Ok... initial tests are under way!
First some back ground and parameters for the test...
My Bradley is a 4 rack digital unit. It is controlled by a PID and I have a circulation fan installed. I also have the unit installed in my heated garage and vented so the ambient temp is 65 degrees ( with no wind
). I have my TC for the PID mounted to the back of the cabinet between the 2nd and 3rd rack (counting from the bottom). The TC bracket holds the TC off the back wall by about 3/4". I also have my smoke generator in a permanent offset installation.
Ok... I turned the unit on and preheated to 200 degrees, vent wide open, while I got 6 racks of ribs ready. I removed the membrane, cut each rack in half and applied my rub. This fills 4 Bradley racks with 3 half racks of ribs on each Bradley rack.
I took my time putting them into the smoker and setting up the Maverick temp probes for the test so by the time I got the door shut I was down to 131 degrees on the PID. I put the Maverick temp probe directly below the very bottom rack because I wanted to track the temps the lowest rack was being exposed to during this test. I left the vent wide open. Within 5 minutes the temps were climbing.
15 minute mark... PID at 150, Bradley at 170, Maverick at 210.
30 minute mark... PID at 174, Bradley at 194, Maverick at 237.
45 minute mark... PID at 190, Bradley at 207, Maverick at 244.
1 hour mark... PID at 200, Bradley at 210, Maverick at 250.
As the temps stabilized in the cabinet and the ribs started to gain some temp the deference between the Maverick under the lowest rack and the PID became a lot closer, typically around 10 degree difference.
Certainly doing a higher preheat would have also helped. I typically do preheat to about 260 but during the test I just wanted to see how it would recover without a higher preheat.
I tried twice to run the auto tune on the PID and I now have it close (2 degree temp swings each side of set point) but I will continue to try to get it dialled in a little closer.
I haven't decided yet but I may move my TC between the lowest rack and the second rack. This would further close the gap between the Maverick and the PID. I could even put it just below the lowest rack but I would like to have a happy medium of keeping the temp of the upper racks close to the target temp as well with a full load.
Just as a disclaimer...
I have been speaking with Bradley about this. More specifically about the rating of the insulation in the Bradley. They are going to get back to me on the specifics and I will let you know. My thought on the "risk" of higher temps are... the only part of the tower that will be exposed to higher heat will be the rear of the cabinet directly behind the elements. In addition the only time it will be exposed to higher heat is when you are trying to bring the cabinet back up to temp after loading. Once the set temp has been achieved the cabinet really isn't exposed to any higher heat than with a single element. Depending on the ratings of the factory insulation a possible solution would be to re-insulation the rear of the cabinet with the same insulation (Roxul Mineral Wool) that I used in the smoker I built. The Mineral Wool is rated at 2100 degrees so using it in a smoker is not a problem.
I know Beefman has been operating with the 900 watt finned strip heater mod for over a year now with no problems so I will wait to see what I hear from Bradley, then make a decision on it.
Overall the test went very well. To say the least the temp recovery is "extremely" improved. I'll keep you all posted.
Mike
PS - I'm whispering this...
I used mesquite on the ribs, In fact I tried it on some Canadian bacon last week and loved it... go figure!
