Installing an OAK. Am I wasting my time?

[Firenutz]

I will be installing a homemade OAK this week but I have a slight issue that's been bothering me. I have a Quadrafire Mt. Vernon (non-AE). I noticed where the OAK attaches to the stove (near the convection fans) is an airbox. My issue is that this airbox has seams all around it with gaps of about 1/8". I would think that this airbox should be air tight and go right to the burnpot area above the ash pan. The ash pan door has a seal around it but what for? The back of the ash pan compartment has the inlet for the OAK and that inlet is far from sealed. If I install this OAK will I be getting cold winter air leaking in through these gaps and the area around the convection fans? Should I seal all of the gaps with high temp RTV? It just seems like there will be plenty of air leaking around the bottom of the stove. I will try to get some pics up if anyone is confused by what I'm getting at. Thanks for any help or suggestions.

 

[Dr_Drum]

My stove is like that as well. When I first installed I posted here that there was very little vacuum when covering the intake hole with a piece of paper. I later noticed the air intake plenum (or cast iron intake section) is not sealed as far as I can tell. I have no idea if sealing it would cause an issue, but would like to know this answer as well. I don't use an OAK so it really doesn't matter for me, but perhaps if this plenum was sealed the benefits of an OAK would be realized. When I tried the OAK I noticed no difference in performance. Maybe this is why I have heard from every dealer I have asked that a OAK is not required (for my stove)? No idea.
Mike -

 

[MCPO]

Oops! I double posted , please see following post.

 

[MCPO]

Since both above have the same 1/8th inch air gaps we can assume it is puposely built that way. Probably to insure that combustion air is always available even if a blockage should occur with an installed OAK.
I say this because my Harman displays the same identical burn with the OAK sealed or open. I have forgotten to unseal the the OAK and have experienced no change in the flame or burn characteristics . That tells me the stove has to pull in combustion air from someplace.
That all said I can easily hear air rushing thru the OAK upon removing the seal.
Regardless, I`d not think about sealing any gaps until you can be certain it is safe to do so.
Anyone else want to chime in?

 

[Dr_Drum]

. . .Probably to insure that combustion air is always available . . .

That's pretty much what I figured, and I didn't dare seal the gap. If you consider the 1/8" or so gap all around the plenum, I would guess it is more square inches than the 3" OAK opening? Became obvious to me that the OAK was providing supplimental air only (in my case). I'm not trying to fuel another OAK debate. :blank:
Mike -

It would be interesting if someone had a hand held air meter. I wonder if you are hearing the actual rush of air flowing thru the oak, or some sort of stethiscope effect, and you're hearing the flow of air at the plenum?

 

[slls]

I sealed all the the gaps on mine, even the holes where the pallet bolted down, runs great since day one.

 

[defield]

Dr_Drum,

I ordered an OAK for my Lopi Leyden to be installed with the stove.

The installers did not even bring the OAK with the stove and the chimney liner as they told me that the way a Lopi intake is designed, it takes in combustion air from a broad area, not a small dedicated intake port.

They said that on many pellet stoves the design of the air intake makes an OAK desireable, but not on the Lopi ( their opinion).

I was not convinced because I had read many posts on this forum that said an OAK was probably necessary, SO, the installers said, try it without the OAK, if you are unhappy, we will come back and install at no charge.

Stove runs great, active flame, no cold drafts on the floor or around the stove without an OAK. I see no reason for needing an OAK for this particular stove and install.

Ranger

 

[slls]

I sealed all the the gaps on mine, even the holes where the pallet bolted down, runs great since day one.

wonder if that voids ul listing & ins co. coverage

Have no idea, no where did it say not too, so.

 

[MCPO]

I sealed all the the gaps on mine, even the holes where the pallet bolted down, runs great since day one.

wonder if that voids ul listing & ins co. coverage

Have no idea, no where did it say not too, so.

The potential situation is that the stove manufacturer or your home insurance co. could refuse to award / pay damages for any problems caused by the stove in the future.
In this day and age the legal ramifications are are always something to ponder.

 

[slls]

I sealed all the the gaps on mine, even the holes where the pallet bolted down, runs great since day one.

wonder if that voids ul listing & ins co. coverage

Have no idea, no where did it say not too, so.

The potential situation is that the stove manufacturer or your home insurance co. could refuse to award / pay damages for any problems caused by the stove in the future.
In this day and age the legal ramifications are are always something to ponder.

I could just see someone looking at the stove with all the factory sealer smatherd on just about everything and saying that should not be there, must be some lawyers on this site LOL.

 

[wil lanfear]

. . .Probably to insure that combustion air is always available . . .

That's pretty much what I figured, and I didn't dare seal the gap. If you consider the 1/8" or so gap all around the plenum, I would guess it is more square inches than the 3" OAK opening? Became obvious to me that the OAK was providing supplimental air only (in my case). I'm not trying to fuel another OAK debate. :blank:
Mike -

It would be interesting if someone had a hand held air meter. I wonder if you are hearing the actual rush of air flowing thru the oak, or some sort of stethiscope effect, and you're hearing the flow of air at the plenum?

I'm not using a OAK on my boiler, wondering if a piece of paper or a tissue might even be a better test, held in front of the pipe outside might help determine actually how much outside air is being pulled in for combustion.

 

[Dr_Drum]

.. .wondering if a piece of paper or a tissue might even be a better test . . .

That's basically what I did, held the paper up to the hole under the stove. There wasn't enough vacuum to hold the paper.
Mike -

 

[Dr_Drum]

. . .I see no reason for needing an OAK for this particular stove and install.

Ranger

Yep, I came to the same conclusion. I know I am using heated room air, but I get some thermal cycle benefits in my house from this. It pulls the cooler air throughout the house at floor level down to the stove. This creates negative pressure upstairs which pulls the heated air up to the bedrooms. Works pretty well in my opinion. My house also doesn't seem to get as dry as my neighbors. If I thought an OAK on my stove would work better I'd hook it back up in a second.
Mike -

 

[Firenutz]

I wanted to install the OAK for a couple of reasons. One is because I have a mobile home. It's secured to a foundation on a concrete slab, but I would assume the construction type of the home is what makes the OAK a must have. Two is because I burned last winter without one and I'd like to see for myself if it makes a difference in burn characteristics. I really didn't want to put a second hole through the wall of my house but if I end up selling it in the future, I'm sure some inspector will pick up on the fact that the pellet stove will need an OAK because it's a mobile home.

 

[wil lanfear]

.. .wondering if a piece of paper or a tissue might even be a better test . . .

That's basically what I did, held the paper up to the hole under the stove. There wasn't enough vacuum to hold the paper.
Mike -

It would be interesting to hear from those that have a OAK installed, perform this test at the inlet outside just to see how much outside combustion air is actually being pulled in. On my Harman boiler, it does not have any openings for inside air to be drawn in for combustion if the OAK has been installed, not sure if all the Harman stoves are like this or not.

 

[Firenutz]

Another way to check air movement is with the wind checker powder that they sell for hunters. It's a very fine powder that moves with the slightest hint of a breeze. I use it to see where my ceiling fans are circulating. The one I use is made by Primos.

 

[tonyd]

I had a Quad castile and had a machine shop make a stub to connect to the back of the stove for the intake. After making the connection I could feel no draft or suction being pulled down the pipe. To many gaps and holes around the burn pot to create enough vacuum to pull from the pipe. My Accentra is made to pull from one source and thats from the intake stub. Plenty of suction. Hths