Is my insulated vertical plan doable?

[Rubitin]

I'm a once-a-month smoker for just the family. My UDS has seen better days, and they definitely have their limitations. That said, I enjoy how efficient it is. And I am so much a "set and forget" guy, I did a DIY PID, so I could sleep all night. I cook at various temps, depending on type of meat, but rarely over 325.


Enough background...on with my plan. My desire to get my grill onto a concrete pad has evolved in my head to include a small outdoor kitchen area with a lean-to like roof. I have a vision to build a clone to the LSG Mini. Plan is roughly 24x20x52. My main question...is there a reason I can't skin just the inside of the smoker with steel, insulate between tube frame, and tack on concrete board for the outer shell? I plan on the smoker to sit in the outdoor kitchen steel stud shell, that will then be covered in something decorative. The whole kitchen area will be covered with a simple metal roof structure. I'm thinking the main reason for a steel outer skin on a vertical is mostly for paint, since they are meant to be stand-alone units. Will the concrete board absorb moisture, even if protected by two weather barriers? I would still plan on sealing edges and painting the concrete board for extra protection.


One more question please...since I don't need a ton of space in a cook chamber, I can design the firebox to be any size. Is there a benefit to having a charcoal basket shallow with more area, or taller with smaller footprint? Does the burn rate change with the shape?
Thanks for reading! As with most of my projects, the journey means more than the result. So I will appreciate any and all feedback.

 

[ebijack]

Concrete board will alot of extra weight. Be more brittle, which could cause a major problem at the wrong time.
A piece of gauge steel would be easier, just sheer, tack into place. Then paint. Dents would be of no issue compared to sheet rock. Don't forget your intake will have to go thru that sheet rock.
You will want a large/tall basket inorder to hold enough coals for long cooks.
You can either use a maze for shorter cooks. Or make a second smaller basket that would hold enough coals for shorter cooks upto say 6 hrs. That would cover most cooks.
I never liked using a maze. I have 3 different coal baskets I use. But that is me.
I modified my reverse flow insulated cabinet. To non-insulated, direct flow. With the ability to burn pure wood and grill or burn pure wood and smoke. Or use coal/wood chunks to smoke. If you are interested in something like that.
I'd suggest you make your cooking grates wider/shallower. Then narrow/deeper. Much easier to access meats.

 

[Rubitin]

Thanks for the feedback!

I was envisioning Having the frame, inner skin, and doors built by my welder. Then finishing up the insulation and outer skin myself. It will be rolled/slid into an enclosure similar to a boxed-in refrigerator, never to be moved again. The concrete board idea was for ease and added insulation vs a thin metal.


I like the idea of a couple different baskets. That would be very doable. I will most likely stick to charcoal with a few chunks of wood for my smokes. Would a smoker like this be any less or more efficient than my UDS? I can get 12-13 hours out of about 15lbs.

 

[ebijack]

You could go with the concrete board. Your choice. Cement board used in most outdoor kitchens is covered with something to protect the cement board. A heavy storm might cause you some problems. Just a thought.
My vertical was designed/built with a coal box area kind of small. Even when insulated, 11hrs max at 275*. Only holding an 8lb bag of lump, again max. Due to the poor design. 10 hrs no problem after removing insulation.

My drum will go 11 hrs on that same bag of lump in summer temps. Or if I fill my drum basket. I can go 22+ hrs easily. 16lbs to fill. So about the exact same cook time. If that makes sense.
In single digit temps my drum burns 1/2 coffee can of more of coals at the most on 8+ hr cooks. One reason I find insulation to be of no real added value. Along with having insulation. Once you open the door to check/rotate/remove food. I would end up with a 60* temp spike. Even shutting off a controller/blocking the intake first. Then the amount of time to get that temp back down. Sometimes the coals would go out (even with a controller) before the temp would drop/come down enough. PIA.
Response time for temp changes on average is 15 to 30 max. Up/down on both drum/vertical without insulation.
Most here love/want insulation.