Outdoor Fireplace NOT venting 100%

[pwgsx]

So here is the background: I got a used wood insert that I placed on a slab outside, bricked around it and installed a 10in wide straight metal stack and plan to brick around for a chimney. ( the exit on the insert is a odd 8 3/4) this is probably not how a pro would do it but this is on a budget. I started a fire and although 50% of the smoke goes up the stack, the rest swirls out of the opening which is not what I expected. The wind was rather calm. The GF and I held up a piece of metal sheet on both sides to see if it would block the wind but it still smoked out of the opening. I even almost covered the whole front and still couldnt get all the smoke to exit out of the stack. Im at a loss and hoped someone might have some ideas. Could wind be blowing down the stack and causing this? I read about a "versa stack" that creates suction when the wind blows but at $100 I may try and make my own. Any help would be great!!

p.s.- here is a pic to get a idea of what I did so far.

 

[billb3]

chimney height ?

 

[Eaglecraft]

So here is the background: I got a used wood insert that I placed on a slab outside, bricked around it and installed a 10in wide straight metal stack and plan to brick around for a chimney. ( the exit on the insert is a odd 8 3/4) this is probably not how a pro would do it but this is on a budget. I started a fire and although 50% of the smoke goes up the stack, the rest swirls out of the opening which is not what I expected. The wind was rather calm. The GF and I held up a piece of metal sheet on both sides to see if it would block the wind but it still smoked out of the opening. I even almost covered the whole front and still couldnt get all the smoke to exit out of the stack. Im at a loss and hoped someone might have some ideas. Could wind be blowing down the stack and causing this? I read about a "versa stack" that creates suction when the wind blows but at $100 I may try and make my own. Any help would be great!!

p.s.- here is a pic to get a idea of what I did so far.

The obvious suggestion is that you problem is caused by a draft (not enough) issue. Wood stoves and inserts are designed to function properly with a sufficiently long and a sufficiently small diameter chimney flue. if you examine the installation requirements for many wood stoves/inserts you will find that they have a minimum chimney length and maximum flue size requirement. The chimney, or chimney flue should be long enough, but not too long. Bigger is not better for the inside flue diameter.

It's often been stated that the chimney is the "engine" of the wood stove setup. Insufficient draft - and that's probably what you have - causes a problem with the engine.

 

[pwgsx]

It is only about a 3 ft tall. I was trying not to go too high since it will look horrible to the neighbors. Ill go ahead and get a 8 inch wide tube and raise the height a foot or 2 more. It looks to be a HEATALTOR brand, im trying to find the specs. Thanks for the input so far.

 

[Flatbedford]

I have the same problem with this outdoor setup. One day I'll get more pipe.

 

[pwgsx]

At least it seems to be coming out the top...........ok, it said the min. is 13 ft tall for a chimney if im reading it correctly, thats not going to work for my location. Any thoughts with adding a suction vent fan to pull the smoke out or that vacu-stack that I keep reading about? I can do the 8 inch wide pipe to keep with the size of the exit on the insert, and ill be able to go about 5 ft for the chimney before it starts looking crappy. I picked up 2 peices of metal sheet that I plan to use as doors when its not used but can double as a wind shield when open to shelter the sides a bit.

 

[pwgsx]

Has anyone tried to make their own VACU-STACK ? It seems simple enough to use galvanized sheet metal and at $8 Im going to try my luck.

 

[Wade A.]

Flatbedford>

Ever thought of capping/screening the end of that stack? I'm trusting that you've got clearance on the back and front of that set-up (always hard to tell in a photo), but embers lofting out that short stack, and a wind that blows it towards the deck and/or woodpile, and you are going to have a lively night!

 

[Wade A.]

PWGSX

I know it is done, but I'm not sure what the point would be to have an airtight enclosure around an outdoor fireplace. I mean, it is not as if you're trying to warm a space....unless you count "The Universe" as a space. ... and efficiency in an outdoor fireplace is never the point, is it?

That said: You're not saying it doesn't perform with the doors closed, are you? If it doesn't, I'd remove them. Frankly, I'd see if you could remove the whole thing and just line the firebox, and construct a smoke shelf above it. The kind of chimney you're going to have to have is going to make it look like a coal fired powerplant by the time you're done, and complicating things with even more technology is getting in deeper. Stop digging, would be my $.02. (This from someone whos has dug MANY a deep hole in his life, believe me!)

 

[sebring]

Its not too late to make a fire pit out of that setup. Having a tall enough chimney on that thing will not look good, and will probably blow over in a good wind.

 

[pwgsx]

PWGSX

I know it is done, but I'm not sure what the point would be to have an airtight enclosure around an outdoor fireplace. I mean, it is not as if you're trying to warm a space....unless you count "The Universe" as a space. ... and efficiency in an outdoor fireplace is never the point, is it?

That said: You're not saying it doesn't perform with the doors closed, are you? If it doesn't, I'd remove them. Frankly, I'd see if you could remove the whole thing and just line the firebox, and construct a smoke shelf above it. The kind of chimney you're going to have to have is going to make it look like a coal fired powerplant by the time you're done, and complicating things with even more technology is getting in deeper. Stop digging, would be my $.02. (This from someone whos has dug MANY a deep hole in his life, believe me!)

Im not sure what you meen by airtight? Having it bricked in?? I did that for looks. I know its not efficient, was just hoping on keeping smoke out of peoples faces like you get wth a firepit. I think you may have miss read about the doors, they are to be closed when its NOT in use- to keep water, animals and whatever else out but was hoping that when they are open and to the side, it may cut down on wind and act like a wind block. Im going to try many ideas this weekend and see if anything works.

 

[eclecticcottage]

We were going to use the old Fisher that was in the Cottage when we bought it as an outdoor fireplace, and it wouldn't burn for a $^$. There was no pipe on it (the old pipe was an absolute disaster, patched with a piece of aluminum wrapped around it and wired on), and it just wouldnt draft. We gave up and sold it, and just use an open pit. I am guessing you can't do the same or don't want to...I would gut the insert and just make it like an open fireplace. My grandfather built a masonry open fireplace style outdoor fireplace and it was pretty neat looking (they used a burn barrel more though, lol).

 

[Wade A.]

Got it..., I was thinking that you were thinking you'd get an efficiency bump by closing it up. By airtight, I mean closed except for your primary/secondary air intakes...you know, with only controlled air. To draw up that 8" pipe, you're either going to have to extend it way up, or knock off the top and just open it up to a regular flue diameter. Good luck with it....looks like it is going to be a nice addition when it is done.

 

[Flatbedford]

Flatbedford>

Ever thought of capping/screening the end of that stack? I'm trusting that you've got clearance on the back and front of that set-up (always hard to tell in a photo), but embers lofting out that short stack, and a wind that blows it towards the deck and/or woodpile, and you are going to have a lively night!

I have moved it since that photo. There are much less embers coming out that stack than from a plan old fire pit. It does not burn unattended either.

 

[Wade A.]

Never hurts to ask, I figure. I depend on the collective experience of this board to steer me right when I say, "Hold my beer. I want to try sumpin'...."

 

[Flatbedford]

Never does and thanks for your concern.

 

[pwgsx]

Made my make-shift versa stack last night, its not the best looking but seems to look similar to the $100 version. Hoping for good results on sat., we will see!!

 

[pwgsx]

No luck this weekend, I extended the chimney and side doors to block the wind. Although it helped there will is no suction it seems. You can see the smoke build up in the box and then roll out the front. It does not seem to be from the wind, it was calm when I noticed this. The wind just blows it around when it rolls out.
My last ditch effort is to install a fan up top and suck the smoke out. Where can I find a fan to withstand the heat and smoke ect. and not pay $1,500 + ?
Thanks