I've read many a thread on this forum regarding dampering down your stove and getting maximum heat output by doing this. It makes sense because the heat is not being wasted by running up the stack. BUT ..... In my experience I notice my house is warmer when my damper is more open then more closed. I know I'm wasting wood by running hot, but that's not the issue here. My house is warmer with a more open damper vs a more closed damper. I usually only put three 16" splits in a 1.7 cubic foot box. Is this the reason ? Does a more closed damper work better when the box is fully loaded with a great coal bed ? Not sure what the answer is, but I'm gonna run my stove by what makes sense to what my experiences are, and not by what common sense implies. My wood is dry. What do you guys and gals think ?
Questiion On Maximizing Heat Output
- Thread starter carlo
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Todd
Minister of Fire
Experiment and do what works best for you. Every stove and setup is different but I always thought full loads turned down to where the flames slow down and get kind a lazy looking is most efficient burn.
carlo said:
My take is this. The most efficient burn you can get will not necessarily be the hottest burn you will get. Dialing your stove into what a lot of folks call the 'zone', you'll get a long burn efficient burn with good secondaries while your stovetop temp stays reasonably stable. For me and my particular stove, that's anywhere between 400 and 500 at the collar. However, my stove is capable of getting much hotter than that I've had it well over 600 at the collar. When I'm there, it's a hell furnace pushing tons of heat but I also know a ton of that heat is going up the chimney too, and the length of that burn goes way down. I'm sacrificing burn time and fuel to get things heated quickly.
So essentially when you're "in the zone", you're getting more heat out of your stove over many hours as you are making the most efficient use of the combustion that's occurring, but you're doing so at a lower temperature.
firefighterjake
Minister of Fire
carlo said:
As mentioned there may be a variety of factors here.
First . . . is the room and stove actually warmer as measured by a thermometer . . . or do you just feel warmer. I know it may sound stupid, but the human mind is a funny thing and sometimes we may believe something when it is not actually true and measured (i.e. we may see more flames and based on our past experience associate more flames with more heat.)
That said . . . I believe you . . . as others have said, different stoves and different situations may result in different results. For example, you may be getting more heat with the draft open more if you have a lot of single wall stove pipe exposed to the room . . . the heat going up the stove pipe and outside will radiate off from the single wall pipe at a pretty decent clip . . . the flipside is that the fire may burn quicker, you may not have enough heat in the firebox to achieve good secondary combustion, you may end up going through more wood faster and as a result the overall efficiency of the burn may suffer . . . on the otherhand . . . if you're warm. . . .
agartner said:
I agree with this. My "zone" is mid damper once the fire gets going. At this point I get efficient heat output and efficient wood burning. When I damp down too much I get the lazy flames, which are supposedly really good, but after time they die down and the fire starts to smolder, and the coal bed diminishes. I can't keep the lazy flames going for more than 15 or so minutes once I damp down.
firefighterjake said:
I don't have a stove thermometer. I know the house is warmer from the thermostat readings around the house. I also have double wall pipe. But the one thing I do have is a metal wall shield behind the stove, and whether it's my imagination or not, I feel since I put that shield up the heat is more intense coming away from the stove, and it keeps my walls cool to the touch.
My secondary burns are maximized when I'm dampered down half way. When I damp down more than half way I go to a lazy flame then to smoldering. Although the smoldering stage is not dirtying my glass much, it just doesn't give me warmth like I read others get.
firefighterjake
Minister of Fire
carlo said:
OK, so we've established you're not going crazy since you have checked the thermostat readings in the house.
And since you have double wall pipe you're probably not gaining all that much more heat vs. having single wall pipe . . . although there is more heat going up the stove pipe as you mentioned.
So here's my thinking now.
I think you may be partly right . . . the shield may be radiating some heat back into the room . . . but if this is right behind the room this should do this regardless of whether the heat is radiating off the stove or stove pipe . . . and in fact one would think it would be more intense if the stove was putting out more heat.
My gut check feeling at this point is that 1) your wood may not be as seasoned as much as it could be as the majority of folks here with well seasoned wood report being able to "close" down the air most of the way or even all of the way and have some very intense and long-lasting secondary burns . . . if the secondary burn stalls out after closing the air too much and/or you have wood that is not fully seasoned I am guessing you would end up with the lazy flames (possibly some Northern Light action or brief time with the Bowels of Hell fires) and then the fire would stall out . . . if the wood is good and the temps are hot enough there should be very little to no dirtying of the glass, secondaries should last for quite a while and you should get some good heat for a long time. If it makes you feel better . . . what you're experiencing is almost what I experienced last year with semi-seasoned wood . . . I had to keep my air open more if I wanted to prolong the secondaries . . . and even then they would sometimes splutter out after a short while.
My other thought is 2) your own stove/chimney set up may be designed so that you in fact do get a better secondary combustion with the air open more . . . this may be the case if you have some drafting issues.
Interesting ..... ya know, I always thought I had good wood because my glass stays nice and clean. But I guess there's a difference between good wood and really really good wood. I read on this forum some people keeping wood for two years or more ! I buy my wood from a very reputable nursery, but even they tell me the wood is seasoned for about 9-12 months. This very well could be the reason for me not being able to fully damp down w/o smoldering. I hope one day to be able to store wood for more than one year, and really get it nice and seasoned. Unfortunately, my wife would freak out because of the bugs the wood attracts in the summer months.
Oh .... and no drafting issues as far as I could tell.
Oh .... and no drafting issues as far as I could tell.
billb3 said:The bugs are there anyway, the wood just helps you notice them. Same as feeding the birds.
Can you damp down more with a window open ?
I'd wager you get a bit better burn and use less wood if you season the wood yourself, though.
I'm sure the bugs are there all the time, but the bigger ugly ones are there more so during the summer months with the humidity.
It helps a little bit if I crack the door while damped down low. I see a draft, but not enough to sustain a consistent low flame.
I wouldn't wager against you ;-)
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