Vertical Insulated Smoker Design Questions

[Steak]

Hi all,

I've been researching smokers and BBQ for months now to get a feel for building an excellent all-around home smoker and learning to use it well.

Now that I'm getting ready to gather my materials and build my smoker I wanted to run my plans by all you Smoker Builder guru's on here first. Along with a few questions of course!

Here are the dimensions:

• The outer walls will be 1/8" steel (yellow on the CAD drawings).
• The inner walls will be 1/4" steel (green on the CAD drawings).
• 1" ceramic insulation between the inner and outer walls.
• The frame will be 1" RHS (red on the CAD drawings).
• The diffuser plate will also be 1/4" steel (pink on the CAD drawings).

The overall inner cook chamber dimensions are 16" wide by 21" deep by 28" tall with firebox the same dimensions except only 10" tall.

The diffuser plate rests on brackets between the firebox and cook chamber and has slots cut around the edges. I've added walls to the inner section of the diffuser in case I decide to try cooking with a water pan I can fill it up, but also to catch drippings.

Here are my questions:

1. Is the firebox an appropriate size for the cook chamber? Too big? Too small?
2. I have a 2" ball valve in the firebox side and a 2" exhaust hole (considering using a ball valve for that) on top. Should this be plenty to work with?
3. Is the diffuser with slots a good idea for an even temperature?
4. Would a false wall be a better idea than a diffuser with slots?
5. Is the smoker a good size for brisket, pork belly (making bacon), whole chickens, pork butt, baby back ribs, and spare ribs? These are the items I want to smoke most.
6. Are the steel thicknesses an appropriate size? Overkill?

Here are the images:

The smoker without the doors.
The doors are just a frame with insulation between the inner and outer wall exactly like the rest of the smoker.

The frame.

The diffuser plate from different angles.

Any help is appreciated! I've already learned so much browsing the forum!!

[Big T]

Welcome aboard! What are you planning on using for fuel, charcoal or wood ? If you are using charcoal, I'd say the FB size will probably work fine depending on how you design the fire basket and ash pan. The basket won't be very deep but it should hold plenty of fuel based on the area of the basket. The 2'' intake will be plenty and 2'' exhaust should be enough also but you don't really need a ball valve on the exhaust. I like to have a grease pan/ diffuser to keep from snuffing out the coals, it my take a little tuning on the diffuser so I would try a few different size slots before you build your final design. You should be able to fit any of those cuts of meat in there, I'm not sure how many at the time but more than enough for a family. IMO the steel thickness is a little overkill for a vertical cooker, 1/4'' is fine for the diffuser but a little heavy for everything else. I believe a lot of guys use 12 gauge on the inside and 14-16 gauge for the outside. I haven't built an insulated cooker yet but I've read that 1.5'' insulation was the minimum thickness if you want to be able to touch the cooker without burning yourself. I'm sure some of the other guys will come along and they can help you out a little better than I can.

[Steak]

Thanks Big T!

I'm planning on using charcoal as the fuel source. I'm yet to design the basket but will try and keep it minimal.

I like to have a grease pan/ diffuser to keep from snuffing out the coals, it my take a little tuning on the diffuser so I would try a few different size slots before you build your final design.

I have a 9" x 1" slot on each side and an 8" x 1" slot on the back so far. Would you cut them smaller to start and enlarge them bit by bit?
What would be the advantage with a false wall? I see a lot of builds using them instead.

1/4'' is fine for the diffuser but a little heavy for everything else.

Do you recommend going thicker? Would a rule of thumb for a diffuser be thicker is better once it gets up to temp?

I haven't built an insulated cooker yet but I've read that 1.5'' insulation was the minimum thickness if you want to be able to touch the cooker without burning yourself.

I'll up the thickness on the insulation and down the thickness on the walls as per your advice. That'll save a few $$ and keep it lighter for sure
I was going on the thicker side with the walls to make this thing as stable on the temps and as fuel efficient as possible. However, I'm sure the thicker insulation will work a treat.
Would you recommend thicker than 1.5"?

[Pete Mazz]

Random ideas:
Size the CC so that you can use typical aluminum pans. Say 24 x 18.
Make your rack spacing 3-4" and put as many in as you can. Make a rail for grates near the top so you can slide unused grates up there when not being used. They'll stay cleaner w/o all the drippings.
Orient the wider side with the door to make it easier to handle food and pans.
Make your diffuser full size and use slots or holes for heat and smoke. Plan on a shelf 2-3" above for an aluminum drip pan on a grate.
If you're not planning on using a blower system, just use sliding vents on either side.
Incorporate an ash pan in the bottom for easy clean up.