Outside Air Kit - Oak - My research after investigating

[Wilbur Feral]

You guys are making my head explode!

Amen on that! I'm done with this one and hereby vow to not argue for or against an OAK for at least 24 hours. And I now feel compelled to make a charitable contribution to the physics departmment at the local high school, 'cause clearly it has become a subject that is not adequately taught to far too many people.

 

[F4jock]

Well said by F4jock.... The people who don't want to use an oak try so hard to justify it to themselves! Which is fine. Enjoy the drafts, and wasting more $ to heat ur home

But if that makes them happy who are we to keep intruding!

 

[F4jock]

Amen on that! I'm done with this one and hereby vow to not argue for or against an OAK for at least 24 hours. And I now feel compelled to make a charitable contribution to the physics departmment at the local high school, 'cause clearly it has become a subject that is not adequately taught to far too many people.

And I'm with you. I'm done with this thread. And as well as the physics department I'm going to see if the English department has any courses on logic that I can support . . .

 

[3650]

My oak is direct outside to firebox and that is probably not as efficient as the kind that use the chimney pipe as a heat exchange. If i could afford the high dollar type I would certainly have it. I say this because my experience in sub zero cold snaps is not all that great. I have noticed that when its like -20 out my stove doesnt seem to throw near the heat it should and I blame this on the extreme cold temps entering the firebox. I actually get frost on my oak at these temps. The heat exhange type would certainly be the way to go If you have the coin.

 

[TimfromMA]

My oak is direct outside to firebox and that is probably not as efficient as the kind that use the chimney pipe as a heat exchange. If i could afford the high dollar type I would certainly have it. I say this because my experience in sub zero cold snaps is not all that great. I have noticed that when its like -20 out my stove doesnt seem to throw near the heat it should and I blame this on the extreme cold temps entering the firebox. I actually get frost on my oak at these temps. The heat exhange type would certainly be the way to go If you have the coin.

One could argue that using your exhaust vent to preheat OAK air will cool exhaust gasses causing an increase in creosote buildup.

 

[F4jock]

One could argue that using your exhaust vent to preheat OAK air will cool exhaust gasses causing an increase in creosote buildup.

And observe that cooler air contains more oxygen thus supporting better combustion but. . . .

 

[FTG-05]

Hey. If you want to suck hot air out of your home for combustion use and cold air in to replace it so your stove works harder it's up to you. You ARE heating air twice. The air you bring into the room frim outside and the air you exhaust from the room for combustion instead of recirculating it but if you want to reinvent physics maybe you should write a paper and you and Sheldon Cooper can present it.

I could be wrong, but you might want to read my last bullet point once more.

Just a thought!

 

[F4jock]

I could be wrong, but you might want to read my last bullet point once more.

Just a thought!

Read it several times. Unclear. At least to me sounds like no OAK but *shrug*.

 

[meisen]

I read the linked article, it is correct grammatically.

Counterpoints
(broken link removed)

Hey John,
We lived in Madtown for 9 years! Miss it some but loving the milder winters here on the East Coast.

Everything I read in your link was to do with wood stoves so is that not an apples and oranges comparison? Even if there was some evidence based data on there it's unclear if it truly applies to pellet appliances. Except maybe in a power outage scenario where spillage is a concern. I think the OAK question is made a little more complex when youtalk in terms of in a passive draft device. Glad I don't have to do that much thinking.

 

[bags]

Hey John,
We lived in Madtown for 9 years! Miss it some but loving the milder winters here on the East Coast.

Everything I read in your link was to do with wood stoves so is that not an apples and oranges comparison? Even if there was some evidence based data on there it's unclear if it truly applies to pellet appliances. Except maybe in a power outage scenario where spillage is a concern. I think the OAK question is made a little more complex when youtalk in terms of in a passive draft device. Glad I don't have to do that much thinking.

The original article cited and attached was about wood burners also. John just attach another contradicting the one that this thread was opened with. And that has been the main point driven home here a gazzilion times that it has almost zero relevance being used with pellet stoves for starters. The second is positive and negative pressures and the happy campers watching their trouser bottoms swirl in the breeze while riding the Lazy Boy in front of their pellet stoves without OAKs hooked up.

 

[bags]

I'll try one more angle here. Your house with a nice warm pellet stove blowing is a hot cup of coffee. The outside is an ice cold glass of water. Ya with me here?
Good.
What happens when you mix the two? You wind up with some luke warm week azz coffee. Agree? Who likes that crap? This is exactly what happens (in a sense) with your living room as the cold air infiltrates your home and IT WILL thru numerous air leaks you have not even realized were included for free with the nice new crib (aka: house). The hot coffee will get watered down with the cold outside water. It is that simple. It really, really is. Now who wants to debate about how great cold watered down coffee is great?

OK, now the OAK sort of works like a sealed restrictive funnel letting the right amount of cold water drip into your HOT coffee and keeps the glass of cold water from being poured in real fast. This way the hot coffee does not burn your mouth and you are not drinking cold watered down week azz coffee. Not being a smart azz, but think about it for a moment. This is about as KISS as I can get with this bizarre and perplexing OAK issue.

 

[checkthisout]

What if I have an outdoor boiler? This boiler uses outside air to feed the combustion, heats the water then puts it into a heat exchanger in my house.

Ok?

You would have a hard time convincing me that running a duct from the combustion inlet on my boiler to the inside of my house so that it pulls the combustion air out of my house would be a good idea or that it wouldn't make any difference in the amount of heat required to warm my house.

 

[checkthisout]

One could argue that using your exhaust vent to preheat OAK air will cool exhaust gasses causing an increase in creosote buildup.

Maybe? Or the heated air would help increase combustion temperatures so that less creosote forms in the first place.

You gotta clean the chimney anyway, lest Santa Claus not bring you any presents.

 

[FTG-05]

Read it several times. Unclear. At least to me sounds like no OAK but *shrug*.

Here's the list without the attempt at humor:

I had three non-negotiables when installing my wood stove this last summer and fall:

- Safety.

- Englander 30-NC wood stove.

- OAK.

 

[meisen]

So one last thing before this gets closed...it seems the main point the anti-OAK-in-pellet stove crowd makes is that using cooler air in the combustion chamber is less efficient...ie it's more work (ie less heat is available for heating) for the stove to hear that air.

Has anyone actually verified that this is the case? Is it really that big a difference? What, intake at 10 or 20 vs 70 degrees inside temps? A modest difference. What is typical combustion temp? I'm reading 450+ off my burnpot, I'm sure it's hotter as the meter maxxes. So does higher oxygen, lower-moisture content air typical of winter really force the stove to work significantly harder to heat the air?

I'm betting it doesn't. Plus you are still having to heat that air as some point to get it to 70. My old, drafty house seals it for me without further ado. Is that the question that needs answering though?

 

[OhioBurner©]

What if the room air temperature and outside temperature are the same?

Then we wouldn't be running the stove?

You guys are making my head explode! You do not NEED an OAK but the physics of the situation doesn't change because you do or do not want one: If you draw combustion air FROM the room and exhaust it to the OUTSIDE it MUST be replaced and the only place that replacement air can ultimately come from is OUTSIDE where it's cold or you wouldn't have the stove running in the first place! If you draw combustion air FROM outside and exhaust it TO outside with an OAK you do not exacerbate cold air infiltration to the room from outside. You figure the rest out! There is no way that this reality can be changed no matter what you think or what is written where unless you have a source of bottled, compressed air you can discharge into your house. You can debate the NEED for an OAK relative to better combustion all you want, and frankly that is also pretty much a given, but you can NOT change the physics of air movement.

I don't think anyone is debating that what you are saying there isn't true.

Edit> Not sure if I made it clear earlier but I support the use of OAK especially where its easy to install . Mine wasn't a great solution and probably would not have done the OAK except that it was required in my case.

 

[checkthisout]

Then we wouldn't be running the stove?
.

What if it ran out of pellets while I was gone and it's 50 degrees outside and inside my house?

 

[TimfromMA]

What if it ran out of pellets while I was gone and it's 50 degrees outside and inside my house?

If it ran out of pellets, it would be off.

 

[alternativeheat]

I think you will find the people who have trouble heating their houses with a pellet stove when it's -30 deg outside will do so because it's -30 deg outside and probably have hit the threshold of the stoves heating capability. It takes a lot of heat to heat a house with that kind of penetrating cold going on. Some furnaces or boilers even run non stop in that kind of cold. I know when it turns cold here it takes about 3 days for the real cold to start doing it's thing and we get down to about 0 around here not -30. The first day of a cold snap is barely felt in the house, the heat source runs a little harder. But by the third day it starts get so your cranking on it, using more fuel etc. If the wind blows hard out there that's another element to consider. Now in my case though I can't really compare this OAK phenomenon in cold as mine is in my chimney picking up relatively warm air by comparison.

I think you will find that the light yellow part of a wood flame is around 1000degC or 1800deg F, measured directly in side the flame. It's unlikely 30 deg differences in in coming air will matter much. In fact cold air might turn that flame even a slightly hotter brighter yellow as it supports more oxygen than hot air ( if the OAK doesn't frost up and restrict flow, in which case a heat tape might be a good thing).

 

[F4jock]

Here's the list without the attempt at humor:

I had three non-negotiables when installing my wood stove this last summer and fall:

- Safety.

- Englander 30-NC wood stove.

- OAK.

Ah. Thanks. More better!

 

[Lake Girl]

Ah. Thanks. More better!

And observe that cooler air contains more oxygen thus supporting better combustion but. . . .

Where does this come from? Hubby, the fire fighter says the same thing - Honeywell study from the 1950s but can't find it on-line.

 

[DBCOOPER]

The cooler air at the surface is more dense and as such contains more o2. Its the opposite of being at a higher altitude.

 

[F4jock]

Where does this come from? Hubby, the fire fighter says the same thing - Honeywell study from the 1950s but can't find it on-line.

Cold air is more dense than warm air thus there are more oxygen molecules per unit volume.

 

[Lake Girl]

Charles's law? Since the Hubby was a diver, well acquainted with Boyle's - pressure and volume inversely related. It's the temperature part of the equation and it's effect I'm after.

Nasty headache interfering with brain function today Just wish I could say it was celebrating the holidays too much but not the case...

 

[F4jock]

Charles's law? Since the Hubby was a diver, well acquainted with Boyle's - pressure and volume inversely related. It's the temperature part of the equation and it's effect I'm after.

Nasty headache interfering with brain function today Just wish I could say it was celebrating the holidays too much but not the case...

If I remember correctly, Charlie was talking about the volume of a gas being directly proportional to temperature at a constant pressure. Here we're talking about density so while the percentage of oxygen is constant no matter the temperature the amount per unit volume is greater.