Testing out the difference between kiln dried, seasoned and green firewood Hometown Acres Amazon Store www.amazon.com... Link to Firewood Guy www.firewoodgu...
The big advantage to kiln dried in addition to the moisture content is kiln drying also kills any bugs IN the wood.....meaning if selling to campers, and they take it with them to another location, they don't transport pests
I was going to make the same comment as I think done outlets require it now. However there may be a difference between the time it takes between sanitizing the wood ( killing the bugs) and kiln drying it. Cost vs benefit choices.
My wife asked where that mosquito came from in the middle of the winter. Hiding in the wood I think. Add a few spiders , wood roaches and the odd ant just to make life interesting.
About 30% of the energy stored in firewood, is released as gases as the wood is heated. If those gases reach a high enough temperature, the gases are burned in the stove, and the heat is recovered. If there is a high moisture content in the logs, the water turns to steam and the steam temperature of 212 degrees F, keeps those volatile gases too cool to be burned. And Voila! you get creosote forming in the chimney.
Michael great point. There’s a lot of energy in those wood gases. And even if you’re able to burn them in a wood stove with a catalytic feature the challenge is to capture the heat before it goes up the chimney as a 400-500F exhaust. A little over 20 yrs ago I built a masonry contraflow heater in our home. The design and principle goes back several hundred years. Long story short, the wood gases burn in a secondary chamber where time, turbulence and temperature allow them to burn completely and then they have to travel downward thru considerable masonry channels where the heat gets more fully absorbed. The flue gases going up the chimney are 250F. The damper is closed when the fire dies down and the heat captured by the massive thermal mass will weep that heat out gently over the next 24 to 36 hours. I’ve read where the efficiency is upwards of 80-85%. With these stoves the idea is to burn hot and fast to achieve complete combustion. My firebox will register between 900-1000F during the peak burn with dry wood. Green won’t begin to approach that. There’s something primal and incredibly satisfying about heating with wood that folks in Florida and warm climates will never know. Take care.
Nice job, as an engineer I noticed the amount of base and volume of wood especially on the kiln dried was about 30-40 lower than the other woods. I believe this fact negates the conclusion on time burning. In addition what really matters is btu output. Did you take the stove temp when you loaded each type? Otherwise keep up the good work!
Very interesting results. Now consider the cost of resources for the seasoned vs. Kiln dried. Seasoned took time which is free. Kiln dried took costly equipment and extra energy/ money.
my dad has a big half-empty greenhouse, so he generally puts a few cords of wood in there to get a sort of half and half in between traditionally seasoned and kiln dried.
Wouldn’t be cost effective if you are making firewood for yourself. But if you are selling the wood you can charge a premium for the kiln dried plus you can get your product to market faster which is extremely important in order to capitalizes on fleeting opportunities. I think kiln dried is the way to go for businesses
@@fowledevolution1710 the fact he put it in a stove that was at full operating temperature, already, made a significant difference. there are a lot of other reasons not to burn green wood if you can avoid it.
That was super informative, Thanks for putting this subject to bed. The only about kiln drying is it's like ethanol fuel, your using a lot of energy to create some sort of perceived energy savings.
Great post. I think the best all around approach is to burn a mix starting with Kiln dried, then seasoned, and if necessary, unseasoned once it is red hot. I try to keep well seasoned wood in a two-year out supply and always use that to start my fires and then go to less seasoned wood once things are roaring. But never fully unseasoned wood due to the creosote and chimney fire issues (indoor fireplace of course). But I burn “wet” wood outside all the time once I get things up to temp. It drys out pretty quickly once it is tossed in. I base that on the hissing and popping which usually goes away within 10 minutes of tossing a wet split into the fire.
My wife and I were just talking about that the other night. We were talking about how that probably goes back to the cave man days when or whenever dogs were first being domesticated. Man, do they love sitting near the fire. Our dog and cat fight for the best spot in front of the fireplace.
@@davelindgren5245 The domestication of dogs only dates back 32,000 years and humans had already moved out of caves and in to purpose constructed buildings.
The better test, would be to take kiln dried wood, and place it next to wood that you are seasoning. Check moisture when you rack it up, then let it sit and check it again in August or September. Chances are high that it will act as a sponge and soak up moisture, and will be the same as seasoned wood. I’ve always believed that kiln dried wood is only beneficial if you burn it within a month or two of it being dried. Letting it season in the weather as you would with your other firewood, will cause the kiln dried wood to climatize to the environment and it was a waste of money at that point. You have to burn kiln dried wood the same winter that you buy it.
That would be an interesting test to see if the wood does acclimatize to the same moisture level as the seasoned wood or if it retains some advantage over an entire year. I would guess that if covered or stored inside it would but not so much if stacked outside, uncovered.
I like that you incorporate the science and various marketability components in your videos...it makes it very interesting. I guess you are the Alton Brown of firewood 😀.
Great video Adam. The best of all perhaps of kiln dried wood is the very low creosote build up in the chimney. No bugs and very little clean up of ash due to neat total burn of the fuel.
Creosote build up comes from any wood burned below the needed contact temperature in a chimney to keep it clean so folks can still get in trouble burning kiln dried wood if they smother it too much of the time.
Great video. I love your charts and graphs for the experiment. I try to never burn any green wood in our wood stove - it creates so much creosote in the burn box, the catalytic combustion chamber, the pipe, and the chimney. It's just too dangerous. I've never burned kiln-dried wood. Great test.
U do a good job on these videos. I live in northern California. I work in log yards and have access to endless wood at moment. Ive hauled a bunch of madrone home. Over 30 cords. I have sold bunch of cords thru out my life. I will b processing a bunch this spring. Going to do some of my own vids on the cord wood game.. Ben looking at the Easton splitters now thanks to ur videos. I normally split a lot by hand but the wood i have is drying out so i will need a machine. Any ways thanks for ur knowledge on processing and selling cord wood.
Dry wood, wet wood, green wood, red wood, logs, pellets, lumps or briquettes... When it comes to heating your home, once you have that hot fire going, all that really matters is the energy content of whatever it is you want to burn. So, throw that stuff in your stove, open a cold one, and enjoy! Good video.
For the feelgood factor, you are right. But dry wood heats better as the evaporation of water sucks up a lot of energy and blows it out of your chimney as steam. If you don't mind to toss a couple more logs in the fire... cheers! ;)
Great video! The amount of heat produced is indicated by the area under each curve on your graph, which clearly shows the added heat generated by the drier wood.
Your videos always get my attention Adam, I also burn my wood in a insert and get obsessive about moisture content, that was a lot of good information!! Thank you very much appreciated
Thanks for the huge effort you put into making this video, it is really good. Great to see your results. Graphically shows the heat energy lost to boiling off the sap/moisture within the logs during the first 75 mins - that is a lot of heat that could have gone into the home! Vince
Adam, great job thx. I’m an accountant as well (CPA/CFO). I applaud your analytics. They complement your videos very nicely. I burn wood in a masonry heater as well as an outdoor sauna. I too, expected a bigger difference between the green wood and the seasoned. I will say the green wood will cause my glass fireplace door to get dirty fast vs seasoned wood which burns it clean. I’m retiring in the next month and will be harvesting more wood from my 80 acres of ADK woodlot. Can’t beat a nice warm fire during those cooler months !! Keep up the good work.
Adam-03-04-21: We have constructed our own firewood & lumber drying kiln. With an Radiant Concrete slab, with 900 ft. of 5/8 PEX tubing. An a LP Hot Water on Demand Heater, to heat the Ethylene Glycol or antifreeze. An a Wood-Mizer HD 150 Dehydration unit, not cheap. Frist run on the fire & sawmill Red Oak planks, was 10-1/2 days at 110 degrees. So after all my windedness , did your friend tell his temperature for a 3 day cook.
Well done demonstration. I have one comment about the seasoned vs. kiln dried. During the seasoning process, that firewood will eventually dry to your area’s “Equilibrium Moisture Content”. On the other hand the kiln dried firewood will eventually gain moisture back to that same EMC. To prove this, take your moisture meter and test the oldest standing barn beam that you can find. In the midwest our EMC will be approximately 16% to 18%. My point is that to kiln dry much below the EMC is possibly not necessary if the firewood will be stacked and stored for some time. I see the main advantage to kiln drying as the insect elimination. Given too much time, even they may return. Just something to think about.
True. Also the EMC for wood furniture inside your home is 8%. Firewood left inside your home long enough will all get to about 8%. (Not that you should store firewood inside.)
I'm curious about cost. Yes, the kiln dried had a higher average temp, but what is your local cost for a cord of green/seasoned/kiln dried? Is that premium for kiln dried worth it in terms of heating cost?
wow, that took commitment. Awesome test. It is neat to see actual mapped results put to the rumors to see what is best. I would never have guessed that the end of the curve, the 3 types of wood would be so close. Also, I would have guessed the kiln dried to burn out quicker. I am surprised it was just a half hour shorter burn time. Can't beat mother nature for drying wood from a cost perspective and end results.
Very nice test, thanks! I'm burning seasoned wood most of the time (with the occasional bit of unseasoned ash). Won't the paying the premium that kiln-dried wood fetches, but it really is wonderful stuff as you can see in your results
I am very impressed by all the time and effort you put into making this video. I was surprised also by the result, but once the moisture is gone it is all the same wood.
As an older chick who man's her own firewood, getting it,hauling, stacking shlepping etc, its a full time job in the cold months in North Carolina, in a historical home. Wood is my main heat source now that my HVAC system broke and can't afford a new one, or propane at this point. I got an insert last year, should have got it years ago. Definitely learned much about wood over the last 30 years. I do wish I had a dollar for every man that sold me wet ( green) wood saying is was seasoned. Saying " ITL BURN" no Bubba it won't if you're not starting with hot coals. It will just sizzle n steam and piss you off. Plus the ceroset build up can cause chimney fires over time. On top of blacking out my insert windows. UGH!!! I'm more mad at myself for not learning this sooner ( thanks boomer) I say to myself. Now I have a wood moisture meter,a fan, and thermometers on my insert. I'm also trying to get wood well in advance now, and tarps so to allow for dry time, uncovering on sunny days, etc. I'm tired...but thanks for the vid. Do a video on starting a fire with no hot coals, using fresh cut oak....lol ssssssssssss
A little late but if you do not have kindling ( sticks, small branches, that need to be cleaned off the lawn ) & do not want to split logs for kindling try using some pallet wood. I also have an insert & do not burn pallet wood for fuel supply but do use the scraps I get from pallet projects. It starts very fast & burns very hot. Stay warm & safe, Joe Z
I had no idea North Carolina got cold enough to require much heating. You’d really have a story to tell if you lived up north! I burn 4 full cords a year (cut/split/stacked in the woodshed by April).
@@joejoe-lb6bw I just use pallets stamped HT ( heat treated ). Instead of using chemicals to treat for insects they are heat treated. Still have to know if possible what they were used to transport to be safe.
Great science experiment. Note that the area under the curve is giving you a value of the heat (BTUs or calories or joules; pick your poison) that you are getting out of the wood. The moisture takes part of the heat to be liberated and to dry the wood. there's where you 'lose' out on the wet wood. Also note that you have to use energy to kiln dry, so there's trade-offs with all that. Keep up the good work.
10-4 on the trade-offs. That’s true in lots of our daily lives. One glaring example is ethanol for vehicles- sure it burns cleaner(less co2 emissions) but the trade off is during fermentation (making the alcohol) the co2 is released and it takes energy to ferment. Anyway thanks for your great video on this subject.
Hi Adam, great insight into the different wood “stages”. I’m interested to know if there’s a difference in price between kiln dried and seasoned, and how much energy has to be put into the kiln process?
Solar wood kilns are a great way to make that energy input requirement negligible. Biomass debris fueled heating from the “waste” of the firewood production process would be second best.
Adam if you had a high efficiency gasification boiler the results are even more amplified being the secondary chambers get @1800-2000*f. Green wood quenches the air and gases and inhibit any sustained secondary combustion.
Hej Adam, thanks for evaluating. Very interesting indeed. But there is one thing I think had to be adressed: the seasoned firewood is dependant on the weather and season (no pun intended ;) ). Normally, you get the best (lowest) moisture from seasoned wood at the end of the summer or better: after a long period of dry weather. If you got the seasoned wood right from a place in the snow, that's may a reason for a higher moisture. I normally prefer to get all firewood for the winter in a dry shelter before the autumn rain starts and then getting it into the warm house 3 to 7 days before burning. With that I normally get a moisture of approx. 15%. Don't know if that would make a big difference in the average temperature... (disclaimer: I don't have cherry, I only use birch)
Thank you for the video. I wonder if one is short on seasoned wood, then placing green wood near the fireplace to expedite its drying cycle. That is something I have done with both a firepit and fireplace. I then move the green after a fire and place a new batch of green wood with a new fire. That would be a good test, seasoned wood versus using the green firewood that was placed near a fire. ???
I done that for our chimney years back when we lost power for a week, i was running short on seasoned firewood, so I started keeping green firewood near the fireplace to attempt to dry it up quicker than the seasons. I have done that also with the firepit, i would keep green wood around the bottom part of the firepit and on the edge of the firepit so it can dry while the fire is burning.
I suppose the dryer wood produced more heat because it ran at higher temperature more quickly, which allowed secondary burning of wood gas. the wetter wood released the gas without burning it. But I see you didn't adjust the air vents during the process. If you aggressively built up the temperature of wetter wood, would it get more secondary burn?
I would try to store the firewood near the stove. This way as the stove gets super hot it basically acts like a. Kiln and helps dry out the firewood right next to it that you’re getting ready to burn.
Stuck around!!! Found very very similar results. At times I did question the length of burn because I felt the kiln dried wood would burn faster. Either way. Cool. Love kiln dried as no insects and it’s ready to roll. Stay safe
Interesting results. Adam, could you do a video on stove maintenance and cleaning out the ash, please. Not sure if you have an ash pan so just wondering how you do it. Thanks
Excellent and comprehensive! It seems like if the first 75 minutes of the burn is useful, kiln-dried firewood is worth any extra cost. I'm thinking fire pits are a prime example of where the benefit is, since for the first 75 minutes you want that higher heat. I'm glad to know that it won't burn longer, but it will burn hotter, and maybe even burn with less smoke. Thanks!
More emissions and creosote for unseasonably, right? Not less. It looked like the fire bricks in the back were pretty black after that first unseasonably burn. I'd imagine that the chimney liner experienced a similar buildup of creosote during the unseasoned burn. Half an hour of low temp burn per load for the entire winter would really add up.
Great video. Can you show follow up of if you had any extra creosote from one versus the other? And how much babysitting for green. I stuff stove and leave for work. Add to when get back about 14 hours later. I produce lots buildup when low and slow . clean every 2 months on 6 inch pipe. 2 weeks if anything green slipps in.
Are you sure your moisture meter is reading right how can you get 0 in a piece of wood lumber is kiln dried to 6 to 8 percent and will go up or down depending where you live and what time of year
You could sanity check your results using the specific heat of water and the heat of vaporization of water. Essentially calculate the amount of water, then calculate how much energy it takes to bring it to the boiling point and then to convert it all to steam.
Nice experiment. My thermodynamics is a little rusty but the other interesting area for comparison would be energy output. This is can be simplified as the area under the temp/time graph taking the x axis as the room temperature - so "fire temp - room temp" is the temperature value rather than the raw fire temp. If you compare thee value of energy output for each type of wood you'd probably see a similar ratio to the average temperature values you got but may be interesting to see. There is obviously lots of variables that will effect the actual energy output which would not be taken into account so an idealised system is assumed with constants which can be ignored.
Nice looking insert you have there! I put off installing an insert until this year and got stuck with a 2020 certified stove (2.5 grams per hour.) With this insert you have to be even more concerned about the moisture content of the wood. I believe the draft control is cut back a bit and more air is injected for afterburn. This is probably the best video I've seen regarding moisture content of wood.
Really enjoying your channel, thinking on starting my own firewood business in 2023. Great experiment, Kilm dried is definitely better burn, but not sure if it's worth the cost to get set up for that.
Now do this style of test with different sized wood. Will large pieces provide more heat over 4 hours than the same volume of smaller pieces? This will tell us if we need to split more or less.
But smaller pieces may give a higher temperature earlier to take the chill off the room. Then add fewer large pieces to maintain the temperature longer.
I would be really interested to see if it makes a difference when you add green, seasoned, and kiln dried wood to an existing. So for instance, in your test, the fire burnt down over 4 hours. Maybe after 2 hours, add 3 pieces of green and burn for 2 hours, then add 3 pieces of seasoned and burn 2 hours. Then add 3 pieces of kiln wood. I'd be curious if the green reduced the heat very much and if it took long to get back to optimal heating.
Adding green to an existing fire will cool it right down, and the steam coming off the greenwood will carry creosote into the chimney where it will condense out into a flammable coating. Try this sometime. Take a paper cup and fill it with water. Take a propane torch and try to burn a hole in the paper cup. It will scorch the cup but it will not burn through. The heat will be dissipated into the water until the water reaches 100C at which point it starts to boil and create steam. Once the water level in the cup boiled down to the level the torch is adding heat, then you can burn the hole. The same thing is happening with that greenwood. You are investing a lot of energy to get that water boiled off and then just as Adam found, it burns like any other dry wood.
Also the type of firewood hardwood vs softwood and the type of fire burning device (ie. firepit, woodburner, or a solostove. These variables also control the intensity and heat/energy produced.
Thanks Adam you answered some of my questions. In my area I can buy all three types of wood, kiln dried being the most expensive, then seasoned and finally unseasoned being the cheapest. Next question. How much creosote does each produce? Just wondering.
the kiln dried had a lot more room to breathe. a weight test probably would have improved the results. the variance would have been insignificant between the differences in moisture, but it would have allowed the same amount of wood for each experiment. it looked as if 2 more sticks would have made it more accurate. the kiln was split smaller i think thats where the 5 stick rule failed.
I think I understand what you are saying, but since firewood is sold by volume (cubic foot, face cord, cord, etc) rather than weight, then weight doesn't really matter. It's how many BTU's per cord that matters.
Wood that’s been dried to 10% is smaller because it has the water removed. Water takes up volume so there is more “wood” per cord with seasoned and kiln dried firewood because it’s measured by volume not weight. For an easier analogy there is more “beef” in a pound of jerky than there is a kilo of fresh “beef”. People have a hard time grasping this concept even those who’ve burnt wood all their lives. This is why these “experiments” are completely faulty because in effect this guy has put more wood in the fire although he is saying the splits are “same size”. To use the analogy again of course beef jerky has more calories per pound than fresh beef just like kiln dried wood has more BTU’s per cord for the same reason. The reason to burn seasoned wood is because it’s safer and gives heat off quickly which is the whole purpose of having a wood stove.
Not sure if the test was done by weight, but the kiln dried was significantly shorter than the seasoned. The surface area and the max average girth would greatly affect the results, I would think. Also, was the stove loaded at the same stove temp each time? The chart showed a temp range of about 75 degs. Interesting info nonetheless.
I’m glad you conducted that experiment and equally glad I watched it. I can basically count on learning something useful from all your videos. Thanks Adam!
I had to burn some green wood towards the end of the burning season. I didnt notice any difference in the burn times. Just the amount of ash and smoke. The creosote is the primary reason not use green or un-seasoned wood.
I could be mistaken, but I believe that the gases that create creosote are caused by higher combustion temperatures which, ironically, the kiln wood achieves.
I would like to see you test each type of wood starting with a cold stove for each type.I would think it would take much longer to bring the stove to operating temp with green wood.Thanks for a very informative video
I am not sure if it just was the time lapse, but it seemed as the green wood had more blue flame throughout the burn. Your numbers really where informational, thank you.
Good stuff. Let’s be honest here, who burns kiln died fire wood the entire season? I think a realistic approach might be to have some on hand to start, or maintain a good hot burn while mixing in seasoned wood. To add, a lot of Ash here in the Midwest isn’t like cherry. Most standing dead trees you can cut and burn same day. But, that’s the reason these experiments are so vital...the variables are great. Thanks for sharing👍🏻
