Re: Welcome to the new Forno Bravo Forum Firing Your Oven Discuss Re: Welcome to the new Forno Bravo Forum in the Oven Management forums; My vent and flue are in the front (located in what is called the breach). It slants back ... Jeanne, ...

[sarah h]

My vent and flue are in the front (located in what is called the breach). It slants back ...

Jeanne, it's hard to tell from your photos but it looks like there may be as much as a 90 degree bend in your flue pipe - and that's just the portion at the back, where it comes out and then goes up - is that so?

Perhaps that's the reason it's not drawing well - anyone more knowledgeable care to comment?

Sarah

[Mitchamus]

I think it's definitely oxygen starvation. IMHO..

A rule of thumb to get effective airflow circulation in any kind of system, the exhaust outlet needs to be around 2.6 times larger than the inlet hole.

Obviously though, you fire requires a certain amount more air to burn as well.

I might also get your chimney swept as a precaution, it might be stuck with soot after all the poor combustion..


cheers,
Mitch.

P.S. - do you have a chimney cap on? it might be dew running down the inside of your chimney.

[AnnieMacD]

Jeanne, Would you post a link to your pics - I can't find them?
Thanks,
Annie

[Jeanne]

Here is the picture. It is under Photo Gallery...Vent and Chimney.. I fired up the oven yesterday. I left the window open about 4 inches. It is directly next to the oven. I did get less smoke actually ony 2 times during the process each time when I added wood and the fire got large ( hit the ceiling ). It took about 3 hours for the whole inside to turn completely white I'm guessing because I kept the fire at a minimum adding wood slowly and using kindleing to keep a constant flame. If you look at the picture it is decieving. The flue is at a 35 degree angle where it conects to the pipe that goes straight up.Then I have the exhaust fan on top of that. ..not to mention I had the fan on high during the whole firing and baking time. I manage to bake 4 loave s of bread that came out nice but the occasional smoke in the kitchen is not good. This morning I contacted the builder who put in the oven and hopefully he can help. someone told me to call an HVAC person to analyze the flue design. All the ovens I see on line the flue goes straight up. Because the oven is in my kitchen wall ( the front opening flush with the wall) my builder had to extend the flue away from the house if you understand what I mean. The other variable that could be effecting this is it has been very cold here 20 dergrees. I have no problem keeping the fire going especially when the oven has been firing for 2 hours. My wood is so well seasoned that it lights fast. it is the beginning stages of the firing when the flames get large that the smoke comes back through the front door. The oven is also very well insulated with plenty of vermiculite as well as a blanket. I know that part of the process was done correctly. Thanks to all of you for taking the time to help me. Yes I love this oven and I am sure we will get it right. Not only did it cost a lot but the pizza is too good to not have it work as easy as everyone says.

Chow,

Jeanne




PhotoPlog - Vent and Chimney

[Mitchamus]

A lot of the pics of ovens I see on here have soot on the front opening arch.

I'm not sure if it's an inherent issue with the vent/chimney design or what.. but I do see it a lot.

Jeanne... silly question - but was it windy at all at the time? it could be something as simple as that...

[dmun]

I'm thinking that there is some sort of serious constriction in your flue somewhere. It might be worth a few bucks to have a chimney sweep come in and put a brush through it, which should go around a thirty degree bend, no problem. If something is pinching up that flue somewhere, that should reveal it.

I don't have photoblog access anymore for some reason. Could someone copy the image locations and paste them in a reply so I could take a look at them?

[Les]

David,

Jeanne only posted 2 pic's - here they are

[dmun]

Hmmm. A couple of observations: That sure looks like a 90 degree bend to me. Code calls for no more than two bends, no steeper than thirty degrees, in a flue. Second, it looks like the chimney outlet is not two feet above anything within 10 feet, although that shouldn't have anything to do with the draw.

I just don't know. That vent, code or not, should draw if nothing is blocking it. Forget about my last suggestion, about getting a chimney sweep brush down it, though.

You say your mason put that flue fan on when he built the oven: Have you tried it without it? Maybe that's the blockage. When you pull it off, you could also look down and see if you see any reflected light through it.

[sarah h]

I'm also thinking that maybe the fan is the problem, causing blockage at times, but perhaps also in preventing the oven from going white - is it possible that it's causing too much of a draw, thus pulling in too much cooler air and sending most of the heat straight up the chimney? Just a thought ... but as David suggests, a good diagnostic would be to remove it and see what happens (still keep the kitchen window cracked open just a bit).

Sarah

[Frances]

Another variable you might try is this:

http://www.fornobravo.com/forum/f9/s...ucer-5190.html (Smoke reducer)

It was very easy to build and has really minimised my smoke issues. And remove the fan and keep the window open - sounds like good advice to me. I'm sure you'll get there in the end, good luck!