What are the advantages of outside air in a pellet stove?

[buildingmaint]

Well the title of this thread says it all,but I will elaborate.What does it do ?Will it make my stove produce more heat? Will it not use as much fuel?My stove's goes right into my combustion chamber,but my friend said that his stove's dosen't.

 

[Gooserider]

Well the title of this thread says it all,but I will elaborate.What does it do ?Will it make my stove produce more heat? Will it not use as much fuel?My stove's goes right into my combustion chamber,but my friend said that his stove's dosen't.

Your stove has to get combustion air from someplace. All the OAK (Outside Air Kit) does is pull that air from the outside rather than inside the room the stove is sitting in.

Unless you have a draft problem at present, it probably won't make you produce more heat, infact you might even get a tiny bit less as the stove will be having to heat up the outside air instead of burning pre-heated room air. However this gives you the benefit that you aren't taking the air in the room that you've already paid to heat and sending it up the chimney. It also means you won't be fighting over combustion air with any other fuel burning appliances in your house (furnaces, h/w heaters, gas dryers, etc.) or have problems when someone turns on an exhaust fan, etc. If you have a nice tight house, this can help your stoves operation and get rid of some flaky intermittent problems. People with older "leaky" houses don't usually have draft related problems, but some report that the house feels warmer because they aren't having as much cold air infiltrating to replace what the stove uses.

With woodstoves, there are some arguements about how much an OAK will help or hurt draft, especially in some wind scenarios. However this isn't as big a deal with a pellet stove since you use forced air combustion.

Downside is that it's another hole in your house, and involves that much more plumbing, and occaisional maintainance to keep it cleaned out, etc. You also need to be careful to locate the OAK so that it is properly separated from the stove exhaust or other fume sources (reburning exhaust doesn't work...) and that it won't get buried under snowfall, leaves, etc...

As to how they connect, different models do it different ways, some go right into the combustion chamber, which keeps the pipe from leaking cold air in when the stove isn't running, but means you are more vulnerable to clogs in the OAK pipe. Others just bring the air close to the regular intake, which makes the operation a bit less reliable, but allows you to still burn room air if the pipe gets clogged, however the pipe may allow more cold air to infiltrate the room when the stove isn't running. It's pretty much a question of how the stove maker feels like doing it.

Hope this helps,

Gooserider

 

[restorer]

Well the title of this thread says it all,but I will elaborate.What does it do ?Will it make my stove produce more heat? Will it not use as much fuel?My stove's goes right into my combustion chamber,but my friend said that his stove's dosen't.

Your stove has to get combustion air from someplace. All the OAK (Outside Air Kit) does is pull that air from the outside rather than inside the room the stove is sitting in.

Unless you have a draft problem at present, it probably won't make you produce more heat, infact you might even get a tiny bit less as the stove will be having to heat up the outside air instead of burning pre-heated room air. However this gives you the benefit that you aren't taking the air in the room that you've already paid to heat and sending it up the chimney. It also means you won't be fighting over combustion air with any other fuel burning appliances in your house (furnaces, h/w heaters, gas dryers, etc.) or have problems when someone turns on an exhaust fan, etc. If you have a nice tight house, this can help your stoves operation and get rid of some flaky intermittent problems. People with older "leaky" houses don't usually have draft related problems, but some report that the house feels warmer because they aren't having as much cold air infiltrating to replace what the stove uses.

With woodstoves, there are some arguements about how much an OAK will help or hurt draft, especially in some wind scenarios. However this isn't as big a deal with a pellet stove since you use forced air combustion.

Downside is that it's another hole in your house, and involves that much more plumbing, and occaisional maintainance to keep it cleaned out, etc. You also need to be careful to locate the OAK so that it is properly separated from the stove exhaust or other fume sources (reburning exhaust doesn't work...) and that it won't get buried under snowfall, leaves, etc...

As to how they connect, different models do it different ways, some go right into the combustion chamber, which keeps the pipe from leaking cold air in when the stove isn't running, but means you are more vulnerable to clogs in the OAK pipe. Others just bring the air close to the regular intake, which makes the operation a bit less reliable, but allows you to still burn room air if the pipe gets clogged, however the pipe may allow more cold air to infiltrate the room when the stove isn't running. It's pretty much a question of how the stove maker feels like doing it.

Hope this helps,

Gooserider

Goose, you have to win the Golden Pellet Award for the most complete answer in a single posting for the year.

My only response is, "Yeh, what he said!"

 

[richg]

Certainly a lot of good info there. I will relate a real-lfe example: I had leaky windows and doores, my stove did not have an outside air kit on it, and it worked fine for two winters. I then tore out all of the windows and doors and installed Andersens, and then had the house sided. Next winter, the stove did not operate well at all, was fouling, etc etc. I installed the outside air kit, and it worked perfectly. Looks like the windows and siding buttoned up the house to the point where there was a negative pressure problem, which the outside air kit solved.

 

[HarryBack]

“Yeh, what he said!”

 

[Gooserider]

Thanks for the kind words... I've decided to also post an edited and slightly expanded version of my reply in the WIKI as well. Please take a look at it and see if there is anything in it that needs fixing. I did have a couple of areas where I needed more info, like the controversey about OAKs on woodstoves where some folks claim they can cause a fire hazard if you get a reverse draft pulling hot stove exhaust into the OAK plumbing that isn't intended to handle it....

I know chimneysweeponline has some stuff on it, and pointers to the opposition, but I'm not sure what the rules are about linking to outside sources and/or borrowing from those to incorporate in the article I just did.

Gooserider

 

[restorer]

Thanks for the kind words... I've decided to also post an edited and slightly expanded version of my reply in the WIKI as well. Please take a look at it and see if there is anything in it that needs fixing. I did have a couple of areas where I needed more info, like the controversey about OAKs on woodstoves where some folks claim they can cause a fire hazard if you get a reverse draft pulling hot stove exhaust into the OAK plumbing that isn't intended to handle it....

I know chimneysweeponline has some stuff on it, and pointers to the opposition, but I'm not sure what the rules are about linking to outside sources and/or borrowing from those to incorporate in the article I just did.

Gooserider

Well, goes to show you, " He who snoozes loses." I worked until eight this evening and thought several times today about recommending a post to the Wiki, with modifications. I'll check it out and add what I think will help. Nice scoop Goose.

 

[Gooserider]

Sounds great, I appreciate the second look at the stuff I put up.

I also posted a bunch of stuff in the "definitions" category that came out of some of the discussions on Starter's thread about her Maltese stove install, where I had tried to explain some of our stove tech terms to her.

Actually it seems to me like there is a lot of stuff that might be more useful if it was put into the Wiki, but is currently rather obscure. There is that HUGE batch of questions that might make a neat FAQ, but are kind of hard to access right now. There's a big glossary of terms, some of which are well defined, but others are either not defined, or have IMHO poor definitions, and lots of other stuff like that. It would be a huge project to put it all into a FAQ or the Wiki, but might be worth while.

Gooserider

 

[begreen]

Certainly a lot of good info there. I will relate a real-lfe example: I had leaky windows and doores, my stove did not have an outside air kit on it, and it worked fine for two winters. I then tore out all of the windows and doors and installed Andersens, and then had the house sided. Next winter, the stove did not operate well at all, was fouling, etc etc. I installed the outside air kit, and it worked perfectly. Looks like the windows and siding buttoned up the house to the point where there was a negative pressure problem, which the outside air kit solved.

What type of siding did you go for Rich? Was this a tear off or a recovering of the old siding?

 

[heydan]

I've seen it said that outside air, being colder, is also denser and therefore contains more oxygen than a similar volume of warmer air and will promote more complete combustion.

 

[Gooserider]

I've seen it said that outside air, being colder, is also denser and therefore contains more oxygen than a similar volume of warmer air and will promote more complete combustion.

Technically true, but I strongly suspect that you would not find that it made a big difference in a real life application... The differences are pretty minute in terms of what you'd see between room air and outside air temps, so I don't think it would make that much of a difference. Other factors would be a bigger influence.

Gooserider