frigid wood = harder gasification?

[pybyr]

Hello all-

please riddle me this-

I just recently finished burning through the maple and cherry that I'd put down cellar earlier this fall, and, until I got around to bringing some loads from the woodshed to replenish the cellar stockpile, have, since yesterday, been bringing it by the armload just prior to each burn (now it is a mix of white ash, eastern hornbeam, and maple).

All of a sudden I started having a much harder time getting a good fire going, and especially getting good gasification going

At first I was a bit freaked out wondering how the rest of my wood could be so different in it's state-of-seasoned-ness-

then my 10 year old son posited that perhaps the cold wood (it's been around and below zero here) has a harder time getting to the same temperature simply because it starts out much colder.

I think he may be on to something - and I probably need to get more of my wood inside to warm up in advance of fires.

Have others experienced similar phenomena?

Thanks

 

[flyingcow]

My wood is stored inside the garage, oops excuse me, my wood storage building. I reclassified it, to keep the insurance company happy. :coolsmile: I don't have a thermometer in there, but it's not heated. It was 15 below this morning, there was not much noticeable difference when I walked into garage. Grabbed wood, went into boiler room, and started a fire. Have had excellent luck firing it up. I doubt it's because of the cold, unless it has ice/snow on it. I have not got a moisture meter, but my adjustment on the secondary tells the tarm people I got the "good stuff"(haven't used that term for a long time, and i wasn't reffering to wood ).

The cold must effect it some, but i doubt it would be noticeable.

 

[Eric Johnson]

I think it's more likely that your "cold" wood has a higher moisture content, since it's been sitting out in sub-freezing temps and has thus not had the same opportunity to dry out as the wood stored inside where it's warm and the relative humidity is a lot lower.

The simple test, of course, would be to warm up the suspect wood and see if that makes a difference.

Since spring is a ways off, you might want to consider getting as much wood into the cellar as possible right now, as it will start to dry out immediately and should be much better in a week or two.

BTW, I store my wood in my barn, outside the boiler room, so it's always pretty cold when it goes into the boiler. I haven't had a problem getting gasification going.

 

[djblech]

I noticed that the wood that I put under cover in Sept and Oct had enough time to evaporate alot more moisture out of it than the wood that I put up in Nov. I have a wood shed is 12' x 20' x 7' tall covered on the back and half the sides. It is about 25 ft from my Greenwood. I bring in enough wood to be about 1 to 2 days ahead of burning. This seems to warm it up enough to burn well.
By the way, -22* today, -30* yesterday. Both stoves going through alot of wood.

djblech
Greenwood 100
VC Duchwest
Stihl 360 and 170
Kioti DK45, winch, dump trailer

 

[Fred61]

Recently someone posted a link to a youtube video that showed someone operating an Eko. He demonstrated that the wood he brought in regestered some high number on his moisture meter and then in a short period of time (don't remember, but short) demonstrated that it had dried to a very low percentage moisture. I didn't believe it and surmized that what he was reading was the condensation that occurred upon entering the warmed space. Video didn't show his face so I couldn't tell if his glasses were fogged up also.

 

[NHFarmer]

I usually keep about 1/2 cord in the cellar next to the boiler,it is nice and dry and gasifies nicely.When I cut off of the cordwood pile and reload the cellar it always takes a day or two to get those really good burns.Now I try to put a couple of days worth aside to keep those good burns going.So it seems to me that the temp does make a difference.just my 2 cents

 

[leaddog]

putting cold wood into the upper chamber will cool things down. I had a hard time figuring out why when I loaded up my 80 why it took it so long for the temp to start to rise and alot of the time would fall several degrees. Then I relized that putting that much cold wood in was drawing down the temp and it took a while to heat up that much mass. Once it got warmed up the temp would go up rapidly.
leaddog

 

[flyingcow]

well you got me thinking now. I've got room in my boiler room, I'll take in a couple of fire boxes full and let them warm up. You guys have defiantly got me curious now.

 

[Tree farmer]

I usually keep about 1/2 cord in the cellar next to the boiler,it is nice and dry and gasifies nicely.When I cut off of the cordwood pile and reload the cellar it always takes a day or two to get those really good burns.Now I try to put a couple of days worth aside to keep those good burns going.So it seems to me that the temp does make a difference.just my 2 cents

Same here, I try to bring in a weeks worth from my woodpile right outside my basement door and stack the higher mc stuff right up against my oil furnace and drier stuff goes in my old linen bin on wheels. I too notice a difference in the quality of burn with the stuff that has been inside awhile but it could be both warmer wood and it has dried more. Bottom line if you can make yourself pile up some in the basement try it out and see what happens.

 

[timberr]

I have about 3/4 of a cord in the basement. That is about 3 weeks worth of wood. Usually on Sunday I replace what I burn during the past week and I take wood from the area that has been in the longest. How is your wood stored out side? Three years ago I built a wood shed, prior to that I had it stacked on pallets and covered with tarps. I have noticed a big difference with the wood shed.

Personally I don't think the temp of the wood matters, I think it is a MC issue. Try bring the wood in, and if you need to use it right away us a box fan to b low air on the wood.

Good luck.

 

[Duetech]

pybyr,
Moisture content of the wood can/could have something to do with the wood being harder to get burning but I also know for a fact your son is on to something. My boiler is outside in an unheated building. The boiler gets air that is whatever the temperature is outside. For a short period cold low moisture wood will collect moisture from the air as any cool surface will do when exposed to moist heat. Putting a large load on a bed of coals is one of the quickest ways to get a guestimate of condensation in practice especially when the wood is ice cold. Do a flash test. Bring in a load from out doors and load it right away (on a bed of coals as the boiler has to be hot) and 1-2 minutes later check the wood by taking some of it out. I had two year old oak splits I have been saving for that cold weather we always seem to get some of. At -15*f I loaded my boiler and checked it just minutes later and it was wet like it had been sprayed. I had been having some trouble with some bl. walnut and I thought it was high in MC but the oak did it too and most of it has been sitting under a roof surrounded by four walls since last winter. I think some of the walnut was high MC as some of it seemed wet enough to drip and actually wet the fingertips of my gloves but it's hard to tell because the walnut has a smoother surface than the oak and is more prone to run. Both dried out in time but the oak was faster. at -15* the boiler temp dropped just from the wood that was put into it and made me think something was wrong (like bridging) and that's how I found out the wood surface was wet and it had been dry only seconds before. Still if the wood is upper level MC it will probably collect condensate longer and take more energy to get it to gasify.
Kindling a fire in a cold boiler is different as the wood shavings and thin splits fire up fairly fast.

 

[timberr]

I have been thinking about this. I think we all agree it is MC, but remeber with unfrozen wood the moisture is in a liquid state, when it is in the boiler it has to change it's state only once. When the wood is frozen the water is in a solid and now it has to change it's state twice. Each change in state would require and increasing amount of energy to accomplish this. So my thinking is yes it is harder to burn frozen wood because the water itself is ICE and not liquid.

 

[DaveBP]

After 30 years of burning wood as my sole source of heat in Maine I am in the habit of bringing in the next days wood before bed. Set it somewhere near the stove.
When I go to put it in the stove it is ambient temperature that way. If you are going to heat it to combustion why not start it out at higher temp? It's got to get going faster that way. Noticeably? I don't know about that, but it's no extra effort to bring it in now rather than later. If you have the room, why not bring in several days or weeks worth. Help to humidify your house if there's free moisture in the wood and lower the MC of the wood.

Whether it's lower moisture content or just pre-warming or both, in any combination you know it is better whether it makes a remarkable difference or not.

I do it anyway.

 

[Piker]

just thinking out loud here...

Wood "burning" is actually rapid oxidization... it's the gasses that burn (gasifiers just do this extremely efficiently). Wood only oxidizes after it reaches a certain temperature... therefore, it would take longer to get the wood to a temperature where it would release the gasses if it's cold.

whether you use warm or cold firewood will likely affect how the boiler runs, but it shouldn't effect overall efficiency... if you bring cold wood in to get it warmed up, you will be adding some cold thermal mass to the structure, thereby requiring more output from your boiler. I think it's just a matter of where you decide to warm the wood up... in the firebox or in the structure.

maybe.

-cheers

 

[pybyr]

just thinking out loud here...

Wood "burning" is actually rapid oxidization... it's the gasses that burn (gasifiers just do this extremely efficiently). Wood only oxidizes after it reaches a certain temperature... therefore, it would take longer to get the wood to a temperature where it would release the gasses if it's cold.

whether you use warm or cold firewood will likely affect how the boiler runs, but it shouldn't effect overall efficiency... if you bring cold wood in to get it warmed up, you will be adding some cold thermal mass to the structure, thereby requiring more output from your boiler. I think it's just a matter of where you decide to warm the wood up... in the firebox or in the structure.

maybe.

-cheers

Thanks, Piker- and thank you again VERY much for the time you spent with me on the phone the other day helping me verify aspects of "care and feeding" of my Econoburn to help me get up the learning curve that goes with transitioning from "traditional" woodburning appliances to gasification

 

[Piker]

Any time, pybyr

cheers

 

[Duetech]

DaveBP,
My wood is ambient when I put it in the boiler the difference between your ambient (+70?) and mine at -15*f is 85*f (LOL) so it don't really help me but it will help pybyr since he has a warm place to put it and let it come up to room temperature. Moving wood like that though takes a little more than a couple of trips. When I had my wood furnace in the basement I always tried to keep a full cord minimum in the basement and it was always a "special" chore. In my boiler outbuilding I only have room for about 2/3 cord and don't have to handle the wood as many times but I never seem to be able to "just" bring in a couple of arm loads when one trip every few days/evenings will do the work more economically time wise because my wood pile is isolated and out of the way. But I am working on that.

 

[DaveBP]

Cave,

Great example. I only had in mind heated indoor spaces. Obviously hadn't remembered that 'ambient' means very different temps to some folks.
But if you're going to carry the wood in anyway ( I put in a door I can run a wheel barrow through in my new house) it won't make extra work to bring it in now rather than later.

The outdoor boiler room suggests to me a door wide and tall enough to drive a tractor bucket loader into. Now that would take a little of the work out of it!

 

[Tony H]

I found the very cold temps by themselves did not make alot of difference but the wind added did make a difference. The stack on my outdoor shed Eko is not very tall and when the very cold wind whips down from over the garage it makes it more difficult to maintain gasification and the unit can not compensate for the extreme cold. The wind does have some effect but when the temp is not so cold 10F and above the EKO can overcome the load and still maintain a warm temp.
All the wood is outside except a 1/2 cord or so that sits in the shed but it does not seem to make a huge difference if I load from wood outside to wood that is in the shed but then again none of it is really warm.