# Controlling heat in side firebox



## twanger1994 (May 30, 2011)

Hey guys Happy Memorial Day All!!!

Quick question:  Seems like every smoke i do i am constantly fighting the temp gauge... "Mav. et 73"

I know that all smokers are different and each has its own personality... I'm a little confused on the chimney and air damper, and how opening or closing them controls the heat...

What happens if I close the chimney and ope the inlet on the firebox?

OR

what happens if I open the chimney and close the inlet on the firebox?

I know I will probably need to find just the right balance, But i'm lost on the science behind the vents!!! Thanks all..

BTW  Spares going now Qview Later....


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## adiochiro3 (May 30, 2011)

It all about oxygen flow; more air flow (oxygen) = higher temp, less = lower temp.  The best way to begin learning to manage temps is to leave the bottom vent wide open and only adjust the top/chimney vent(s).  Either one fully closed will snuff out the fire because air flow will be essentially stopped. 

To learn your rig, start with both vents wide open and see what the constant, stable temp is.  If it is too high for a smoke, start closing the top vent in small increments until you get the desired temp to hold.  Each vent adjustment will take a minimum of 10 minutes to get the new resulting temp, so be patient.  If you get to the point where the top vent is 2/3 closed, leave that one alone and start closing the intake vent a little at a time -- waiting for the temp to re-stabilize after each change until you achieve the optimal temp range of 225-250*.

Of course, with a SFB, you have to balance all of that with adding fuel as well.  I keep the fire close to the SFB door -- away from the cook chamber -- and add fuel _*next *_to the bed of coals in a strip down the center of the fire box, rather than piling it all on top of the coals.  When I add more, I first sweep everything toward the door before adding the new row of coals/wood.  This creates a slower start up for the new fuel and a more even burn without temp spikes for my rig.  I never burn anything in the firebox right next to the entry into the cook chamber.

Hope this helps!


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## cliffcarter (May 30, 2011)

What is the problem you are having, temps too high or too low?

I always leave the exhaust vent of my CG open and regulate temps using the intake on the SFB. If you have significant wind make sure that the intake vent is toward the wind direction otherwise the wind will knock down the fire and make it difficult to maintain your temps.


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## alblancher (May 30, 2011)

Yea, I would leave the exhaust vent full open, you don't want the smoke hanging around in the cook chamber.  Regulate the dampers on the firebox.  I have also found that with a partially closed exhaust I have more trouble keeping the temp even in the cook chamber.  All smokers are different, one you get some control you can close off the exhaust a bit and maybe raise cook chamber temps by 15 degrees or so.


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## venture (May 30, 2011)

Except for cold smoking, I would think it fair to say the consensus is to leave the exhaust vent fully open or nearly so.  The rational is to get air flow and to avoid stale smoke from hanging around creating creosote. On my CGSP I regulate temps by what I do in the firebox with the fire and with the air inlet control.

Good luck and good smoking.


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