How to minimize smoke on Facade

[DrakeRemoray]

Re: How to minimize smoke on Facade

Those parts are all precast GRFC (Glass reinforced fiber concrete). I purchased them from a guy here in Denver Architectural Accents - Fireplace mantels, fireplace surrounds, columns, medallions, crown molding.

If you think about ordering some precast stuff, make sure you stetch out the actual dimensions, since most of these pieces are made to go on houses, many of them are huge!

The sill is a fireplace mantle that came in three pieces and we cut it down (we being me and the masons, I built the oven and framed it, but masons put the decorative stone on...it had to look good you know?)

I do not have an inner lip to close the door up against, but I would add that if I did it again. I do a lot of baking and my door (before I burned it up, but that is another story) rests against the bottom of the vent.

[tdibratt]

Re: How to minimize smoke on Facade

Drake, very nice oven facade. Those pieces on the outside framing the entrance, are they precast stuff? What about the sill? Where do you get those? Also, I cannot tell do you have an inner lip to close the door up against?

Thx

[RTflorida]

Re: How to minimize smoke on Facade

If I could do it all over, I would copy Drake's vent. Looks like it should draw extremely well - can't imagine any smoke escaping the entry. At the time, I was unsure of using a castable and didn't want any potential "do overs".
Yet another idea I will "steal" if I ever build another. In fact, I may copy the entire design...I love the brick/stone look.

RT

[DrakeRemoray]

Re: How to minimize smoke on Facade

I think a cast or metal vent instead of the typical arch is the best way to keep smoke off the facade.

My cast vent broke when I removed it from the form, but it makes a nice cutaway view. Smoke exiting the mouth of the oven does not really have any chance to roll out the front. I feel this is often overlooked when current builders use the arch design. Note that I put a fake arch on the front of the oven to keep the arch look...

Drake

[Les]

Re: How to minimize smoke on Facade

I have the flue sitting on 2 half bricks at either end of the landing so the opening into the flue is smaller than the flue itself.

I think this may be the problem. My oven, 2 fires, seems to be doing well. I am going to add another 12 inches to the height and drop the decorative brick down one inch on the front arch - someone else mentioned that and it seemed to solve the problem. My flue is 8 x 19; here are a few pics to show you the depth. Hope this helps.

Les...

[brokencookie]

Re: How to minimize smoke on Facade

Here is another problem oven and a fix.

http://www.fornobravo.com/forum/f21/...moke-1523.html


I think the pictures on this one demonstate the problem quite well. The fix is not as nice but it seemed to work.


Bruce

[brokencookie]

Re: How to minimize smoke on Facade

I pulled that 15-20 inch number out of my head. I don't think I have seen a recommended lenght for the landing but if you look at the construction photos it looks like most builders are using 1 2/3 bricks ( about 15 inches assuming "standard" firebrick) and then a 2 to 4 inch decrative arch. I found the discussion I had seen before here.

http://www.fornobravo.com/forum/f8/s...size-2711.html

This builder built a 50 inch monster. He fixed the smoke problem by extending the landing. It's a nice looking fix and seemed to have solved the problem. You should check out the photos and consider a fix like this if you do not want to build a new oven.

Bruce

[tdibratt]

Re: How to minimize smoke on Facade

No critters.

The only thing I can think of is the comment made re the depth of the vent landing. I have the flue sitting on 2 half bricks at either end of the landing so the opening into the flue is smaller than the flue itself.

As I am starting to build another here at my home I want to make sure I make this one better. I have seen many designs out there and find that I am never quite sure how to do that landing part until the time comes and I look to see what fits and perhaps this time I should do some planning ahead.

So if the vent landing should be 15-20 inches, I should set the oven opening back say 20 inches and if you count for the facade which let's say is a brick, then you probably need to set it back 24 inches or so. Is this correct? I did not see specific dimensions set forth in the online instructions. Or is the entire landing from the entry bricks to the facade 20 inches" Seems wide. If you had a 4 inch brick on the facade, your opening would be 16 inches wide from the back of the facade to the entry bricks.

Thx

[dmun]

Re: How to minimize smoke on Facade

Yes, I agree with Karl. Before you start modifying your entry, make up a draft door to tilt from oven opening to flue back. This will get you more air in the fire and channel smoke up the chimney.

Here's Jim's excellent draft door. note the air inlet at the bottom, and the tilt forward to the front of the flue:



You have quite a tall chimney. You shouldn't be having these problems unless there is an actual chimney obstruction. No dead critters up there?

[karl]

Re: How to minimize smoke on Facade

If you make a screen to shield off the top of your outer arch (entrance), which you can put in (like a kind of "door") during firing up it will probably force the smoke out the chimney.

karl

[tdibratt]

Re: How to minimize smoke on Facade

Oven is 36 inches. Dome height 18-19 inches. Door is 12 x 19 .


You're right about the distance from the entry door to the outside facade is probably about 10".

[brokencookie]

Re: How to minimize smoke on Facade

I think what Karl means is that the transition between the outside and the oven appears to be a little short. It looks like the distance from the oven opening to the outside of the flue is only about 8 to 10 inches. Check out the other ovens on the forum and I think the transitions are between 15 and 20 inches.
There might also be an issue with the ratio of the opening size to the oven size. How big is the chamber in your oven and what are the dimensions of your opening ?
Bruce

[tdibratt]

Re: How to minimize smoke on Facade

What do you mean by "From the photo it looks like the flue void is very narrow (and short). For the smoke to "roll out" there need to be a certain volume around the entrance to the flue channel."?

Thx

[karl]

Re: How to minimize smoke on Facade

Hi,

From the photo it looks like the flue void is very narrow (and short). For the smoke to "roll out" there need to be a certain volume around the entrance to the flue channel.

karl

[tdibratt]

Re: How to minimize smoke on Facade

I'd say any fire. Probably within the first 20-30 mins when the smoke is the heaviest on initial firing.

Thx