conversations over and over. Oh well. The search function doesn't seem to work well anyway. I typed moisture into the search box and it won't even come up with this thread. What's up with that?

 

[donatello]

Why get anal retentive about the moisture content of wood. It's not like you just cut a tree down/bucked it/split it/and into the stove it goes. Let it season as long as you can - preferably longer then 1 1/2 years. Just don't make the splits big, maybe just a bit larger than size of a carton of cigarettes. In September I heard the sound of a chainsaw outside. My neighbor and his son (who are really nice people),were bucking and splitting red oak that he cut down that week in his front yard. I strolled over and jokingly said, "Gettin' ready to burn it this season?" My neighbor said "Yup, sure am!" His son yelled from behind, "It'll burn!" Later, after they were done throwing all the splits in a chain link fenced in area, under the cover of trees and against the side of a shed, all was covered with a green plastic tarp, I guess to lock in the freshness.... They said they don't get "fancy" like me. I stack all neatly on pallets in long rows under the sun.

 

[gyrfalcon]

My Great Great Granmothers rocking chair sitting by the fire for 200 yrs is not down to 0% yet.

'course not...its probably oak

HAHAHAHAH! <wheeze!> ROTFL

 

[gyrfalcon]

Why get anal retentive about the moisture content of wood. It's not like you just cut a tree down/bucked it/split it/and into the stove it goes. Let it season as long as you can - preferably longer then 1 1/2 years. Just don't make the splits big, maybe just a bit larger than size of a carton of cigarettes. In September I heard the sound of a chainsaw outside. My neighbor and his son (who are really nice people),were bucking and splitting red oak that he cut down that week in his front yard. I strolled over and jokingly said, "Gettin' ready to burn it this season?" My neighbor said "Yup, sure am!" His son yelled from behind, "It'll burn!" Later, after they were done throwing all the splits in a chain link fenced in area, under the cover of trees and against the side of a shed, all was covered with a green plastic tarp, I guess to lock in the freshness.... They said they don't get "fancy" like me. I stack all neatly on pallets in long rows under the sun.

I have some friends with the same attitude. Then they had a chimney fire. I didn't say a word, just tried not to let "Told you so" show on my face when they told me about it. I hope your neighbor and his son clean that chimney every few weeks.

 

[Battenkiller]

These endless threads about moisture are getting old. If I thought I was learning something in each new thread, then I'd be cool with it, but it seems to just be the same conversations over and over.

Well, now, shucks lil' buddy, I kin learn ya some new stuff. I jest bin waitin' fer the rest of the class to catch up. ;-P

 

[Danno77]

These endless threads about moisture are getting old. If I thought I was learning something in each new thread, then I'd be cool with it, but it seems to just be the same conversations over and over.

Well, now, shucks lil' buddy, I kin learn ya some new stuff. I jest bin waitin' fer the rest of the class to catch up. ;-P

Pfft, we've got other things to discuss. My superwalnut will be subjected to some testing soon... I need you available for consultation.

 

[jimbom]

'course not...its probably oak

:lol: Winner winner.

 

[Heatmiser5]

I'm sorry I asked. I was just wondering because I had a load
Delivered and it had some elm in it with the bark already off
And I tested it with my new trusty meter. It tested around
20%. Will it dry out at all this winter and be useable late winter?
I split it down to about three inch splits.

 

[Danno77]

I'm sorry I asked. I was just wondering because I had a load
Delivered and it had some elm in it with the bark already off
And I tested it with my new trusty meter. It tested around
20%. Will it dry out at all this winter and be useable late winter?
I split it down to about three inch splits.

As long as you split a piece and took your reading from the fresh face. That number should make for good wood right now.