I cannot figure out if I should install the cold air kit (CAK) on my SL300 chimney. It seems to me that if I draw cold air from outside and run it up through the chimney, I will get condesation issues because the chimney chase is in the middle of the room, meaning that it is warm. Am I way off base on this?
Can the experts please explain how a air cooled chimney works?
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highmark,
Well, I'm kind of new here but what I've learned is the OAK (outside air kit) connects to your woodstove (not your chimney) so your woodstove draws air from outside and heats the outside air as it draws it in. The basis behind the OAK is that by drawing outside air your woodstove is not drawing already heated air from inside your home. Drawing air from inside your home causes cold air infiltration through your foundation, windows, doors, etc.
(Hope I got that right guys.......)
Shari
Well, I'm kind of new here but what I've learned is the OAK (outside air kit) connects to your woodstove (not your chimney) so your woodstove draws air from outside and heats the outside air as it draws it in. The basis behind the OAK is that by drawing outside air your woodstove is not drawing already heated air from inside your home. Drawing air from inside your home causes cold air infiltration through your foundation, windows, doors, etc.
(Hope I got that right guys.......)
Shari
LLigetfa
Minister of Fire
I would think you would want to use the chimney to extract a bit more heat from the flue rather than sent it outside.
73blazer
Member
I'm not an expert by any means. But, I did a bit a research on this.
First off, as pursuant to the other person who mentioned OAK, this is not an OAK per say. An OAK is usually referred to as outside air for combustion. THis is a CAK, a Chimney air kit. It draws air from the outside and runs up the inside cavity between the two walls of the SL300 pipe and out the bottom holes on the termination cap up top.
IMO, the design is really more economical, than purposeful. It works to keep the outside layer of the pipe cool enough during a chimney fire as UL tests dictate (so many degrees for X period of time), and any combustibles within 2", from catching fire. They use it, because it's the cheapest. Alot of people looking to install a fireplace, would opt out if the cost included another $1200+ of triple wall stainless insulated chimney. Also, to certify other chimneys, costs money. Personally, I do not like the SL300, or any double wall air cooled, it just is prone to too many issues. As you mention, if running cool outside air (the colder it is outside, the more persistent the issue) on a hot pipe, yes depending on conditions, it might be prone to condensation. That said, if you read the install instructions carefully, they always make sure to tell you to insulate any chase, whether the chase is inside the home, or on an outside wall, so the air inside the chase will become balanced quickly and not prone to outside 70degree, or 10 degree air. With those conditions, it should not develop condensation, or so they say. The other complaint is, it might develop more creosote, because your running outside air up the pipe to cool it. For anti-cresote conditions, it'd be best to keep that pipe as hot as possible.
That said, the pipe acts differently depending on conditions, every install and every temperature might be different. The best thing to do is, watch it carefully at different outside temperatures and see how it acts. It might develop condensation, it might not. And you should always inspect a new install every few weeks the first year to see how creosote, if any, is progressing, to learn how your chimney and install work together and how creosote develops in your particular conditions. If installed according to specs, it shouldn't, but I've heard of complaints of condensation. I have the SL300 on my North Star fireplace, it's installed 28' of it in an insulated chase, the chase on an outside wall. It does not develop condensation that I've noticed.
First off, as pursuant to the other person who mentioned OAK, this is not an OAK per say. An OAK is usually referred to as outside air for combustion. THis is a CAK, a Chimney air kit. It draws air from the outside and runs up the inside cavity between the two walls of the SL300 pipe and out the bottom holes on the termination cap up top.
IMO, the design is really more economical, than purposeful. It works to keep the outside layer of the pipe cool enough during a chimney fire as UL tests dictate (so many degrees for X period of time), and any combustibles within 2", from catching fire. They use it, because it's the cheapest. Alot of people looking to install a fireplace, would opt out if the cost included another $1200+ of triple wall stainless insulated chimney. Also, to certify other chimneys, costs money. Personally, I do not like the SL300, or any double wall air cooled, it just is prone to too many issues. As you mention, if running cool outside air (the colder it is outside, the more persistent the issue) on a hot pipe, yes depending on conditions, it might be prone to condensation. That said, if you read the install instructions carefully, they always make sure to tell you to insulate any chase, whether the chase is inside the home, or on an outside wall, so the air inside the chase will become balanced quickly and not prone to outside 70degree, or 10 degree air. With those conditions, it should not develop condensation, or so they say. The other complaint is, it might develop more creosote, because your running outside air up the pipe to cool it. For anti-cresote conditions, it'd be best to keep that pipe as hot as possible.
That said, the pipe acts differently depending on conditions, every install and every temperature might be different. The best thing to do is, watch it carefully at different outside temperatures and see how it acts. It might develop condensation, it might not. And you should always inspect a new install every few weeks the first year to see how creosote, if any, is progressing, to learn how your chimney and install work together and how creosote develops in your particular conditions. If installed according to specs, it shouldn't, but I've heard of complaints of condensation. I have the SL300 on my North Star fireplace, it's installed 28' of it in an insulated chase, the chase on an outside wall. It does not develop condensation that I've noticed.
LLigetfa
Minister of Fire
In my former home I ran a regular SS insulated chimney up the middle of the house. I chased it in using metal studs and vented the chase both top and bottom. The amount of heat I got and the volume of air it moved through convection heated the upstairs very evenly. The chimney stayed warm enough because of the room temperature chase for good draft and with the insulation the flue stayed very clean.
In my current home, the chimney chase goes through our walk-in closet, not central to the house and is much shorter so I could not salvage as much heat from it. I ran an extra radiation shield the length of the vented chase and so the heat I draw from it is just enough to heat the closet and adjacent bedroom.
In my current home, the chimney chase goes through our walk-in closet, not central to the house and is much shorter so I could not salvage as much heat from it. I ran an extra radiation shield the length of the vented chase and so the heat I draw from it is just enough to heat the closet and adjacent bedroom.
oconnor
Minister of Fire
There is another thread here this week were the fellow is battling condensation because his air cooled chimney is not vented to outside air. The air in the house is really moist, and he has a lot of condensation. Folks are recommending he connect the chimney cooling air outside. Run a search on condensation and see what you find.
I guess each of us implies our own living circumstances on any given topic. I am having a hard time understanding how this air cooled method would work in Wisconsin winters. Example: This morning it was -8 with a wind chill of -32. Wouldn't 'air cooling' in that type of weather be a prime situation for creosote creation? I ask because when I install, I am going to max out on the insulation in and around my liner - just the opposite of 'air cooling'.
Shari
Shari
Shari, I agree, I am in Northern MN where it was -15 today, and I just don't see how this would be ideal. My dealer is of no help, so I am turning to the experts.
73blazer, if my chase runs in the middle of the house, then exits into the attic where there is no heat, won't I have problems even if I insulate the chase in the attic because it is cold up there? I really wish now I would have done a brick chimney.
73blazer, if my chase runs in the middle of the house, then exits into the attic where there is no heat, won't I have problems even if I insulate the chase in the attic because it is cold up there? I really wish now I would have done a brick chimney.
Backwoods Savage
Minister of Fire
I too would shy away from this.
btw, we have an outside SS chimney and have no problems with it even when the temps are below zero. If we did, then I would consider building a chase. Until then, all is well.
btw, we have an outside SS chimney and have no problems with it even when the temps are below zero. If we did, then I would consider building a chase. Until then, all is well.
73blazer
Member
A valid concern, and I don't have a good answer for you. Which fireplace are you installing? All I can say is, follow the recommendations to the letter in the manual. Knowing the attic's in a few homes I've been in, the temperature in the winter is usually well above the outside temperature, perhaps a properly insulated home isn't that way, but most builders skimp out on insulation because they can. In the attic, if it's possible, I'd say try to enclose the pipe in an insulated attic chase. The idea is to keep the majority of the run of the pipe at a constant temperature.highmark18 said:
It's a concern for sure. All you can do is follow the recomendations and watch it carefully for the first few weeks of burning and see if it's developing condensation or creosote.
It is the Royal hearth 36 from Heat n Glo. I guess all I can do is build it and see what happens.
LLigetfa
Minister of Fire
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