Wik, great thread; I suggest making this a sticky.
I have some data points to contribute.
I received a WSD-1500GPH this week and got the wall-mount probe installed on my SI3, 3/4" from the top of the chamber with a 1/2" spacer behind the rear wall. Started playing with it. Here's what I got:
| Contributor | P | I | D | SI Model | Air Temp | Meat/Lbs | Start/End | ByPassed | Notes |
| Valid Range | 1-999 | 0-999 | 0-999 | | | | | | |
| Preset | 70 | 600 | 150 | | | | | | |
| FunkedOut | 106 | 999 | 734 | #3 | 90F | empty | Start | Yes | set temp = 100F; auto-tune = 5.5 hours; no wood |
| FunkedOut | 80 | 765 | 191 | #3 | 90F | empty | Start | Yes | set temp = 200F; auto-tune = 1.5 hours; no wood |
| FunkedOut | 72 | 510 | 127 | #3 | 90F | empty | Start | Yes | set temp = 300F; auto-tune = 1.5 hours; no wood |
| FunkedOut | 57 | 441 | 110 | #3 | 90F | empty | Start | Yes | set temp = 400F; auto-tune = 1.4 hours; no wood |
I want to point out the values I put in the
Valid Range row.
Both, the manual on the auber site (v.1.0) and the manual that is on the CD included with the unit (v.1.5) list the "Range" for P, I and D the same as the values you listed in your original post. However, when playing with the unit, I am able to set the P, I and D values anywhere from 0/1-999. The 100F auto-tune yielded results for both I and D that are out of that range.
Looks like when trying to tune with the set temp (100F) only 10F above the ambient temp (90F), the unit calculated a value for I approaching infinity. This says the SI3 is outside of its operating range in those conditions; cold smoking conditions. I need to try an auto-tune with set temp to 100F and the cold smoking plate and a block of ice...
I hypothesize that increased airflow, say by adding a small fan blowing air into the chamber would have similar impacts to the PID values as does increasing the set temp.
Increased temperature results in more convection (airflow) which slows down the heating of the box a bit and also cools it down faster.
The difference between a fan and increased temp is the difference from ambient temp. The higher the temperature of the chamber, the greater the temperature difference, the faster the chamber will cool down towards ambient.
Maybe a fan would bring the SI3 into proper operating conditions under cold smoking conditions.
While I am on the airflow discussion, I would like to bring up that I have an extra drip hole at the rear of my SI3 bottom, doubling my airflow and changing the system behavior a bit. This hole is where I plan to enlarge and add a fan.
Although, at the moment (just before adding the auber), the SI3 was making great BBQ. 8)
I don't want to mess up a good thing.
