250 gallon offset smoker

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Artur
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250 gallon offset smoker

Postby Artur » Tue Apr 13, 2021 10:26 pm

I built a 250 gallon offset smoker using the feldon pit calculator. It seems to work but the temperature variation is pretty big I can't really get the temperature on the end of the smokestack over 200 F. The temperature varies up to a 100 degrees from one side to the other and the top grates run hotter then the bottom. Can anyone give me advice why this happens or how to correct the problem? How much should the variation be?
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Re: 250 gallon offset smoker

Postby GRailsback » Wed Apr 14, 2021 5:54 am

You may need to add tuning plates. And the top grate is always going to be hotter. There is a guy on here that will be able to help you more than I can. He will see this and ask the right questions from you and provide accurate answers. His name is KAM.
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Re: 250 gallon offset smoker

Postby k.a.m. » Wed Apr 14, 2021 7:00 am

Pics and dimensions would help.
Reverse flow or standard offset
Firebox size
Exhaust size and length
Firebox opening into the cook chamber
Fire grate yes/no
Intake sizes
Always remember slow and steady wins the race.



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Re: 250 gallon offset smoker

Postby Perfectdraft1 » Wed Apr 14, 2021 8:18 am

Try using our Perfect draft Blower it will reduce your wood and it provides a 124 cfms of airflow to get the temperatures the same across the pit
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Re: 250 gallon offset smoker

Postby Artur » Wed Apr 14, 2021 10:43 am

It's a standard offset. Tank length is 30"x96", FB 30x25x27, smokestack inside measures 5.75"x 48" long. The FB to CC opening is a half-moon 25x8. I have no intake on the FB because I was told that I could just leave the door open. I'll attach a few pictures. Thx.
Attachments
IMG-20210125-WA0068.jpg
IMG-20210123-WA0029.jpg
IMG-20210126-WA0069.jpeg
IMG-20210131-WA0029.jpeg
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Re: 250 gallon offset smoker

Postby Rambo » Wed Apr 14, 2021 10:54 am

That’s really nice
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Re: 250 gallon offset smoker

Postby k.a.m. » Wed Apr 14, 2021 3:00 pm

Your firebox is undersized by about 10%
Your firebox opening calls for 20" Wide x 10" Tall. Yours is 25" Wide x 8" Tall so that may equate.
My biggest concern is no intakes. You see you have a huge chamber to heat and the heat smoke is taking the course of least resistance in my opinion and that is Right outside your door.
Now if you had an 8" exhaust on the cooker and could preheat the chamber I would say she could draft.
I would add a fire grate about 6" tall and add three intakes on the door 3" wide and 8" tall.
Like this.
12.JPG
Always remember slow and steady wins the race.



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Re: 250 gallon offset smoker

Postby Artur » Wed Apr 14, 2021 7:50 pm

Thx for the advice. I had installed an 8" smokestack already but didn't seem to really make a difference. I'll try if it works better if I make air inlets. I don't really understand what you mean with fire grate. Can you explain that?
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Re: 250 gallon offset smoker

Postby GRailsback » Wed Apr 14, 2021 8:03 pm

The fire grate he is talking about sits on the bottom of your fire box. It appears from your picture you have your fire built on the bottom of the box. That’s not what you want to do. You elevate the fire and the ashes fall and the bed of coals stay on the grate and keep plenty of air moving around them.
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Re: 250 gallon offset smoker

Postby Artur » Wed Apr 14, 2021 8:25 pm

Thanks!
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Re: 250 gallon offset smoker

Postby GRailsback » Wed Apr 14, 2021 8:31 pm

You can search around on the pit build section and find plenty of examples of the fire grates get mentions.
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Re: 250 gallon offset smoker

Postby Artur » Thu Apr 15, 2021 9:24 am

I have another question. Is my smokestack to small? Or what would you all recommend?
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Re: 250 gallon offset smoker

Postby hogaboomer » Thu Apr 15, 2021 10:55 am

It might be a little long, but not sure how much difference it makes. I had better luck with my smokers when I added door vents, instead of just leaving the door cracked open.

I'm also a tuning plates fan. Makes it much easier to control the heat horizontally.
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Re: 250 gallon offset smoker

Postby k.a.m. » Thu Apr 15, 2021 11:21 am

Artur wrote:I have another question. Is my smokestack to small? Or what would you all recommend?

I would have gone with 6" ID minimum or 8" max.
I am also not a fan of having my exhaust below grate level like you've done. I would have placed it slightly above the grate or at the top.
But my first alteration would be the fire grate and door intakes then go from there.
Always remember slow and steady wins the race.



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Artur
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Re: 250 gallon offset smoker

Postby Artur » Thu Apr 15, 2021 12:02 pm

It's my first ever offset. It perfectly makes sense that the exhaust would work better if higher. I'll install a slightly larger smokestack and make the modifications you all advised me to. I'll get back after test running the pit after the modifications.

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