Greenhorn wood stove install questions

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refertech

New Member
Nov 27, 2021
5
Pennsylvania
I figured my family would be better off if we wouldn't freeze to death at the flip of a switch so I decided to buy a wood stove. I do commercial refrigeration service work for a living but I am not very knowledgeable when it comes to these types of heating systems. I'd appreciate any help from you guys who are in the know. As far as I can tell, I've got 2 options. I can put this stove in a corner where I'd have to run the flue off the stove, 90 into a wall and 45 it out 10 feet where I could secure it to my patio roof and then 90 upwards another 2 feet. Alternatively, I can put the stove in another corner, 90 off the stove, go through the wall and then 90 up again, through my patio roof another 8 feet (to maintain the 2 feet above any combustible structure within 10 feet rule). My question is, is there a scenario here that is preferable or are either one going to give me problems?
 
Generally, the fewer bends the better. First one as far above the stove as possible...
 
The first option is not possible. As soon as the flue exits the room envelope it must be class A chimney pipe. 45º elbows are not made for chimney pipe.

The best and often less expensive option would be to centrally locate the stove and go straight up thru the house and then the roof. Otherwise option 2 is the next choice, however it is not advised to 90º directly off of the stove. Better to go up a few feet, then 90 to the wall thimble and tee outside for the second 90º turn upward.

Draft is the engine of the stove and the flue system needs enough height to achieve this. Each 90º turn reduces draft by a rough equivalent of 2 ft of pipe. Therefore, a 3' vertical off the stove, then 2 - 90s to an 8 ft chimney will be insufficient height. The stove will likely have draft issues meaning incomplete combustion and poor heat. Even an easy breathing stove will need at least 12-13' of vertical rise to get sufficient draft to burn well.
 
The first option is not possible. As soon as the flue exits the room envelope it must be class A chimney pipe. 45º elbows are not made for chimney pipe.

The best and often less expensive option would be to centrally locate the stove and go straight up thru the house and then the roof. Otherwise option 2 is the next choice, however it is not advised to 90º directly off of the stove. Better to go up a few feet, then 90 to the wall thimble and tee outside for the second 90º turn upward.

Draft is the engine of the stove and the flue system needs enough height to achieve this. Each 90º turn reduces draft by a rough equivalent of 2 ft of pipe. Therefore, a 3' vertical off the stove, then 2 - 90s to an 8 ft chimney will be insufficient height. The stove will likely have draft issues meaning incomplete combustion and poor heat. Even an easy breathing stove will need at least 12-13' of vertical rise to get sufficient draft to burn well.
Thanks for the insight. I suppose I could put it in another location where heat distribution throughout the house would be more limited but I could have a straight flue run. My house is an A-frame with two additions on the side and back. If I wanted this stove in the core of the home, I'd have stove pipe running directly through the center of the house, through the first floor ceiling, the second floor ceiling, the attic and finally the roof. seems like way too much of a fire hazard to do it that way. There is one other option, but it would still require one 90. I could, after penetrating the wall, secure the flue pipe to the existing chimney, although it would be a 20 foot vertical run.
 
Thanks for the insight. I suppose I could put it in another location where heat distribution throughout the house would be more limited but I could have a straight flue run. My house is an A-frame with two additions on the side and back. If I wanted this stove in the core of the home, I'd have stove pipe running directly through the center of the house, through the first floor ceiling, the second floor ceiling, the attic and finally the roof. seems like way too much of a fire hazard to do it that way. There is one other option, but it would still require one 90. I could, after penetrating the wall, secure the flue pipe to the existing chimney, although it would be a 20 foot vertical run.
A-frames can be tough due to the sharp roof pitch and the 10-3-2 rule. Running the chimney pipe up through floors is a hassle, but not a fire danger as long as done correctly. There needs to be a fire stop at the 2nd floor penetration and the chimney pipe needs to be chased, maintaining minimum 2" clearances.

10-3-2 rule.JPG
 
I don't see why running straight up, thru two floors, would be a fire hazard? Use double wall pipe and a ceiling box, and then class A pipe onward. Doing it right (clearances) is safe.
 
I would go straight up if at all possible. Draft is key to stove performance. Nothing worse then doing a project and when your done it doesn't work right, then where are you at. All that time and money for something that won't work properly..
 
I would go straight up if at all possible. Draft is key to stove performance. Nothing worse then doing a project and when your done it doesn't work right, then where are you at. All that time and money for something that won't work properly..
Straight up it is then. Thanks for all the help guys.
 
Straight up it is then. Thanks for all the help guys.
Keep asking questions as they come up. With good planning and a proper install it should work out well. Don't scrimp on the components for the chimney system. It's infrastructure and will last a long time if the stove is properly run.
 
I've got another question for you guys. I purchased some DuraVent 6" ID double wall pipe (7 1/4" OD). When I go through the ceiling, all the fittings I'm finding are for a transition from single wall to double wall. This pipe reduces the clearances from combustibles from 18" to 6". I figured I could find pass through thimble for ceilings that would work for this OD but I'm not having any luck. Also, for the final penetration through the roof, I purchased a Dektite silicon pipe boot (5-9") to seal around the metal roof but I'm going to have to cut a larger hole through the plywood beneath the metal roof to adhere to the 6" from combustibles rule. I obviously don't want to cut a 20" diameter hole in my metal roof. Given the proximity of the plywood and the metal roof, does anyone have any tricks of the trade to only cut the plywood away, allowing for a hole in the metal roof to accommodate the pipe boot? I was thinking about trying an oscillating tool.
 
There are single and double-wall stovepipes and there are double and triple-wall chimney pipes. They are completely different products. The stovepipe stops at the point of the room exit. From that point on it's Class A chimney pipe only. DuraTech chimney pipe is 8" OD. There are better flashings to use for metal roofs. Look at the flashings from Excel or Ventis (Olympia, Champion) for this purpose and a smaller hole in the roof.

Go to DuraVent's website and download their directions for installing stovepipe and for DuraTech chimney. That will provide you a better picture of the process.
 
There is single and double-wall stovepipe and there is double and triple-wall chimney pipe. They are completely different products. Stovepipe stops at the point of room exit. From that point on it's Class A chimney pipe only. DuraTech chimney pipe is 8" OD. There are better flashings to use for metal roofs. Look at the flashings from Excel or Ventis (Olympia, Champion) for this purpose and a smaller hole in the roof.

Go to DuraVent's website and download their directions for installing stovepipe and for DuraTech chimney. That will provide you a better picture of the process.
So, the DuraTech double wall pipe (6DVL) is not suitable for outdoors? DuraTech, as far as I can tell, makes a triple wall pipe that is considered class A. Maybe I should have gone with a manufacturer that makes double wall insulated.
 
So, the DuraTech double wall pipe (6DVL) is not suitable for outdoors? DuraTech, as far as I can tell, makes a triple wall pipe that is considered class A. Maybe I should have gone with a manufacturer that makes double wall insulated.
Duratech also makes double wall insulated chimney pipe as well. The triple wall is dura plus their cheapest line.
 
Go thru the roof and attack space with Duratech class A chimney pipe, use the DVL stove pipe from the ceiling down to the stove. Duratech class A needs a 2” from combustibles. Your DVL stove pipe needs 6” to combustibles.
 
So, the DuraTech double wall pipe (6DVL) is not suitable for outdoors? DuraTech, as far as I can tell, makes a triple wall pipe that is considered class A. Maybe I should have gone with a manufacturer that makes double wall insulated.
That is DuraVent DVL stovepipe. DuraVent is the company. DuraTech is their good chimney brand.