Pre-Heating wood: Jotul on Social Media

[tabner]

I saw the attached post on Jotul’s instagram page. Found it interesting. This forum talks a ton about clean and efficient wood burning, but I don’t think I’ve seen this idea mentioned - specifically that warming wood up to room temp prior to burning it, is cleaner and more efficient. Would others agree?
Interestingly, I think I’ve actually observed this a bit myself. If I stage wood in front of the stove for 24 hours it tends to ignite quicker. Could be because the wood decreases in moisture content being in the dry room air, but I don’t think that’s the case Jotul is making. It seems like they are referring more to the temperature effects of “pre-warming” the wood.

 

[tabner]

Sorry, I just realized the full instagram caption didn’t show in that pic

 

[SpaceBus]

I have a hoop that holds a week's worth of wood and I like to refill it when there's a day's worth of wood remaining. I save that last bit of wood for burning that day, and then the new wood has acclimated when the old wood is used up. During acclimation the surface moisture on the wood evaporates. Sometimes I don't plan things well enough, but if the wood is properly seasoned it's a non issue. Maybe five or ten more minutes are needed to get the stove(s) going.

 

[30WCF]

I have a wood burning BBQ smoker. When I feed it a split, I set a second split inside on the opposite side of the fire box to warm and dry.
When it needs to be fed again, the warm log gets rolled to the coals and a new one replaces it. It burns cleaner smoke for cooking with this way and ignites faster for more even cooking.

 

[CentralVAWoodHeat]

I definitely see a difference in ignition times between wood that has been in the house for a few days and wood that was just brought in from the cold outdoors.

 

[begreen]

Their posting may also help reduce catalyst thermal shock if folks are putting in icy splits into the F500v3.

 

[cahaak]

That is a bunch of bs. The heat capacity of a piece of wood would say that there is virtually no difference between wood at 0 F and room temperature. It's an entirely different location thing if the wood is all wet or covered in ice. I store my wood outside on a covered porch and bring it in directly to burn. It burns great, of course it is dry which is really what matters

 

[30WCF]

Nope. Warmed wood ignites faster and cleaner.

 

[BrownT10]

I put my next couple loads a few feet in front on my stove to "pre warm" it. I don't know the science, or lack thereof, but it definitely seems to ignite pretty quick. Either way, the wood is dry to start with, so that is numero uno.

 

[30WCF]

It’s either 15-20% moisture that’s drying out by the day, or 15-20% ice inside the wood.

 

[begreen]

Folks run hot and cold on this topic.

Wood warm or cold??

I was just curious if you burn wood directly from stack or let it warm indoors before it is thrown in the stove?? Or does this even matter??

www.hearth.com

 

[fvhowler]

Have never preheated firewood or stored inside. Bringing wood from outside to the stove has never been a problem for me but I'm not dealing with subzero temps nor feet of snow.

 

[mdocod]

Starting fires with wood that has been in the house for a day or 2 is much easier than starting fires with wood that has frost and/or surface moisture. We have a piece of custom furniture just for storing wood inside made from cedar. It holds about 10-20 days of wood (3-4 heaping wheel barrow loads) depending on weather and our motivation.

 

[EbS-P]

50# of wood at zero degrees, assume it’s all water for easy math (we know it’s 20% water so we’ve over estimated), warmed to 70 degrees. Needs 3500 btus. Or 1/2 # of burnt wood.

I do think warm wood catches faster as it’s had time to really dry out the outside 1/4” of wood and all the little fuzzy protruding wood fibers really well.

So can you get a cleaner but fast maybe. Does that improve efficiency maybe a little bit. But after that temp spike it’s back to burning as usual.

And to argue a pro if cold wood. A tight stacked cold load would have a slowe out gassing rate. Not sure how much, so if you don’t want a load to runaway keeping it outside might be a good thing.

 

[Bobbob]

...and I do believe it takes the same BTU to heat up the wood whether it's inside the stove or outside the stove. Just personal preference. Do what works for you

 

[Eman85]

I'd say anything that's cold that you placed in a stove would drop the temperature. If you had a firebrick out in the cold and put it in your hot stove it would use some of the heat to equalize the temps. 20% moisture in the wood would freeze if it's cold enough and absorb heat from the stove when placed in it.
I don't have to worry as I have an indoor rack that holds a few days worth of wood.

 

[30WCF]

It may be negligible in gained benefits in a wood stove. But it’s true. While smoking food, you are looking for a certain clean smoke, not billowing clouds. Lots of heavy smoke tastes very bad. Warmed wood, ignites faster and smokes heavy smoke less than ambient wood, even on a hot summer day. I don’t taste the smoke from my chimney, although, sometimes I wish I could smell it more than I do when I pull up to the house. I do miss that smell that the newer stoves have done away with. I get we are not talking about brisket here, but the warmer the wood, the faster it gets a char, the less smoke there is, unless it’s wet wood. I leave my stove wood outside. I warm my smoker wood because it makes a difference there.

 

[Caw]

Starting fires with wood that has been in the house for a day or 2 is much easier than starting fires with wood that has frost and/or surface moisture. We have a piece of custom furniture just for storing wood inside made from cedar. It holds about 10-20 days of wood (3-4 heaping wheel barrow loads) depending on weather and our motivation.

Id like to see it! (The furniture)

 

[30WCF]

I always thought that was thought that was a burlap mask like on the Batman movie where the roaches come out of the mouth. I just zoomed in on it. It’s a log.

 

[BillBurns]

I would say that warm wood lights easier, probably due to it being closer to burning temps compared to icy logs. I have a rack, hoop, and a spare room to keep wood.

 

[EatenByLimestone]

Even if it’s only 5 or 10 minutes faster, being able to engage that cat, or getting those secondaries going quicker, will significantly increase the amount of smoke that gets reburnt and allows you to use more of the heat. Is it going to save you a cord a year? Not unless you burn massive amounts of firewood a year, but over the life of a stove… you might save a cord.

 

[willisj318]

I split some wood that was outside yesterday, about a year old. White Oak. Most logs were reading about 20% after the split. 24 hours inside and they are now reading 15-17%. I don't know if this means anything or is normal, but I found it interesting.

 

[Caw]

Fresh split oak that's only 1 year old reading 20% is definitely unusual. It must have been long standing dead and from the top or limb of the tree.

Also you aren't measuring correctly. You need to get the whole log to temp inside then split and read it fresh. When you bring it in post split the moisture in the outside of the log evaporates and gives false low readings.

Take one of the chunks you've had inside for 2 days now and split that and read the freshly split face. Prongs going with the grain. That will be a truly accurate number.

 

[PaulOinMA]

I have a wood burning BBQ smoker. When I feed it a split, I set a second split inside on the opposite side of the fire box to warm and dry.
When it needs to be fed again, the warm log gets rolled to the coals and a new one replaces it. It burns cleaner smoke for cooking with this way and ignites faster for more even cooking.

I put some splits on top of the firebox to preheat.

 

[30WCF]

I put some splits on top of the firebox to preheat.

It that in an offset smoker?