Firebox size confusion

All the calculators you'll need to design your own smoker.
Post Reply
bzprod
Newbie
Newbie
Posts: 2
Joined: November 7th, 2018, 7:42 pm
Title: Member
BBQ Comp Team Name: Not competing yet...
Location: Austin, Texas

Firebox size confusion

Post by bzprod » December 11th, 2018, 8:57 pm

Hello builders!

I've read tons of posts here, and first off -- thanks so much for the treasure trove of data!

I'm about to embark on my first custom offset, and I'm having a bit of a hard time wrapping my head around the firebox dimensions. I'd love a pointer or two!

According to the calculator:
-- 20" x 42" cook chamber
-- 20" x 16" firebox

This firebox would be 114% of the chamber. As I understand it, this is on the higher end of what's acceptable, but should be fine.

But... it seems really odd! I'm not sure I've ever seen a smoker like this, with such a short firebox. Am I missing something, or would this be optimal regardless of my smoker-brainwashing :) ?

That said, what would be the difference in fire management between 20" x 16" and 20" x 20"?

Thanks for the help, I really appreciate it and I can't wait to cook on my dream smoker! The calculators and advice have been eye opening!

=====
Some extra info:
I currently have a Klose 20" x 30" pit, with a massive 20" x 20" firebox (250% of the cook chamber!). If I build a raging fire, I can cook at 350-500 degrees fairly easily. But, I'm into briskets and ribs and such, and if I try to build a small compact fire, the wood smolders and smoke comes out of the firebox instead of drafting properly. I've tried extending the chimney a few feet, fire baskets, etc. Heck the most effective method was simply placing a charcoal chimney starter inside the firebox and tossing a log into it every once in a while.

So, my goal is to obey the laws of physics and thermodynamics, and to let nature do its thing. I'm a bit nervous, but ideally I'd solve these issues and have a pit that's enjoyable to use.



User avatar
Big T
Moderator
Moderator
Posts: 5368
Joined: September 1st, 2013, 2:40 pm
Title: Go Getter
BBQ Comp Team Name: Backyard Boys
Location: Lower Alabama

Re: Firebox size confusion

Post by Big T » December 11th, 2018, 9:26 pm

Welcome aboard!! The best piece of advice that I can give you is to trust the calculator. I would also recommend that you take a look at a reverse flow if you haven't already done so, they're the best option for the 200-325 degree in my opinion and the temps are pretty even across the cook chamber. With that being said, there's nothing wrong with a well built traditional offset.


Measure Twice.....Cut Three Times.

User avatar
ajfoxy
Expert
Expert
Posts: 2058
Joined: April 12th, 2016, 8:07 pm
Title: Neophyte Smoker Bldr
BBQ Comp Team Name: Not competing yet...
Location: Brisbane, Queensland, Australia

Re: Firebox size confusion

Post by ajfoxy » December 11th, 2018, 11:40 pm

Welome!


Learning generally boils down to "Repetition or the avoidance of pain", some people learn by doing, some by watching and some just have to pee on the electric fence.

Whether you think that you can, or that you can't, you are usually right. Henry Ford

User avatar
Dirtytires
Expert
Expert
Posts: 1869
Joined: November 24th, 2015, 12:36 am
Title: It ain't broke...yet
BBQ Comp Team Name: Dont compete...cook for events once in a while
Location: Phoenix, Az

Re: Firebox size confusion

Post by Dirtytires » December 11th, 2018, 11:47 pm

remember, the calculator gives you the size of the box but you can customize the dimensions to some extent. For instance, my wood supplier cuts standard to 18 incheson his logs. If I had a 16 inch firebox, I would either need to pay extra to have him custom cut mine shorter. I, obviously would want a 20 inch firebox front to back so would shrink the other dimensions to keep it to the square inches specified.



bzprod
Newbie
Newbie
Posts: 2
Joined: November 7th, 2018, 7:42 pm
Title: Member
BBQ Comp Team Name: Not competing yet...
Location: Austin, Texas

Re: Firebox size confusion

Post by bzprod » December 12th, 2018, 12:59 am

Big T wrote:
December 11th, 2018, 9:26 pm
Welcome aboard!! The best piece of advice that I can give you is to trust the calculator. I would also recommend that you take a look at a reverse flow if you haven't already done so, they're the best option for the 200-325 degree in my opinion and the temps are pretty even across the cook chamber. With that being said, there's nothing wrong with a well built traditional offset.
Thanks for the tip. I never really thought about reverse flow, but I've heard great things about them.
Dirtytires wrote:
December 11th, 2018, 11:47 pm
remember, the calculator gives you the size of the box but you can customize the dimensions to some extent. For instance, my wood supplier cuts standard to 18 inches on his logs. If I had a 16 inch firebox, I would either need to pay extra to have him custom cut mine shorter. I, obviously would want a 20 inch firebox front to back so would shrink the other dimensions to keep it to the square inches specified.
Good point, it looks like 18" x 19" would also work well, and give me a little extra length in the firebox. I'll keep playing with the calculator for the perfect ratios and dimensions!



Post Reply

Return to “SmokerBuilder® Calculators”