About 2 weeks ago, I was able to find local help to install a new Drolet Myriad III woodstove I bought last winter. I moved the stove over 5 ft to get it away from blocking an exterior door and to get it towards the center of the north wall on my home. I needed to move it a full 5 ft sideways to clear a post and beam, or I would have just moved it 4 ft and had more vertical pipe coming up from the stove. So the installer was able to make this work by using (2) 45 degree angle duravent durablack angles with 7 ft of pipe angled at 45 degrees between them as I have 10 ft high flat ceiling. We got all the clearance to combustibles good or better than code.
My concern is if 7 ft of stove pipe too long of a distance to run at a 45 degree angle? Basically there is really no straight vertical sections at all, the flu goes from the stovetop adaptor directly into the lower 45 angle section then runs 7 ft at the 45 degree angle and then connects directly into the ceiling pipe adaptor pipe that is attached to the ceiling support box. The top 45 degree angle is about 16" from the ceiling support box metal with a 6 to 8" increaser/reducer section the installer used to connect to my existing 8" double wall Class A chimney. There is 18 ft of vertical 8"class A chimney to the roof cap that goes through a 6 ft high open closet space before going through the roof (6" joisting with R19 insulation).
A bit more detail, I am having the installer come back to replace the old 8" chimney with a new 6" duratech duraplus stainless steel triple wall pipe to be compliant with Drolet recommendations and to update my 35 year old chimney. The guy thought it would work with the 8" existing chimney and he knows the home as he did some of the work on this chimney in the past before I got the home. But we had a big storm come in last week with 30 to 45 MPH North winds and extreme cold to 10 degree F which was a good test. The draft was actually pretty good and I was able to light the stove with just a few hot coals, even with the cold winds gusting hard. But the next few days, I could tell the stove was not "breathing" well and I could hear creosote dripping into the stove pipe. I think the North winds slowed down the draft and cooled the chimney so much that I got a build up of creosote in the cap or chimney. And I woke up the next night at midnight with a smell of creosote in the home and was able to witness a "back-puffing event" the following day which again filled the home with the smell of creosote. I think I got the blockage out by burning a real hot fire for about 10 minutes ( stove top to 600 and the first 45 angle at 750 and about 300+ at the top 45) for a short time and it seems to be running better. But it was scary for me to be getting a reading of 750 degrees at that first elbow with a handheld infrared temp sensor with visons of the metal elbow exploding from excessive heat and pressure. I cannot find a rating on the durablack for heat??? With a normal fire start up, I get the stove top to 400 to 500 degrees and the first/lower elbow is reading about 600 degrees, but just 4 ft up the 7 ft long angled stove pipe, it is already down to about 300 to 400 degrees and at the top elbow where it hits the 6 to 8" increaser, it might read 130 to 180degrees. I know that creosote will start forming in the chimney under about 250 degrees, so that was the no brainer for me to decide to upgrade the Class A pipe to 6" from the old 8" and was the advice I got here earlier this year when I was trying to figure out the new stove install.
The 8" double wall is 10" outside diameter and the new triple wall 6" also has the same 10" diameter, hoping to make this an easy swap without tearing into the roof, replacing the roof jack and cutting new holes and such. The installer likes using the durablack 24 gauge pipe inside the home over double wall as I get more heat inside the home and I agree that is a good thing and I probably should have gotten the next size stove with my 1910 2650 sq ft 2 story old victorian church. It has some improvements to make it more insulated,And I am working on more as well, but is still an old leaky structure. I am concerned about creosote, draft and if the single wall durablack can hold up well to the stove firing up at max temperature, especially that lower 45 section sitting right on top of the stove which gets to 700 to 750 degrees when I fire up the new stove hot to start a big burn on a cold day. I am fine with pulling the stovepipe out a few times a year and doing a bottom cleaning, but I am not wanting to risk having a blocked chimney or cap every big winter storm event.
I know I might be better off with the duravent double wall stove pipe, but I would like to capture a bit more heat in the home if I can do it safely and without creating a problem with cooling my flu gasses and blocking my chimney. But if the consensus here is I need to go that route, then I will install double wall. It is so hard to find help here and to get the parts I need, but I did find a great price on 6 sections of stainless steel duraplus 6" triple wall pipe at a local orange big box store a mere 6 hour round trip drive across a few 11,000 ft mountain passes away, lol. I think I have what I need, support box, new cap, storm collar, but maybe I need to order, or just fabricate, an attic insulation shield to keep the insulation in the 6" joist space away from the pipe. I already removed the insulation that was touching the old 8" chimney pipe, but I think code requires a 24 gauge metal shield in case the insulation moves around. Plus now I have a 2 inch gap between the drywall attic ceiling where the chimney goes into the 6" insulated roof joist space and I am not sure if that needs to be enclosed properly?? Guess I have a few questions than just the 7 ft angle stovepipe. Off to go split and stack wood and will check back tonight, thanks again!
My concern is if 7 ft of stove pipe too long of a distance to run at a 45 degree angle? Basically there is really no straight vertical sections at all, the flu goes from the stovetop adaptor directly into the lower 45 angle section then runs 7 ft at the 45 degree angle and then connects directly into the ceiling pipe adaptor pipe that is attached to the ceiling support box. The top 45 degree angle is about 16" from the ceiling support box metal with a 6 to 8" increaser/reducer section the installer used to connect to my existing 8" double wall Class A chimney. There is 18 ft of vertical 8"class A chimney to the roof cap that goes through a 6 ft high open closet space before going through the roof (6" joisting with R19 insulation).
A bit more detail, I am having the installer come back to replace the old 8" chimney with a new 6" duratech duraplus stainless steel triple wall pipe to be compliant with Drolet recommendations and to update my 35 year old chimney. The guy thought it would work with the 8" existing chimney and he knows the home as he did some of the work on this chimney in the past before I got the home. But we had a big storm come in last week with 30 to 45 MPH North winds and extreme cold to 10 degree F which was a good test. The draft was actually pretty good and I was able to light the stove with just a few hot coals, even with the cold winds gusting hard. But the next few days, I could tell the stove was not "breathing" well and I could hear creosote dripping into the stove pipe. I think the North winds slowed down the draft and cooled the chimney so much that I got a build up of creosote in the cap or chimney. And I woke up the next night at midnight with a smell of creosote in the home and was able to witness a "back-puffing event" the following day which again filled the home with the smell of creosote. I think I got the blockage out by burning a real hot fire for about 10 minutes ( stove top to 600 and the first 45 angle at 750 and about 300+ at the top 45) for a short time and it seems to be running better. But it was scary for me to be getting a reading of 750 degrees at that first elbow with a handheld infrared temp sensor with visons of the metal elbow exploding from excessive heat and pressure. I cannot find a rating on the durablack for heat??? With a normal fire start up, I get the stove top to 400 to 500 degrees and the first/lower elbow is reading about 600 degrees, but just 4 ft up the 7 ft long angled stove pipe, it is already down to about 300 to 400 degrees and at the top elbow where it hits the 6 to 8" increaser, it might read 130 to 180degrees. I know that creosote will start forming in the chimney under about 250 degrees, so that was the no brainer for me to decide to upgrade the Class A pipe to 6" from the old 8" and was the advice I got here earlier this year when I was trying to figure out the new stove install.
The 8" double wall is 10" outside diameter and the new triple wall 6" also has the same 10" diameter, hoping to make this an easy swap without tearing into the roof, replacing the roof jack and cutting new holes and such. The installer likes using the durablack 24 gauge pipe inside the home over double wall as I get more heat inside the home and I agree that is a good thing and I probably should have gotten the next size stove with my 1910 2650 sq ft 2 story old victorian church. It has some improvements to make it more insulated,And I am working on more as well, but is still an old leaky structure. I am concerned about creosote, draft and if the single wall durablack can hold up well to the stove firing up at max temperature, especially that lower 45 section sitting right on top of the stove which gets to 700 to 750 degrees when I fire up the new stove hot to start a big burn on a cold day. I am fine with pulling the stovepipe out a few times a year and doing a bottom cleaning, but I am not wanting to risk having a blocked chimney or cap every big winter storm event.
I know I might be better off with the duravent double wall stove pipe, but I would like to capture a bit more heat in the home if I can do it safely and without creating a problem with cooling my flu gasses and blocking my chimney. But if the consensus here is I need to go that route, then I will install double wall. It is so hard to find help here and to get the parts I need, but I did find a great price on 6 sections of stainless steel duraplus 6" triple wall pipe at a local orange big box store a mere 6 hour round trip drive across a few 11,000 ft mountain passes away, lol. I think I have what I need, support box, new cap, storm collar, but maybe I need to order, or just fabricate, an attic insulation shield to keep the insulation in the 6" joist space away from the pipe. I already removed the insulation that was touching the old 8" chimney pipe, but I think code requires a 24 gauge metal shield in case the insulation moves around. Plus now I have a 2 inch gap between the drywall attic ceiling where the chimney goes into the 6" insulated roof joist space and I am not sure if that needs to be enclosed properly?? Guess I have a few questions than just the 7 ft angle stovepipe. Off to go split and stack wood and will check back tonight, thanks again!
