Should I change this chimney?

Well, here's the deal. A while back I picked up an old Alaska Kodiak II to try out coal. It's a triburner, very nice shape, and I didn't spend much for it so it was a great option for my experiment. I had 8 inch class A chimney in my pole barn that I used for my wood stove, So, I got a 6 to 8 adapter and ran about 7 feet of 6 in blach pipe from the stove to the adapter. I do have a "t" with an old barometric damper (came with the stove). Cleaned the stove good and ran it for a while. Was pleased, but it wasn't putting out a tremendous amount of heat and the stoker/combustion motor sometimes squeeled a bit. Replaced the motor. And got one of those Mark II manometers. Got the manometer installed last weekend. Now I am scratching my head trying to figure this out before I plunge ahead. I like this coal much more than wood, and I think I want to get another (bigger is better) stove for the barn and maybe a boiler to hook into the home system. But, I'm still not getting much heat out of this stove so the experiment isn't over and the manometer is confusing me.

Basically, with the damper closed and the stove going at a decent rate, the manometer (afer being zeroed and leveled) is off the scale on the negative side. The stove (with magnetic temp guage) registers about 250 F and the stove pipe (again magnetic temp guage) reads about 100 F just a little above the stove outlet and below the T. When I manually open the barometic damper all the way I can get the manometer to read "0" and I get a little drop in stovepipe temp and maybe a marginal increase in stove temp. Light a match and hold it a few inches from the barometric damper and the chimney pulls the flame in till it goes out. The barn is not tight, nor is it insulated. If I leave the stove running it does warm things a bit but I would think it should get quite a bit hotter.

This chimney seemed to draw okay for my wood stove, but when I shut the stoker fan off and open the door to the coal burner it seems like there is no air movement inside the stove. So, I'm thinking running the 6 to 8 inch pipe may be my problem. I probably have at least 12 feet of 8" insulated pipe running from the connection and up through the roof. I could replace it, but I might consider getting a power vent instead (probably about the same price as replacing the chimney) so I can move the stove to a different location in the barn. I'll cap the pipe or hook up one of my wood stoves if I go the power vent option. But, before I do anything else I figured I'd see what you experts think.

First connect the tube from the pipe to the manometer to the low side connector (the one on the right). The fluid in the tube should move up the scale that has the graduations on it going up to 3. Even though this is the "positive" scale, this is the one you will use. Leave the other connection port open to room air. Run only one line to the stove pipe, connected before the barometric damper. Build a fire in the stove and run it up to a full burn, then take your reading. The fluid in the meter will expand as it warms up, so disconnect the tube and re-zero it. For a stoker stove the reading should be .02 to .03, which is actually -.02 to -.03" of WC. Adjust the baro weight accordingly. See how it burns and the heat produced and let us know.
Also, whats the size of the burn area on the grate? 1 inch, 2 inches, etc.

This thread should be read...give you what it should be doing. He is right, reverse the hook up tube. Looks like just a bit of fine tuning.

manometer install

Where do you have your tap for the Manometer? After the Stove and Before the Baro, hopefully.

The 6 to 8" transition shouldn't make much difference, as long as you have the height, it should draw good.

Is the chimney mostly inside or outside.?

Did you clean the chimney of creosote after the wood burner was removed?? the wood burner is removed right? only the stoker is on the chimney right now, correct??

It takes a LOT of heat to heat an uninsulated shop.. I know, I've tried... If you have a ceiling in the shop that's a start, if the shop is open to the underside of the roof sheathing, you are just melting the snow off the roof with your stove.. You can get a significant increase in air temps just by covering the bottom of your joists with a layer of plastic sheet stapled up.. Keeps the hot air from rising to the peak. No insulation, but at least an air-flow barrier.

A wood stove puts out a lot of heat. but for a short time, and needs frequent feeding... your stoker will make a moderate amount of heat,, I think your's is 60 or 70K btu?? but it will burn for a full day on a fill up usually.

this was mentioned above, you should have the fire on the grate all the way till the last 1" or so. You don't want hot coals falling off the grate, but nearly so. this will be the max heat output for the stove..

Let us know what you find when the Manometer hoses are hooked up right.. Make sure the baro damper is clean, doesn't have creosote on the back of the flapper. once set you should have better heat output.. But insulation is critical.

Greg L

Okay, thanks for the suggestions. I'm headin home so I'll switch the connection on the manometer and see what I get. The chimney was completely cleaned before I hooked up the coal stove and I ran a brush through the pipe again before I hooked up the manometer. My test point was drilled about 18 inches above the stove's flue connection and about six inches below the T that has the manometer. I inserted a piece of brake line for a permanent manometer connection. I know the uninsulated barn is a lot of space to heat. I'm slowly getting it ready for insulation, but for now I'm happy if I can crank out enough heat to take the chill off so I can get some work done. I've got about three inches of glowing coal on the bed, which is why I am confused about why I am not getting more heat. I could see a little "heat radiation" out of the top of the chimney, so I assumed I had too much draft. That's why the manometer reading really confused me. Pretty sure I do have the tube hooked to the left side, though, so I'll see what it looks like in an hour or so when I switch to the right.

thanks all

steve

You said you have 3" of hot coal, how many inches of ashes between the hot coal and the end of the coal bed?

Like Greg said, you should have ~1" of ashes at the end of the coal bed. The rest should be HOT HOT HOT!

Well, switched the tube on the manometer last night to the right port and the reading moved to the right side of the scale. That's progress! Looks like about .3 (third line, .5 is the first numeral indicator after O). Now I need to fiddle with the feed to see if I can get a little more heat. Baro is about half open, stove pipe is maybe 90 F below the baro and the stove is about 275 F. Maybe 2.5" of glowing coals and 3 " of ash. Need to get some more Blaschak coal. Burning Reading now and if I up the feed too much the amount of unburned dramatically increases. I think separate fan/feed controls would definately be a plus. Does seem like I'm heading in the right direction. Even with this low heat level the barn was about 15 degrees warmer than outside temp (26 F) this morning, measured at the furthest point from the stove.

Draft reading sound about perfect .02-.04 is typical for most stoves. As long you are not much higher, that is a good thing. when it start getting higher, you are loosing heat up the chimney.

If you still have 2-3" of ash, you have to make MINOR adjustments to increase the feed rate slowly. You should be able to get it almost to the end without hot coals going over.

Do you just have the Rehostat controls for feed/speed? Or is there a thermostat. It is much hard to adjust the reohstats, since it is constantly feeding. Maybe put a timer box on the stoker to slow/stop for a certain period of time, that's what most of the newer stokers have, independant stoker blower controls.

Sounds like you are getting there, it just sometimes takes a little time to Fine Tune these things for optimum performance.

Any better today?

Steve, you need to hook the stoker/blower motor up to an outlet with out the rheostat and adjust the stroke to achieve the size fire you want. From the temps you posted there is not enough combustion air going through the grate to produce any significant heat. With 2.5 inches of burn you should have flames at least 5 inches high and the stove temp should be around 350*F. The issue with these triburners is not enough air a low stoker motor speeds since the blower is attached to the same motor.

Also you are trying to heat a very large uninsulated space so actual results will be different from folks on the forum burning a stove in a house or basement. Just don't give up!

Spent all day yesterday locked in a room with about 300 managers talking about what they could do to make their employees like them. I couldn't sell them on more money and fewer managers. Anyway, didn't get to do more with the stove than fill the hopper and empty the ash. That was the best part of the day.

Did tweak the feed a bit but I think Matthaus has the solution. More air. Even with the new motor that combo stoker/fan arrangement doesn't seem to do much more than get a good glow on the coal. Gonna play with that tonight.

Katman, you can see if it will help by putting a hair dryer, or a shop vac on 'blow' and point the outlet/hose at the inlet of the fan... the forced air will add air pressure and volume even when the fan isn't running.. not perfect, but you should see a significant increase in flame height off the coal and a lot brighter fire.

This is just a temporary 'science experiment'... Matthaus has done this already, that's why he rewires the fan motor to run full time, It works best this way.

Greg L

Right Greg. I think the wife is going to be out with her buddies this evening so I was planning to borrow her hair dryer. Didn't think about the shop vac, but that could be the noisy option if she ends up being home. Matthaus sent me a lead on a new fan. Darn thing even has a flange. Great Board!

steve

Matthaus is da man! yesterday I did as he suggested and hooked the stoker/combustion fan motor up to power directly, bypassing the rheostat. Got nice flames (that's new!) and heat. So, tomorrow I think I'll head over to grainger and see if I can pick up a fan with a little more puff that can run by itself. I cleared all the holes in the bed but I'm still not getting the fire to travel more towards the end. Maybe a little more air will help.

If the fire is not burning all the way to the last 1" of the grate, you need to increase the amount of coal the feed mechanism is feeding to the fire.. Are you maxed out on the feed adjustment??

Greg L