Barometric damper in wall for wood insert?

[acordeon]

We're about to buy a new wood burning insert (see my other thread https://www.hearth.com/talk/threads/inserts-lopi-answer-vs-pe-super-vs.179784/ for more on that). The salesman at the local dealer said that he always recommends installing a barometric damper in a wall to help with the draft of the stove.

His main reason was that with tighter houses these days it's actually required to meet code in many municipalities. I told him we always crack a window when we burn but he said the regs don't take into account operator common sense. He said that in the end our county might not require it but to find that out you gotta go through a bunch of red tape, they have to come out and measure your house, etc., and he thinks it's easier to just put the thing in. Not sure he'd be wiling to do the install without either the damper or the red tape.

My concern is that we spent a bunch of money recently for insulation and air sealing, and I don't want to have a hole in a wall, especially as our insert is supplemental and won't be used most of the time.

Is this guy way off base? I haven't heard anything about this from other dealers or on this forum. But it's a well-respected dealer that's been around for decades.

Thanks!

 

[bholler]

Well yes allot of the info he gave you was far from correct. Starting with the fact that what it sounds like he is talking about is an outside air supply to the stove not a barometric damper. As far as I know there is no national code requirements calling for outside air supply unless you are in a manufactured home. But regardless as long as it is hooked up properly there is no downside to it at all

 

[acordeon]

Thanks, @bholler. Yeah, it is an outside air supply, but i think the device he's suggesting to provide that supply is the same kind of round barometric damper that you'd use in a stove pipe.

Why do you say there's no downside? My concern is that in the winter, when I'm not burning, we turn on a bathroom fan or something and now we have cold air coming into the house. Not to mention that it's simply a hole in the insulation, and one more thing that could fail, leak, etc.

He said we could plug it when we're not burning, but then what's the point. Now we have to remember to remove the plug instead of remembering to crack a window.

 

[kennyp2339]

I believe in WA its code to have a fresh air supply for solid fuel heaters. Unsure which stove you finally decided with, check if either comes with a dedicated outside air connection, then you'll have a direct pipe for supply air and not have to worry about other appliances stealing air from the insert when running.

 

[acordeon]

@kennyp2339 thanks, but not sure what to look for there. With inserts I thought they just came with the box and a place to attach the exhaust pipe, and the rest is up to the installer.

Leaning a little toward the PE Super (https://www.pacificenergy.net/products/wood/inserts/super-insert/) and don't see anything about fresh air supply there. But really haven't decided what to get.

Can someone point me to an insert that has a fresh air supply so I know what that looks like?

 

[acordeon]

Found this, which seems very sensible on this topic: https://woodheat.org/the-outdoor-air-myth-exposed.html

 

[acordeon]

After a little more digging, looks like PE in particular no longer offers "Outside Air Kits" (OAK), although they used to. Their FAQ now includes this:

Outside air, do I need it?

• Outside air is recommended when possible as it helps with combustion air. In colder climates this is not always practical but the stove will not perform well in a negative pressure environment.
• There is many solutions to help with negative pressure in the home, please consult with your local Pacific Energy Retailer for more information

This old thread from 2008 (https://www.hearth.com/talk/threads/pacific-energy-med-insert-to-use-outside-air-or-not.20220/) says that they advised the poster to duct in air to the masonry fireplace and seal the surround. That sounds quite a bit more involved/expensive than just putting a passive intake in a wall somewhere, given that our fireplace is in the center of the house.

Gonna call the county planning dept tomorrow and see what they say. But keep advice coming in the meantime if you got it.

 

[bholler]

After a little more digging, looks like PE in particular no longer offers "Outside Air Kits" (OAK), although they used to. Their FAQ now includes this:



This old thread from 2008 (https://www.hearth.com/talk/threads/pacific-energy-med-insert-to-use-outside-air-or-not.20220/) says that they advised the poster to duct in air to the masonry fireplace and seal the surround. That sounds quite a bit more involved/expensive than just putting a passive intake in a wall somewhere, given that our fireplace is in the center of the house.

Gonna call the county planning dept tomorrow and see what they say. But keep advice coming in the meantime if you got it.

Yes with the fireplace in the middle of the house it definitely makes things more complicated.

 

[acordeon]

I called the local planning dept and they confirmed they require this. (Well, this or a OAK, which won't work for us.)
Honestly thinking about putting in gas instead of wood. We'd much prefer wood, but we really don't want a hole in the wall.

 

[bholler]

I called the local planning dept and they confirmed they require this. (Well, this or a OAK, which won't work for us.)
Honestly thinking about putting in gas instead of wood. We'd much prefer wood, but we really don't want a hole in the wall.

Why are you so set against this? Is there a basement under the fireplace?

 

[acordeon]

Why are you so set against this?

Because we just got done insulating and sealing our house, and this would be a permanent hole through the building envelope. We know we can plug it with something during the non-burn season (more than half the year for us) but it's never going to be as air- or moisture-tight as the wall is now.

Is there a basement under the fireplace?

Just a very narrow crawlspace.

 

[bholler]

Because we just got done insulating and sealing our house, and this would be a permanent hole through the building envelope. We know we can plug it with something during the non-burn season (more than half the year for us) but it's never going to be as air- or moisture-tight as the wall is now.



Just a very narrow crawlspace.

If your house is as tight as you think it is you need an oak or the stove won't work.

Run down into the crawl space and out I have done quite a few like that.

You will need outside air for gas as well

 

[ABMax24]

Why not put in an outside air supply that you can shutoff?

Osburn makes something like this available in 3", 4" and 5" that has a cable that connects the wall selector to the valve.

Granted I'm not sure whether or not this is acceptable in your jurisdiction. But with an insulated vent and this I don't see why this would allow anymore air infiltration than you already have.

Adapters

www.osburn-mfg.com

 

[ABMax24]

I also don't think you'd be happy with gas if you already want wood. We have a gas fireplace on the main floor where we spend most of our time and the wood stove in the unfinished basement, I've turned on the gas fireplace once for half an hour since we installed the wood stove in the fall, we spend far more time in front of the stove.

 

[acordeon]

Run down into the crawl space and out I have done quite a few like that.

Sounds like a big job. Do you put a hole in the bottom of the masonry fireplace? Or go out the side and then down?
The PE Super insert seems to not have an attachment for an air duct, just a hole on the underside. So I guess this would be a "get air into the masonry fireplace and seal the surround" kind of deal?

You will need outside air for gas as well

Apparently w/ a "direct vent" appliance it can be gotten via the chimney.

 

[bholler]

Sounds like a big job. Do you put a hole in the bottom of the masonry fireplace? Or go out the side and then down?
The PE Super insert seems to not have an attachment for an air duct, just a hole on the underside. So I guess this would be a "get air into the masonry fireplace and seal the surround" kind of deal?



Apparently w/ a "direct vent" appliance it can be gotten via the chimney.

Yes you go down through the bottom.

And yes you get the air for a direct vent through a pipe run down the chimney just as you get air for a wood stove through a pipe run down and out.

 

[bholler]

Sounds like a big job. Do you put a hole in the bottom of the masonry fireplace? Or go out the side and then down?
The PE Super insert seems to not have an attachment for an air duct, just a hole on the underside. So I guess this would be a "get air into the masonry fireplace and seal the surround" kind of deal?



Apparently w/ a "direct vent" appliance it can be gotten via the chimney.

What are you doing for air exchange in the house. If you are running an hrv some jurisdictions will allow that for makeup air

 

[acordeon]

What are you doing for air exchange in the house. If you are running an hrv some jurisdictions will allow that for makeup air

We don't have anything dedicated for air exchange yet. According to blower door test we're right on the edge of tight enough to really need something. An HRV might be in our future. But my understanding there is that an HRV operates when the HVAC system does -- so how would that help w/ combustion air, esp. since we'd be less likely to be running HVAC when we have a fire going.

 

[acordeon]

Osburn makes something like this available in 3", 4" and 5" that has a cable that connects the wall selector to the valve.

Granted I'm not sure whether or not this is acceptable in your jurisdiction. But with an insulated vent and this I don't see why this would allow anymore air infiltration than you already have.

Thanks for this!
This isn't quite what we need, I think, since this is meant for putting inline in a duct, where we need a very short vent just in a wall. But it does make me wonder if they make dampers that have a lock-out similar to this. Will look around.

 

[bholler]

We don't have anything dedicated for air exchange yet. According to blower door test we're right on the edge of tight enough to really need something. An HRV might be in our future. But my understanding there is that an HRV operates when the HVAC system does -- so how would that help w/ combustion air, esp. since we'd be less likely to be running HVAC when we have a fire going.

If your house isn't tight enough to need an air exchanger why are you worrying about the tiny amount of air that might leak out of an oak? It is insignificant.

 

[bholler]

Thanks for this!
This isn't quite what we need, I think, since this is meant for putting inline in a duct, where we need a very short vent just in a wall. But it does make me wonder if they make dampers that have a lock-out similar to this. Will look around.

I thought the fireplace was in the middle of the house. So why would you be going through a wall?

 

[acordeon]

@bholler there are two options being discussed here.

Option 1, and what the dealer recommended, is not a true OAK but just a "barometric damper" (that's what everyone here calls them, even the planning dept) installed in the wall, to allow combustion air into the room w/ the insert.

Option 2 would be a real OAK setup, which would be more difficult than most since the fireplace is in the middle of the house. But you brought up that it can still be done via the crawlspace.

If we went w/ option 2 I wouldn't be worried about air/heat leakage, but would be concerned about expense. But option 1 is basically just a 4" hole in the wall in the living room, which would let in cold air anytime we ran a bathroom fan or the range hood fan, and is uninstulated even when closed.

 

[bholler]

@bholler there are two options being discussed here.

Option 1, and what the dealer recommended, is not a true OAK but just a "barometric damper" (that's what everyone here calls them, even the planning dept) installed in the wall, to bring combustion air into the room w/ the insert.

Option 2 would be a real OAK setup, which would be more difficult than most since the fireplace is in the middle of the house. But you brought up that it can still be done via the crawlspace.

If we went w/ option 2 I wouldn't be worried about air/heat leakage, but would be concerned about expense. But option 1 is basically just a 4" hole in the wall in the living room, which would let in cold air anytime we ran a bathroom fan or the range hood fan, and is uninstulated even when closed.

Well yeah a hole in the wall with a flapper to let air in is just a bad idea. No way I would go for that.

 

[rwhite]

Man, I am confused. The 1st post you stated you'd open a window to burn but opposed to an oak. No matter how tight your house is you have to go out at some point. I'm betting the oak is equivalent to opening the door 1-2 times more a day. I'd go through to the crawl space and out. Summer time you can just cap the pipe if needed or wanted.

 

[acordeon]

Well yeah a hole in the wall with a flapper to let air in is just a bad idea. No way I would go for that.

Yep that's what I think too. But apparently it's quite a common setup around here, I guess b/c people don't want to pay for a true OAK setup? Anyway I'm asking the dealer what the options/costs are for a real OAK.