Calculating stove height to reduce back draft.

[jb6475]

Hello, new member here. I am in the planning stage of installing a new wood stove with cook oven. I installed and owned a Vogelzang log wood stove previously but always got a down draft, a little smoke/soot into the house as the fire started to die/when it was windy/when the stove was not in use. I have since removed that stove and stove pipe to upgrade the stove and put the new one in a better location.

I have recently read that having the stove to close to the floor can promote a down draft like the one I describe. (I believe our 10' ceilings also promote the down draft because the neutral pressure zone inside the house is higher off the floor..I think?).

At the same time I understand that longer pipe lengths promote to much draft, and with 10' ceilings and a 12/12 roof I think I will need at least 17' of 5" stove pipe.

Where I am placing the new stove I will need to build a hearth and I have the option to raise it several inches off the floor. I can also buy extended legs for the stove which raise it another 3" off the floor.

My question is even if I can raise the bottom of the firebox off the floor by 6"-12" how can I know if we will still get a down draft back into the house as the fire dies? Is there some way to calculate at what height the firebox needs to be to avoid down draft?

 

[bholler]

Hello, new member here. I am in the planning stage of installing a new wood stove with cook oven. I installed and owned a Vogelzang log wood stove previously but always got a down draft, a little smoke/soot into the house as the fire started to die/when it was windy/when the stove was not in use. I have since removed that stove and stove pipe to upgrade the stove and put the new one in a better location.

I have recently read that having the stove to close to the floor can promote a down draft like the one I describe. (I believe our 10' ceilings also promote the down draft because the neutral pressure zone inside the house is higher off the floor..I think?).

At the same time I understand that longer pipe lengths promote to much draft, and with 10' ceilings and a 12/12 roof I think I will need at least 17' of 5" stove pipe.

Where I am placing the new stove I will need to build a hearth and I have the option to raise it several inches off the floor. I can also buy extended legs for the stove which raise it another 3" off the floor.

My question is even if I can raise the bottom of the firebox off the floor by 6"-12" how can I know if we will still get a down draft back into the house as the fire dies? Is there some way to calculate at what height the firebox needs to be to avoid down draft?

The height of the firebox doesn't matter. Draft and house pressure is what matters

 

[begreen]

Agreed. In Colorado another factor in play here is the altitude. A taller flue system is going to be required at higher altitudes due to the thinner air. 17' is far from being too tall.

What cook stove is this for?

 

[xman23]

Are there some caps that help with this issue?

 

[jb6475]

This is for a 5kw Dwarf wood stove by Tiny Wood Stoves LLC with a cookstove upgrade on top. I just noticed yeaterday that on this website there is a classifieds thread so will scroll through that and see if I can find a cooktove that will work for us, rather than buing new.

I will try to find the document I read which refers to he height of the firebox and the neutral pressure zone within the house.

If that isn't the case, how is a down draft normally avoided? This is a major issue for us because my wife has had bouts with bronchitis , then pneumonia and whatever we can do to keep our air inside cleaner we will do. So if there isn't a sure way of avoiding down drafts, I might have to forget about the idea of a wood stove altogether.

 

[Zack R]

First things that come to mind:

-Minimize 90 degree turns in the chimney
- Install a taller chimney
- Position the stove in the center of the house so that the chimney exits the tallest part of the house and is kept warm
- Start fires with the "top down" method

 

[Traveler004]

Hello, new member here. I am in the planning stage of installing a new wood stove with cook oven. I installed and owned a Vogelzang log wood stove previously but always got a down draft, a little smoke/soot into the house as the fire started to die/when it was windy/when the stove was not in use. I have since removed that stove and stove pipe to upgrade the stove and put the new one in a better location.

I have recently read that having the stove to close to the floor can promote a down draft like the one I describe. (I believe our 10' ceilings also promote the down draft because the neutral pressure zone inside the house is higher off the floor..I think?).

At the same time I understand that longer pipe lengths promote to much draft, and with 10' ceilings and a 12/12 roof I think I will need at least 17' of 5" stove pipe.

Where I am placing the new stove I will need to build a hearth and I have the option to raise it several inches off the floor. I can also buy extended legs for the stove which raise it another 3" off the floor.

My question is even if I can raise the bottom of the firebox off the floor by 6"-12" how can I know if we will still get a down draft back into the house as the fire dies? Is there some way to calculate at what height the firebox needs to be to avoid down draft?

Raising the stove up is going to make such a minuit difference. I mean a whole floor might take some pressure off but I would, as other have said here, focus on chimney height and warmth. Make sure your chimney is up past the peak of your house. Mine isn't but my attic is closed off and not a factor in the pressure. if you use the attic or have a poor seal you need to put the chimney up past it. Also the warmer a chimney is the better the draft. If your chimney is outside along the side of the house think about enclosing it and keeping it warm. But with these high ceiling and 12/12?? roof you should put the stove in the center of the house IMO. You could also buy a more insulated chimney.
also isn't a 12/12 slope just vertical?