Chimney Design and Stove for Single Story Addition

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Northsker

New Member
Sep 17, 2025
4
Minneapolis
New member here, and I've learned tons already--thank you everybody.

I'm installing my first wood stove but cannot decide how to finalize my setup. It will be going in a single story addition--230 sqft 3 season porch--on a 1.5 story house. I will be installing either a Hipster 14 (Green Mountain) or a 2015 PE series D T5 Alderlea. Reason for stove is primarily ambiance (evening / weekend) and space heating though emergency backup heat for house is a plus, as would the ability to burn overnight. Room is sealed off from the house now but with cheap geothermal heating (or stove heat) I'm inclined to open it to the house via the door and two small windows. First question out of curiosity, is if it makes more sense to have the smaller stove for the small room, or the medium stove. Furthermore, will soapstone radiative heat be more comfortable, or will convective heat be better to move warm air into the house? Or will the easy breathing PE stove be the smart move? The Alderlea is absolutely gorgeous in enamel, though the Hipster efficiency would be nice.

Now more critically, I have to decide placement--it will be either a corner a) on the interior wall with flue passing through wall and running through house, or b) exterior wall with a straight vertical flue.

I had planned on installing this myself but found a recommended dealer with a very reasonable cost who I decided to hire for this job. This contractor tells me the outside corner is the preferred location for him. He also initially told me if I place the stove on the interior wall, they would still run the chimney up through the roof and then along the outside wall of the house, to which I told him no, it would go inside the house to keep the chimney warm and eliminate the possibility of cold hearth syndrome and back drafting. He maintains that option b is preferred because the straight flue will draft better (12-15' no bends). I think he may also be underestimating required chimney height for 10-2-3 rule, as whole porch is only 10-11' deep and with roof overhangs and pitch (4/12 on porch, 8/12 on house) I think I need 10' chimney above roof. Related to this setup, I would love to know how high above the roof can I go with my chimney in my frigid climate and not be affected by creosote buildup and stack cooling problems? I would love to get insight into this. My concern with this location is the house acting as a better chimney than my new stove's chimney (house is not tight but better than average). I expect I could close off porch to start the fire, then open up to house while it's going, but then likely I would have to close off porch as the fire dies overnight?

Conversely, option A on the interior wall will be more expensive but I think I could burn any stove any way I want without a problem other than maybe needing a flue damper with the PE when it's very cold. I think my installer doesn't do a lot of wood stoves and new chimneys and much prefers a simple installation. The ceiling on porch is a bit low, and then chimney would have to pass through interior wall into a closet on the main floor and into another closet on the next floor before exiting a sloped ceiling (8/12 pitch) just inside the knee wall and up another 10' above the roof. My installer said they could do it, but it will be bad aesthetically, and they would use a sloped wall thimble (first I was told 30 deg, now 45 deg). NexVent 2100 chimney. But do they make angled thimbles? And if I do have a big chunk of class A sticking into my porch, can I paint it to match my stove pipe? I saw a spec sheet online that the angled wall pass-through was only acceptable for fireplaces but not wood stove, but I don't understand why that would be. I contacted SBI and they initially told me I could use it for a stove but I referred to their own documentation on this and they have yet to respond. I also thought 45 deg class A was illegal in the US but could be mistaken. I originally assumed we would just use a T here, but if that's where we would clean the chimney I don't think it would be wise to do that in the master bedroom closet, though I could also drop the chimney down to the basement. I assumed the angled thimble would allow for clean out from the stove end.

Maintenance is also important. Ideally I would love to have a short chimney on a low pitch roof I could easily inspect and clean. I don't know anything about cleaning chimneys yet but would hope to do that myself in the future, so that is difficult for me to form a design opinion on yet. I also would ask if an OAK would be useful here, but I've asked enough for now and need to scour more forums first.

Much to unpack, but thank you for any input to any part of this!
 
I would lean toward the PE as the more easy breathing stove. There is a chance that the install may be problematic due to this being in a lower addition.

 
I have pretty much made up my mind in favor of the PE for this reason, and that I value the simplicity factor.

I've also entertained the idea of improving draft by air sealing the attic / upper floor. Furthermore, I have lots of leaky air ducts in the basement. If I seal those up I should also decrease the total stack effect. Conversely, I am also planning on sealing the rim joists in the basement with spray foam which will raise the height in the building where air enters the house and increase the likelihood of backdrafting--or maybe this would also help me by decreasing stack effect due to less total leakage of the house.

Another idea I had was to duct in forced air from my central heat into the porch to help pressurize it and exclude any return ducts. I've never heard of anyone consider this before but maybe it would work better for me than most individuals considering my blower runs nearly 24/7 in the winter, excepting milder sunny days with high heat gain.
 
I elected to install the chimney up through the house--being as I'm doing the installation now I want to guarantee success rather than hope for no problems. I also had the idea to reduce stack effect in the house to add a vent in the basement without a return vent into my HVAC system. But of course, I won't bother with these potential mitigation strategies with the chosen chimney option.
 
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New member here, and I've learned tons already--thank you everybody.

I'm installing my first wood stove but cannot decide how to finalize my setup. It will be going in a single story addition--230 sqft 3 season porch--on a 1.5 story house. I will be installing either a Hipster 14 (Green Mountain) or a 2015 PE series D T5 Alderlea. Reason for stove is primarily ambiance (evening / weekend) and space heating though emergency backup heat for house is a plus, as would the ability to burn overnight. Room is sealed off from the house now but with cheap geothermal heating (or stove heat) I'm inclined to open it to the house via the door and two small windows. First question out of curiosity, is if it makes more sense to have the smaller stove for the small room, or the medium stove. Furthermore, will soapstone radiative heat be more comfortable, or will convective heat be better to move warm air into the house? Or will the easy breathing PE stove be the smart move? The Alderlea is absolutely gorgeous in enamel, though the Hipster efficiency would be nice.

Now more critically, I have to decide placement--it will be either a corner a) on the interior wall with flue passing through wall and running through house, or b) exterior wall with a straight vertical flue.

I had planned on installing this myself but found a recommended dealer with a very reasonable cost who I decided to hire for this job. This contractor tells me the outside corner is the preferred location for him. He also initially told me if I place the stove on the interior wall, they would still run the chimney up through the roof and then along the outside wall of the house, to which I told him no, it would go inside the house to keep the chimney warm and eliminate the possibility of cold hearth syndrome and back drafting. He maintains that option b is preferred because the straight flue will draft better (12-15' no bends). I think he may also be underestimating required chimney height for 10-2-3 rule, as whole porch is only 10-11' deep and with roof overhangs and pitch (4/12 on porch, 8/12 on house) I think I need 10' chimney above roof. Related to this setup, I would love to know how high above the roof can I go with my chimney in my frigid climate and not be affected by creosote buildup and stack cooling problems? I would love to get insight into this. My concern with this location is the house acting as a better chimney than my new stove's chimney (house is not tight but better than average). I expect I could close off porch to start the fire, then open up to house while it's going, but then likely I would have to close off porch as the fire dies overnight?

Conversely, option A on the interior wall will be more expensive but I think I could burn any stove any way I want without a problem other than maybe needing a flue damper with the PE when it's very cold. I think my installer doesn't do a lot of wood stoves and new chimneys and much prefers a simple installation. The ceiling on porch is a bit low, and then chimney would have to pass through interior wall into a closet on the main floor and into another closet on the next floor before exiting a sloped ceiling (8/12 pitch) just inside the knee wall and up another 10' above the roof. My installer said they could do it, but it will be bad aesthetically, and they would use a sloped wall thimble (first I was told 30 deg, now 45 deg). NexVent 2100 chimney. But do they make angled thimbles? And if I do have a big chunk of class A sticking into my porch, can I paint it to match my stove pipe? I saw a spec sheet online that the angled wall pass-through was only acceptable for fireplaces but not wood stove, but I don't understand why that would be. I contacted SBI and they initially told me I could use it for a stove but I referred to their own documentation on this and they have yet to respond. I also thought 45 deg class A was illegal in the US but could be mistaken. I originally assumed we would just use a T here, but if that's where we would clean the chimney I don't think it would be wise to do that in the master bedroom closet, though I could also drop the chimney down to the basement. I assumed the angled thimble would allow for clean out from the stove end.

Maintenance is also important. Ideally I would love to have a short chimney on a low pitch roof I could easily inspect and clean. I don't know anything about cleaning chimneys yet but would hope to do that myself in the future, so that is difficult for me to form a design opinion on yet. I also would ask if an OAK would be useful here, but I've asked enough for now and need to scour more forums first.

Much to unpack, but thank you for any input to any part of this!
Sealing the air access to the attic will save a ton of heat loss, as well as reduce stack effect. Keeping as much as possible inside the structure to limit heat loss is preferred. The 45-degree offset is not code in most of the US, and it isn't a good idea in my opinion if you can avoid it. Creosote is not the problem it used to be with a new SBI stove. The EPA requirements require the fuel that used to cause creosote to burn in the stove. Performance could be a factor, particularly if you are also trying to overcome stack effect.

To look for air loss that can contribute to stack effect you can do a couple of things. I had a customer weigh down a helium balloon enough that it was floating freely and could move where it wanted. They launched it shortly before going out for a couple of hours. When they got home is was up against the attic door. After weather stripping was added, their fireplace worked great.

Replacing can lights with LEDs that don't require venting is a great idea for energy efficiency.
 
Can you expand why you don't like the 45 deg? I realize it adds significant turbulance inside the flue, but how many flues have a horizontal run? Are offsets really that much worse than short cold chimneys, particularly for the recreational burn? I like the idea of ventless LED fixtures to seal ceiling to attic.