Vermont Castings Vigilant Mod

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Narcea

Member
Nov 6, 2018
6
Hudson Valley NY
I just wanted to post this experiment I have been working on to see what you all think.
I have a Vermont Castings Vigilant wood stove smoke dragon. So I fixed it. Here's what I did.

I relined the firebox with refractory material, added a smoke shelf, added combustion tubes, and combustor.
When started the stove burns in updraft mode utilizing the combustion tubes and bypassing the combustor. When switched to down draft the smoke after the secondary combustion tubes after the combustor, is directed across the top of the stove then down a side chamber to the rear of the stove and zig-zags up and out of the stack.

When up to temp very little smoke is visibly in updraft and often none. Stack temp immediatly above the stove is 450f to 500f. When in down draft no smoke at all is visible. Stack temp is typically around 180f. I can hold my hand on the exhause comfortably. Placing a pain of glass over the top chimney in the exhaust stream shows only water vapor deposits. Very little oder is noticed outside. On very cold days it looks like natural gas exhaust.

This is now a true hybrid stove with burn times as long as 13 hours. I determine burn time as the stove temp is above 200f and able to relight the fire using only coals and fuel, no matches. This mod is completely reversible. It was important to me to not drill into or damage the stove.

I can give more details and pictures if anyone wants.
 
Pictures are attached. Please be kind. I have been running the stove for ~ 3 years and it could use a little cleaning. It was an experiment and has undergone several re-dos. I was planning to shrink the side chamber but never got around to it so the firebox is a little smaller than it should be and the right side glass/door gets very dirty.

I really should diagram the airflow but I didn't so I'll just explain it instead. :)

Air enters from the rear of the stove as designed. It flows along a tube on the bottom left and across the bottom front then along the bottom left. It then flows up a vertical tube in the rear right and then along the top back of the stove. From there the tube flows forward along the left top until the reaches the front of the stove. Lastly, it flows along the front top of the stove. The air tube is routed this way to preheat the air as it gradually decreases in size to maintain airflow.
Along this tube on the bottom of the stove (primary air) there are holes on the left rear, front, right, and rear. Also, there is some air from the tube along the top of the doors which can be considered primary air. The secondary air comes from the tube holes on the top rear of the stove.
Tertiary combustion is achieved in the combustor located above the smoke shelf after it has been engaged. Typically this is done about an hour after the stove has been started. Even before engaging the combustor the smoke from the chimney has decreased to nearly nothing. The stove can be run cleanly w/o engaging it and will run hotter but for a shorter period of time. When engaged the stove will operate for a much longer duration but not as hot.

Without the combustor engaged the exhaust exit the top rear of the stove. When the combustor is engaged (down draft mode) the top rear exhaust is blocked and the exhaust is forced across the top of the stove, down a side chamber, then up the rear (zig-zagging), and out.

A thermocouple & o2 sensor are placed in the exhaust once a few inches from the top of the stove. The thermocouple reads ~500f in "updraft" mode and ~200f in "down draft" mode while the stove is operating mid-cycle.




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Pictures are attached. Please be kind. I have been running the stove for ~ 3 years and it could use a little cleaning. It was an experiment and has undergone several re-dos. I was planning to shrink the side chamber but never got around to it so the firebox is a little smaller than it should be and the right side glass/door gets very dirty.

I really should diagram the airflow but I didn't so I'll just explain it instead. :)

Air enters from the rear of the stove as designed. It flows along a tube on the bottom left and across the bottom front then along the bottom left. It then flows up a vertical tube in the rear right and then along the top back of the stove. From there the tube flows forward along the left top until the reaches the front of the stove. Lastly, it flows along the front top of the stove. The air tube is routed this way to preheat the air as it gradually decreases in size to maintain airflow.
Along this tube on the bottom of the stove (primary air) there are holes on the left rear, front, right, and rear. Also, there is some air from the tube along the top of the doors which can be considered primary air. The secondary air comes from the tube holes on the top rear of the stove.
Tertiary combustion is achieved in the combustor located above the smoke shelf after it has been engaged. Typically this is done about an hour after the stove has been started. Even before engaging the combustor the smoke from the chimney has decreased to nearly nothing. The stove can be run cleanly w/o engaging it and will run hotter but for a shorter period of time. When engaged the stove will operate for a much longer duration but not as hot.

Without the combustor engaged the exhaust exit the top rear of the stove. When the combustor is engaged (down draft mode) the top rear exhaust is blocked and the exhaust is forced across the top of the stove, down a side chamber, then up the rear (zig-zagging), and out.

A thermocouple & o2 sensor are placed in the exhaust once a few inches from the top of the stove. The thermocouple reads ~500f in "updraft" mode and ~200f in "down draft" mode while the stove is operating mid-cycle.




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Looks like your mod is cleaning some of the glass, too! That alone is worth the effort, the classic vc stoves always had dirty glass. Nice!