How to best rig an OAK for basement use

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tsh2002

Member
Jan 23, 2018
58
Michigan
Hello. I am starting to plan out putting a stove in our basement (house is a single story ranch style). We have an inside solid masonry chimney ready to go with an insulated SS liner in it. The house is pretty tight, so I prefer to use outside air. The outside air duct is already run, but it comes in at the basement ceiling then down in the masonry chimney and comes out near the floor behind the stove. I've found here on this forum and talking with various stove vendors that it shouldn't run above the stove but I cannot change that. Other than using an air gap in the OAK, are there other ways people have dealt with this? I'm tossing around some ideas such as running the intake duct down to the floor first then up to the stove, putting in an air gap as mentioned, or getting a very light non-springed damper in the OAK. Just looking for ideas and thoughts on this, thanks.
 
Hello. I am starting to plan out putting a stove in our basement (house is a single story ranch style). We have an inside solid masonry chimney ready to go with an insulated SS liner in it. The house is pretty tight, so I prefer to use outside air. The outside air duct is already run, but it comes in at the basement ceiling then down in the masonry chimney and comes out near the floor behind the stove. I've found here on this forum and talking with various stove vendors that it shouldn't run above the stove but I cannot change that. Other than using an air gap in the OAK, are there other ways people have dealt with this? I'm tossing around some ideas such as running the intake duct down to the floor first then up to the stove, putting in an air gap as mentioned, or getting a very light non-springed damper in the OAK. Just looking for ideas and thoughts on this, thanks.
Does the stove have a duct to attach OAK, or are you just bringing fresh air near the stove?
 
Yes, the stove has the standard 4" intake for the OAK to attach direct.
I don't know why there is an issue with running it down? You don't have any choice unless it could come down in a wall or other room. If it looks good, and has the clearance than it is good. I'm not sure what the issues are you read about ?
 
I would rather run no OAK than connect an OAK duct that is open to atmosphere above the firebox. By making the connection to the stove in your basement you are providing two chimneys to your stove and bad things can happen when it chooses to exhaust through the intake.
 
I would rather run no OAK than connect an OAK duct that is open to atmosphere above the firebox. By making the connection to the stove in your basement you are providing two chimneys to your stove and bad things can happen when it chooses to exhaust through the intake.
That does not sound good. Maybe just let the air come into the room with a damper?
 
The issues I've heard/read about seem to deal with the possibility of the draft reversing and going out the OAK.
I didn't know about this issue. I'm glad I found about it. I have a pellet stove in my basement with OAK, but of course it has a combustion blower. Best to not connect your OAK, but bring it to the floor near the stove. A damper would be good so you can shut it off, or trim it.
 
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Basement installs already have so many problems with chimney flow reversal. Hard to start fires and smoke spillage until the flue reverses direction. I know people make it work and it's best to keep the chimney warm and flowing the right way along with closing off air leaks in the home up high. The house itself can be a chimney of sorts.
 
What stove is this for? Some have a built-in air gap on the outside air connection to avoid reverse drafting and some don't. If the latter, the best solution is to run the outside air to within a few inches of the stove's OAK connector, leaving an airgap. In that circumstance, a shut-off valve for when the stove is not in use may be desired.
 
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house is pretty tight
Can you back that up with some evidence? Tight means different things to different people. How many cfm is the kitchen exhaust is it has one?
 
Basement installs already have so many problems with chimney flow reversal. Hard to start fires and smoke spillage until the flue reverses direction. I know people make it work and it's best to keep the chimney warm and flowing the right way along with closing off air leaks in the home up high. The house itself can be a chimney of sorts.
The concept makes sense, but I'm not sure how different this would be than to a single level home with no basement. Would the intake duct need to run under the floor? Wouldn't that have similar issues, or does a second level (basement, and main level and/or a second level on top of that ) make that much difference? I agree there would be several factors, we're hoping to make this work since the chimney is mostly inside so hopefully it stays as warm as possible.
 
What stove is this for? Some have a built-in air gap on the outside air connection to avoid reverse drafting and some don't. If the latter, the best solution is to run the outside air to within a few inches of the stove's OAK connector, leaving an airgap. In that circumstance, a shut-off valve for when the stove is not in use may be desired.
Thanks, I think this is probably what I will do to start with and see how it goes. We are planning on getting the Woodstock Progress Hybrid for this one.
 
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Can you back that up with some evidence? Tight means different things to different people. How many cfm is the kitchen exhaust is it has one?
The house is only 5 years old and had decent insulation and sealing done when it was built. We do have a kitchen exhaust vent which I am showing is 380 cfm. Plus I do know that running the dryer will also pull air, etc. There was a blower door test done at construction, too, it says 65 cfm infiltration rate.
 
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I think the PH will need the air gap. Note that basements often end up as negative pressure zones. Just leakage through an attic door, or out of upstairs vents (bath, dryer, kitchen) can cause this. Sometimes it takes a whole house ventilation system or a heat-recovery ventilator (HRV) to balance this out. Check the draft with no stove installed by holding an incense stick or smoke next to the chimney thimble. If the draft quickly pulls it up the chimney, that is a good sign.
 
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I think the PH will need the air gap. Note that basements often end up as negative pressure zones. Just leakage through an attic door, or out of upstairs vents (bath, dryer, kitchen) can cause this. Sometimes it takes a whole house ventilation system or a heat-recovery ventilator (HRV) to balance this out. Check the draft with no stove installed by holding an incense stick or smoke next to the chimney thimble. If the draft quickly pulls it up the chimney, that is a good sign.

While you’re smoking, run over to the oak stub and see which way it’s flowing too.

And yes on a single story home you go down into the floor or out the wall. Not up above the firebox.
 
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