Chimney not drawing smoke

[brads]

I'm just in the process of curing my 36" pompeii oven and have been getting a lot of smoke coming out the front of the oven as opposed to going up the chimney, the chimney opening in the oven has been built according to the plans and has an 8" by 4" brick chimney as shown in the photo from the plans.

i'm not sure is it because i'm only lighting small fires now so obviously its not very hot or is it something to do with my chimney opening design. i'm planning on adding a couple more courses of bricks to the top of the chimney to see if that helps. i live by the coast so there's a lot of wind. Any help would be welcomed.

thanks

[Wiley]

Re: Chimney not drawing smoke

Brad, The photo is a bit washed out on my computer but if I am seeing what I think I'm seeing the back of your WFO is facing the bay. It also appears that the top of your chimney is open and flat. If what I'm seeing is correct and if that is the direction of the prevailing wind, then here's something you can try that doesn't involve much and perhaps will remedy the problem:

I would suggest you try laying a brick on its long edge on the top of the chimney on the side closest to the wind. If it improves the draw but doesn't correct it try setting another on top of the first and see if the draw gets better.

I'm not exactly sure why this works (but have my suspicions) but I have seen it done with some success and, as if doesn't involve much time or expense, would be worth the try.



Hope this helps,
Wiley

[Mitchamus]

Re: Chimney not drawing smoke

I think most people with the Pompeii oven get some smoke out the front.

if you look through the gallery, nearly all of them have smoke marks on the front.

[fxpose]

Re: Chimney not drawing smoke

I'm not exactly sure why this works (but have my suspicions) but I have seen it done with some success and, as if doesn't involve much time or expense, would be worth the try.

I believe by doing this it creates negative air pressure, thus increasing draw.

Something in this effect....

[Tscarborough]

Re: Chimney not drawing smoke

A spark arrestor will help. Until there is some heat in the flue, any oven will smoke. Build a small fire to start and get the throat of the flue warm, say 50 degrees over ambient.

The brick trick mentioned above can help by creating an eddy or roll of air that helps with the draw.

[DaveW]

Re: Chimney not drawing smoke

We have the same opening and I have learned to build the fire underneath the chimney. Once the fire is blazing I push it back into the oven. Whatever you do, there will be smoke out the front until the flue heats up.

Nice Oven,
Dave

[david s]

Re: Chimney not drawing smoke

A new oven tends to be more smokey until it has properly dried out.
Some folk start the fire under the flue first so it heats up and begins to draw.
Don't overfill the chamber with fuel.
Try the "top down method" of fire lighting for a smokeless start.

[nissanneill]

Re: Chimney not drawing smoke

Brads,
I don't like the way these chimneys are documented and how poorly they work.
There are a couple of things that could be done to i,prove the situation but I don't think that you will prevent the smoke escaping the oven via the front arch.
My chimney void is huge compared to yours and the smoke is funneled up into the flue where it has no option but to continue up the 8" flue.
What I would do in your case would be to get yourself a diamond disc on your small angle grinder and cut a 45˚ chamfer on both the front of the oven opening and the back of your facia arch bricks. This would provide a slightly better directing the smoke up into your chimney. I also don't like the brick chimney as I feel thst unless they are lined, they provide friction of the hot fumes and smoke whereas a flue is slicker and slippery/ The only time I have ever got smoke out the front of my oven was when I pointed a petrol powered leaf blower and gave it heaps to get the fire really going.
Option #2 is to make up a blind which will fill the top 1/3 of your front arch, (leave enough room under to allow the cold air to enter the oven) but making it difficult for the smoke to come out under the blind/deflector.

Just a thought.

Neill

[david s]

Re: Chimney not drawing smoke

Neill,
Whilst I agree with all you have advised, I think in Brads case it is mostly because his oven is new. They are nearly all notoriously difficult to fire (smokey) when they're new. Before making any drastic adjustments Brad I think you will find the smoke less of a problem the more you fire it. Perhaps reappraise the problem after 7 or 8 firings.
Dave

[Neil2]

Re: Chimney not drawing smoke

Under some circumstances, you will get smoke out the front of your oven especially during initial firing.

In my opinion, as long as it is not blowing in my face when I am cooking I don't care. A bit of soot on the outside doesn't bother me.

[asiapizza]

Re: Chimney not drawing smoke

A chimney do not have maximum draw for the smoke, you need it to be round inside and perhaps a foot higher..may help. My chimneys are 15 feet up to 45 feet long and they are round. Refer to forno bravo materials, they spec round chimney. And perhaps you star tyr fire in the centre of the oven. It helps.

[jmhepworth]

Re: Chimney not drawing smoke

Make sure the wood is dry. Mine smokes a lot worse with wet wood than dry wood.

[brickie in oz]

Re: Chimney not drawing smoke

A chimney do not have maximum draw for the smoke, you need it to be round inside and perhaps a foot higher..may help. My chimneys are 15 feet up to 45 feet long and they are round. Refer to forno bravo materials, they spec round chimney. And perhaps you star tyr fire in the centre of the oven. It helps.

My chimney is rectangle and draws fine.

[brads]

Re: Chimney not drawing smoke

Just to update, we added another few courses on the chimney and widened the base of the chimney but i generally think it was just the curing process causing the smoke, obviously when starting with small fires the chimney doesnt heat up and therefore the smoke doesnt draw out the top. Since the curing process has been completed there is only a very small amount of smoke out the front but once it gets going theres no problem, thanks for all the help.