Outside Air

[timusp40]

Ok I know that this topic has been put thru the wringer a million times, and there are plenty of burners on both sides of the fence (OAK vrs No OAK). But as I make my decisions for the upcoming purchase, I intend to investigate all the options. I found a reputable company that sells a product that really has me confused. They have a pipe (chimney) system that draws air from your attic space down the outside layer of a multi-wall stovepipe. There is a T or exit near the stove where a smaller pipe is attached and ran to the outside air connection on your stove. Sounds simple enough, but what about that cold attic air cooling down the stovepipe or does the multi-wall pipe eliminate the issue?

 

[Todd]

What's the name of the company? I've never heard of this for wood stoves but have seen it for gas stoves and fireplaces.

 

[madison]

Are you sure you are not confusing and misunderstanding a direct vent option for a gas stove/insert

 

[HotCoals]

Are you sure you are not confusing and misunderstanding a direct vent option for a gas stove/insert

x2

I I see no reason to do what he is saying if it is for a wood stove.
If you want a OAK I'm thinking it should be below the stove and go outside..maybe the basement..not sure that's even cool.

 

[timusp40]

Duravent Combustion Air System Page 10 of their catalog. What am I missing?

http://www.duravent.com/docs/product/L820_2011-oct.pdf

 

[LLigetfa]

You didn't say what stove you had in mind. A stove would have to be designed specifically for weak OAK pressure since the natural updraft would reduce the pressure that most OAK provisioned stoves require.

The cold air being drawn in could cool the flue a little but as it's explained, there is an insulating layer between it and the innermost layer so it would be minimal. A system such as that would be best suited for a system that has more flue above the ceiling support box than below it so that it tips the balance of flue updraft versus OAK updraft.

Excessive OAK pushing can be a problem with some stoves so a system like that could help tame a stove. Some stoves also don't adequately preheat the secondary combustion air so that bitterly cold air may take the stove out of the sweet spot if too much air is given so the additional preheating could help with that also.

I would discuss the use of such a system with your installer/supplier/manufacturer and provide them the specifics of your install.

 

[HotCoals]

Interesting.
Anybody use this?
Click the pic once or twice.

 

[Woody harrelson]

anybody using this?

 

[DougA]

I use an OAK but not this one. My opinion is that you do NOT want cold outside air incoming directly against your hot outgoing stove pipe. Outgoing air needs to be as hot as possible to create more draft and to help keep creosote/ash build-up in the pipe to a minimum. Creosote likes to stick to cooler walls, particularly near the top of your chimney and I would think this design would exacerbate the problem.
Also, in most cases, you want any heat coming off your stove pipe to help heat your home, not incoming air on the outside wall, which would cool the home.

IMHO, preheating incoming air for an OAK is a dumb idea anyway. It's much more important that the air going into the stove be fresh and full of oxygen, than cold or warm. It's not air the fire wants, it's oxygen.
It seems like an overly complicated design. Last thought - I prefer an OAK that you can throttle back the air supply if you ever need to with a damper on the OAK. If you have an over fire (I have) chocking back incoming air makes the fire far more controllable than a damper on the chimney.