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.