Chimney Not Drawing

[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

[Raffy]

When I started my small fires I got a lot of smoke out the opening instead of the chimney. When the fires got progressively bigger, I noticed the chimney drawing the smoke better because the hot air helped lead the smoke to the chimney better.

Raffy

[brokencookie]

Nice looking build - congrats

The draw is a function of flow, size and temperature. It looks like the size is ok. You can try a couple of different things. I would start with trying a search on this site for starting fires. There is a particular method ( that I can't remember the name of) that seems to work the best. Second, build the initial fire directly under the flue. The warmer your chimney gets, the better the draw. So if you "pre-warm" the chimney you should have less smoke.
As a last resort, what does your transition between the oven and the entry area look like. Some people have experienced problems here. Post another picture of this area and we will try and help.

Bruce

[brads]

Originally Posted by brokencookie

Nice looking build - congrats

The draw is a function of flow, size and temperature. It looks like the size is ok. You can try a couple of different things. I would start with trying a search on this site for starting fires. There is a particular method ( that I can't remember the name of) that seems to work the best. Second, build the initial fire directly under the flue. The warmer your chimney gets, the better the draw. So if you "pre-warm" the chimney you should have less smoke.
As a last resort, what does your transition between the oven and the entry area look like. Some people have experienced problems here. Post another picture of this area and we will try and help.

Bruce

thanks but i can't take the credit for the build it was my brother-in law who did all the brick and stone, we've taken a diamond blade to the base of the chimney to widen it and added a few more courses of brick on top of the chimney. we're waiting for the mortar to dry out then we'll try a few small fires again. Let you know how we get on.

[karl]

The draught in the chimney is a result of the flue gases high temperatur and hence their lower density compared to the air outside (i.e. the column of gases inside the chimney is lighter than the same column of air outside). As temperature increases inside the chimney so will the draw. Likewise, - if the column/chimney is higher the draw will be better.

[david s]

I think that the main problem is that your oven is new and still wet. All new and wet ovens will be smokey. Just keep firing it and the situation should improve.

[Ageo308]

A recessed arch will help alot as shown. I find only a little amount will come from the door when its pouring with smoke or very windy that day.

[brickie in oz]

The chimney needs to be 10%+ of the oven door opening size to work.

[brads]

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.

[lwood]

Glad it's resolved....I think adding more courses and widening the base both helped the chimney draw.