Damper and door questions

[christo]

Re: Damper and door questions

Enquiring minds want to know.

Just how do I know if I need a damper?

When I fire my oven I can see that roughly the upper half of the oven is full of smoke and the bottom half is clear. I presume the bottom half is air coming in from the opening. Should it be more like 1/4 clear and 3/4 smoky?

So far the oven heats up in about 45 minutes with a good steady fire. Could a damper help it to heat up faster?

Thanks!

[gjbingham]

Re: Damper and door questions

Christo, good question. You'd think there'd be an authoratative or scientific recipe for the perfect fireplace/oven. I've got a feeling that some engineer (or many), somewhere, has done the work, but I've yet to see it on a web page. I've done many searches, but perhaps not used the correct terminology to find what I was looking for.

[brokencookie]

Re: Damper and door questions

It appears that controlling your airflow, either down the chimney or through the door gives you more precise control of the oven heat. Here is a link to a ceramic BBQ that claims you can adjust and control the heat by adusting the bottom and top dampers.

FAQ

It looks like the object is to contain the heat filled smoke to warm the entire cooking chamber. The trick appears to be balancing the need for oxygen for combustion with the desire to trap all the heat possible. My thoughts are that using a damper is like fine tuning your oven. It works just fine without one, but you can tweak and adjust your oven with one.

I'm starting to think of this as hedging your bets. If your chimney diameter/ height/ transition/ etc is too big for your oven, you can make an adjustment without having to rebuild your oven.

Just what I need, one more thing to twiddle with while I'm trying to cook

[Xabia Jim]

Re: Damper and door questions

I believe that's it...more control and flexibility. The hottest fires in my woodstove was with the chimney damper closed and the door dampers open. I would get a surface temperature between 500 and 600 F.

All dampers are wide open when you start your fire. I would then reduce the flow to the primary air and the chimney damper, leaving the secondary air open as that burns off the gases above the fire.

A wood fired oven may be different, particularly if you're only firing for a short period for pizzas. There you're using a big fire and curling the flames to heat the hearth or cook the pizzas! And I believe some of the pizza ovens don't even use a chimney.

For other cooking, roasts & bread, etc when the oven will operate for hours, you'll get the benefit of a damper, holding heat and using less wood.

Now chimney height....yes, once warmed the taller chimney tends to draw better and again, I think a damper is beneficial. Even in my short chimney I can dial down the damper until smoke comes out the top of the door crack, then open a bit, that's the sweet spot. I do want a taller chimney though to improve on this draw.

[jeff]

Re: Damper and door questions

Look out you mob, an' settle eh.
Fellers, you all have good points on this "air-flow" thing.
I reckoned James had missed the point re fire and fires when warming up. (If you care to look, I actually asked about increasing exhaust efficiency.),when he said that he couldn't see how a chimney damper may be usefull.

Mate, depends at what stage of firing one uses it. Very pertinent to each individual setup .And once you're up to temp, you guard that temp like you'd guard an illicit fling.
I must admit to being a tad bemused by this thread. Here I am in a climate that ever-so-rarely drops below 18*C. One of our masochistic mates (a bloody sheila, eh, god bless her adventurous little arr,soul), was cooking in minus 30*.!!! Crappers eh!!
[Sorry Love, you're totally bonkers. Love ya, eh, and tellumfukum.]
X Jim runs close to my thoughts. Authority over 'gas in' cf 'gas out' is a bit like street cars cf race cars. fine tuning, each to their own
Mates.To those of us wot cook in caves: shall we raise a glass to James?
I'd like to think we could. Tomato juice/vodka, and all things in between?
So fill yer glass and sip to Jimmy, eh.
Not often that The Boss is so honest as this pric, eh. If he doesn't know, then he'll ask.
And I reckon I'd be proud to have him visit my humpy.
Luddite Jeff.

[CanuckJim]

Re: Damper and door questions

Jeff,

Yet another shining example of Aussie lore and language. Strewth, mate, you should pen a bleedin Ozinary for all those sheilas in the bush. Onya.

Jim

[jeff]

Re: Damper and door questions

CJim,
Why don't i just keep my big mouth shut?
Jeff.

[CanuckJim]

Re: Damper and door questions

Jeff,

Now what kind of fun would that be for all of us; you included ?

Jim

[asudavew]

Re: Damper and door questions

CJim,
Why don't i just keep my big mouth shut?
Jeff.

NO don't do that!!

but I would appreciate an English translation !

[gjbingham]

Re: Damper and door questions

hahahaha

Funny stuff Jim!

[asudavew]

Re: Damper and door questions

George..

i have this tooth that I cracked..a while ago
it doesnt hurt..but ...

does that mean root canal?

I would hate to tell you how long it's been ...............
but it's been a loooooooooooong time..

help a fellow wfo'er out!

dwats

[gjbingham]

Re: Damper and door questions

Dave,
No telling without putting the eyes on the poor tooth and probably seeing some X-rays. Cracked is a relative term. Take a picture of it and send it to me on PM.

Holy smokes! I missed Jeff's post on the last page yesterday. What a tirade! Great stuff!

[Marcel]

Re: Damper and door questions from Marcel, back for awhile

After some searching here is a thread that discusses dampers. Both Xabia Jim and Marcel have dampers, neither seems to use them...

Drake

(M) Correct Drake. I installed one in the metal flue and do *not* use it. Dmun (David's) comments are also in agreement with my view. It's a lot of work but I *might* use it if I were going to try a hot smoke for meats. But that was not it's original purpose. Same yourself the effort.

(M) I've been off the forum for many months and got an email from a new member, Toad, about thermal expansion which is not my forte. After replying I thought I'd see who was still contributing.

(M) I found a lot of questions I've not answered and as time permits, I'll try to get to at least a few of them.

Ciao, Y'all,

Marcel