RF offset temperature variance from right to left

[Lobsterbake]

Hello,

I have always heard the thermometers on a pit are just for casual reference and not indicative of the true temperature so I decided to do a test with my Fireboard on my RF 24x55 offset smoker to see what the true temps were and temperature left to right. My Tel Tru's are 5" dials with a six inch stems so compared to a 3 or 4" stem they are farther in the pit so should be closer to actual temperature in theory.

I found that the temperature varies anywhere from 10-50 degrees right to left when the cooker is level. I used my Fireboard and put a grate probe on the middle rack (have three racks) about an inch from where the Tel Tru thermometer probes sit above the rack on both the left and right side. I wanted my FB probes to be as close as possible to the Tel Tru's inside but not touching.

The right probe which was the one closest to the firebox was always higher than the left one which was the farthest from the FB, but closest to where the heat comes up under the baffle plate on the hitch side of the trailer.

When I added wood to the FB the variance between left and right was the greatest, but the temperatures would level out and I would say on average the difference between the left and the right over the whole 5 + hour test was 20 degrees hotter on the right side but the lower the pit temperature the closer the left and right were such as when the pit was warming up or cooling off. The Tel Tru's on my test underreported the actual temperature according to the FB - this was true on both gages and I have found the FB's to be very accurate.

Couple of questions:

I ran the pit level - should the nose or none firebox side be level, up or down in regards to temperature? If you run nose up or down - how does that affect the pit temperature?

What is normal temperature variation for a RF pit to be left to right? I know the bottom rack, middle rack and top rack will be different but thought side to side would be closer. It is fine - will use to my advantage when cooking but just curious.

Here is the Fireboard graph of my entire test - I love my Fireboard - amazing what it does and great customer service FYI if you are in the market:

https://share.fireboard.io/8D4DBC

I love my pit - just trying to learn as new to offset smoking. I attached a picture so you can see my Tel Tru's location on pit and the probe for both sits just above the middle rack of three.

Thanks,

Mark

 

[Westx]

Nose down should help even the temp out a little more non mine with the RCs I have about a 10 to 15 degree difference. Middle grate with my Smoke compared to the RCS ther is about a 25 degree difference.

 

[smoke ninja]

20 degrees aint bad. Loaded up with food and result may vary

 

[pjtexas1]

Here are mine from my last cook. I know the doors read about 30 lower than the middle of the grate. I try to leave the doors closed until ready to wrap. The one thing I do is start the fire and leave both cabinet doors wide open for 20 minutes or so. For some odd reason that helps temps left to right. Learned this trick from my good friend buttburner. I always run my Shirley level unless I'm off-site cooking and I forget my level.

Sent from my SM-G955U using Tapatalk

 

[OklaDustDevil]

I believe the smokers are intended to be used level. Not to say you can't use them nose up or down . . . .

 

[IXL]

Since the temp spread is greatest following the addition of new splits, I would think the FB side temp increase is due to convective heat from the FB. Sufficiently strong drafting through the cooker should result in much-more-hotter air moving through it's established path quicker, balancing the two sides in the process.

 

[SmoothBoarBBQ]

I also wanted to make a suggestion here that maybe the rectangular cabinets aren't going to have the same convection as the round cooking chambers, so maybe that is something to take into account when talking about the Shirley's.

I've brought this up before but after I did my first review here on the forum about my Johnson Smokers cooker, Chad Johnson reached out to me and gave me some guidance on how to even out the temps. Initially I was running about 25-30 degrees difference from left to right, and I was running the pit perfectly level. So Chad told me to try and give the nose (end opposite the firebox) a slight decline and I was shocked at how well it evened things out. I spent most of a whole day feeding the fire and going up and down in temp and from left to right I was within 5° the entire time.

Just food for thought.