Chimney Path Question - With CAD

[WoodBurningLearn]

Hi Everyone,

I'm new to wood burning and we are hoping to put our woodstove in the location I've shown in the attached images. I'll try my best to explain everything using the photos and would appreciate any help/opinions. In terms of location we are in Muskoka, Ontario, Canada.

The first image provides an overall model of the house. The location we would like to place the woodstove is in the corner of the room on the first floor, passing through a living space on the second floor, and then running through the attic. Our long term plans involve removing a lot of that wall to the left of the woodstove (shown blue/grey) to open up the house which is why we would like to place it in the corner as shown.

The clearances surrounding the stove are all in compliance with the manual. The question is the almost horizontal length of doublewall stovepipe that I've shown.


A side view of the proposed installation. Again, we are hoping to remove about 4-5' of the wall shown in blue/grey. The reason that I believe we need to run the chimney to the center of the house is because of the slope of the roof. If we ran a straight chimney up from the woodstove position it would need to stick out of the roof by about 12' to clear anything within a 10' radius by 3'. I believe avoiding this scenario is best for 3 reasons:
1) I've heard that when the chimney is very high it is prone to damage from ice buildup,
2) Poorer draft because I believe desire is to keep as much chimney in house as possible,
3) Visual look of house.

It's a little tough to see but I've put a 90 degree clean-out where the double wall stovepipe terminates to assist in cleaning the chimney.


The image below shows the wood beams that we have running in the room with the woodstove.


The proposed chimney location to get a straight vertical run requires the chimney location to be near the wood beams as shown below. I know the double wall stove pipe requires 6" clearance to combustibles however am I correct in assuming that a heat shield can be attached to the wood beam to reduce the clearance (6" to 3") allowing me to position the chimney as shown? The 2.5" clearance is between the "bell" for the ceiling support kit which contains the stainless chimney that requires 2" clearance to combustibles.


I'm hoping to get feedback on the location of the stove. Basically trying to understand if the horizontal run of double wall stovepipe is acceptable or if it's just asking for problems. I do know that it won't be truly horizontal but have a bit of slope.

Any help or insight would be much appreciated.

 

[begreen]

It's not ideal. Usually horiz. runs should be as short as possible and not over 4'. Why the long offset into the tee before the chimney? Could the stove be placed directly under the ceiling support?

I have not heard of reducing the 6" clearance for double-wall pipe with a shield. That would be up to your inspecting authority or maybe allow the class A chimney to drop 6" below the beam.

 

[bholler]

or why not move the chimney over closer to the stove if you dont want to move the stove? I would not put in that long of a horizontal it is just asking for trouble. And like begreen said i dont think you can reduce clearance or the double wall connector below 6" but you can check with local codes guys

 

[begreen]

I would move the stove first. Moving the chimney over toward the corner would put a ton of chimney outdoors. It would look like a silver missile and would need extensive bracing. If the stove has to stay there I would come up a few feet off the stove into a 45 elbow and diagonally connect to another 45 on the end of the support box.

 

[WoodBurningLearn]

It's not ideal. Usually horiz. runs should be as short as possible and not over 4'. Why the long offset into the tee before the chimney? Could the stove be placed directly under the ceiling support?

I have not heard of reducing the 6" clearance for double-wall pipe with a shield. That would be up to your inspecting authority or maybe allow the class A chimney to drop 6" below the beam.

Thanks for the reply begreen.

The reason that we would like to have the woodstove in the corner of the room rather than placing it under the ceiling support kit is because we intend on removing a portion of the wall (see image below) to provide us with more access to a dining room. Also, the location we have the ceiling support kit allows us to keep as much of the chimney in the house as possible. That being said however we could move the ceiling support closer to the woodstove to achieve a horizontal run of less than 4' (currently it's shown as 6'). The trade-off moving it closer is having more chimney "stick up" through the roof of the house.



Thanks for the info regarding reducing the double-wall stovepipe clearances. I had always assumed that a reduction was possible however a quick look online didn't yield anything. Your suggestion of dropping the ceiling support to clear the beam is valid and sounds like a great idea.

 

[WoodBurningLearn]

or why not move the chimney over closer to the stove if you dont want to move the stove? I would not put in that long of a horizontal it is just asking for trouble. And like begreen said i dont think you can reduce clearance or the double wall connector below 6" but you can check with local codes guys

Hi bholler. I've created a quick model showing how much chimney would be sticking beyond the roof (if we moved the chimney above the woodstove). The minimum is just under 11'. The concerns I would have are: 1) Damage to chimney (wind/ice/snow), 2) Draft (I'm not an expert at this but reading stuff on the web suggests the more chimney indoors the better), 3) Aesthetics (I think it would look quite strange).


Thanks for the comment on the double wall stove pipe clearance reduction. I would have probably made a mistake there.

 

[begreen]

Consider a 45 deg offset for the chimney connector. That should remove justified concerns about the horiz. run.

 

[WoodBurningLearn]

I would move the stove first. Moving the chimney over toward the corner would put a ton of chimney outdoors. It would look like a silver missile and would need extensive bracing. If the stove has to stay there I would come up a few feet off the stove into a 45 elbow and diagonally connect to another 45 on the end of the support box.

I agree with your comment about the "silver missle"

I've created a model where I've moved the chimney closer to the woodstove. The chimney would stick out of the roof by about 7'. I've shown two concepts in the model. A horizontal run of 3' into a clean-up and a 45 degree run using a single length of telescope double wall stovepipe to achieve the same horizontal run. This design would eliminate the clean-out Tee.

In my opinion the 3' horizontal length looks better (and allows us to remove the wall) however understand the 45 degree pipe would have better flow. Is there a risk of going horizontal? It seems that horizontal installations are often used to put a chimney through an exterior wall.
[ATTACHl]143733[/ATTACH]

 

[WoodBurningLearn]

Consider a 45 deg offset for the chimney connector. That should remove justified concerns about the horiz. run.

Sorry - I didn't see this latest post prior to posting.

Would you mind elaborating on "justified concerns"? Would going from the original 6' horizontal span to a 3' horizontal span reduce these to be more comfortable?

 

[begreen]

A long horizontal run is going to get hot and radiant. That will cool down flue gases rapidly, even with double-wall pipe. That can lead to increased creosote accumulation in that section of pipe. Reducing it to 3 ft would make a large difference as long as it still has some uphill pitch. So would using the 45 deg offset.

 

[WoodBurningLearn]

A long horizontal run is going to get hot and radiant. That will cool down flue gases rapidly, even with double-wall pipe. That can lead to increased creosote accumulation in that section of pipe. Reducing it to 3 ft would make a large difference as long as it still has some uphill pitch. So would using the 45 deg offset.

Thanks for the explanation

Anyone else have any thoughts or things to consider?