square stack question
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- Pilgrim
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square stack question
Hi all. So I have a smoker that I have had for years. The more I look at it the more I think it's supposed to be a reverse flow. The box is 36x26x20 inches. The chamber is 23x52 inches. There's a pipe (about 8 inches in diameter) that runs from the firebox to the opposite end. But my problem is - the stack is right by the pipe opening. So I want to move the stack to the firebox side. But with the calculator the round pipe will be really long. So I am wondering about making a square stack. But don't know size or length.
- garyspriggs
- Pilgrim
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Re: square stack question
What is your Cook Chamber size, and I will help you ' We did a square stack on the last smoker build
- RWBTEX
- Outlaw
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Re: square stack question
This should help;
http://www.feldoncentral.com/bbqcalculator.html
http://www.feldoncentral.com/bbqcalculator.html
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Hasty Bake Legacy
Pitts and spitts 24x48 stick burner
Napoleon Kettle
Weber bronze kettle
Traeger Pellet Pro 34
PK Grill for steak comps and fajitas at home
and then some
- k.a.m.
- Chuck Wagon
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Re: square stack question
A 6" ID round exhaust would need to be 33" long.
A 6" ID square exhaust would need to be 26" tall.
A 6" ID square exhaust would need to be 26" tall.
- garyspriggs
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Re: square stack question
Sorry I missed your dimensions, My Bad a 4 x 4 sq. tubing would need to be 28 1/5 inches a 5 x 5 would need to be 18 1/4 inches a 6 x 6 needs to be 12. 6 inches
I would probably go with the 4 x 4 or 5 x 5 just for aesthetics The stack Volume is 453.5 ci. in
Gary
I would probably go with the 4 x 4 or 5 x 5 just for aesthetics The stack Volume is 453.5 ci. in
Gary
- garyspriggs
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- Chuck Wagon
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Re: square stack question
garyspriggs wrote:Sorry I missed your dimensions, My Bad a 4 x 4 sq. tubing would need to be 28 1/5 inches a 5 x 5 would need to be 18 1/4 inches a 6 x 6 needs to be 12. 6 inches
I would probably go with the 4 x 4 or 5 x 5 just for aesthetics The stack Volume is 453.5 ci. in
Gary
Just curious garyspriggs.
How did you figure the volume at 453.5Cu. in.?
If you use the 1/3 rule for the pit calculator the cooker would need 936. Cu. in. of exhaust according to the cookers dimensions.
Link to BBQ Pit Calculator
- garyspriggs
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Re: square stack question
Sure , no problem. For Years everyone has used Feldon's Pit Calculator, There are some problems with it when calculating for a Reverse Flow
One problem is Smoke Stake should never be calculated on Fire Box Size EVERYTHING is calculated off Cook Chamber Volume
After quite a few RF builds and conversations with other RF builders if you use .020 or even up to .022 this works much better
Also I agree somewhat with the 1/3 rule for the Fire Box. 1/3 is the Minimum you can go larger with no problem and often
better results
But remember EVERYTHING is based OFF OF COOK CHAMBER VOLUME
Gary
One problem is Smoke Stake should never be calculated on Fire Box Size EVERYTHING is calculated off Cook Chamber Volume
After quite a few RF builds and conversations with other RF builders if you use .020 or even up to .022 this works much better
Also I agree somewhat with the 1/3 rule for the Fire Box. 1/3 is the Minimum you can go larger with no problem and often
better results
But remember EVERYTHING is based OFF OF COOK CHAMBER VOLUME
Gary
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- Chuck Wagon
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Re: square stack question
garyspriggs wrote:Sure , no problem. For Years everyone has used Feldon's Pit Calculator, There are some problems with it when calculating for a Reverse Flow
One problem is Smoke Stake should never be calculated on Fire Box Size EVERYTHING is calculated off Cook Chamber Volume
After quite a few RF builds and conversations with other RF builders if you use .020 or even up to .022 this works much better
Also I agree somewhat with the 1/3 rule for the Fire Box. 1/3 is the Minimum you can go larger with no problem and often
better results
But remember EVERYTHING is based OFF OF COOK CHAMBER VOLUME
Gary
A lot of the information on the calculator is based on my knowledge of cooker builds I kinda helped design it years ago. My email is attached to it for folks that have questions. Morgan did not design the calculator, he merely made it web based so others could use it. The original which I still use is in Excel.
I have never had a problem with the calculator building a reverse flow cooker. Every cooker I have built and helped folks build work flawlessly. What do you see as a problem on the calculator?
- garyspriggs
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Re: square stack question
OK fair enough, Why should the smoke stack size be based on FB size
Gary
Gary
- garyspriggs
- Pilgrim
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Re: square stack question
According to Feldon's a 4" stack should be about 6ft long to me that wouldn't look right at all and a 6 " stack almost 3 ft.
I'm not trying to cause a problem, I'm just stating what we do and a lot of research. And I sure don't want to step on any ones toes.
Gary
I'm not trying to cause a problem, I'm just stating what we do and a lot of research. And I sure don't want to step on any ones toes.
Gary
- k.a.m.
- Chuck Wagon
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Re: square stack question
garyspriggs wrote:According to Feldon's a 4" stack should be about 6ft long to me that wouldn't look right at all and a 6 " stack almost 3 ft.
I'm not trying to cause a problem, I'm just stating what we do and a lot of research. And I sure don't want to step on any ones toes.
Gary
I agree on the 4" exhaust on looks and function. This is when common sense comes into play and you increase the ID of the exhaust to compensate. A cooker has to breathe and I would never put a 4" exhaust on a 23" x 52" chamber in my opinion it simply is not large enough.
No problems here but I can tell you the calculator if used properly works but it is just a tool like any other that helps get the job done.
When my Good Friend Paul Shirley of Shirley Fabrication was breaking out into the cooker business I helped him design his cookers. They are all based off the pit calculator and still are today. They sell reverse flow cookers Nation wide with about a 6 month back log on builds.
The calculator must be working for some.
I am sure we will agree to disagree on this it makes good conversation.
- garyspriggs
- Pilgrim
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Re: square stack question
Cool, Are you Tom ? at the bottom of Feldon's it give credit to Tom ? Here is what it says
Again I apologize if I stepped on your toes, I started out using that calculator and then started making changes
This calculator is based upon the BBQ pit building ratios and formulas developed by Alien BBQ in his revelatory BBQ pit building guides. One of his best articles is Lessons Learned in Pit Building / Modifying. My starting point for this calculator was the Excel worksheet created by Tom C on TheSmokeRing.com (an excellent BBQ discussion forum and website).
Gary
Again I apologize if I stepped on your toes, I started out using that calculator and then started making changes
This calculator is based upon the BBQ pit building ratios and formulas developed by Alien BBQ in his revelatory BBQ pit building guides. One of his best articles is Lessons Learned in Pit Building / Modifying. My starting point for this calculator was the Excel worksheet created by Tom C on TheSmokeRing.com (an excellent BBQ discussion forum and website).
Gary
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- Chuck Wagon
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Re: square stack question
garyspriggs wrote:Cool, Are you Tom ? at the bottom of Feldon's it give credit to Tom ? Here is what it says
Again I apologize if I stepped on your toes, I started out using that calculator and then started making changes
This calculator is based upon the BBQ pit building ratios and formulas developed by Alien BBQ in his revelatory BBQ pit building guides. One of his best articles is Lessons Learned in Pit Building / Modifying. My starting point for this calculator was the Excel worksheet created by Tom C on TheSmokeRing.com (an excellent BBQ discussion forum and website).
Gary
You have not stepped on any ones toes garyspriggs. We are all adults and have opinions I respect everyone's input
No I am not Tom. That would be Tom C we are members of the Smokering.
Alien BBQ is the original designer of the calculator he is a Professor in I believe Thermal combustion. The original version was very basic Tom C with Aliens permission created the Excel Version. Back then (2008) it was limited to folks that could use it so With Tom C's permission Morgan Feldon ( A web designer who likes to cook) created the online version. My part in all this is mostly additions like the half moon opening sizes and what not. Over the years as folks asked questions we tweaked it. Morgan does not build cookers so he asked me if he could tag my email to his calculator to help folks with questions.
I know the calculator works but you also need to know some basics of what not to do like putting a 72" tall 4" exhaust on a cooker. The smoke will cool and stall causing the chamber to fill with stale smoke. We run into these questions all the time that is why I try to adjust the number to what I know will work.
I hope this explains it.
- garyspriggs
- Pilgrim
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Re: square stack question
Thanks for the reply, answers a lot. I do understand about a 6' stack, only used that for an example. Me and My #2 son build a pit or two a year. so I'm pretty familiar with sizing
It needs look good ans well as function properly. A long stack cools too rapidly and will not evacuate properly.
I have my own fill in the blank calculator I have used for quite a while Of course it's based on my calculations.
Maybe we could compare notes sometime.
Gary
It needs look good ans well as function properly. A long stack cools too rapidly and will not evacuate properly.
I have my own fill in the blank calculator I have used for quite a while Of course it's based on my calculations.
Maybe we could compare notes sometime.
Gary
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