Stove air intakes - how air tight are they?

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Krik

Member
Jan 24, 2012
40
Windham ME
New member. I just installed a pair of Regency's, with some "interesting" issues ... but more on that some other time :)

Stoves are running, but I'm still working on fine-tuning the design. The outside air still needs to be hooked up for both, but in testing the setup I ran into an odd issue.

When I put my hand over the air intake pipe on the back of the stove, the flame changes only a little. It appears there are some other openings that allow room air to keep flowing into the burn pot. I believe the stove is designed like this on purpose, but doesn't that kind of defeat the purpose of adding outside air in a leaky house because it will pull in air through both at any time? (I get that it helps in tight houses, because the hookup is the only low-resistance air intake).

Are all stoves designed like this, or do some have a tighter air intake?
 
I am not sure about other stoves but my Harman P43 is sealed very well. There are gaskets between all fittings on the air intake. So when I have the OAK hooked up, all of the combustion air is coming from outside. I was thinking recently that it seemed a bit overkill to have all of these gaskets on the air intake side of things but it works well and I am no engineer. :)
 
It varies. Some stoves require additional parts to attach outside air. Some have the intake all in one piece to the back of the stove shell. Some stoves have slots in the intake tube that the OAK tubing has to cover to completely seal it and on the variations go.

Mine has a a tube that goes from the area behind the burn pot to outside of the shell. There is a single penetration in that tube's wall for the igniter wire to pass trough.
 
SmokeyTheBear said:
Mine has a a tube that goes from the area behind the burn pot to outside of the shell. There is a single penetration in that tube's wall for the igniter wire to pass trough.

Interesting. Mine has a tube that goes into a box that then has a tube going into the burn pot. As you can see in the picture, however, there's a hole the size of the intake tube right next to it with the ignitor wire running through it. No wonder the manual specifies only 2 inches for the air intake pipe --- it happily pulls in air through that other hole if there's not enough flow through the outside air. Either I don't get it, there's a missing part (e.g., a cover plate), or it's a hare-brained OAK design. Or something else I can't think of now haha.
 

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Wouldn't air also be pulled in through the auger and pellet hopper? They aren't air tight either.

Dave
 
DneprDave said:
Wouldn't air also be pulled in through the auger and pellet hopper? They aren't air tight either.

Dave

On both my stoves the hopper lids are sealed.
 
DneprDave said:
Wouldn't air also be pulled in through the auger and pellet hopper? They aren't air tight either.

True, the hopper lid on the GF55 isn't sealed. It can pull air through the draft measurement hole and the hole for the heat exchanger cleaner rod as well. But I imagine those should be relatively small compared to the air intake.

The only reason I'm questioning the design is because some members say they feel a noticeable reduction in cold air drafting in the room when hooking up the outside air. But in this design it'd still pull in air through that big hole next to the pipe.

You're right, though. It may be a non-issue given the many other ways for combustion air to get into the stove.

EDIT: another reason I'm asking is because my OA designs will run through the same chimney the pipe/liner is in. And what I definitely don't want to happen is for the OA pipe to become warm and then pull extra air OUT of the house because of the chimney effect (or for the OA to have no effect because the hole is much lower resistance air intake).
 
DneprDave said:
Wouldn't air also be pulled in through the auger and pellet hopper? They aren't air tight either.

Dave

Depends entirely on the stove, even so the amount of air entering in that manner is very small.

A lot of stoves these days have gasketed hoppers and even the older stoves have a warning about not letting the pellets in the hopper to run below a certain point and to keep the hopper lid closed while the stove is running except to fuel it.

A hooper full of pellets and a full auger doesn't allow much air to pass through.
 
Krik said:
DneprDave said:
Wouldn't air also be pulled in through the auger and pellet hopper? They aren't air tight either.

True, the hopper lid on the GF55 isn't sealed. It can pull air through the draft measurement hole and the hole for the heat exchanger cleaner rod as well. But I imagine those should be relatively small compared to the air intake.

The only reason I'm questioning the design is because some members say they feel a noticeable reduction in cold air drafting in the room when hooking up the outside air. But in this design it'd still pull in air through that big hole next to the pipe.

You're right, though. It may be a non-issue given the many other ways for combustion air to get into the stove.

EDIT: another reason I'm asking is because my OA designs will run through the same chimney the pipe/liner is in. And what I definitely don't want to happen is for the OA pipe to become warm and then pull extra air OUT of the house because of the chimney effect (or for the OA to have no effect because the hole is much lower resistance air intake).

Those combustion fans are pretty good air movers... most folks WILL feel the difference with an oak...
 
Hello

My Avalon Astoria has a 1" Square hole inside the stove cut into the square tube that feeds the intake air below the fire pot.
I tried putting a square piece of aluminum flashing over it to seal it up.

Then I found that was there by design to mix inside warm dry air with the outside air to feed the fire.

So the hole is nice to have in the shoulder seasons to keep the ash from clumping in the burn pot from the damp outside air.

In the dead of winter when there is cold dry air, it is better to cover the hole to keep the warm air from going up the chimney!

So it depends upon how dry your outside air is in your climate zone!!
 

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My Outside Air Kit is the dog door about six feet from the stove. That old stove will cook us out of the room!
The exhaust is directly above the stove, real good natural draft!

Dave
 
My Quads have absolutely no sealing around the ash pan, the hopper lid, or anywhere else. They leak like a sieve. I've begun to pile up layers of high temp silicone around the ash pan but it's probably a waste of time. You can put your hand right on the hole for the OAK and feel absolutely nothing. A piece of paper just hangs there with nothing pulling on it. Horrible Chinese design. BUT THEY KEEP RUNNING!!!!! Knock on wood!!!
 
I was wondering this as well. I have had my OAK hooked uped for about 4 days. I added the OAK a month ago and when i first hooked it up i didnt notice a difference either way. Like TJ^^^^^^^said, i have a PS50 heatilator same as the quads and there is no seal between the ash drawer as well. I was wondering how this was as even if i block my OAK hole air will still be a ble to be pulled in by the leaks around the ash drawer. I dont know if this is engineered that way or a mishap on the designers. I dont if TJ ^^^^^^^^^^^^^^^^ has this but when i remove my ash drawer, directly underneath it.. there is what Heatilator states is the Damper. I think it is kinda crazy on the Mnf part as if the ash drawer was sealed the damper may work as engineered, but since if i close the damper then it will just draw air in from the unsealed ash drawer, love the stove... jhust wish someone put a little more thought into the things that matter and make a difference.
 
Even when it has different passages. If an OAK is installed, the air will take the path of least resistance.

It will pull the air from the outside tube, before it pulls air through the window sill in your kitchen. IMO

Once that connection is made, your house wont be under the same negative pressure, as if it wasn't on there (No OAK = serious negative pressure and pull through all leaks within the house).


OAK's always will improve the efficiency of the unit. Even if its not a sealed and isolated system. There is still the hole there and air takes the easiest way possible.

My 2 pennies.... ;-P
 
On the other hand my so called bag of parts of dubious location of manufacture will go out if I plug my OAK.

Very good examples of the YMMV doctrine along with the left hand doesn't know what the right hand is doing and this is before it gets "assembled" by someone, somewhere.

Gives one the warm fuzzies doesn't it?

ETA: Anyone want to discuss other interesting differences?
 
tjnamtiw said:
My Quads have absolutely no sealing around the ash pan, the hopper lid, or anywhere else. They leak like a sieve. I've begun to pile up layers of high temp silicone around the ash pan but it's probably a waste of time. You can put your hand right on the hole for the OAK and feel absolutely nothing. A piece of paper just hangs there with nothing pulling on it. Horrible Chinese design. BUT THEY KEEP RUNNING!!!!! Knock on wood!!!

I doubt the Chinese designed it, they do like to try to copy.
 
My Ecotech outside air is tightly sealed, BUT the airwash pulls house-air into the stove; They should have run a tube from these airwash holes to the OAK tube. I might add this so that no house air is drawn into the stove. My hopper is not sealed, I guess it relys on the pile of pellets to block air movement through the auger tube. My ashpan is enclosed within the door gasket sealed combustion chamber.
 
Well seal the air wash, don't really need to see the fire.
 
As I said, I would like to add tubes from the airwash intakes to the OAK, so that the airwash is still functional.
 
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