WILL TWO 90 DEGREE ELBOWS ON STOVE PIPE RUIN MY DRAFT ?

[fatrabbit]

I am changing to double wall pipe on my Jotul 600. The install is offset from the the thimble.
Previousley I was using single wall pipe with a 45 elbow to an 18 inch run and 90 elbow out to the thimble. I have an exterior chimney with a 9x13 clay liner. I was told with the double wall pipe I will need an adapter off the stove. The thing is with an adapter and then the 45 elbow I will be too high and pass above the thimble. If I go straight up then 90 elbow to the right and 90 out to the thimble will this dramaticly reduce draft/ cause creosote build up ?

 

[fatrabbit]

I realize you cant rise above the thimble . Thats why Im asking if two 90 degree elbows are ok.
If I have the two 90 turns it would be straght up a short horizontal run and then out. Would this reduce draft too much ?

 

[Metal]

You didn't say the amount of vertical rise you have in your exterior chimney, but with an over-sized exterior chimney you already have some issues, then by adding in 90's you are adding more. Can it be done, yes, just make sure you minimize the horizontal run. If your current system works, I would just leave it alone.

 

[fatrabbit]

Metal-
The chimney has about a 25' run. The proposed horizontal run on the stove pipe is about 24" and the 90 degree turn and out through thimble. I made a mistake with my first install and used single wall pipe. I have noncombustible durock behind with 7" of clearance. I did not however think of counting the studs behind the wall as combustible and would have needed additional clearnce 18". The stove did draft very well before though. This may have been due to a small crack in the bottom plate. I am having the plate replaced and stove rebuilt and would like to have the re-install done correctly and not have to worry any more.

 

[fatrabbit]

So can anyone tell me if using two 90 degree turns with a short horizontal run is a bad idea. Would like to get the install done before it gets much colder.

Thanks for any advice,

 

[ProjectX]

I would say yes you can. Look at the picture section here get some ideas. Look at it this way... you say right now you are too close with single wall then you don't have a choice needs to be fixed.

2 - 90s not a great thing but you have to do what you have to do to be safe. Dry seasoned wood, good hot fire daily clean and maintain your stove and chimney on a regular basis. If you have draft issues you cant live with raise the thimble and do it right.


Just my thoughts please correct me if I'm wrong.

John

 

[ProjectX]

Yes Yes I see. Lower the thimble would be better only one 90 would be used.

Great point

 

[fatrabbit]

Thanks guys,
It may just be easier to lower my raised hearth. Its about 16' off the floor and wood framed with two layers of durock and then blue stone. It would be a shame to break it down but easier than cutting through the wall and lowering thimble. In the mean time I have been checking with the local dealer and cant get a straight answer as to whether or not I actually need to have an adapter to connect to double wall pipe. Without the adapter I would just go right to a 45 elbow 30 " up at that angle and then 90 elbow out to thimble.

Thanks again for the help, will post pics when done.