I have a Kingsman stove bought early 1980s. I am second owner. It doesn't burn well. It could be a number of factors so I want to eliminate some of them. It needs firebrick on both sides and possibly clean the pipe above the roof which I can't do til spring. It's not used in the winter. I replaced the baffle plate when I got it about 15 years ago. The plate is about 1 inch bigger and 1 inch higher than the old one. I have a bend in the pipe, about 45 degrees, about 2 feet above the stove. It is an 8 inch stove going into a 6 inch pipe. The reducer is 1 inch around the bottom of the pipe but it is flat. Would the baffle plate and shape of the reducer make that much difference to make it smoke? Thanks
Smoky stove
- Thread starter Bob Ro
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Could be insufficient draft. The stove is not meant to be choked down. Or it could be that the wood is not fully seasoned.
When was the chimney last cleaned?
When was the chimney last cleaned?
I figure insufficient draft as it flares up when I blow on it. New pipe up to roof. I think outside pipe may be there since 1960s and probably never cleaned (that I know of). I can't get up on roof til spring. It's a summer cabin. It's probably the outside pipe but just trying to eliminate other possibilities. Also the cap is about 6 inches above pipe and about 2 feet above roof peak. I use windfalls so should be seasoned.
Why would you assume windfalls would be seasoned? How long do you have the wood cut split and covered?
They have been down a few years so I figure the sap is out of them. I have them junked and split and under the cabin. There may be several things causing the problem but my question is how critical is the clearance around the baffle and would the shape of the reducer make much difference?
Your wood is most likely over 30% moisture content. You will have trouble getting it to not smoke.
Any reducer will cause a reduction in draft. Yes one of the ones with a flat transition are worse. And yes the baffle design matters
If it was getting draft, it should suck the smoke up. I'll look around for a better reducer or get one made. I'll also check the top pipe in the spring. The baffle is just a square piece welded at the back. I wrote the clearances down, just have to find them. I may be back lol Thanks
That's not how it works.
As hot gasses lighter than outside air rise in the chimney, it creates a low pressure area in chimney, pipe and stove. The lowest pressure is measured at the stove collar, called draft. The greater the temperature difference between inside and outside of chimney, the greater the pressure differential. (less differential than in winter) This lower pressure in the stove allows atmospheric air pressure to PUSH into the stove. This is what feeds the fire oxygen.
Since the chimney creates draft (low pressure), everything else takes away from it, adding resistance to flow, reducing draft. The cap or screen at top, reducers, straight pipe, elbows, tees, and a flue pipe damper which is a variable resistance. The most resistance is the air inlet setting, and a baffle in the firebox ads internal resistance.
The larger the chimney flue diameter, the more capacity the chimney has, meaning it can make a larger stove work. Since the chimney is the engine that drives the stove, you have a small engine, probably clogged even smaller than 6 inches in diameter. The square inch area of your chimney flue is 28.26 inches. (if round) Depending on size of stove, if it requires 8, that is 50.24 square inches. 8 to 6 may not seem that much, but it is half the size you need for maximum heat output.
Square inch area is calculated by radius squared, (1/2 the diameter X itself) x pi or 3.14. So 6 inch is 3x3=9 x 3.14= 28.26 and 8 inch is 4x4=16 x 3.14= 50.24. This is the calculation needed for baffle size.
The space smoke travels over and around the baffle is critical. It can not be smaller than the square inch area of stove outlet, pipe and chimney flue which should be the same size. In your case no smaller than the chimney flue square inch area. This will give the stove reduced capacity since it was designed for a larger chimney. So measure the "smoke space" or area the exhaust travels around baffle. Length x width of space giving you the square inch area the stove has to exhaust. Originally it would not be smaller than 50.24 square inches for a 8 inch outlet. You are already choking the stove down with a smaller flue, so you can't be smaller than flue size.
The velocity coming in is what mixes the flammable gasses coming out of the wood mix with oxygen. When kindling is lit, it should roar up the chimney, quickly igniting larger wood as it is added.
You may be able to clean your chimney from the bottom with a chimney whip. Look into a "Soot Eater" which is flexible rods, with what looks like a string trimmer head on the top. It takes a drill to rotate, so if you don't have electric at this area, you would need a battery operated drill. You will be amazed how much better this does than a brush.
Inspect the chimney flue at least yearly. Burning below 250* to the top allows water vapor from combustion to condense on chimney flue walls, allowing smoke particles to stick. This is creosote which can accumulate rapidly when other factors allow the flue to drop below 250* while smoke is present.
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WOW. There's a mouthful. I have 3.5 " clearance on the sides and 6.5" on the front. I calculate 300 sq in around the baffle. Maximum heat from the wood is not critical, it's a summer cabin. Would just like to stop the smoke coming out when I open the door. A few months ago, it was smoking really bad so I checked and the screen was blocked about 75%. I cleaned that and it cleared up. I suspect the outside pipe is the main problem. I don't recall it ever being cleaned. Job for next year. Thank you very much. Much appreciated.
Most of that explanation is for a stove that smokes all the time, not roll in when doors are open.
I gave you reasons for excessive smoke all the time from chimney.
You have an obstruction if smoke leaks into the building.
The screen is the first to reduce open area since wind cools the screen and cap becoming the coolest part for water vapor to condense on.
Then near the top of chimney.
I gave you reasons for excessive smoke all the time from chimney.
You have an obstruction if smoke leaks into the building.
The screen is the first to reduce open area since wind cools the screen and cap becoming the coolest part for water vapor to condense on.
Then near the top of chimney.
Then the obstruction has to be above the roof as the rest of the pipe is new. Next year job. Thanks. Merry Xmas.
Check out the Sooteater. That should allow you to clean from the bottom up instead of getting on the roof.
jetsam
Minister of Fire
I'm gonna place my bet on the flue that hasn't been cleaned since 1960 here, not sure why that isn't the popular answer so far... 
I'm with you. Cabin was built about 1960 and I assume the wood range was put in about the same time. The current stove about 2005. I don't remember dad ever cleaning it and I know I didn't. I'll take pics when when I take off the outside pipe in the spring. Happy New Year.
I was being nice by referring to "an obstruction". I'm guessing 3 1/2 five gallon buckets worth.I'm gonna place my bet on the flue that hasn't been cleaned since 1960 here, not sure why that isn't the popular answer so far...
At this age, it's possible that the interior of the chimney has started to corrode out too.
nothing to do with this thread but if it is corroded it does. we just just had a major fire in concord mass. very rich town. the house was built by president adams for his grandson. whole house burnt down to ashes from a chimney fire. hole in the chimney started it and no one was home they were all away.
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