Outside Insulated Steel Stove Chimney or Bust - How well do they work?

[Mr. Kelly]

Hi all,

I have a lonely stove option... outside metal pipe - or bust. I hear conflicting stories about the efficiency and effectiveness of this kind of vent. I wish I had other options.

I'll be trying to heat a zigzaggy 1600 sq. ft. very old cranky house, with a stove on an "outside" wall, and the vent going out through the wall and up. The pipe will go straight up from the stove a couple of feet, and then likely go 90 degrees and then horizontal to the outside, then about 15ft. straight up of Metalbestos Class A chimney pipe. Sound familiar

Anybody have a similar setup? Has it worked out alright, or has it been a draft pain in the beehind? Duravent just as good?

How about a 90 degree elbow compared to a couple of 45s and a more gradual turn? My initial thought is that 90 degree turn would be more resistance to vertical air flow.

Also, what's the likelihood that I'll be able to comfortably heat a good chunk of this house with an Avalon 1750 stove? It's 2.2 c/ft firebox.

How much wood should I expect to burn if I attempt to go 24/7?

If anyone has a similar situation, it would be great to hear your experiences and stories!

GO WOOD!

 

[Dune]

Pipe outside will work. Box it in and it will work better. Two fortyfives are always better than one ninety no matter what you are piping. Whether you can heat your "cranky very old house" depends upon how well it is insulated and how drafty it is.

 

[JotulOwner]

I have two 90 degree bends to the outside with an overall height over 20 feet. It works. Not as well as straight pipe inside, but it works without any major problems in my situation.

 

[Pauly]

Ive been running a selkirk metalbestos 6 inch chimney with a 90 degree about 2 feet above the stove for about the past 12 years from 2 diffeerent locations, from an old craftstove fireplace insert converted to a free standing stove. I have about 16 feet of chimney pipe of which about 14 feet is out of doors. Ive never had a draft problem with it and I probably dont actually meet the 3 feet above anything witin 10 feet ratio. Hope this helps.

 

[LLigetfa]

My father's house had three chimneys. One was masonry with clay tile for the cook stove, another a Selkirk up the middle of the house, and one a Selkirk up the outside of the house (chased in). It was the outside one that burned his house to the ground. Mind you, he did everything wrong and the outside Selkirk just happened to be the least forgiving. It was also the worst drafting and the other two chimneys out-drafted it so much it would reverse.

 

[Pauly]

My father's house had three chimneys. One was masonry with clay tile for the cook stove, another a Selkirk up the middle of the house, and one a Selkirk up the outside of the house (chased in). It was the outside one that burned his house to the ground. Mind you, he did everything wrong and the outside Selkirk just happened to be the least forgiving. It was also the worst drafting and the other two chimneys out-drafted it so much it would reverse.

I would be very interested to hear what actually caused and started the fire that caught the house.

 

[LLigetfa]

Mind you, he did everything wrong...

I would be very interested to hear what actually caused and started the fire that caught the house.

Like said, he did everything wrong. Basement burner, poor draft, three story home with bad stack effect, terrible Franklin stove, poorly seasoned wood, never ever cleaned the Selkirk chimney... My mother would get on his case to clean the masonry chimney when her cook stove didn't work right but for whatever reason, the Selkirk chimneys were neglected.

He had heated with wood his entire life and there was no convincing him to do anything different.

 

[madrone]

I'll be trying to heat a zigzaggy 1600 sq. ft. very old cranky house, with a stove on an "outside" wall, and the vent going out through the wall and up. The pipe will go straight up from the stove a couple of feet, and then likely go 90 degrees and then horizontal to the outside, then about 15ft. straight up of Metalbestos Class A chimney pipe. Sound familiar


Also, what's the likelihood that I'll be able to comfortably heat a good chunk of this house with an Avalon 1750 stove? It's 2.2 c/ft firebox.

My setup exactly. 90's. No problems whatsoever. Easy to clean, but never too dirty. Boxing it in might make sense in your climate.

The stove might be a tad on the small side on really bad nights, but probably sufficient most of the time.

 

[btuser]

I'd think the insulated liner/pipe would have no problem at all, no matter how cold it got. You might have to fight with it to get the draft rolling up at first, but I was surprised how well my short little chimney drafts for the insert compared to our old fireplace.

 

[wsorg]

If you've got a well insulated liner, it should be OK.

 

[Backwoods Savage]

Ours runs horizontally (with 1/2" rise per foot) into a tee outdoors and then up. No chase. No problems. Have never had a problem with draft even though we are surrounded by tall trees.

In your climate, which is a tad warmer than MI, I would not think it necessary to build a chase but they do help. If you burn 24/7, then there is always heat going up the chimney therefore there should be no draft problem.

 

[firefighterjake]

This story sounds quite familiar Mr. Kelly since I was in a similar situation. I have a 30 x 40 Cape (not so old since it was built in the 1970s, but definitely "cranky" since the folks who built it did some pretty odd-ball things which has resulted in minor tasks turning into major projects since they did things that weren't quite right in terms of being built to code or even the standards of the day.)

One of these quirks that I ran across was how they laid the stringers of the first floor ceiling/second floor and the stringers of the second floor ceiling perpendicular to each other . . . add in a supporting wall and some plumbing from the baseboard heat and it all resulted in the fact that I could not easily install or build an interior chimney and so I had to go with an outside chimney.

I had read a lot of negatives about outside chimneys . . . they supposedly have draft issues, they can result in more creosote build up, you lose heat that you would have gained from the stove pipe being inside, etc. . . . and after a year plus I am pleased to say that many of these issues were non-events in my case.

First, the particulars. I have 2-3 feet of double wall stove pipe running straight up from the stove . . . it hits a 90 degree elbow and runs into a short length of pipe which goes into the wall thimble to the outside . . . at which point it connects into a T-pipe . . . and then from there it's 20 feet or so up along the outside wall of the house to the cap. The whole she-bang is secured to the side of the house and has two bracing connecting to the roof.

Draft: Some folks have reported drafting issues. This has never been the case with my set up. Draft is excellent and I don't need to use any means of pre-heating the whole kit and kaboodle as some folks have had to do.

Creosote: I regularly check and clean my chimney, but honestly I would be surprised if I got more than a cup of fine black creosote from the chimney when I do the monthly sweep. The key here truly is to burn seasoned wood and burn hot.

Loss of Heat: I have no doubt that I am not getting the full heating potential that I would get with a centrally located stove with pipe running straight up through the livable areas of the house . . . but that said, I am able to keep the entire house heated (with the exception of the mudroom/utility room on the far side of the house where I have an electric space heater . . . to keep the oil boiler lines and water pipes from getting too cold.) The room with the woodstove is always toasty warm and the rest of the house is typically at 70 degrees or so.

Expense: Another negative here, but nothing I could do about it. Going straight up would probably have cost me less instead of using more of the Class A pipe . . . but I believe the price to probably have been pretty close when you factor the pass through devices and need to move plumbing, build walls, etc.

Looks: At first I was convinced I would run the whole system for a year and then build a box around the chimney as a chase to make the whole thing look more visually appealing . . . but then I realized something . . . in my own case, the insulated Excel pipe was doing a fine job of insulating the pipe and unless you walked around the side of the house you wouldn't see the stainless steel chimney . . . from the road you can barely see the cap, much less the pipe . . . and so I left it the way it is.

Now it should be noted, in my own case I am burning 24/7 for the most part which may affect things such as the draft and I do have 20 feet of pipe so it is a bit longer than what you have described for your own needs.

Finally, I did discover one benefit to the outside install . . . and it's a nice one . . . checking and cleaning my chimney is now a 5-minute job thanks to the T. I remove three screws holding the cap on one end of the T . . . pop the cap and then from the ground run the rodded brush up the chimney . . . quick and easy and I don't have to get on my house's rather steep roof.


Now to some of your questions:

90 vs. 45 degree: I haven't noticed any real issues with the two 90 degree turns that the stove pipe takes . . . again, just my real world experience.

Avalon 1750 stove and the heating capacity: No real experience or opinion. My only suggestion is to figure out how much space you want to heat, find a stove that is rated for that space . . . and then go one size larger.

Wood consumption: Varies on a lot of factors, including climate, winter weather conditions, insulation in the home, etc. . . . it seems as though most 24/7 burners in the New England area are going through 3-6 cords of wood each year.

 

[Mr. Kelly]

Thank you FF Jake for your detailed reply. It's worth a chuckle to think of someone who puts out fires for our towns who now likes to set them, too!

I'm presuming that capes are by definition two story? Is your sq. footage roughly 2,000? How "open" is your house? Ours is a typical old farm house, with a parlor on one side, dining room on the other, separated by doorways and a foyer, which is where the stairs going up are. The kitchen is in the back, separated by another foyer. All rooms have doorways, so there's no easy path for heat to travel. Do you use any artificial means to get heat moving? Do you have an on-board fan on your stove? If so, how effective is it?

Unfortunately, our chimney will be right at the front of the house, although the far side from the street. It will be likely an eyesore. Maybe someday, when we win the lottery, I'll consider boxing it it and finishing it. Still detracts from our very old farm house.

What company did you go with for piping?

I appreciated your story. Thanks a bunch up there!

MK

 

[Mr. Kelly]

Two more thoughts... now that I already sent the last one...

What kind of stove did you get? What size is it?

Also, where did you get a chimney brush? I suspect they're easily found, but I've never looked for one

Best<

MK

 

[firefighterjake]

Messed up post.

 

[firefighterjake]

Thank you FF Jake for your detailed reply. It's worth a chuckle to think of someone who puts out fires for our towns who now likes to set them, too!

Oh, I've always liked setting fires too . . . probably why I'm a firefighter.

I'm presuming that capes are by definition two story? Is your sq. footage roughly 2,000? How "open" is your house? Ours is a typical old farm house, with a parlor on one side, dining room on the other, separated by doorways and a foyer, which is where the stairs going up are. The kitchen is in the back, separated by another foyer. All rooms have doorways, so there's no easy path for heat to travel. Do you use any artificial means to get heat moving? Do you have an on-board fan on your stove? If so, how effective is it?

I think most Capes are two-story. I figure my Cape is around 1,800 square feet . . . a little more than 2,000 perhaps when you figure in the Mudroom/Bathroom/Utility Room addition. The house isn't really open in terms of large open areas leading from one area to another -- I do have two standard size doorways leading out of the living room -- one leads to a short hall and the other leads to the dining room (which is open to the kitchen.) I do use a fan on the floor to help move the air . . . I find that without the fan I get a lot of heat in the living room and the other areas not as much . . . although with time the heat will move out and heat the other areas. What the fan does is move the air into the other areas faster and it "levels" out the heat so when you move from one area of the house to another you don't notice the temp difference as much. I would say the fan is very effective. I have it placed 20-25 feet away from the stove in one of the doorways pushing the air towards the stove.

Unfortunately, our chimney will be right at the front of the house, although the far side from the street. It will be likely an eyesore. Maybe someday, when we win the lottery, I'll consider boxing it it and finishing it. Still detracts from our very old farm house.

If the chimney is placed on the downside of a roof you will want to make sure it has some sort of protection from snow and ice so you don't end up with a large build up of snow and/or ice sliding off the roof and pulling the chimney down.

What company did you go with for piping?

Excel ICC . . . I've been very happy with the quality of this product . . . it was recommended by several sweeps who work at the fire department.

I appreciated your story. Thanks a bunch up there!

No problem . . . just giving back whenever and however I can since this site was wicked useful for me when I was starting out . . . only a little more than a year ago . . . believe it or not.

MK

 

[Skier76]

I'm thinking I may have the worst chimney setup on this entire website. I've got about 14' of 8" Metalbestos on the exterior of our weekend place in Southern VT. First off, the chimney is probably about a foot or two too short. Second, it's a 6" exit off the stove going into an 8" pipe, Third: one 90 degree bend just aft of the thimble and forth, this thing wouldn't know what the 10/3 rule was if I read it right out of the book out loud. The cap doesn't cleart the roof of our A-Frame...not even close.

That being said, the good folks here warned me that this would not be an ideal set up. Problems may happen...or not.

Luckily, the stove and chimney have worked out just fine. This is a weekend house, so dropping thousands into a new chimney wasn't that cost effective. I figured I'd take a calculated risk and try it out. If it didn't work, then we'd look into solutions. We've been doing fires on the weekends fairly regularly since September. The only problem we've had is a little smoke rollout when reloading. I think that has to do more with the top baffle on our Castine than our chimney. I'm thinking I may have to reverse the draft now and again when the stove is cold and the chimney is cold when we get there after being away all week. Again, we'll just cross that bridge when we come to it.

Cliffs: I think you'll be OK. I'm betting mine is crappier and it works.

 

[firefighterjake]

Two more thoughts... now that I already sent the last one...

What kind of stove did you get? What size is it?

Jotul Oslo . . . I can't remember the exact size of the firebox.

Also, where did you get a chimney brush? I suspect they're easily found, but I've never looked for one

You can find them at any hardware store . . . I opted for a poly brush though after reading through some pros and cons of going with the conventional steel vs. poly . . . bought at Northlineexpress.com . . . quick service, good prices.Best<

MK

 

[LSaupe]

Dunn:

You mention that two 45's are better than one 90. When I look at the loss factors (sum) for the two 45's are the same or even higher than a single 90. Ref: Crane pipe flow standards.

Stove pipe might have some nuances though. Do you know if there is anything out there as a good reference?

Many thanks,

Larry S.