Anyone have good draw with a 1 story addition stove in a 2 story house?

[enigmablaze]

Title says it all I guess. I know a stove in a one-story addition of a two story house is not ideal ("stack affect" http://www.woodheat.org/fireplace-tight-house.html), but I have also read of this setup having a good draw.

Anybody have this situation or first hand experience and like it or is it nothing but trouble?
Thanks a lot

 

[Simonkenton]

The first pic shows that a smoke shelf, and a curved back wall, decrease the draft.
I completely disagree. This is the exact design of the fireplace that I built.
I made the smoke shelf because it stops smoke from blowing into the house in case of a downdraft if a gust of wind hits the top of the fireplace.
My back wall does angle in towards the living room. This is so that, as the back wall heats up, the heat radiates down and inwards towards the house. This is part of the Rumford design.

My fireplace draws great. I also have a damper right at the top of the fire box, not at the top of the chimney as is recommended in this pic.

I do agree with them on one thing. Best to put the fireplace entirely inside the house. This way, heat will radiate out of the back wall and produce considerable heat inside the house, for many hours.
.
Also, this story says ". If you insist on a traditional fireplace, make sure to equip it with doors."

Nein! Verboten!

Doors look like crap! Also, glass doors block much of the radiant heat that comes from an open fireplace.

I have used my fireplace for 20 years. Great heater and draws well.
The guy who wrote this article doesn't know what he is talking about.

 

[LondonNeil]

I've no experience of it but I'm watching with interest as my neighbors finish off a large single storey extension to the rear of their house, which last year they raised the roof height of and put rooms up in loft, making a 3 storey house. Their planning application showed a wood burner going in the new single storey extension with a very short flue out through the low roof. Best of luck.

 

[Destructor]

My fireplace is a traditional fireplace built in 1954, nothing special just built to the proper proportions with good materials. It draws beautifully. I can have a raging fire on a gusty day without it smoking. It throws enough heat to warm my living room. I do have glass doors but I never burn when they are closed except for the end of the night when there are only coals left and I go to bed. The only thing I wish I had was an inside chimney, mine is a typical exterior chimney on a cape. I’ve never had a problem getting an immediate draft from a cold start. As a teenager and in my early 20’s I worked for masons who built brick and stone fireplaces and chimneys, I learned a lot.

 

[bholler]

The first pic shows that a smoke shelf, and a curved back wall, decrease the draft.
I completely disagree. This is the exact design of the fireplace that I built.
I made the smoke shelf because it stops smoke from blowing into the house in case of a downdraft if a gust of wind hits the top of the fireplace.
My back wall does angle in towards the living room. This is so that, as the back wall heats up, the heat radiates down and inwards towards the house. This is part of the Rumford design.

My fireplace draws great. I also have a damper right at the top of the fire box, not at the top of the chimney as is recommended in this pic.

I do agree with them on one thing. Best to put the fireplace entirely inside the house. This way, heat will radiate out of the back wall and produce considerable heat inside the house, for many hours.
.
Also, this story says ". If you insist on a traditional fireplace, make sure to equip it with doors."

Nein! Verboten!

Doors look like crap! Also, glass doors block much of the radiant heat that comes from an open fireplace.

I have used my fireplace for 20 years. Great heater and draws well.
The guy who wrote this article doesn't know what he is talking about.

He is right about smoke shelves they are completly pointless and yes they do hurt draft. Otherwise i agree with you for best heat (although still totally lousy when compared to even the worst stoves) you want an internal chimney. And no glass doors

 

[bholler]

But to answer the origonal question yes i have worked on plenty of installs like you are proposing and most work ok. But they are usually going to be a relativly short chimney so they will be on the weak side when it comes to draft. Which is why we are all telling you to do everything you can to maximise draft. Like top vent double wall pipe and extended chimney.

 

[begreen]

Doors on a fireplace are for when the fire is dying down. Without them being closed at that point, a large portion of the heat generated gets sucked back up the chimney. A fireplace may provide a lot of radiant heat with a good fire, but the losses up the chimney are large. It's a very inefficient way to heat.

Back to the OP question. As long as the chimney is tall enough to draft properly for the stove's requirements then a single story chimney can work fine. This can be compromised however by its location relative to other roofs or structures, prevailing winds and local terrain.

 

[Bill 700]

You could also reduce the stack effect in the 2 story portion by tightening up the ceiling in the second story. If there is a drop down ladder or ceiling exhaust fan to the attic of the 2 story, these would be a major contributors.

 

[Simonkenton]

You want an adjustable damper on your fireplace.
You have an adjustable air intake on your wood stove, goes without saying. Sometimes you want 600 degrees, sometimes you want 350 degrees.
Same thing with a fireplace, except we are controlling the air that goes out of the fireplace.

I have a sliding damper on my fireplace, it can be 100 percent open, or it can be closed off totally. Or it can be set at 15 percent air. Whatever you want. This damper is not on top of the chimney it is at the top of the firebox, in the throat.
So, when cranking up the fire, or when burning the fire on high, the damper is wide open.
After a while, when the fire has burned for several hours and is now burning on "medium", I set the damper at 50 percent or so.
This cuts air intake by half and maximizes heat output into the room.

A few hours, or, a few glasses of wine, later, I want the fire out. Just some coals are burning. I set the damper at about 10 percent air flow. Now, very little air is being drawn into the chimney.

Don't need those ugly doors you control it all with a properly built damper.
And, I had a fireplace once, with those glass doors, it was surprising how much radiant heat was blocked by the glass.

Once the fire is out, I shut the damper and all that massive heat, stored in the masonry, radiates back into the house for many, many, hours.

I certainly agree that a fireplace, even one like mine that is a great heater, is nowhere nearly as efficient as a wood stove.
Takes about 5 times as much wood for the fireplace to get as much heat as you get from the wood stove.

 

[bholler]

You want an adjustable damper on your fireplace.
You have an adjustable air intake on your wood stove, goes without saying. Sometimes you want 600 degrees, sometimes you want 350 degrees.
Same thing with a fireplace, except we are controlling the air that goes out of the fireplace.

I have a sliding damper on my fireplace, it can be 100 percent open, or it can be closed off totally. Or it can be set at 15 percent air. Whatever you want. This damper is not on top of the chimney it is at the top of the firebox, in the throat.
So, when cranking up the fire, or when burning the fire on high, the damper is wide open.
After a while, when the fire has burned for several hours and is now burning on "medium", I set the damper at 50 percent or so.
This cuts air intake by half and maximizes heat output into the room.

A few hours, or, a few glasses of wine, later, I want the fire out. Just some coals are burning. I set the damper at about 10 percent air flow. Now, very little air is being drawn into the chimney.

Don't need those ugly doors you control it all with a properly built damper.
And, I had a fireplace once, with those glass doors, it was surprising how much radiant heat was blocked by the glass.

Once the fire is out, I shut the damper and all that massive heat, stored in the masonry, radiates back into the house for many, many, hours.

I certainly agree that a fireplace, even one like mine that is a great heater, is nowhere nearly as efficient as a wood stove.
Takes about 5 times as much wood for the fireplace to get as much heat as you get from the wood stove.

You do realize the op is talking about a stove right? And i think 5 times is still a pretty low estimate

 

[enigmablaze]

The first pic shows that a smoke shelf, and a curved back wall, decrease the draft.
I completely disagree. This is the exact design of the fireplace that I built.
I made the smoke shelf because it stops smoke from blowing into the house in case of a downdraft if a gust of wind hits the top of the fireplace.
My back wall does angle in towards the living room. This is so that, as the back wall heats up, the heat radiates down and inwards towards the house. This is part of the Rumford design.

My fireplace draws great. I also have a damper right at the top of the fire box, not at the top of the chimney as is recommended in this pic.

I do agree with them on one thing. Best to put the fireplace entirely inside the house. This way, heat will radiate out of the back wall and produce considerable heat inside the house, for many hours.
.
Also, this story says ". If you insist on a traditional fireplace, make sure to equip it with doors."

Nein! Verboten!

Doors look like crap! Also, glass doors block much of the radiant heat that comes from an open fireplace.

I have used my fireplace for 20 years. Great heater and draws well.
The guy who wrote this article doesn't know what he is talking about.

Ok I adore Rumford fireplaces! I think it is such a beautiful design.

 

[enigmablaze]

He is right about smoke shelves they are completly pointless and yes they do hurt draft. Otherwise i agree with you for best heat (although still totally lousy when compared to even the worst stoves) you want an internal chimney. And no glass doors

Question, does "going straight up through the single story ceiling" constitute internal chimney, or will the fact that half of it will probably be above the roof ruin that benefit?

 

[enigmablaze]

But to answer the origonal question yes i have worked on plenty of installs like you are proposing and most work ok. But they are usually going to be a relativly short chimney so they will be on the weak side when it comes to draft. Which is why we are all telling you to do everything you can to maximise draft. Like top vent double wall pipe and extended chimney.

Gotcha, that's what I was looking for....so it obviously isn't the "ideal" but it has a good shot at performing pretty well...is that fair? With the extended chimney and double wall like you say?

 

[enigmablaze]

Doors on a fireplace are for when the fire is dying down. Without them being closed at that point, a large portion of the heat generated gets sucked back up the chimney. A fireplace may provide a lot of radiant heat with a good fire, but the losses up the chimney are large. It's a very inefficient way to heat.

Back to the OP question. As long as the chimney is tall enough to draft properly for the stove's requirements then a single story chimney can work fine. This can be compromised however by its location relative to other roofs or structures, prevailing winds and local terrain.

I am guessing that no one could tell for SURE how this would perform until it's installed...does that sound reasonable? It just seems like there are so many factors it would be almost impossible to know for sure. We will try to get it as very far away from the main house as possible.

 

[enigmablaze]

You could also reduce the stack effect in the 2 story portion by tightening up the ceiling in the second story. If there is a drop down ladder or ceiling exhaust fan to the attic of the 2 story, these would be a major contributors.

The second story is completely finished living space up to the ridge, does this help? The only cold space would be storage areas behind the knee-walls in the second story (cape cod slanted roof upstairs).
ETA no whole house fan, just two bathroom fans, and a hood vent.

Does the fact that the addition is by far the draftiest room in the house help or hurt me here? I thought it would help because the stove should get all the air it needs but then I wasn't sure...the rest of the house is certainly much tighter than the addition.

 

[enigmablaze]

You want an adjustable damper on your fireplace.
You have an adjustable air intake on your wood stove, goes without saying. Sometimes you want 600 degrees, sometimes you want 350 degrees.
Same thing with a fireplace, except we are controlling the air that goes out of the fireplace.

I have a sliding damper on my fireplace, it can be 100 percent open, or it can be closed off totally. Or it can be set at 15 percent air. Whatever you want. This damper is not on top of the chimney it is at the top of the firebox, in the throat.
So, when cranking up the fire, or when burning the fire on high, the damper is wide open.
After a while, when the fire has burned for several hours and is now burning on "medium", I set the damper at 50 percent or so.
This cuts air intake by half and maximizes heat output into the room.

A few hours, or, a few glasses of wine, later, I want the fire out. Just some coals are burning. I set the damper at about 10 percent air flow. Now, very little air is being drawn into the chimney.

Don't need those ugly doors you control it all with a properly built damper.
And, I had a fireplace once, with those glass doors, it was surprising how much radiant heat was blocked by the glass.

Once the fire is out, I shut the damper and all that massive heat, stored in the masonry, radiates back into the house for many, many, hours.

I certainly agree that a fireplace, even one like mine that is a great heater, is nowhere nearly as efficient as a wood stove.
Takes about 5 times as much wood for the fireplace to get as much heat as you get from the wood stove.

We're looking at the Morso 1440 stove, I'm concerned even though it's small it might be too powerful for that room (about 200 sq ft)!

Do I want an adjustable damper with this stove? This is something that I feel I do not know much about. Dampers go in the chimney pipe right?

 

[bholler]

Question, does "going straight up through the single story ceiling" constitute internal chimney, or will the fact that half of it will probably be above the roof ruin that benefit?

The main benifit comes from the lack of a tee. So no it does not negate that

 

[bholler]

We're looking at the Morso 1440 stove, I'm concerned even though it's small it might be too powerful for that room (about 200 sq ft)!

Do I want an adjustable damper with this stove? This is something that I feel I do not know much about. Dampers go in the chimney pipe right?

He is talking about a fireplace damper totally different. And no you should not need a damper. With a tall chimney you might want one to limit draft but that shouldnt be an issue

 

[enigmablaze]

The main benifit comes from the lack of a tee. So no it does not negate that

Haha yeah I think you and begreen have probably convinced me to top vent..sigh!

 

[bholler]

Gotcha, that's what I was looking for....so it obviously isn't the "ideal" but it has a good shot at performing pretty well...is that fair? With the extended chimney and double wall like you say?

I am not there looking at it. From your description i think it will probably work but i would top vent.

 

[bholler]

Haha yeah I think you and begreen have probably convinced me to top vent..sigh!

Like you said as long as you allow for it you could try rear venting. If the draft is to weak switch it

 

[enigmablaze]

He is talking about a fireplace damper totally different. And no you should not need a damper. With a tall chimney you might want one to limit draft but that shouldnt be an issue

Gotcha, thanks. I assume there's no other "special" pieces I should be thinking about? I know there's some sort of Vaccu-stack thing, not sure if that's applicable or advisable to me...I'm sure there's lots of stuff I don't know about.

 

[bholler]

Gotcha, thanks. I assume there's no other "special" pieces I should be thinking about? I know there's some sort of Vaccu-stack thing, not sure if that's applicable or advisable to me...I'm sure there's lots of stuff I don't know about.

No those really are more for controlling wind effect. And they are a p.i.t.a. to clean

 

[enigmablaze]

Like you said as long as you allow for it you could try rear venting. If the draft is to weak switch it

That's true, I want to get all the clearances marked out tomorrow...I can probably find out if the T is an expensive piece and if it's not too bad we could try that.

 

[enigmablaze]

No those really are more for controlling wind effect. And they are a p.i.t.a. to clean

Gotcha, good to know that's not something to look into any farther.
bholler, do you think the heat from this guy (max 3,500 btu, max 1,200 soft) will be ok in that room? We could always open a window I guess but I don't want us cooked out all the time, but I'm not sure how to get any smaller stove and still have a reasonable viewing window. That room is about 200 sqft and very cold (plank roof, concrete floor, thin walls, mediocre windows). This is my last significant concern.