Make up air supply?

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Blueox4

Member
Nov 20, 2017
32
Syracuse, NY area
First year burning in my Osburn 2400 insert and just going over the manual and see strong recommendation for a make up air supply. What is that like a window partially open? It states combustion and air quality could be impacted if there is not a make up air supply. Do most people just leave a window cracked or what is the proper way to supply a make up air supply?
 
OAK. (outside air kit)

Basically a dryer vent that runs backward.
 
Unless your house is extremely tight and you are noticing burn issues, I wouldn't worry about it. I don't have one on my PE Summit, and it burns just fine. If you think it's not burning right crack a window, if you notice a difference, then an OAK might be beneficial.
 
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If you have a supertight home that has or should have and air to air heat exchanger than an OAK is important. Folks with radon issues should also consider one.
 
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Regardless, it will reduce discomfort in adjacent rooms from drafts. So goes the theory.
 
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It seems to me an OAK will always improve heating efficiency, I have trouble imagining many scenarios where it would not. Your stove requires air, much less than an open fireplace, but still a relatively large amount of air is drawn from the house and sent up the chimney. That air has to come from somewhere, and it is usually obtained by drawing air thru every leak and crevice in the house, most often around doors and windows.

The result of this is that rooms far from the stove can end up very cold, as they’re seeing an equal amount of fresh air intrusion to every other part of the house, but receiving the least amount of heat from the stove. An OAK eliminates this problem, by eliminating this constant draw on the house, and providing a separate path for make-up air to the stove.
 
It seems to me an OAK will always improve heating efficiency, I have trouble imagining many scenarios where it would not. Your stove requires air, much less than an open fireplace, but still a relatively large amount of air is drawn from the house and sent up the chimney. That air has to come from somewhere, and it is usually obtained by drawing air thru every leak and crevice in the house, most often around doors and windows.

The result of this is that rooms far from the stove can end up very cold, as they’re seeing an equal amount of fresh air intrusion to every other part of the house, but receiving the least amount of heat from the stove. An OAK eliminates this problem, by eliminating this constant draw on the house, and providing a separate path for make-up air to the stove.
Excellent post, my experience to the Tee..
OAK made a BIG difference with cold air intrusion..
So many times when this subject comes up, the first thing many people say and think are, " if your house is super tight, and your stove won't burn right, then you need an OAK "...
That's simply not the only reason to have one, my stove burnt just fine without one...
 
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How do I install a OAK? Does it go into the wall similar to a dryer vent or does it need to be connected directly to the insert somehow? My Osburn 2400 insert is already in place so I’m not sure I can connect it directly to the stove now. Advice please as I would like optimal burning conditions and feel maybe a OAK will improve on that. How do I put one in?
 
True, but there's a difference between the question of whether you need one and what benefits can be granted by one.

I dunno... a lot of people will say, “if there’s some benefit to be had, then I need it.”
 
It allowes the fresh air to go right into the stove without creating a vacuum in the house pulling in cold air through all the leaks. So it helps with heating a little. More importantly it helps with humidity, that cold DRY outside air being sucked into your house causes the air in the house to become very dry, so sucking that cold dry air right into the stove is much better for the humidity levels in the house. That is my main reason, to prevent it from getting to dry when real cold.
 
It allowes the fresh air to go right into the stove without creating a vacuum in the house pulling in cold air through all the leaks. So it helps with heating a little. More importantly it helps with humidity, that cold DRY outside air being sucked into your house causes the air in the house to become very dry, so sucking that cold dry air right into the stove is much better for the humidity levels in the house. That is my main reason, to prevent it from getting to dry when real cold.

True ‘dat. My indoor humidity runs around 20% all winter. It really interferes with my drinking.

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Just curious, what makes you feel like an OAK will help you? What have the outside temps been when you're burning?

I have learned here that it certainly can’t hurt so that is why I want to put one in. As far as temps go it’s been warm here in upstate NY but that’s getting ready to change. This is my first year burning. How do I install one?
 
I have learned here that it certainly can’t hurt so that is why I want to put one in. As far as temps go it’s been warm here in upstate NY but that’s getting ready to change. This is my first year burning. How do I install one?

Not to walk both sides of the fence, but there are rare cases where they can hurt. When installed on the leeward side of a house in a windy location, they can actually pull a vacuum on the stove, causing draft reversal or stall. I have seen this theorized and mentioned many times, but have to admit I can’t think of anyone who has actually had that problem, on this forum.
 
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I have been only done the 3 test burns that Osburn recommends prior to using the insert normally. The test burns were with outside temps in the 50s and my draft was good it seemed as if I cracked the door when burning the flame increased in intensity and no smoke came into the room.
 
I’ve been contemplating putting an OAK in as well. In a perfect world I would run the stove for a season to see how it performs then make a decision but I think now is the time to do it as everything is still in its raw form as I’ve not finished the hearth.

Getting through this first burning season is a task!
 
I promise you I'm not fighting you on this :)

The reason I asked about temps is because draft will naturally be sluggish when it's relatively warm outside compared to say January-February.

I looked at the 2000 model, the size down from yours, and they do list an OAK and they show where it gets installed. So me thinks Osburn doesn't have an OAK for the 2400.
 
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I’ll probably call Osburn. Here is a copy and paste from the manual...pg 25...


We recommend that you have a fresh air or make up air supply for the insert. In Canada this is a building code requirement. If this is not done, it could cause poor air quality in the home, poor and incomplete combustion, and poor efficiency in the insert.”
 
I’ll probably call Osburn. Here is a copy and paste from the manual...pg 25...


We recommend that you have a fresh air or make up air supply for the insert. In Canada this is a building code requirement. If this is not done, it could cause poor air quality in the home, poor and incomplete combustion, and poor efficiency in the insert.”

Yeah, I read that, however, all of the other manuals I've read of theirs, say the opposite about Canada. At best, it's confusing as to what they're actually talking about in yours. Anybody knowledgeable about Canada care to comment?

In the 2400 stove version, they list an OAK as optional in the manual. For installation, it's on the rear. Perhaps something about the insert this was left out or they didn't want to certify for mobile home use? Other members have their makeup air provided to the room and not directly to the stove/insert.
 
They might not have one for the Osborn insert I think the manual covers the free standing and the insert. You can go to their website and ask a question. They have been extremely responsive to questions I asked about the 2200 I have.
 
I honestly think the benifits of paks for most houses is greatly exaggerated. Yes some houses need them and others can benifit from them but most houses have enough leaks that the ammount of air used by a woodstove is nothing compared to the air that is changing over naturally. That being said if one can be installed properly with a reasonable ammount of effort there is really no downside.