Chimney Top Fan

[rennman]

I have a big, heavy duty chimney fan that I want to install to get a steady, even draft. Who has experience with a power failure while such a device is operating? I know there is room beneath the fan blade plate and the expanded metal at the sides for smoke to escape naturally, but I have a situation now with occasional puff-backs and I want to make this thing as safe as possible with no possibility of soot and smoke in the house if it stops. What if I add some angle-irons to the frame to make it sit higher above the smoke exit. Would that be O.K.?

 

[begreen]

I would be very leary of this. Is there any way to improve the chimney system without power? Is this the same chimney/flue in which the stove would run away on you due to strong draft?

https://www.hearth.com/econtent/index.php/forums/viewthread/65084/

 

[cmonSTART]

There is usually SOME room for natural draft to work in the event of a power failure, but usually people install these fans because their chimney doesn't draft for whatever reason in the first place, so space isn't really an issue.

 

[rennman]

I cleaned out all the joints on this stove and re-caulked them with furnace cement. Could be that the stove was not air tight, but since that day when the soot spewed out all over the house my wife doesn't want the stove lit at all. Instead of too much draft, I think there is an erratic, non-constant draft. I warmed the flue the other day when my wife wasn't home with cardboard and even after warming it really well I never saw a healthy draw... window open or not. There is 16 feet of 6 inch stainless flue. Will adding a length of double walled 6 inch to the top fix this problem? I'm not sure. That's why I thought I would top the chimney with the fan. I've already burned mucho gallons more oil without this baby fired up.

 

[begreen]

With a 16 ft insulated liner, the draw should be pretty good, but as a test, temporarily stick a 3-4' length of cheap 6" vent pipe in the top and see if it helps.

 

[Beardog]

I would first make sure I didn't have any branches or other obstructions near the chimney first. If none, add some length and that should help the draft.

 

[rennman]

I put a 5 foot length of smoke-pipe on top of the chimney today. The increase in up-draft was very little. I think that the only way out of this is the electric chimney fan. What do you guys say?

 

[pen]

what stove is this and how old?

pen

 

[cmonSTART]

Personally I would try to find the cause of the issue. If you have a marginal draft and then stick a fan on top, you're going to have a smokey house when the power goes out.

 

[rennman]

Hey Pen,
The stove is a 1976 Comforter from Lochmere, NH. But that doesn't seem to be the issue. The updraft in 16 feet of 6 inch flue liner is very poor. Chimney top is 2 to 3 feet above roof peaks and there are no trees or other buildings near the house. The surrounding woods are out and away from the chimney about 75 to 125 feet.

 

[pen]

If you found suspect joints I'd be surprised if superficial patches would do to much. It may be time to rebuild.

Are there 90 degree bends going from that stove to the chimney? If so, how long is the horizontal section? Does it pitch up?

I just can't believe a fan would be a solution for this as that is plenty of chimney, especially for a pre-epa stove.

Is it a 6 in chimney matched w/ a 6 in flue on the stove (sorry I'm really not that familiar w/your stove)

pen

 

[Loco Gringo]

Ill chime in renn for what its worth. Instead of trying to remedy the problem, I would look to solve it. Things may not get better with the fan and the cause of your problem will still exist.