Cabinets , 44gal drums that have a fire in the bottom then choked either
by the chimney/ exhaust or inlet are harder to control , in the sense
you want to do say a 65 deg 40 min smoke , then next time a 40 deg 5 hr
smoke.
Doesnt matter if a LPG burner type of a fire.
Once
have the choked fire going temps are controlled by chimney diameter and
chimney height (increase height more draw).. basically less flow more
heat in the smoker section.
The fire.. If Pit style setup..
offset fire box... the chimney diam (adjustable) and height ( fixed)
determine oven temps parameters
For the fire it is experience to
adjust the chimney draw and the actual fire air inlet , balanced with
coals and raw woods to determine smoke and heat.
Cabinets with
fire.. chips wood not in a separate controllable fire box and not rely
on a LPG burner are harder to adjust heat and smoke at the same time.
Generally
it is fixed inlet (eg vent holes in the bottom of a drum just large
enough to allow the max required flow... and limit the chimney (large
enough diameter height combo ) to allow min required temps... eg the wet
sack over the top of the drum.
There can also be side vents in
the smoker to control flow thru the oven part to also help control temps
but not change the fire box part.
I strongly suggest adding such an adjustable vent....
How
and what one does to be able to adjust parameters such as heat , smoke ,
or straight heating over coals is determined by what one wants to be
able to do with the unit... from say 35/40 deg long warm smokes thru to
95 deg short smokes (or 6 hr smokes for slabs pastrami)
Which have just put down to cure near full cabinet of slabs of venison ready to cook/ smoke Sunday or Monday.
The the venison 'ham' leg and after that the home cured slabs bacon... with 1 slab venison to see what its like as bacon.
Then
at the other end is slow (5//6 hrs) smoked 35 /40 deg fillets fish,
king / marlin chunks... home kill and home made venison sausages,
chicken ribs veggies etc.
'roast' type cooking is done in the
smaller charcoal cooker... or a off set fire pit type cooker... Note
that these are far more suited to pit cooking which only has small
amount smoke, mainly coals type heat with little bit raw wood.
Son
has been making these for a few yrs now.. LPG tanks and plate steel...
again a lot gone into understanding the fire , the cook , design ,
inlets, chimney heights diameters etc.
Even my 2 (different size/
designs) LPG cabinet ' smokers have had serious mods to chimney,
inlets, chip boxes inlets exhaust, and the size of the burner and LPG
regulator its self ,
To get to be able move to low temps range the
burn and size of flames is so small they have to be inside with no
slight breeze..
So its not all quite as simple as seems... on the other hand a basic set up once one gets the hang of it and its limitations... magic results.
This was the setup at our last home.. once again similar in the current shed.. warm, dry all weather
This was setting up as proof of concept .. getting parameter right.
The chimney was then moved inside and vented out the wall up around that support beem is... Also note the ply scarap at theside (and back) of the smoker base to stop the smallest breath of wind.. the burner is down so low.