Update on ST temp swing issue:
Hi folks,
For any following the discussion around modifying the SmokinTex/
Smokin-It by adding extra airholes, I did have some further info to post regarding the temp swing issue I mentioned earlier in this thread.
What had gotten me alarmed was when I took the SmokinTex, added some extra airflow, and set the temp dial to 225 deg F. Initially the temp went up to 300-305 deg or so before starting to come back down. After this initial overshoot, it started stabilizing out to a temp swing of say + 50 deg/-30 deg. When cooking a pork butt a couple of days ago, after 2 hours of running the smoker the temp swing was around + 35 deg/-15 deg. It was suggested by an ST owner that the initial temp swing might have been caused by the extra airflow in the smoker due to adding the extra drill holes. This is a fair point, so I decided to talk to Scott Wallace at SmokinTex to find out what is normal regarding temp swings and temp overshoot in the ST1400.
I just wanted to update this thread to let people know what Scott at SmokinTex said regarding temp swings on the 1400. First, he said that when you first turn the smoker on and set it to 225 deg, that to have an initial overshoot to 300 deg or so is not uncommon. It relates to the design of how the thermocouple connects to the thermostat....I'm afraid I didn't entirely follow the explanation, but Scott did assure me that an initial overshoot to 300 or so was normal. Second, he said that after this initial overshoot and maybe another cycle of the heating element turning on and off, that the temperature swings do stabilize out to something around + 40 deg/-15 deg. He said that it takes around 1-1/2 hours for the temp swings to stabilize out, but that the unit gets more stable as the cook time goes on. He also said that the swings do tend to be bigger in amplitude to the high side of your setpoint. He said that the thermostats are supposed to be accurate to around 5-7 deg F, but that is based on the average temp in chamber after that initial 1-1/2 hours of stabilizing time. The way to check this would be to place a temperature probe right on top of the ST thermocouple at the back of the unit. Turn the unit on to your setpoint, and then go away. Come back about 1-1/2 hours later. Start recording your chamber temperature as often as you can tolerate.....every 30 seconds, minute, 3 minutes, whatever. Do this for a long time. Calculate the average temperature and compare it to your setpoint....it should be within 5-7 deg. Don't include data from the first 1-1/2 hours when the temperature was still stabilizing.
Another interesting point......
The SmokinTex manual specifically says not to preheat the smoker. I asked Scott about this, as it seems like giving the smoker time to recover from its first overshoot wouldn't be a bad thing. Scott says that you can do this, but to leave the woodbox out of the smoker during the preheat time. He said the reason why is that the SmokinTex chamber is
starved for oxygen. If you open the door while the wood is still smoldering you can cause a fire. If you let the smoker preheat without the woodbox, then open the door and put in the woodbox, it will be fine. The chamber will just lose a little heat and the heating element will kick on.
So. I'm sure I didn't improve the temperature stability of the ST by adding extra airflow, but according to Scott Wallace (who is an absolute peach, by the way), the variation I am seeing is not abnormal. So I probably haven't effed-up the unit too badly by this modification, which I find really reassuring.
I would also like to say to any considering buying an electric smoker, that Scott Wallace and SmokinTex customer support is absolutely amazing.