I grew up with my parents firing a King brand smoke-dragon in our living room during the winter. Dad always had this super-big splits, and of course they were green ("green wood burns longer, it's best for overnight"). Knowing what I know now, those huge green splits scare the crap out of me. We used to watch the "tar" ooze through any seam in the stove pipes (where the damper went through, etc), and slowly run down the pipe. I'm amazed that I only recall 1 flue fire growing up... Now, we have a Kuuma Vapor Fire 100 in our home. The home is slightly oversized for the furnace, but the furnace provides 100% of the heat until the temps get to the mid-high teens (Central MO). Then the propane furnace kicks in as well. This is the 4th year we've had the Kuuma, and I've had to un-learn some of the bad habits picked up in my youth. Split sizes, for one. Dad always had big monster splits, so that's what I started making with the Kuuma. Over the years, I've realized that even small splits seem to burn just as long (and possibly hotter) than the big splits. What I consider "small" splits (4-5" or so, IIRC) are the recommended size for the Kuuma. Now that I see how long it can burn on small splits, I'm considering 1) splitting much smaller (this will happen), and 2) burning more branch/limb wood. The part I hate the most about cutting up a tree is the limbing/dragging brush pile anyway. With the Kuuma doing so well on small splits, I'm considering using more of the branch/limb wood as firewood. I'm currently thinking I'll keep anything that's about the girth of a spray-paint can, instead of putting the limbs on the burn pile. I'm curious, how small do you guys go on your "small pieces" for heat? I figure I've already downed it and going to limb it from the truck anyway. May as well burn it instead of hauling it to a brush pile.
4x6” or so... if momma can’t pick it up with her bad hands... she ain’t gonna put it in the stove !!!
I’m not in a rush to get rid of my brush. So I don’t generally do burn piles unless I’m getting rid of a stump. When I process a tree, the limbs under about 2.5” get stacked in a pile and left for a year. When I get time, I process the limbs on a compound mitre saw and they go into the stove. I’m pretty sure that I’m not getting the same heating BTUs per pound of wood that I put in the stove with the limb wood. But it’s still free heat that doesn’t take much labor to process. Waiting a year to process the limbs makes them brittle too, so a lot of stuff an inch and under can be broken up by hand.
I also have a Kuuma Vapor Fire 100. I have found that it isn’t picky on the size of the splits. I burn big splits and limbs down to 1.5 in diameter. If I have to deal with the limbs they are eventually ending up in the furnace. We also have plenty of junks trees like tree of heaven and autumn olive. I take pride in burning those too. I just did a reload of small diameter ash and apple. It’s chugging along just fine.
Welcome to FHC fellow Kuuma-ite! I agreed, the Kuuma is a completely different creature from old school burners...different than any other modern fireboxes too. I still have to get used to the recommended 18-28% MC wood instead of the under 20% that almost everything else wants these days...I have been told by both Daryl and Dale of Lammpa MFG that my 15-20% MC wood is a bit dryer than optimal...something about they don't want the wood fiber/cellulose burning up too much/too fast before the gasification phase is done. I have found that the big ole chunks that I had cut for my old Yukon furnace last a bit longer, but at a lower overall heat output...a whole load of real small stuff burns hotter, but not as long. A mixed load of sizes and wood types seem to do the best overall. I will take limb wood down to 2" or so...even a bit smaller if it is easy pickins. Limb wood is actually denser than trunk wood too...its just hard to stack the same amount of limb wood into the firebox as with nice square splits with hardly any air space between.
Oh. And welcome motoguy !!!! Just realized that was your first post!! I think you’re gonna like it here..
First of all I would like to say that I’m impressed with your willingness to learn a better way of burning. So many people just do what they were raised doing. Congrats on breaking out of the mold. I burn down to 4-6 inch splits. I do have some smaller that I dry in my stacks that are ready to help light a fire or coax coals back to life if I let it get too low.
Wow. Sounds like "as small as you want to mess with" is the answer. I hate to spend the time cutting/dragging/processing wood that I'm not going to get heat out of. Seems like wasted time/effort/material. I've got 7 trees that need to come down in the near future. I'll likely experiment with them, and find where the "worth the hassle" line is, then. It seems like I'll want a separate storage area for the "limb wood". Doesn't seem right for some reason to mix it with the larger splits in the stacks (for storage). I really like the idea of it being "filler wood", though. Drives me nuts when I have an opening in the furnace, but no wood sized right to fit it. Played too much Tetris as a kid, I guess!
I'm not sure it's open mindedness, as much as it's just me being "cheap". lol I hate to put the time into processing (cutting, limbing, dragging) wood, and not get the benefit from it. Seems like I can get "more wood for the same effort" if I start cutting up the limbs I am currently tossing in the brush pile. I've been using the standard blade on my DHT 35t splitter, as it works well. However, it obviously takes more time to re-process splits to get smaller splits. I have the 4-way attachment for the splitter (which I tried in the past, but didn't like), which I may put to use for getting smaller splits. The King unit was in my childhood home. I grew a love for wood heat from this unit. As a little kit, I'd have my mom lay my underwear on top of it when I was in the bath, so I could dry off, run out, and put on some warm undies on a cold winter night! Before school, I'd lay on the carpet in the living room, tuck my socks up under the blower vent, and let it toast my feet while I watched morning cartoons. Turned more than one pair of socks "brown" from heat doing that! lol Our home was smallish, around 1300 sq ft or so. That King would run us out of the house. I remember more than one occasion where my aunts/uncles were over playing cards with my parents, and the front and rear house doors were open...in the middle of December. I remember another time when my friends (we were of driving age by this time) came over to pick me up, but wouldn't come in...they were dressed for the snow/cold outside, and said it was "too hot" to come inside. I remember the thermostat saying low 90's in the house at that moment...my mom was (and still is) cold-natured. When I was in my early teens, my folks built a much larger house on the lake. They installed a Clayton wood furnace in this house, and it was a consistently poor performer. I'm not sure if it was the ducting (unit was installed in the garage, trying to push heat "sideways" to heat the living levels, and trying to push heat "down" to heat the walk-out basement), or if it's the fact that the Clayton was little more than an oversized smoke dragon. Either way, it was a pretty dismal failure. I remember my parents going through 13 cord of wood one winter, trying to heat that 4k sq ft house...and we were still always cold. Our Kuuma is in our walk-out basement, heating a similar sized house. While it's a bit under-sized for the house, it still does an excellent job providing 100% of the primary heat down to the high teens (outside temps). At that point, we need to kick the propane furnace on, in order to get the heat level we want (68). Daryl sent a baffle which I installed, in order to get some "extra" heat out of the unit. He also advised me about adjusting the pot on the control computer, to increase the heat output (at the trade-off of lower burn time, and more ash). Burning everything as hot as we can, we still get 12 hour burn cycles (give or take), and burn 4.5-5 cord a year. I think 5 cord is a hard upper limit on how much CAN be burnt in a VF-100. Blows me away that we satisfactorily heat this home on about 1/3 of the wood my parents used in their similar sized home. When we purchased this home in 2014, I had been away from wood heat for 20 years. The home had a small Avalon Arbor (same as a Lopi Leti (sp?), I believe) wood stove downstairs, when we moved in. The first winter, we ignored it. The 2nd, we decided to use it, as I had dropped a couple of trees cleaning up the property. I was amazed at 1) how much heat it put out, 2) how little wood it used, 3) what a PITA it was to get into gassification, and 4) what a TREMENDOUS difference it made in our propane usage. In addition to drastically reducing the propane usage, we also enjoyed a nice warm floor on the upper level. We spent a lot of time downstairs that year, enjoying the fire (do miss seeing the fire) and the thick, soothing heat around that little stove. Seeing the dramatic difference made by such a small wood stove, and being annoyed at the PITA time/attention needed to go from "starting the fire" to "in gassification burn" the the Avalon, we decided to move to something 1) more capable of providing the heat we needed, and 2) easier to use. Based on my research (2014) the Kuuma was the top of the line furnace, and the most recommended "set it and forget it" computerized option available. We installed the Kuuma in the same location as the Avalon, using the existing flue. I added an exterior door nearby, to aid with wood handling/loading (and to avoid dropping crap all over the carpet in the living area, using the existing door). I then walled the Kuuma in, and essentially gave it it's own "furnace room". The Kuuma has certainly met my expectations. It's somewhat regrettable that the "entertainment" offered by the Avalon stove (due to being able to see the fire) is gone, and the Kuuma is now strictly a "utilitarian appliance". However, that's just how it works, I guess. The Kuuma is CERTAINLY much more "set and forget". It's excellent in that regard. If I leave the firebox undisturbed, I can usually go 24 hours between fills, and still have enough active embers to re-start the fire without "help" (kindling, or worst case my propane weed-burner, which I used to jump-start a fire from scratch). That's a trick I learned to get through shoulder season, where it's cold enough at night to want the Kuuma burning, but warm enough during the day that it'll run you out of the house if it's burning. So, I'll start a fire at night, let it sit untouched during the day, and have enough coals to re-start the fire the following evening. Crazy what a good insulator ash is. My DHT 35t splitter has been one hydraulic leak after another since I purchased it in 2016. I finally rebuilt the cylinder last week, after blowing the shaft seal a year or two ago. I went ahead and sealed all the other fittings as well. For the first time in my ownership experience, it appears to be fluid-tight. My trusty Poulan 4418 died last year (user error, not the saws fault), so I currently don't have a "small" saw. I still have my Echo CS-501p and CS-620pw. I was considering adding another Poulan to the lineup, but I think I'll just go with a CS-400 with a 14" or 16" bar instead. The Echos are all new saws to me, replacing a fleet of 4 Stihl 028 Supers. Dad had (has) an 028 Super, and that's the saw I grew up with. I picked up several used ones, but they all need maintenance of some form or another (mostly carb replacements). Rather than continuing to deal with Stihls, I decided to go with modern saws and sell off the Stihls to offset the cost. I haven't gotten around to cleaning up / selling the Stihls yet, but it's on my "short term to do list".
That is odd about the higher MC recommendation. 28% is almost green depending on the species and climate. I spent a lot of time mowing brush with a tractor. Anything smaller than your wrist can be "mowed" so I consider that stuff grass and don't process anything smaller than my wrist for firewood. The other drawback to processing such small stuff is the increased likelihood of sticking the saw chain into the dirt. I also find it very unsafe as the tiny "log" isn't heavy enough to stay put while you buck it. Finally, most chippers eat wood smaller than 4" so that is a logical cutoff. These days, I've been getting log loads delivered so the highly labor intensive part of harvesting of forest products is severely reduced!
Speaking of which...why is it that the Kuuma can get into gassification without any catalyst, or any other "consumables" that most of the EPA stoves have? That was another thing I liked about it...no consumables to replace/keep spares on hand. I was wondering about that. Is the catalyst a stove thing, and not a furnace thing?
Welcome aboard motoguy From my understanding (limited as it is), gasification is akin to secondary burn, while the catalyst consumes particles in the smoke. Hopefully someone has a better description, especially if I'm off in left field.
Not really any difference in stoves vs furnaces...furnaces just have a larger firebox and fan, more or less. I suppose any tube type stove could be considered a gasifier...kinda, sorta...the water gets murky once you wade into this stuff deeper...the Kuuma is considered an "updraft gasifier" and would be one more so than a stove, but IMO they are not entirely different...Kuuma just has that upper burn chamber, whereas a stove does everything in one spot...not sure how a cat stove would figure in here...just a different way of doing the same thing I suppose...
It's just a noncat stove. Secondary air supply and a firebox temp above the temperature where smoke will spontaneously combust. Nothing wrong with that! Even the catalyst in a cat stove, by definition, does not get consumed but they do lose effectiveness as they age due to masking and physical degradation. All of the precious metals are still there though. SOrry, this is just splitting hairs, you need a new cat every 12000 hours.
The furnaces also have that awesomely huge heat exchanger in the exhaust to steal the heat from the flue gasses. They also have automation and safety devices to allow them to work unattended. Some, unfortunately, don't have a window.
Welcome to the forum motoguy. Wondering if you are perhaps in the more northern part of MO? I've read your posts and those of others and this indeed is an interesting thread. First of all I'd like to state there is nothing wrong with cutting up the limbs for firewood. Around here, it all depends upon if my wife is helping or not as to how small of a limb we'll cut up. She wants to cut up some that are way too small for what I like whereas I would throw those on the brush pile. When I'm cutting, I'd say around wrist size is about as small as I'd go. But something else to keep in mind is that it takes a lot longer to put up wood when you are cutting small stuff rather than the larger ones that need splitting. Still, we've always saved limb wood. As for the moisture content, for sure gasifier type stoves have different requirements on moisture content. With most stoves though, drier is always better. Rather than using moisture to slow the burning process, we use the draft control. For cutting up those limbs and also for cutting up some of the smaller trees, it can be a time saver and a saw saver to use a saw buck. It really can be a big help having extra help, even if they don't want their picture taken. You can even make them straight up. I guess this post is long enough but will sign off by giving you a link that you no doubt will find interesting and helpful: Primer on Woodburning by Backwoods Savage
That is the truth; the few times my sister has helped me I got twice the amount of work done in the same time. She was helping me split by handing the wood off to me instead of me having to walk over to the trailer and lift it off.
Welcome Motorguy to the FHC. It is a great place to sit a spell as they say down here in the Kangaroo State.
