Offset smoker - different temperatures [please help]

tmaven

Newbie

Original poster

Apr 17, 2017

22

13

• Apr 17, 2017

• #1

Hello pitmasters!

I just built my custom smoker. As you can see in the gallery - https://goo.gl/photos/rwgCEvfQtVKchkJN7

Parameters (I'm in Czech Republic / Europe ... centimeters, sorry guys!)

Chamber - 120 x 59 (1 wall thickness)

Firebox - 50x50x50 (0.6 wall thickness)

Chimney - 9x9x100 (0.4 wall thickness)

I have 2 grade levels in 2 separate positions.

Thermomethers are in the middle of grades. They are accurate (tested side by side).

But I have problem:

I'm getting different temperatures on both sides. (0-20°C difference)

I have ceramic roof tile as heat shield inside. But it does not fix it.

I tried water pan as well, but no joy.

What can be the problem?

I checked few smoker calculators - looks like I have long chimney... Should I cut it? Will it help to fix temperature problem?

Thank you!

 

daveomak

SMF Hall of Fame Pitmaster

OTBS Member

★ Lifetime Premier ★

Nov 12, 2010

27,123

4,979

Omak,Washington,U.S.A.

• Apr 17, 2017

• #2

First....  it appears you have a plate at the outlet of the firebox that is angled downward...    That is choking off the air flow...   Plates exiting the FB should be level and above the opening...  Gaps in the plates are used to adjust temperature across the cooking surface....   Adjust the gaps....

Second...  I can't see the FB door....  You should have an adjustable air inlet at the top of the door, across from the firebox / cook chamber opening....  That will allow you to adjust the movement of heat from the FB to the CC...

Smoker Exh and Intakes 2.jpg

• daveomak
• Apr 17, 2017

 

Last edited: Apr 17, 2017

tmaven

Newbie

Original poster

Thread starter

Apr 17, 2017

22

13

• Apr 17, 2017

• #3

Hi DaveOmak,

more pictures https://goo.gl/photos/wmvM1DuXGCvrrQUj8

I did few holes into doors - so if below vent is fully open - air-intake = outtake to chamber from firebox  (cm^2)

Regarding shield - as you can see its on top of chamber-intake from firebox. It was small (about 10cm wide). So I put roof pile on it. 

IMG_20170325_060511.jpg

• tmaven
• Apr 17, 2017

IMG_20170304_103901.jpg

• tmaven
• Apr 17, 2017

Should I do something like that?

DSC_6546.jpg

• tmaven
• Apr 17, 2017

 

Last edited: Apr 17, 2017

daveomak

SMF Hall of Fame Pitmaster

OTBS Member

★ Lifetime Premier ★

Nov 12, 2010

27,123

4,979

Omak,Washington,U.S.A.

• Apr 17, 2017

• #4

Is the plate I have circled in RED, on a downward angle..  It needs to be at the level of the perforated plate, and level...  The perforated plate is fine...  it's not adjustable to allow for temp adjustment across the cooking grate, but it helps..

aa11.jpg

• daveomak
• Apr 17, 2017

Below is an example of the upper air inlet holes I was speaking of..  make them adjustable...

aa111.jpg

• daveomak
• Apr 17, 2017

 

tmaven

Newbie

Original poster

Thread starter

Apr 17, 2017

22

13

• Apr 17, 2017

• #5

That first picture is not my smoker. Its just to show perforated plate. If you meant that.

Ye I can do upper air inlet.

 

daveomak

SMF Hall of Fame Pitmaster

OTBS Member

★ Lifetime Premier ★

Nov 12, 2010

27,123

4,979

Omak,Washington,U.S.A.

• Apr 17, 2017

• #6

To even out temps....  "tuning" plates are installed above the FB/CC opening.. Spacing is tightest closest to the FB...   wider as they get closer to the exhaust...   The spacing can be adjusted to allow for more heat to rise to the cooking surface.....  

The upper air inlets on the FB are used to reduce the heat inside the FB...  That reduces the hot spot, on the cooking surface...   The FB temp should be close to the CC temp... maybe 30-40 F degrees higher or something like that....    Reduces wood consumption...   makes for temperatures that are fairly even on the cooking surface...

You can weld angle iron, along the inside of the CC, above the FB/CC opening and rest tuning plates on the angle iron, making them totally adjustable..

...click on picture to enlarge...

900x900px-LL-f5ea6463_TuningPlates.jpg

• daveomak
• Apr 17, 2017

 

daveomak

SMF Hall of Fame Pitmaster

OTBS Member

★ Lifetime Premier ★

Nov 12, 2010

27,123

4,979

Omak,Washington,U.S.A.

• Apr 17, 2017

• #7

For the upper air inlets....  You can make them adjustable...   Try 3 each  1" holes...  fire it up leaving them open...  see what the results are..   You may be able to operate without adjusters...